CN110996858A

CN110996858A - Surgical operating instrument for an expandable and adjustable lordotic interbody fusion system

Info

Publication number: CN110996858A
Application number: CN201880049470.3A
Authority: CN
Inventors: 安德鲁·罗格斯; 罗宾·伯罗斯-欧贝
Original assignee: Thought Hundred Benefit Ltd By Share Ltd
Current assignee: Thought Hundred Benefit Ltd By Share Ltd
Priority date: 2017-07-27
Filing date: 2018-07-15
Publication date: 2020-04-10
Anticipated expiration: 2038-07-15
Also published as: SG11202000543YA; JP7227218B2; CN110996858B; EP3658079A1; WO2019022976A1; JP2020528785A; EP3658079A4

Abstract

An operating instrument includes a housing, a chassis, first and second drive shafts, a gear assembly, a shift assembly, and a bearing lock assembly. The first and second drive shafts each have a first portion supported by the chassis in the housing and a second portion extending from the housing. The gear assembly includes a first gear member fixedly received on the first portion of the first drive shaft and a second gear member slidably received on the first portion of the second drive shaft. The switching assembly is operable to position the second gear member in engagement with the first gear member to couple the second drive shaft with the first drive shaft to provide a first mode of operation in which the second drive shaft is rotatable with the first drive shaft, or to displace the second gear member out of engagement with the first gear member to decouple the second drive shaft from the first drive shaft to provide a second mode of operation in which the second drive shaft is not rotatable with the first drive shaft. The bearing lock assembly is operable to lock the first and second drive shafts to the chassis whereby the first and second drive shafts are constrained from sliding out of the housing and are free to rotate, or operable to unlock the first and second drive shafts from the chassis to allow the first and second drive shafts to slide out of the housing.

Description

Surgical operating instrument for an expandable and adjustable lordotic interbody fusion system

Technical Field

The present invention relates to surgical procedures and devices for treating low back pain.

Background

Lumbar fusion is a surgical procedure used to correct problems associated with the human spine. Lumbar fusion generally involves removing a damaged intervertebral disc and bone from between two vertebrae and inserting bone graft material that promotes bone growth. As bone grows, the two vertebrae join or fuse together. Fusing the bones together can help to stabilize specific areas of the back and help to reduce problems associated with nerve stimulation at the site of fusion. The fusion may be performed at one or more sections of the spine.

Interbody fusion is a common procedure to remove the nucleus pulposus and/or annulus fibrosus that make up an intervertebral disc at a point of back problem and replace it with a cage configured in shape and size to restore the distance between adjacent vertebrae to an appropriate state. The surgical procedures used to accomplish interbody fusion vary and the spine of the patient may be accessed through the abdomen or back. Another surgical approach for performing lumbar fusion in a less invasive manner involves accessing the spine through a small incision in the side of the body. This procedure is known as lateral lumbar interbody fusion.

When removing a disc from the body during lateral lumbar interbody fusion, the surgeon typically forces the insertion of different trial implants between the vertebral endplates in specific areas to determine the appropriate size of the implant for maintaining the distance between adjacent vertebrae. Another consideration is maintaining a natural angle between the lumbar vertebral bodies to accommodate lordosis or the natural curvature of the spine. Therefore, both disc height and lordosis must be considered during the selection of a cage for implantation. Prior art cages are typically pre-configured with top and bottom surfaces that are angled with respect to each other to accommodate the natural curvature of the spine. These values are unlikely to be accurately determined prior to the procedure, which is a disadvantage in current surgery. Typically, once the prepared bone graft is appropriately sized and encapsulated into the cage implant prior to insertion between the vertebral bodies.

Current lateral interbody cage devices are generally limited to providing a high degree of expansion, but do not have the ability to accommodate lordosis. The patient is subjected to significant invasive activity while trial and error is performed to size and fit the interbody fusion cage into the target region for that patient's particular geometry. Bone graft material is typically added and encapsulated into the fusion device after the desired high degree of expansion has been achieved and final adjustment has been made.

Disclosure of Invention

One embodiment of the device includes an expandable housing constructed of opposing housing members. A movable tapered screw-like element having an external helical thread is disposed in the housing and is operatively engaged against the top and bottom housing members to force the top and bottom housing members apart to cause expansion of the height of the housing. This function allows the distance (height) between adjacent vertebrae to be adjusted when in place. The tapered members are arranged in a double arrangement such that independent engagement of the tapered members on lateral portions of the top and bottom shells causes an angle of inclination with respect to the outer surface of the outer shell when the wedge members are moved to different degrees. This function allows for adjustment of the angular relationship between the adjacent vertebrae and facilitates lordotic adjustment of the patient's spine. When the functions of the device are combined by the surgeon, the device provides an effective tool for in situ adjustment while performing lateral lumbar interbody fusion.

One embodiment of the device further includes a track configuration within the housing for guiding engagement of the tapered externally threaded member with the top and bottom housing members. The track includes a raised element on each of the inner surface of the top and bottom housing members that allows interlocking engagement for lateral stability of the housing when in the retracted position. The rail region provides space for storing bone graft material when the shell is expanded. One embodiment may provide an elastic membrane to be positioned around the housing to prevent bone graft material from oozing out of the cage and to provide a compressive force around the cage to provide structural stability to the housing.

One embodiment of the device further comprises a drive shaft for operating the tapered externally threaded member. The drive shaft allows a surgeon to manipulate the shaft by using an auxiliary tool that operatively moves the tapered externally threaded member to control expansion of the outer shell and angular adjustment of the top and bottom shell members for in situ assembly of the interbody fusion device. A locking mechanism is provided for preventing rotation of the shaft when the tool is not engaged and after manipulation by the tool is complete. The tool also facilitates insertion of bone graft material into the fusion during in situ adjustment.

One embodiment of the present invention provides the surgeon with the ability to expand the cage and adjust the lordotic angle of the cage in situ during the procedure on the patient, as well as the ability to introduce bone graft material at the operative site while the device is in place. Thus, this embodiment of the invention provides a cage with geometric variability to accommodate the unique spinal conditions of each patient.

Accordingly, embodiments of the present invention provide an interbody cage device for lateral lumbar interbody fusion that combines a high degree of expansion for adjusting the distance between adjacent vertebrae and a lordotic adjustment for controlling the angular relationship between the vertebrae. The interbody cage device of embodiments of the present invention also provides a storage capacity for containing bone graft material in the interbody cage device as disc height and lordosis adjustments are made in situ.

The present invention also provides a device that can be used in an environment other than for interbody fusion applications. The device may be used to impart a spacing effect between adjacent elements in general and a variable angular relationship between the applied elements.

Embodiments of the operating instrument include a handle, a first drive shaft, a second drive shaft, and a gear assembly. The first drive shaft is operatively connected to the handle. The gear assembly includes: a first gear member received on the first drive shaft; a second gear member slidably received on the second drive shaft; and a lever member. The lever member is operable to position the second gear member in engagement with the first gear member to couple the second drive shaft with the first drive shaft to provide a first mode of operation in which the handle is operated to rotate both the first drive shaft and the second drive shaft, or to position the second gear member out of engagement with the first gear member to decouple the second drive shaft from the first drive shaft to provide a second mode of operation in which the handle is operated to rotate only the first drive shaft.

Embodiments of the operating instrument include a handle, a housing, first and second drive shafts, first and second tubular shafts, and a gear assembly. A first drive shaft is operatively connected with the handle, the first drive shaft is rotatably secured to the housing, and the first drive shaft includes a first portion received in the housing and a second portion extending from the housing. The second drive shaft is rotatably secured to the housing and includes a first portion received in the housing and a second portion extending from the housing. The first tubular shaft surrounds the second portion of the first drive shaft and is rotatably secured to the housing. A second tubular shaft surrounds a second portion of the second drive shaft and is rotatably secured to the housing. A gear assembly is received in the housing and is operable to couple the second drive shaft with the first drive shaft to provide a first operating mode in which the handle is operated to rotate both the first drive shaft and the second drive shaft, or to decouple the second drive shaft from the first drive shaft to provide a second operating mode in which the handle is operated to rotate only the first drive shaft.

Embodiments of the present disclosure provide a surgical instrument for an expandable and adjustable lordotic interbody fusion system. The instruments provide an improved and more efficient way to attach and physically implant an interbody fusion implant device in a patient, and further expand and lordotically adjust the implant in situ. The instrument allows for a smoother, more efficient, and more secure operation of the interbody fusion implant once the implant is inserted into the patient. The instrument enables a surgeon to expand, lordotic adjust and position an implant in a patient's disc space using a more stable instrument manipulation interface, while also being able to transfer more force to the instrument if desired without damaging the instrument. The instrument, when connected to an implant, may be operable and function as a distraction system in which two vertebral bodies may be forced away from each other or distracted away from each other. This allows patients with Degenerative Disc Disease (DDD), deformities, and tumors to recover normal disc height anatomy. This allows for a more streamlined and efficient device for distracting the intervertebral disc space. The human-machine interface aspect of the instrument is more intuitive, allowing for more seamless interaction between the surgeon and the instrument during the procedure, which ultimately makes the procedure easier and faster. The instrument facilitates post-operative assembly and disassembly, allowing the instrument to be cleaned and sterilized so that it can be reused for more operations.

Embodiments of a surgical operating instrument include a housing, a chassis, first and second drive shafts, a gear assembly, a switching assembly, and a locking assembly or bearing locking assembly. The first and second drive shafts each have a first portion supported by the chassis in the housing and a second portion extending from the housing. The gear assembly includes: a first gear member fixedly received on a first portion of the first drive shaft; and a second gear member slidably received on the first portion of the second drive shaft. The switching assembly is operable to position the second gear member in engagement with the first gear member to couple the second drive shaft with the first drive shaft to provide a first mode of operation in which the second drive shaft is rotatable with the first drive shaft, or to displace the second gear member out of engagement with the first gear member to decouple the second drive shaft from the first drive shaft to provide a second mode of operation in which the second drive shaft is not rotatable with the first drive shaft. The bearing lock assembly is operable to lock the first and second drive shafts to the chassis whereby the first and second drive shafts are constrained from sliding out of the housing and are free to rotate, or operable to unlock the first and second drive shafts from the chassis to allow the first and second drive shafts to slide out of the housing.

This summary is provided to introduce a selection of embodiments in a simplified form, is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The embodiments selected are presented merely to provide the reader with a brief summary of certain forms the invention might take and are not intended to limit the scope of the invention. Other aspects and embodiments of the disclosure are described in the detailed description section.

These and other features of the present invention are described in more detail below in the section entitled detailed description of certain embodiments.

Drawings

Embodiments of the invention are described herein with reference to the following drawings, wherein greater emphasis is placed on clarity and not scale:

FIG. 1 is a side view from the side of an expandable housing device.

FIG. 2 is a perspective view of a bottom portion of the expandable housing.

FIG. 3 is a top plan view of a bottom portion of the expandable housing.

FIG. 4 is a top plan view of the expandable housing device.

Fig. 5 is a perspective view of a tapered male screw member.

Fig. 5A is a side view seen from the side of the tapered male screw member.

Fig. 5B is a side view as viewed from the front of the tapered male screw member.

Fig. 6 is a cross-sectional view of the device taken along line 6-6 in fig. 1.

Fig. 7A-7C are a series of side views of the device as it undergoes expansion.

FIG. 8 is a side view of the device showing expansion of the device to accommodate the lordotic effect.

Fig. 9A is an enlarged perspective view of a thrust bearing for the drive shaft.

Fig. 9B is a perspective view of the drive shaft and the thrust bearing.

FIG. 9C is a cross-sectional top plan view of the engagement area of the drive shaft and thrust bearing.

Fig. 10 is a side view of the housing when expanded.

Fig. 11A is a top plan view of another embodiment of the device.

Fig. 11B is a top plan view of yet another embodiment of the device.

Fig. 12A is a top plan view of the drive shaft disengaged by the locking mechanism.

Fig. 12B is a top plan view of the drive shaft engaged by the locking mechanism.

Fig. 13A is a perspective view of the locking mechanism.

Fig. 13B is a top plan cross-sectional view of the drive shaft disengaged by the locking mechanism.

Fig. 13C is a top plan cross-sectional view of the drive shaft engaged by the locking mechanism.

Fig. 14 is a view taken along line 14-14 in fig. 11A.

Fig. 15A-15C are a series of side views taken from the end of the device showing the lordotic effect as the device undergoes expansion.

Fig. 16 is a perspective view of the operating tool.

Fig. 17 is a view showing a manner of operating the tool attached to the drive shaft of the device.

Fig. 18 is an exploded perspective view of the handle of the operating tool.

Fig. 19 is a perspective view of gears in the handle engaged for operation of two drive shafts.

Fig. 20 is a perspective view of the gears located in the handle disengaged for operation of a single drive shaft.

Fig. 21A is a cross-sectional perspective view of an exemplary manipulation instrument according to an embodiment of the present disclosure.

Fig. 21B is an exploded perspective view of the operating instrument illustrated in fig. 21A.

Fig. 22A is a perspective view of a drive shaft according to an embodiment of the present disclosure.

Fig. 22B is an enlarged perspective view of the tip end portion of the drive shaft shown in fig. 22A.

Fig. 22C is an enlarged plan view of a portion of the drive shaft shown in fig. 22A.

Fig. 23 is a perspective view of an exemplary rod member according to an embodiment of the present disclosure.

FIG. 24 is a perspective view of a portion of the operative instrument illustrated in FIG. 21A more clearly illustrating the lever member in an expanded position.

FIG. 25 is a perspective view of a portion of the operative instrument illustrated in FIG. 21A, more clearly illustrating the lever member in a lordotic position.

FIG. 26 is a perspective view of a portion of the operative instrument illustrated in FIG. 21A more clearly illustrating the lever member in a locked position.

Fig. 27A is a perspective view of an exemplary external connection shaft according to an embodiment of the present disclosure.

Fig. 27B is a plan view of the external connection shaft shown in fig. 27A.

Fig. 27C is a plan view of an end portion of the external connection shaft shown in fig. 27B.

Fig. 28A is a perspective view of an exemplary handle according to an embodiment of the present disclosure.

Fig. 28B is a side view of the handle shown in fig. 28A.

Fig. 28C is a cross-sectional view of the handle taken along line a-a in fig. 28B.

Fig. 28D is an end view from the first end of the handle shown in fig. 28A.

Fig. 28E is an end view from the second end of the handle shown in fig. 28A.

FIG. 29 is a perspective view of a portion of the operative instrument illustrated in FIG. 21A more clearly illustrating the housing, the external coupling shaft and the drive shaft.

Fig. 30 is a perspective view of an exemplary adapter according to an embodiment of the present disclosure.

Fig. 31 is a perspective view of an exemplary dial according to an embodiment of the present disclosure.

Fig. 32 is a perspective view of an exemplary dial according to an embodiment of the present disclosure.

Fig. 33 is an exploded view of an exemplary surgical operating instrument according to an embodiment of the present disclosure.

Fig. 34 is a partial cross-sectional view of an exemplary surgical operating instrument according to an embodiment of the present disclosure.

Fig. 35 is a perspective view of an exemplary surgical operating instrument, according to an embodiment of the present disclosure.

Fig. 36 is a perspective view of an exemplary surgical operating instrument, according to an embodiment of the present disclosure.

Fig. 37 is an exploded view of a housing including a housing cover according to an embodiment of the present disclosure.

Fig. 38 schematically illustrates a housing enclosing a chassis according to an embodiment of the present disclosure.

Fig. 39 is a perspective end view of a housing according to an embodiment of the present disclosure.

Fig. 40 is a perspective elevation view of a housing according to an embodiment of the present disclosure.

Fig. 41 is a perspective side view of a housing showing a switch guide feature according to an embodiment of the present disclosure.

Fig. 42 is a perspective view of a switch washer according to an embodiment of the present disclosure.

Fig. 43 is a perspective view of an exemplary chassis according to an embodiment of the present disclosure.

Fig. 44 is a perspective view of an exemplary chassis with sleeves and drive shaft bearings and other components positioned thereon according to an embodiment of the present disclosure.

Fig. 45 is a partial perspective view illustrating an exemplary chassis, locking assembly, and other components according to embodiments of the present disclosure.

Fig. 46 is a perspective view of an exemplary gear member according to an embodiment of the present disclosure.

Fig. 47 is a perspective view of an exemplary toggle switch according to an embodiment of the present disclosure.

Fig. 48 is a partial perspective view illustrating the gear assembly and the switch assembly in the first operational setting according to an embodiment of the present disclosure.

Fig. 49 is a partial perspective view illustrating the gear assembly and the switch assembly in the second operational setting according to an embodiment of the present disclosure.

Fig. 50 is a partial perspective view illustrating the gear assembly and the switch assembly in a third operational setting according to an embodiment of the present disclosure.

Fig. 51 is a perspective view of an exemplary gear lock according to an embodiment of the present disclosure.

Fig. 52 is a partial perspective view illustrating the bearing lock assembly and other components of an exemplary surgical operating instrument according to an embodiment of the present disclosure.

Fig. 53 schematically illustrates a bearing member that may be used as a drive shaft bearing or a sleeve bearing according to an embodiment of the present disclosure.

Fig. 54 is a partial cross-sectional view of an exemplary surgical operating instrument showing a locking assembly including a retention plate and other components according to an embodiment of the present disclosure.

Fig. 55 is an isometric view of an exemplary surgical operating instrument including a slap hammer according to an embodiment of the present disclosure.

Fig. 56 is an isometric exploded view of the example surgical operating instrument illustrated in fig. 55, in accordance with an embodiment of the present disclosure.

Fig. 57 is an isometric view of an exemplary slap hammer according to an embodiment of the present disclosure.

Detailed Description

Referring to the drawings, interbody fusion devices are described, illustrated, and otherwise disclosed herein in accordance with various embodiments of the present invention, including preferred embodiments. An interbody fusion device 10 is generally shown in fig. 1. The interbody fusion device 10 includes a housing 12 having a top shell 14 and a bottom shell 16. As an example, the entire housing may have a length of 50mm and a width of 20 mm. The housing material may be composed of a suitable material such as titanium alloy (Ti-6AL-4V), cobalt chromium or Polyetheretherketone (PEEK). Other materials that provide sufficient compositional integrity and have suitable biocompatibility are also suitable. The interior of the housing is configured with cascaded stepped

rails

18 and 20 disposed along the side edges of the housing. As shown in fig. 2, the stepped track 18 begins toward the midpoint of the inner surface of the bottom housing 16 with successive track steps that increase in height as the track extends to the first end of the bottom housing 16. Accordingly, the stepped rails 20 begin toward the midpoint of the inner surface of the bottom housing 16 with successive rail steps that increase in height as this portion of the rails extends to the opposite second end of the bottom housing 16. As shown in fig. 3, the stepped track 18 includes dual-track runs 22 and 24, while the stepped track 20 includes dual-track runs 26 and 28. As shown in fig. 4, corresponding stepped

rails

30 and 32 are provided on the top housing 14. When the device is in a fully compressed state of the device with the top housing 14 resting adjacent to the bottom housing 16, as shown in fig. 1, the stepped rails 18 are intermeshed with the stepped rails 30 and the stepped rails 20 are intermeshed with the stepped rails 32.

The respective orbiting portions comprise a series of spaced risers or orbital steps to receive the threads of the tapered outer helical threaded member. The tapered externally threaded member provides a wedging action for separating the top and bottom shells, increasing the height of the shell to effect expansion between the vertebral bodies for placement of the device. As shown in fig. 4, the orbiting portion 22 receives a tapered male threaded member 34, the orbiting portion 24 receives a tapered male threaded member 36, the orbiting portion 26 receives a tapered male threaded member 38, and the orbiting portion 28 receives a tapered male threaded member 40. The orbiting portion 22 is aligned collinearly with the orbiting portion 26 such that travel of the tapered male helical threaded

members

34 and 38 within the respective orbiting portions occurs within the collinear alignment. The thread orientations of the tapered externally threaded

members

34 and 38 are opposite to each other such that rotation of the tapered externally threaded

members

34 and 38 will result in movement in opposite directions relative to each other. As shown in fig. 4, the drive shaft 42 extends along the collinear span of the orbiting

portions

22 and 26 and through the tapered outer helical threaded

members

34 and 38. The shaft 42 has a square cross-sectional configuration for engaging and rotating the tapered externally threaded member. As shown in fig. 5, the central axial opening 44 of the tapered externally threaded member is configured to receive and engage the shaft 42. Alternatively, the shaft 42 may include any shape effective to form a spline, such as a hexagon, and the central axial opening 44 may include a corresponding configuration for receiving the shape. As the shaft 42 is rotated in a clockwise direction by its end 48, the tapered externally threaded

members

34 and 38 rotate and the respective thread orientations of the tapered externally threaded

members

34 and 38 cause the screws to travel away from each other along the orbiting portion 22 and the orbiting portion 26, respectively. Accordingly, when the shaft 42 is rotated in a counterclockwise direction by its end 48, the tapered externally threaded

members

34 and 38 are caused to travel toward each other along the orbiting portion 22 and the orbiting portion 26, respectively.

Similarly, orbiting portion 24 is aligned co-linearly with orbiting portion 28 such that travel of tapered male helical threaded

members

36 and 40 within the respective orbiting portions occurs within the co-linear alignment. The thread orientations of the tapered externally threaded

members

36 and 40 are opposite to each other such that rotation of the tapered externally threaded

members

36 and 40 will result in movement in opposite directions relative to each other. In addition, a shaft 46 passes through and engages the tapered externally threaded

members

36 and 40. However, the orientation of the tapered externally threaded

members

36 and 40 is opposite to the orientation of the tapered externally threaded

members

34 and 38. In this orientation, when the shaft 46 is rotated in a counterclockwise direction by its end 50, the tapered externally threaded

members

36 and 40 rotate and the respective thread orientations of the tapered externally threaded

members

36 and 40 cause the screws to travel away from each other along the orbiting portion 24 and the orbiting portion 28, respectively. Accordingly, when the shaft 46 is rotated in a clockwise direction by its end 50, the tapered externally threaded

members

36 and 40 are caused to travel toward each other along the orbiting portion 24 and the orbiting portion 28, respectively.

As shown in fig. 2, the stepped track is configured with a series of cascaded risers of increasing height. For example, each of the railways has a riser 52-60 as shown for the stepped track 18 in fig. 2. As the threads of the tapered externally threaded member travel to the clearance between the stand pipe 52 and the stand pipe 54, the positional height of the body of the tapered externally threaded member increases within the housing 12 as it bears on the stand pipe 52 and the stand pipe 54. As the tapered outer helical threaded member continues to travel along the orbiting portion, the threads of the tapered outer helical threaded member pass from the clearance between the riser 52 and the riser 54 and into the clearance between the riser 54 and the riser 56, which causes the tapered outer helical threaded member body to further raise within the housing 12 as it bears on the riser 54 and the riser 56. The height of the position of the tapered outer helical thread member increases further as it continues to travel along the remainder of the stepped

risers

58 and 60. As shown in the series of fig. 7A-7C, the top housing 14 is forced away from the bottom housing 16 by the tapered male screw member as the height of the position of the tapered male screw member body increases.

As shown in fig. 7, the combined effect of rotating the tapered male helical threaded members to move them toward the outer ends of the respective orbiting portions causes the outer shell 12 to expand. The fully expanded shell is shown in fig. 10. The housing 12 may be contracted by reversing the motion of the tapered male helical threaded member to cause the tapered male helical threaded member to travel back along its respective orbiting portion toward the midpoint of the housing. In this embodiment, the housing will optimally provide expansion and contraction to give the implant device a height in the range of about 7.8mm to 16.15 mm. The device of this embodiment of the present invention may be adapted to provide different dilation sizes.

The pair of tapered male screw members in each collinear double-rail running section can be rotated independently of the pair of tapered male screw members in the parallel orbiting sections. In this arrangement, the degree of expansion of the portion of the housing on each of the co-linear orbiting portions can be varied to adjust the lordotic effect of the device. As shown in the example of fig. 8, the tapered male threaded

members

36 and 40 have been extended along the orbiting portion 24 and the orbiting portion 28, respectively, to a certain distance, causing the top shell 14 to separate from the bottom shell 16, thereby expanding the outer shell 12. The tapered male helical threaded

members

34 and 38 have extended to a lesser distance along the parallel orbiting

portions

22 and 26, respectively, causing the portion of the top shell on the orbiting

portions

22 and 26 to separate to a lesser extent from the bottom shell. A series of fig. 15A to 15C show this effect: wherein the tapered externally threaded

members

36 and 40 extend apart from each other in further increasing increments, wherein the tapered externally threaded

members

34 and 38 maintain the same relative distance with respect to each other.

In fig. 15A, the respective positioning of the set of tapered externally threaded

members

36 and 40 is substantially the same as the set of tapered externally threaded

members

34 and 38 in the respective tracks. In this position, the top housing 14 is substantially parallel to the bottom housing 16. In fig. 15B, the set of tapered externally threaded

members

36 and 40 are further moved apart distally along the trajectory of the set of tapered externally threaded

members

36 and 40 while the set of tapered externally threaded

members

34 and 38 are held at the same positions as those in fig. 15A. In this setting, the side edges along which the tapered externally threaded

members

36 and 40 of the top housing 14 travel are moved higher relative to the side edges along which the tapered externally threaded

members

34 and 38 of the top housing 14 travel, thereby imparting an inclination to the top housing 14 relative to the bottom housing 16. In fig. 15C, the set of tapered externally threaded

members

36 and 40 are moved farther apart distally along the tracks of the set of tapered externally threaded

members

36 and 40 than the set of tapered externally threaded

members

34 and 38 along the tracks of the set of tapered externally threaded

members

34 and 38, thereby imparting a greater inclination to the top shell 14 relative to the bottom shell 16. In this embodiment, the device can achieve a lordotic effect between 0 ° and 35 ° by independent movement of the respective sets of tapered external helical screw members. The device of this embodiment of the present invention may be adapted to provide different lordotic inclination dimensions.

As shown in fig. 5, the tapered male helical threaded member has a configuration including the following body profile: the body profile has a profile from D_r1To D_r2Is small in diameter. As shown in fig. 4, the thread 33 has a pitch to match the spacing between the riser elements 52 to 60 in the orbiting portion. The threads 33 may have a square profile to match the configuration between risers, but other thread shapes may be used as appropriate. The increased diameter and tapered aspect of the helical threaded member causes the top and

bottom housings

14, 16 to move apart as described above. The contact at the top of the risers 52-60 is made at the small diameter of the helical threaded member.

A thrust bearing is provided to limit axial directional movement of the drive shaft within the housing 12. As shown in fig. 9A, the thrust bearing 62 comprises a two-piece yoke configuration that fits together and is press fit around the end of the shaft. The top portion 64 of the thrust bearing yoke defines an opening for receiving the rounded portion 66 of the shaft end. In fig. 9C, the square shaft 42 has a circular portion 66 of smaller diameter than the diameter of the shaft's square portion. A mating piece 65 of the thrust bearing engages the top portion 64 to surround a circular portion 66 of the drive shaft 42.

Pin elements 68 in the top and

bottom portions

64, 65 engage corresponding holes 69 in the mating piece to provide a thrust bearing press fit around the shaft. A journal groove 67 may also be provided in the thrust bearing 62. As shown in fig. 9C, the shaft 42 may have an annular ridge 63 surrounding a circular portion 66 of the shaft 42, the annular ridge 63 being received in a journal groove 67. As shown in fig. 9B, a thrust bearing is provided at each end of the drive shaft. As shown in fig. 6, the thrust bearing limits axial movement of the drive shaft in the housing.

A safety lock is provided at the proximal end of the device for preventing undesired rotation of the shaft. As shown in fig. 12A and 12B, a safety lock member 70 is provided for engagement with the proximal end of the

drive shafts

42 and 46. The opening 73 in the safety lock member 70 is configured in the shape of the cross-sectional configuration of the drive shaft (see fig. 13A). A portion of the drive shaft has a narrower circular configuration 71 so that the drive shaft can rotate freely when the circular portion of the shaft is aligned with the safety lock member opening 73 (see fig. 13C). Fig. 12B illustrates this relationship between the safety lock member 70, the thrust bearing 62, and the

drive shafts

42 and 46. When the non-narrower portion 75 of the shaft is positioned in alignment with the safety lock member opening 73, then rotation of the shaft is prevented (see FIG. 13B). Fig. 12A illustrates this relationship between the safety lock member 70, the thrust bearing 62, and the

drive shafts

42 and 46. A compression spring 77 may be disposed between the thrust bearing 62 and the safety lock member 70 to force the safety lock member back onto the square portion 75 of the drive shaft. FIG. 12B shows the locking disengaged when the safety lock member 70 is pushed forward out of alignment with the square portion 75 and is positioned in alignment with the circular portions 71 of the

shafts

42 and 46. A post 79 may be disposed between the safety lock member 70 and the thrust bearing 62 and a compression spring 77 may be seated on the post 79. The post 79 may be fixedly connected to the safety lock member 70 and an opening may be provided in the thrust bearing 62 through which the post 79 may slide. Post 79 is provided with a head 81 to limit the rearward movement of safety lock member 70 due to the compressive force of spring 77.

According to the power screw theory, the interaction of the tapered male helical threaded member with the stepped track contributes to self-locking. Certain factors are relevant when considering variables that are used to facilitate self-locking aspects of tapered threaded members. In particular, these factors include the material used, such as the coefficient of friction of Ti-6Al-4V 5 grade, the pitch length of the helical thread and the average diameter of the tapered member. The following equation explains the relationship between these factors in determining whether the tapered male helical threaded member can self-lock when traveling along a stepped trajectory:

the above equation determines the torque required to be applied to a drive shaft engaged with the tapered externally threaded member to expand the housing member. The torque is dependent on the average diameter of the tapered male helical threaded member, the load (F) exerted by the adjacent vertebral bodies, the coefficient of friction (F) and the lead (l) of the working material or, in this embodiment, the pitch of the helical thread. All of these factors determine the operating torque required to translate rotational motion into linear lift to separate the shell members in completing expansion and lordosis.

The following equation describes the relationship between factors related to the torque required to back the tapered externally threaded member in the track direction:

in this equation, the torque (T) required for the tapered male helical threaded member is reduced_L) Must be positive. When (T)_L) Is zero or positive, the self-locking of the tapered external spiral thread member in the stepped track is realized. If (T)_L) The value of (A) decreases to a negative value, the tapered male helical threaded member is in a stepped trackThe self-locking in the channel is not performed. Factors that may cause failure of self-locking include compressive load from the vertebral bodies, insufficient pitch and average diameter of the helical thread, and an insufficient coefficient of material friction. The conditions for self-locking are as follows:

πfd_m>l

in this case, it is necessary to select a suitable combination of tapered members with sufficient average diameter dimensions and product material much larger than the lead or pitch in that particular application so that the tapered members can self-lock within the stepped track. The cross-sectional area of the lumbar vertebral body was about 2239mm, based on the average patient lying on his side²And the axial compression force at this region was 86.35N. With the working material selected to be Ti-6Al-4V, the operating torque to expand the housing shell 12 between L4 and L5 of the spine is about 1.312Ib-in (0.148N-m), and the operating torque to contract the housing shell 12 between L4 to L5 of the spine is about 0.264Ib-in (0.029N-m).

Alternative embodiments of the expandable shell housing provide different surgical approaches. Fig. 11A shows the housing 100 for use with a surgeon accessing the lumbar region from the anterior aspect of the patient. The overall configuration of the orbiting portion for this embodiment is similar to that for the device 10, but the drive shaft for moving the tapered male helical threaded member is applied with torque transmitted from a vertical pathway. To this end, as shown in fig. 14, two sets of worm gears 102 and 104 transmit torque to drive

shafts

106 and 108, respectively.

Fig. 11B shows the housing 200 for use with a surgeon accessing the lumbar region from the patient's intervertebral foramen. The overall configuration of the orbiting portion for this embodiment is also similar to that for the device 10, but torque is applied to the drive shaft from a skew (offset) approach. To this end, two sets of bevel gears (not shown) may be used to transmit torque to the drive shafts 206 and 208.

The housing 12 is provided with a number of cuts and open areas in its surface and interior areas to accommodate the storage of bone graft material. The void space between the risers of the cascaded stepped rails also provides a region for receiving bone graft material. A membrane may be provided around the shell 12 as a supplement to help maintain compression on the top and bottom shells and retain bone graft material. As shown in fig. 10, an extension spring element 78 may be provided to hold the top member 14 and the bottom member 16 together. These elements may also be used to provide an initial tensile force in the opposite direction against expansion of the interbody fusion device. This allows the tapered outer helical threaded member to climb up the riser without contact having been made between the outer shell and the vertebral body.

Thus, this embodiment of the interbody fusion device of the present invention is capable of expansion to provide support between the vertebral bodies and accommodate the loads imposed on this region. In addition, the interbody fusion devices of the present invention enable configurations that can provide the affected region with a suitable lordotic inclination. Thus, the device provides significant improvements with respect to patient-specific disc height adjustment.

The device is provided with means for operating the interbody fusion device while adjusting it in situ in the spine of the patient. The operating tool 300 is generally shown in fig. 16, and the operating tool 300 includes a handle member 302, a gear housing 304, and

torque rod members

306 and 308. The torque rod member is connected to the drive shaft of the expandable housing 12. One embodiment of a drive shaft for connecting the torque rod member to the expandable housing 12 is shown in FIG. 17. In such an arrangement, the ends 48 and 50 of the

drive shafts

42 and 46 may be provided with hexagonal heads. The ends of the

torque rod members

306 and 308 may be provided with correspondingly shaped receivers for clamping around the

ends

48 and 50.

Within the gear housing 304, the handle member 302 directly drives the torque rod member 308. The torque rod member 308 is provided with a spur gear member 310 and the torque rod member 306 is provided with a spur gear member 312. Spur gear 312 is slidably received on torque rod member 306, and spur gear 312 may be moved into and out of engagement with spur gear 310. Spur gear lever 314 is engaged with spur gear 312 for moving spur gear 312 into and out of engagement with spur gear 310. When the torque rod member 308 is rotated by the handle 302 and the spur gear 312 is engaged with the spur gear 310, the rotation is transferred to the torque rod member 306. In this case, the torque rod member 308 rotates the drive shaft 46 while the torque rod member 306 rotates the drive shaft 42 to effect expansion of the housing 12 as shown in fig. 7A-7C. As shown in fig. 20, the spur gear 312 may be moved out of engagement with the spur gear 310 by retracting the spur gear lever 314. With spur gear 312 disengaged from spur gear 310, rotation of handle 302 turns only torque rod member 308. In this case, the torque rod member 308 only rotates the drive shaft 46 and the drive shaft 42 remains inactive to achieve the tilt relative to the top member of the housing 12 as shown in fig. 8 and 15A-15C to achieve lordosis.

To effect expansion of the device in the described embodiment, the operator will rotate handle member 302 clockwise to initiate (engage) twisting. This applied torque will then launch the compound reverse spur gear train comprising

spur gear members

310 and 312. The series of gears will then cause the

torque rod members

306 and 308 to rotate in opposite directions from one another. The torque rod member 308 (aligned with the handle member 302) will rotate clockwise (to the right) and the torque rod member 306 will rotate counterclockwise (to the left). The torque rod member then rotates the drive shaft of the interbody fusion device 12, thereby expanding the interbody fusion device 12 to a desired height.

To achieve lordosis, the operator moves the spur gear lever 314 back toward the handle member 302. By doing so, the spur gear 312 connected to the torque rod member 306 disengages the entire gear train, which in turn disengages the torque rod member 306. Thus, the torque rod member 308 will be the only member that engages the interbody fusion device 12. This will allow the operator to retract the posterior side of the implant device to create the desired degree of lordosis.

Referring to fig. 21-32, a surgical operating tool or instrument according to various embodiments of the present disclosure will now be described.

Fig. 21A is a cross-sectional perspective view of an exemplary manipulation tool or instrument according to an embodiment of the present disclosure. Fig. 21B is an exploded perspective view of the working tool or instrument illustrated in fig. 21A. As shown, the example working tool 400 generally includes a handle 402, drive

shafts

404, 406, a gear assembly 408, and optional external connecting shafts or

tubular shafts

414, 416. The gear assembly 408 may be received in a housing 410. The

drive shafts

404, 406 and optional outer

tubular shafts

414, 416 may be rotatably secured to the housing 410.

The handle 402 may be any suitable handle that a user may apply torque to the

drive shafts

404, 406. The handle 402 may be shaped in a variety of configurations including an I-shaped or T-shaped configuration. The handle 402 may be a two-way ratchet handle that can apply torque by both clockwise and counterclockwise rotation. The handle 402 may be a torque limiting ratchet handle that may limit the torque applied by the user so that damage to a workpiece (not shown) does not occur. In some embodiments, the workpiece is an expandable and adjustable spinal implant device as described above in connection with fig. 1-15, and the handle 402 is a bi-directional torque-limiting ratchet handle to effect expansion, contraction, and/or tilting of the spinal implant device. Torque limiting ratchet handles are commercially available from Bradshaw Medical, Inc.

The

drive shafts

404, 406 may include a first drive shaft 404 and a second drive shaft 406. The first drive shaft 404 may be operably connected to the handle 402 and rotated by the handle 402. The second drive shaft 406 may be operably coupled with the first drive shaft 404 or decoupled from the first drive shaft 404 via a gear assembly 408, which will be described in more detail below. When the second drive shaft 406 is operably coupled with the first drive shaft 404, a first mode of operation is provided in which the handle 402 can rotate both the first drive shaft 404 and the second drive shaft 406. When the second drive shaft 406 is disengaged from the first drive shaft 404, a second mode of operation is provided in which the handle 402 only rotates the first drive shaft 404.

The first drive shaft 404 and the second drive shaft 406 may each include a

first portion

404a, 406a that is received in the housing 410 when assembled and a

second portion

404b, 406b that extends from the housing 410. The first drive shaft 404 and the second drive shaft 406 may be rotatably secured to the housing 410 via screws 418 or keys, pins, or the like, which will be described in more detail below. The first drive shaft 404 and the second drive shaft 406 may have substantially the same length and the same cross-sectional geometry along the length. Alternatively, the first drive shaft 404 and the second drive shaft 406 may have different lengths and cross-sectional geometries. The first drive shaft 404 may be connected with the handle 402 via an adapter 420, which will be described in more detail below. Alternatively, the first drive shaft 404 may have its length extended beyond the housing 410 to connect with the handle 402.

Fig. 22A-22C illustrate exemplary drive shafts that may be used as the first drive shaft 404 and/or the second drive shaft 406. As shown, the example drive shaft 404 may include a first portion 404a and a second portion 404 b. When the operational tool 400 is assembled, the first portion 404a may be received in the housing 410 and the second portion 404b may extend from the housing 410. The first portion 404a and the second portion 404b may be integrally machined as a single component, or alternatively, the first portion 404a and the second portion 404b may be separately machined and then assembled. The first portion 404a and the second portion 404b may be generally cylindrical in shape and have the same or different diameters from each other.

The first portion 404a of the drive shaft 404 may include a portion 404d at the proximal end that is configured to receive a gear member, adapter, or dial that will be described in more detail below. For example, the portion 404d at the proximal end of the first portion 404a may include a flat surface configured to receive a gear member, adapter or dial having a channel, cut-out or aperture with corresponding flat and cylindrical surfaces, and a remaining cylindrical surface. When the gear member, adapter, or dial is received on portion 404d, the flat surface prevents rotational movement of the gear member, adapter, or dial relative to the drive shaft 404. At the distal end, the first portion 404a of the drive shaft 404 may include an undercut or groove forming a circular portion 404e having a reduced diameter. The undercut or groove provides space for a screw, key, pin, etc. to fit in or flush against the circular portion 404e, thereby limiting axial movement or sliding of the drive shaft 404 out of the housing 410 while allowing the drive shaft 404 to rotate freely.

The second portion 404b extends from the first portion 404a, and the second portion 404b includes a workpiece engaging tip 404c, the tip 404c having features configured to engage a workpiece. As shown, the workpiece engaging tip end 404c has a quincunx or hexalobal configuration. Other suitable configurations or features known in the art may also be used to engage workpieces having corresponding engagement features. The workpiece may be a spinal implant device as described above in connection with fig. 1-15. The workpiece may also be other medical devices that can be manipulated to expand, contract, or tilt by using a manipulation tool.

Returning to fig. 21A-21B, a gear assembly 408 is used to couple the second drive shaft 406 to the first drive shaft 404 or to decouple the second drive shaft 406 from the first drive shaft 404. In some embodiments, the gear assembly 408 may also lock the second drive shaft 406 and the first drive shaft 404 such that rotation of the first drive shaft 404 and the second drive shaft 406 is prevented. As shown, the gear assembly 408 may include: a first gear member 408a, the first gear member 408a being received on the first drive shaft 404; a second gear member 408b, the second gear member 408b being received on the second drive shaft 406; and a lever member 408c, the lever member 408c operable to place the second gear member 408b in engagement with the first gear member 408a or out of engagement with the first gear member 408 a.

The first gear member 408a may be fixedly secured to the first drive shaft 404 via screws, keys, pins, or the like. The second gear member 408b may be slidably received on the second drive shaft 406. The lever member 408c may be coupled to the second drive shaft 406, the second drive shaft 406 being configured to move the second gear member 408b along the second drive shaft 406, thereby allowing the second gear member 408b to engage the first gear member 408a, allowing the second gear member 408b to disengage from the first gear member 408a, or allowing the second gear member 408b to be locked in a locked position, which will be described in more detail below. Fig. 23 depicts an exemplary lever member 408c that may be used in the operating tool 400. As shown, the rod member 408c may include a first annular ring 422a and a second annular ring 422b, the first annular ring 422a and the second annular ring 422b being spaced apart, such as by a generally U-shaped structure 424 coupled with a rod member 426. When assembled, the first and

second collars

422a, 422b of the rod member 408c are slidably received on the second drive shaft 406 and the rod member 426 extends out of the housing 410. The second gear member 408b, which may be slidably received on the second drive shaft 406, is retained between the first annular ring 422a and the second annular ring 422b and is moved by the rod member 426.

Fig. 24, 25 and 26 more clearly illustrate the gear assembly 408 in the housing 410. In fig. 24, the lever member 408c is disposed in a proximal or first position, which allows the second gear member 408b to engage the first gear member 408a, thereby operably coupling the second drive shaft 406 with the first drive shaft 404. When the second drive shaft 406 is operably coupled with the first drive shaft 404, rotation of the first drive shaft 404 by the handle 402 causes rotation of the second drive shaft 406, thereby providing a first mode of operation in which, for example, the expandable spinal implant device may be expanded or contracted. In fig. 25, the lever member 408c is disposed in the distal or second position, which allows the second gear member 408b to disengage from the first gear member 408a, thereby disengaging the second drive shaft 406 from the first drive shaft 404. When the second drive shaft 406 is disengaged from the first drive shaft 404, the handle 402 only rotates the first drive shaft 404 and the second drive shaft 406 becomes inactive, thereby providing a second mode of operation in which, for example, the spinal implant device may be tilted.

In some embodiments, the lever member 408c may be disposed in a third position in which the second gear member 406 and the first gear member 404 are locked in the housing 410 and rotation of the first drive shaft 404 and the second drive shaft 406 is prevented. In fig. 26, the lever member 408c is disposed at an intermediate position between the proximal and distal positions, allowing the second gear member 408b to engage both the first gear member 408a and a toothed configuration 428 built into the housing 410 as will be described in more detail below. When the second gear member 408a contacts or engages the toothed configuration 428, rotation of the second gear member 408b is restricted, and thus, rotation of the first gear member 408a is also restricted due to engagement with the second gear member 408 b. When the lever member 408c is disposed in the third position, the operating tool 400 is locked, wherein rotation of the first and

second drive shafts

404, 406 is prevented.

Returning to fig. 21A-21B, in some embodiments, the working tool 400 can include externally connected shafts or

tubular shafts

414, 416, the externally connected shafts or

tubular shafts

414, 416 configured to connect the working tool 400 to a workpiece, such as a spinal implant device. The

outer coupling shafts

414, 416 may include a first tubular shaft 414 surrounding the second portion 404b of the first drive shaft 404 extending from the housing 410 and a second tubular shaft 416 surrounding the second portion 406b of the second drive shaft 406 extending from the housing 410. The first and second

tubular shafts

414, 416 may be rotatably secured to the housing 410, which will be described in more detail below, such that the first and second

tubular shafts

414, 416 are prevented from sliding out of the housing 410 while being free to rotate or spin independently of the rotation of the first and

second drive shafts

404, 406, respectively.

Fig. 27A-27C illustrate exemplary tubular shafts that may be used as the

external connection shafts

414, 416. As shown, the example tubular shaft 414 may be generally cylindrical in shape having an inner diameter greater than an outer diameter of the second portion of the drive shaft 404. The tubular shaft 414 may include: a first end portion 414a, the first end portion 414a configured to be rotatably fixed to the housing 410; and a second end portion 414b, the second end portion 414b having a feature configured to be coupled to a workpiece. Finger grips 414c, which may be machined as an integral part of the tubular shaft, may be provided to facilitate rotation or swiveling of the tubular shaft when it is connected to a workpiece. As shown in detail in fig. 27C, the first end portion 414a of the tubular shaft 414 may include an undercut or groove formed with a reduced diameter circular portion 414 d. When assembled, screws 419 (fig. 21B), keys, pins, etc. may fit into spaces in the undercut or groove or flush against the rounded portion 414d, preventing the tubular shaft 414 from moving axially or sliding out of the housing while allowing the tubular shaft 414 to rotate freely. The second end portion 414b of the tubular shaft 414 can be provided with internal threads or other suitable features configured to connect with a workpiece, such as a spinal implant device, having corresponding connection features, such as external threads.

Returning to fig. 21A-21B, the operating tool 400 may include a housing 410, the housing 410 configured to receive or enclose the gear assembly 408, rotatably secure the

drive shafts

404, 406, and optional

external coupling shafts

414, 416. Fig. 28A-28E illustrate an exemplary housing according to an embodiment of the present disclosure. As shown, housing 410 may be ergonomically shaped for easy handling by a user. Housing 410 may also be designed in any other suitable shape or configuration. The housing 410 may include a first end portion 410a proximate the handle 402 and a second end portion 410b distal from the handle 402. In the first end portion 410a, a cavity 430 may be provided for receiving the gear assembly 408. A tooth-like formation 428 may be built into the inner surface of the housing for receiving or locking the second gear member 408 b. An opening 432 may be provided in the side of the housing 410 for receiving the rubber slide 409 and allowing the lever member 408c to be displaced.

Passages

434a, 434b may be provided for receiving the

first portions

404a, 406a of the first drive shaft 404 and the second drive shaft 406, respectively.

Passages

436a, 436b may be provided in the second end portion 410b of the housing 410 for receiving the first end portions 414a, 416a of the first and second

tubular shafts

414, 416. An aperture or channel 438 may be provided at the second end portion 410B of the housing 410 for receiving a screw 418, pin, key, or the like (fig. 21B) to rotatably secure the

drive shafts

404, 406 to the housing 410. Optionally, apertures or channels 440 may be provided for receiving screws 419, pins, keys, etc. (fig. 21B) to rotatably secure the

external connection shafts

414, 416 to the housing 410.

Fig. 29 more clearly shows the

drive shafts

404, 406 and the outer connecting

shafts

414, 416 rotatably fixed to the second end 410b of the housing 410. As shown, when assembled, the screws 418, keys, pins, etc. may flushly abut the reduced diameter circular portions of the first and

second drive shafts

404, 406, thereby preventing the

drive shafts

404, 406 from sliding in an axial direction away from the housing 410 while allowing the

drive shafts

404, 406 to freely rotate or spin. Likewise, screws 419, keys, pins, etc. may flushly abut the reduced diameter circular portions of first and second

tubular shafts

414, 416, thereby preventing

tubular shafts

414, 416 from sliding in an axial direction away from housing 410 while allowing

tubular shafts

414, 416 to freely rotate or spin.

Returning to fig. 21A-21B, the operating tool 400 can include an adapter 420, the adapter 420 configured to connect the first drive shaft 404 with the handle 402. Fig. 30 illustrates an exemplary adapter 420 according to an embodiment of the present disclosure. As shown, the adapter 420 may include a first end portion 420a and a second end portion 420 b. The first end portion 420a of the adapter 420 may be shaped and sized to be received by the handle 402. The second end portion 420b may be provided with a channel 442, the channel 442 being configured to receive the first drive shaft 404. As shown, the channel 442 may be shaped or configured to allow the end portion 404d (fig. 22A) of the first drive shaft 404 to freely slide into or out of the channel 442 during assembly or disassembly, and to prevent rotation of the drive shaft 404 relative to the adapter 420 once the end portion 404d is received in the channel 442. Apertures or channels 444 on the side of the second end portion 420b may be provided for receiving screws, keys, pins, etc. to secure the first drive shaft 404 to the adapter 420. The use of an adapter allows the first drive shaft 404 and the second drive shaft 406 to be made to the same length and/or geometry. In this way, the cost of operating the tool 400 may be significantly reduced because the first drive shaft 404 and the second drive shaft 406 may be manufactured in the same manner and the number of parts required in manufacturing is reduced.

Returning to fig. 21A-21B, the operating tool 400 may include a first dial 446 for providing information to the user regarding the rotation of the first drive shaft 404. The first dial 446 may be operatively coupled to the first drive shaft 404 and rotate with the first drive shaft 404 when operated. Fig. 31 illustrates an exemplary dial that may be used as the first dial of the operating tool. As shown, the first dial 446 may include: indicia 448, indicia 448 indicating rotation of the dial; and an aperture 450, the aperture 450 configured to allow the first drive shaft 404 or the adapter 420 coupled to the first drive shaft 404 to fit therein. In use, the first dial 446 rotates with the first drive shaft 404, and indicia 448 on the first dial 446 provide information to the user regarding the rotation of the first drive shaft 404.

Referring to fig. 21A through 21B, the operating tool 400 may further include a second dial 452 for providing information to a user regarding the rotation of the second drive shaft 406. The second dial 452 may be operatively coupled to the second drive shaft 406 and rotate with the second drive shaft 406 when operated. Fig. 32 illustrates an exemplary dial 452 that may be used as a second dial of an operating tool. As shown, the second dial 452 may include indicia 454 indicating rotation of the dial and a portion having a channel 456 configured to receive the second drive shaft 406. In use, the second dial 452 rotates with the second drive shaft 406, and the indicia 454 on the second dial 452 provides information to the user regarding the rotation of the second drive shaft 406. When the second drive shaft 406 is coupled to the first drive shaft 404 through the gear assembly 408 in an operation in which the handle 402 rotates both the first drive shaft 404 and the second drive shaft 406, both the first dial 446 and the second dial 452 are rotated, thereby providing indicia to the user of a first mode of operation of the operating tool. When the second drive shaft 406 is decoupled from the first drive shaft 404 through the gear assembly 408 in a situation in which the handle 402 rotates only the first drive shaft 404, only the first dial 446 coupled to the first drive shaft 404 is rotated, thereby providing indicia to the user of the second operating mode of the operating tool.

Referring to fig. 21A-21B, in use, the working tool 400 can be connected to a workpiece, such as a spinal implant device (not shown), via an external connecting or

tubular shaft

414, 416. The user may, for example, turn or rotate the outer connecting

shafts

414, 416 inwardly to screw the working tool 400 onto the implant device. When connected with the implant device, the user may first place the lever member 408c in a locked position (e.g., the neutral position in fig. 26) such that the

gear members

408a, 408b are locked in the housing 410 and rotation of the

drive shafts

404, 406 by the handle 402 is prevented.

Once the manipulation tool 400 is connected with the implant device, to effect expansion of the implant device, the user may position the lever member 408c in an expanded position (e.g., the proximal position in fig. 24) such that the first and

second gear members

408a, 408b are out of the locked position and engage to couple the first and

second drive shafts

404, 406. The user may then rotate the handle 402 in a direction, such as clockwise, to apply a torque to the first drive shaft 404. Rotation of the first drive shaft 404 simultaneously causes rotation of the second drive shaft 406 to effect a slight incremental expansion of the implant device. If desired, the user may rotate the handle 402 in the opposite direction, e.g., counterclockwise, to retract or fine tune the level of expansion of the implant device. In some embodiments, the

gear members

408a, 408b may be configured such that rotation of the first drive shaft 404 in a first direction, e.g., clockwise, causes rotation of the second drive shaft 406 in a second direction, e.g., counterclockwise, opposite the first direction. Alternatively, the

gear members

408a, 408b may be configured such that rotating the handle 402 causes the first drive shaft 404 and the second drive shaft 406 to rotate in the same direction.

To achieve lordosis, the user may position the lever 408c in the lordosis position (e.g., the distal position in fig. 25) such that the first and

second gear members

408a, 408b are disengaged, thereby disengaging the second drive shaft 406 from the first drive shaft 404. The user may then rotate the handle 402 in, for example, a clockwise direction, applying torque only to the first drive shaft 404 as the second drive shaft 406 becomes inactive. Rotation of only the first drive shaft 404 causes the implant device to tilt, thereby achieving lordosis. If desired, the user may rotate the handle 402 in the opposite direction, e.g., counterclockwise, to adjust or remove the level of lordosis.

To disconnect the manipulation tool 400 from the implant device, the user can place the lever member 408c in the locked position and then rotate the external connection or

tubular shafts

414, 416, e.g., outward, to unscrew the manipulation tool 400 from the implant device.

Embodiments of the operating instrument have been described. Those skilled in the art will appreciate that various other modifications are possible within the spirit and scope of the invention. For example, although embodiments of the exemplary operative instrument are described in connection with the figures depicting a straight drive shaft and a straight external coupling shaft, in some embodiments, the drive shaft and optional external coupling shaft may include portions that are at an angle, e.g., in a range from 0 degrees to 90 degrees, relative to the straight portions of the drive shaft and external coupling shaft. The angled drive shaft allows the surgeon to reach sections of the lumbar disc space that are not accessible by a straight drive shaft in some patients. The angled portion and the straight portion may be machined as a single drive shaft or outer connecting shaft component, or alternatively, the angled portion and the straight portion may be separately machined and then assembled as a drive shaft or outer connecting shaft. In some embodiments, the angled portion may be an adapter profile that may be inserted or connected to an existing set of straight drive shafts or external connection shafts. As an example, the external connection axis may be angled by a variation of the ball joint allowing for vertical twisting. The drive shaft may be angled by some variation of a ball joint, worm gear or bevel gear configuration that allows for vertical twisting.

With reference to fig. 33 to 57, various embodiments of the surgical operating instrument will now be described.

Fig. 33 is an exploded view of an exemplary surgical operating instrument 500, according to an embodiment of the present disclosure. Fig. 34 is a partial cross-sectional view of instrument 500. As shown, the instrument 500 can generally include a handle 502, a housing 540, a chassis 560, a pair of

drive shafts

510, 512, a pair of

sleeves

520, 522, a gear assembly 580, a switch or switch assembly 610, and a locking assembly or bearing locking assembly 630. The handle 502 may be operatively coupled to the pair of

drive shafts

510, 512, allowing torque to be applied through the drive shafts to a workpiece, such as an interbody fusion device (not shown), to effect expansion, contraction, and/or lordotic adjustment of the fusion device. The pair of

sleeves

520, 522 surrounding a portion of the pair of

drive shafts

510, 512 that is exterior to the housing 540 are used to attach the instrument 500 to a workpiece, such as an interbody fusion device. The housing 540 encloses and protects the gear assembly 580, the bearing lock assembly 630, a portion of the

drive shafts

510, 512 and a portion of the

sleeves

520, 522, as well as other components supported by the chassis 560. The chassis 560 serves as the foundation for the instrument 500, providing support for the

drive shafts

510, 512,

sleeves

520, 522, and the housing 540. The chassis 560 may also serve as part of a housing for the gear assembly 580 and other components. The switch assembly 610, in conjunction with the gear assembly 580, operates to provide various operating modes of the instrument 500. Bearing lock assembly 630 operates to lock or unlock

drive shafts

510, 512 and

sleeves

520, 522 to chassis 560 inside housing 540. Fig. 35 is a perspective view of an instrument 500 assembled in accordance with an embodiment of the present disclosure.

Referring to fig. 33 and 34, the handle 502 may be any suitable handle that a user may apply torque to the

drive shafts

510, 512. The handle 502 may be manually driven or driven by a motor or robot. The handle 502 may be shaped in a variety of configurations including an I-shaped or T-shaped configuration. The handle 502 may be a two-way ratchet handle that can apply torque by both clockwise and counterclockwise rotation. The handle 502 may be a torque limiting ratchet handle that may limit the torque applied by the user so that no damage to the workpiece occurs. In some embodiments, the workpiece is an interbody fusion device and the handle 502 is a bi-directional torque-limiting ratchet handle to effect expansion, contraction, lordosis, kyphosis, and/or coronal adjustment of the device. Torque limiting ratchet handles are commercially available, for example, from Bradshaw Medical, Inc.

The handle 502 may be removed and replaced with an impact cap 503. Fig. 36 is a perspective view of an exemplary handling instrument 500 including an impact cap 503 according to an embodiment of the present disclosure. Impact cap 503 may be made of stainless steel, allowing the user to apply a forward force through the instrument by striking the impact cap with, for example, a mallet. This feature of the instrumentation may help to more easily push or wedge, for example, an interbody fusion device into a vertebral space of a patient. The impact cap 503 may avoid or reduce damage to the instrument when a hammering force is applied during surgery.

In some embodiments, the handle 502 or impact cap 503 may be removed and replaced with a clapper. If the surgeon desires to remove the implant after expansion and adjustment of the device in a second removal procedure, or possibly even after partial fusion of the device, the clapper may help provide a pulling or removal force to the instrument 500 and the interbody fusion device. Fig. 55 is an isometric view of an exemplary surgical operating instrument including a slap hammer 670, according to an embodiment of the present disclosure. FIG. 56 is an isometric exploded view of the exemplary surgical operating instrument illustrated in FIG. 55. Fig. 57 is an isometric view of an exemplary slap hammer according to an embodiment of the present disclosure. As shown, clapper 670 may include an elongated bar 672 and a weight 674. Weight 674 is configured to be grasped by a user and to slide along elongated bar 672 when a force is applied. A stop 676 may be provided at the first or proximal end of the elongated rod 672 to prevent the weight 674 from falling off the elongated rod 672. The stop member 676 can be removably coupled to the rod 672 via, for example, a threaded connection. A connection site 678 may be provided at a second or distal end of elongate rod 672 to couple slap hammer 670 with instrument 500. By way of example, connection site 678 may be configured such that hammer 670 may be coupled to adapter 504 of instrument 500 via a threaded connection, a clip-on connection, a slotted "key-like" connection, or the like.

Referring to fig. 33-34, the housing 540 encloses the gear assembly 580, the chassis 560, the bearing lock assembly 630, a portion of the

drive shafts

510, 512, and a portion of the

sleeves

520, 522, etc., protects the components from contamination by biological material, and/or prevents foreign objects from obstructing or interfering with the operation of the components. The housing 540 may be constructed of a material capable of withstanding high sterilization steam temperatures over many cycles and/or a material that provides mechanical strength to the instrument. Suitable materials for construction of the housing 540 include stainless steel, medical grade plastics such as

R5500 polyphenylsulfone (PPSU), a medical grade plastic commercially available from Solvay Advanced Polymers of brussel, belgium. The housing 540 may be shaped to impart aesthetic appeal and/or ergonomically shaped for a user to grasp the instrument.

Referring to fig. 37, the housing 540 may include a first end portion 542 proximate the handle 502 and a second end portion 544 distal from the handle 502. In the first end portion 542, the housing 540 may include two

housing covers

546a, 546 b. The housing covers 546a, 546b may be separate components that are secured to the chassis 560 with, for example, screws 548, bolts, or the like. The housing covers 546a, 546b may be unattached from the chassis 560 during cleaning and sterilization to help clean the instruments more efficiently and allow the interior of the instruments to dry more quickly after sterilization. The

removable housing covers

546a, 546b allow for exposure of the gear assembly, gear lock, and chassis or other components inside the housing, which in turn allows for quick and more efficient drying after sterilization. To add mechanical strength to the instrument, the

housing covers

546a, 546b may be constructed of medical grade plastic or metal such as stainless steel. In some embodiments, the

housing covers

546a, 546b may each be configured to provide a

shoulder

550a, 550b for seating the impaction cap 503 (fig. 33 and 36). As noted above, in some instances it may be desirable to apply a forward force through the instrument to help push or wedge, for example, an interbody fusion device into a vertebral space of a patient. By removing the handle 502 from the instrument and placing the impact cap 503 on the instrument, the user may apply a forward force through the instrument by striking the impact cap with, for example, a mallet. Because the impact cap 503 sits on the

shoulders

550a, 550b of the housing 540 and is not coupled to the

drive shafts

510, 512 or other functional components, the hammering force exerted on the impact cap 503 will allow the force to be evenly distributed throughout the cross-sectional area of the body of the instrument and will not further damage the instrument. Fig. 38 shows the housing 540 enclosing the chassis 560, wherein the

housing covers

546a, 546b attached to the chassis 560 provide

shoulders

550a, 550b to allow the impact cap to sit.

In the second end portion 544 of the housing 540, the housing 540 is provided with an opening 552, the opening 552 being configured to allow a main portion of the chassis 560 to be positioned inside. The housing 540 may sit on a bottom base 567 of the chassis 560, the bottom base 567 may include a raised rim 571 (fig. 43) to surround the distal end of the housing 560. Threads may be provided on the distal end of the housing 560 for connection to the chassis 560. Gaskets may be used to provide a tight fit and seal to prevent biological material and water from entering the enclosure. Two sub-housings or

chambers

554a, 554b may be provided at the second end portion for receiving a bearing lock assembly 630 as will be described in more detail below. The sub-housings 554a, 554b may be integrally formed with the main body of the housing and disposed opposite to each other. The sub-housings 554a, 554b may be configured to allow retention plates 652, 654 (fig. 54) of the bearing lock assembly 630, which will be described below, to be inserted inside by press fit and easily removed for cleaning and sterilization. Apertures may be provided in the side walls of the sub-housings 554a, 554b to allow access of the torque application tool to the fasteners and connection of the fasteners to the bearings of the bearing lock assembly 630, which will be described in more detail below. Fig. 39 is a perspective end view of the housing 540 showing the opening 552, the opening 552 configured to receive a chassis and sub-housings 554a, 554b for the bearing lock assembly 630. Fig. 40 is a perspective front view of the housing 540.

Referring to fig. 41, housing 540 may include a switch guide track 556, switch guide track 556 for guiding a user to operate an instrument through switch or switch assembly 610. The guide rail 556 may include slots corresponding to different operating modes or settings when the switch is positioned. Markers 558 may be provided near the guide track 556 to indicate various operational settings. In some embodiments, a washer 559 (fig. 42) may be coupled to the guide rail 556 to allow a user to more smoothly and seamlessly operate the switch. The gasket 559 can also help keep biological material from entering the interior of the housing through the switch site. Fig. 42 schematically illustrates an exemplary gasket 559. The washer 559 may be fitted on a hook in the guide rail 556 by tension or by other suitable means. The gasket 559 may be made of an elastic material such as silicon rubber. The silicone rubber material allows the gasket to withstand high sterilization temperatures without melting or deforming.

Referring to fig. 33 to 34, the chassis 560 serves as a main base of the operating device 500. The chassis 560 provides support for the

drive shafts

510, 512, the

sleeves

520, 522, and the housing 540. The upper portion of the chassis 560 may also serve as a partial housing for the gear assembly 580 and other components and provide attachment points for the

housing covers

546a, 546 b. The chassis 560 may be made of metal such as stainless steel or metal such as

R5500 polyphenylsulfone (PPSU) medical grade plastic, providing a robust handling instrument that does not break when dropped on the floor. The chassis 560 in combination with the housing 540 and the impact cap 503 allow a user to apply a hammering force to the instrument without damaging the instrument. The inclusion of the chassis 560 in the instrument 500 simplifies assembly, disassembly, and cleaning of the instrument.

Fig. 43 schematically illustrates an example chassis 560 according to an embodiment of the present disclosure. As shown, the chassis 560 may generally include a first or lower portion 561 and a second or upper portion 563. The lower portion 561 may include a body 562 that provides support for the

drive shafts

510, 512 and

sleeves

520, 522. The upper portion 563 may include spaced apart arms 564 that define portions of the housing 565 for the gear assembly 580, the gear lock 592, and the switch assembly 610, as will be described in greater detail below.

In the lower portion 561 of the chassis 560, the body 562 can be provided with a pair of elongate channels 566 extending between the bottom base 567 and the upper base 568. The pair of elongate channels 566 may be disposed parallel with respect to one another along opposite sides of the body 562. The channel 566 may be configured, for example, to have a generally arcuate surface to allow a generally cylindrical drive shaft or sleeve to fit therein and rotate. A plurality of ridges 569 may be provided on the channel surface to hold the drive shaft and sleeve tight against the undercarriage when secured by a bearing lock assembly 630, which will be described in more detail below. Ridges 569 on the channel surface may keep the drive shaft and sleeve tightly pressed against the chassis body 562 when tightened to limit free movement of the drive shaft and sleeve in the axial direction. A divider 570 may be provided to divide the channel 566 in two. The spacer 570 allows a separate bearing to lock the traction shaft and sleeve to the chassis independently of each other. For example, the

drive shaft bearings

632, 634 may lock the

drive shafts

510, 512 to the chassis 560 at an upper portion of the channel 566, while the

sleeve bearings

642, 644 may secure the

sleeves

520, 522 to the chassis 560 at a lower portion of the channel 566 (fig. 44 and 45). The spacer 570 may keep the

drive shaft bearings

632, 634 and

sleeve bearings

642, 644 separate from each other and allow the bearings to rest as a support structure on the chassis 560 during assembly and operation. The bottom base 567 has a raised edge 571 to allow the housing 540 to rest on the chassis 560. An opening 572 provided in the bottom base 567 allows the

drive shafts

510, 512 and

sleeves

520, 522, respectively, to pass through and fit into the channel 566 on the chassis 560. The upper base 568 is provided with an opening 573 to allow the

drive shaft

510, 512 to pass through and extend into the portion of the housing 565 defined by the spaced apart arms 564. The upper base 568 may also provide support for the gear assembly 580 and the gear lock 592, while increasing the strength of the chassis or operating instrument.

In the upper portion 563 of the chassis 560, the spaced apart arms 564 define part of the housing 565 for the gear assembly 580, the gear lock 592, and the switch assembly 610. Arm 564 may also be configured to secure a gear lock 592, which will be described in more detail below. For example, arms 564 may be configured with an inner surface profile that mates with an outer surface profile of gear lock 592. By way of example, arm 564 may have a convex inner surface portion that mates with a concave outer surface portion of gear lock 592, such that when gear lock 592 is flexed and/or slid into portion housing 565 and seated on upper base 568, gear lock 592 is fixed and does not rotate when a torque is applied. Alternatively, arms 564 may have concave inner surface portions that mate with convex outer surface portions of gear lock 592. The arm 564 may be provided with features, such as an internally threaded bore 574, for securing the

housing covers

546a, 546b to the chassis 560 (fig. 37 and 38).

Fig. 44 is a perspective view showing the chassis 560 with the

drive shaft bearings

632, 634 and

sleeve bearings

642, 644 seated on the body 562 in the lower portion 561, and with the gear lock 592 and gear assembly 580 received in the partial housing 565 in the upper portion 563. Fig. 45 is a partial perspective view showing the chassis 560 with the gear lock 592 and gear assembly 580 received in a partial housing in the upper portion 563, and the pair of drive shafts 510, 512 (not shown in fig. 44) and

sleeves

520, 522 secured to the body 562 in the lower portion 561 by the bearing lock assembly 630. In fig. 45, the housing 560 is removed to more clearly show the positional relationship between the chassis 560 and the bearing lock assembly 630, which will be described in more detail below.

Referring to fig. 33 and 34, the pair of

drive shafts

510, 512 are operatively coupled to the handle 502 to apply torque to a workpiece (not shown). The pair of

drive shafts

510, 512 may include a first drive shaft 510 and a second drive shaft 512. The first drive shaft 510 may be operably connected with the handle 502, for example, via the adapter 504. The second drive shaft 512 may be coupled to the first drive shaft 510 or decoupled from the first drive shaft 510 via a gear assembly 580. When the second drive shaft 512 is operably coupled with the first drive shaft 510, a first mode of operation is provided in which the handle 502 can rotate both the first drive shaft 510 and the second drive shaft 512. When the second drive shaft 512 is disengaged from the first drive shaft 510, a second mode of operation is provided in which the handle 502 rotates only the first drive shaft 510.

The pair of

drive shafts

510, 512 may be rotatably secured to a chassis 560 in the housing 540 by a bearing lock assembly 630, which will be described in more detail below. The pair of

drive shafts

510, 512 may each include a

first portion

510a, 512a that is received in the housing 540 when assembled and a

second portion

510b, 512b that extends from the housing 540. The

first portions

510a, 512a of the pair of

drive shafts

510, 512 may be configured to be received in the pair of elongate channels 566 of the chassis 560 and rotatably secured to the chassis 560. For example, the

first portion

510a, 512a of the pair of

drive shafts

510, 512 may include an increased diameter portion and a

groove

510c, 512c, the

groove

510c, 512c providing a space for a bearing recess to fit within or flush against, thereby limiting the

drive shafts

510, 512 from sliding out of the housing 540 while allowing the

drive shafts

510, 512 to rotate freely. The

first portions

510a, 512a of the pair of

drive shafts

510, 512 may extend into a portion of the housing 565 of the chassis 560 to receive a gear member, dial, or adapter. For example, the

first portion

510a, 512a may include a planar surface and a remaining cylindrical surface at the proximal end configured to receive a gear member, adapter, or dial, which may be provided with a channel, cut-out, or aperture having corresponding planar and cylindrical surfaces. When the gear member, adapter or dial is received on the

first portion

510a, 512a, the flat surface prevents rotational movement of the gear member, adapter or dial relative to the

drive shaft

510, 512 when secured with set screws or the like. The pair of

drive shafts

510, 512 may have substantially the same length and substantially the same cross-sectional geometry along the length. Alternatively, the pair of

drive shafts

510, 512 may have different lengths and cross-sectional geometries. For example, the first drive shaft 510 may extend the length and be directly connected to the handle 502 without the need for an adapter.

The

second portions

510b, 512b of the

drive shafts

510, 512 include

tip portions

510d, 512d, the

tip portions

510d, 512d having features configured to engage a workpiece. The workpiece engaging tip end may have a quincunx or hexalobal configuration, or a modified quincunx or hexalobal configuration. Other suitable configurations or features known in the art may also be used to engage workpieces having corresponding engagement features. The workpiece may be an interbody fusion implant device as described in U.S. patent No.9,889,019, the entire disclosure of which is incorporated herein by reference. The workpiece may also be other medical devices that can be manipulated to expand, contract, or tilt by using a manipulation instrument.

Referring to fig. 33-34, the pair of sleeves or

tubular shafts

520, 522 are operative to connect the manipulator apparatus 500 to a workpiece, such as an interbody fusion implant device. The pair of

sleeves

520, 522 may include: a first sleeve 520, the first sleeve 520 surrounding a second portion 510b of the first drive shaft 510 extending from the housing 540; and a second sleeve 522, the second sleeve 522 surrounding a second portion 512b of the second drive shaft 512 extending from the housing 540. The pair of

sleeves

520, 522 may be rotatably secured to the chassis 560 via a bearing lock assembly 630, which will be described below, such that the

sleeves

520, 522 may be freely turned or rotated independently of the rotation of the pair of

drive shafts

510, 512 and restricted from sliding out of the housing 540 during operation, but the

sleeves

520, 522 may be removed after operation for cleaning and sterilization purposes.

The pair of

sleeves

520, 522 may be generally cylindrical in shape having an inner diameter greater than an outer diameter of the

second portions

510b, 512b of the

drive shafts

510, 512. The

sleeves

520, 522 may each include a

first end portion

520a, 522a configured to be rotatably secured to a chassis 560 in the housing 540 and a second end portion 520b, 522b having features configured to be coupled to a workpiece. Finger grips 520c, 522c may be provided on each of the

sleeves

520, 522 to facilitate rotation or turning of the sleeve when connected to a workpiece. The

first end portions

520a, 522a of the pair of

sleeves

520, 522 may be configured to be received in the elongate channel 566 of the chassis 560 and rotatably secured to the chassis. The

first end portions

520a, 522a of the pair of

sleeves

520, 522 may each include a

groove

520d, 522d, the

grooves

520d, 522d providing a space for a bearing notch to fit within or flush against, thereby restricting the

sleeves

520, 522 from sliding away from the housing 540 while allowing the

sleeves

520, 522 to rotate freely. The second end portions 520b, 522b of the

sleeves

520, 522 can be provided with internal threads or other suitable features configured to connect with a workpiece, such as a spinal implant device, having corresponding connection features, such as external threads.

Referring to fig. 33 and 34, a gear assembly 580 is used to couple the second drive shaft 512 with the first drive shaft 510 or to decouple the second drive shaft 512 from the first drive shaft 510, thereby providing various operating modes. In some embodiments, the gear assembly 580 may lock the first and

second drive shafts

510, 512, thereby preventing rotation of the first and

second drive shafts

510, 512.

The gear assembly 580 may include a pair of spur gears having substantially parallel gear axes. The first gear member 581 may be received on the first drive shaft 510 and the second gear member 582 may be received on the second drive shaft 512 (fig. 48-50). The first gear member 581 may be fixedly secured to the first drive shaft 510 via a screw, key, pin, or the like. The second gear member 582 may be slidably received on the second drive shaft 512, but not rotate relative thereto via set screws, keys, pins, etc. The toggle switch 610, which will be described in greater detail below, may be received on the second drive shaft 512 and slidably moved on the second drive shaft 512 to place the second gear member 582 in and out of engagement with the first gear member 581.

Fig. 46 schematically illustrates an example gear member 586 that may be used in a gear assembly 580 according to embodiments of the present disclosure. As shown, the gear member 586 comprises a plurality of teeth 587, each tooth of the plurality of teeth 587 having two opposing

side surfaces

588a, 588b extending between two

end surfaces

590a, 590 b. The side surfaces 588a, 588b of the teeth may be generally parallel to the axis of the gear member 586, with the gear member 586 being configured to engage with the teeth of a mating gear member. The end surfaces 590a, 590b of the teeth 587 are chamfered or chamfered at least at one end of the gear member 586, or preferably at both ends of the gear member 586. The surfaces between adjacent teeth at the end surfaces may also be chamfered. A chamfered or lofted (cut-out) feature along one or more ends of the teeth of the gear member allows the gears to smoothly shift and mesh back with each other when the user operates the switch 610 to have a seamless transition.

Referring to fig. 33 and 34, the switching assembly 610 allows the user to smoothly and seamlessly operate the instrument 500 via an intuitive interface. As an example, a user may position the switch assembly 610 in a first position, e.g., an "expanded mode" position, disposed in the switch guide 556 (fig. 41) to allow the second gear 582 to engage with the first gear 581, a second position, e.g., a "lordotic mode" position, to allow the second gear 512 to disengage from the first gear 510, or a third position, e.g., a "locked mode" position, to allow the second gear member 512 to engage both the first gear member 510 and the gear lock 592.

Fig. 47 schematically shows a toggle switch 610 that can be used in the operating instrument 500 according to an embodiment of the present disclosure. As shown, the toggle switch 610 may include a first ring structure 612 and a second ring structure 614, the first and

second ring structures

612, 614 being spaced apart, for example, by a generally U-shaped structure 616, which may be coupled to a shroud member 618 having a switch knob 620. The first ring structure 612 and the second ring structure 614 may each have open ends. During assembly, the toggle switch 610 may snap onto the second drive shaft 512 through the open end, or the toggle switch 610 may be allowed to slide from the top of the drive shaft 512 through the top opening of the housing 540. The toggle switch 610 may retain the second gear member 582 between the first ring structure 612 and the second ring structure 614 and slidably move the second gear member 582 over the second drive shaft 512. The snap feature allows toggle 610 to be easily attached to or detached from the assembly, enabling more efficient cleaning and sterilization of the instrument and reuse for another procedure. The shield 618 on the toggle switch 610 may more effectively prevent biological material from entering the interior portion of the operating instrument through the toggle switch.

Fig. 48-50 illustrate the operation of the switch assembly 610 and the gear assembly 580 more clearly. In fig. 48, the toggle switch 610 is disposed in a first position or "extended mode" position, which allows the second gear member 582 to engage the first gear member 510, thereby operatively coupling the second drive shaft 512 with the first drive shaft 510. When the second drive shaft 512 is operatively coupled with the first drive shaft 510, rotation of the first drive shaft 510 by the handle 502 causes rotation of the second drive shaft 512, thereby providing a first mode of operation in which, for example, an expandable spinal implant device may be expanded or contracted. In fig. 49, the toggle switch 610 is disposed in a second position or "lordotic mode" position, which allows the second gear member 582 to be disengaged from the first gear member 581, thereby separating the second drive shaft 512 from the first drive shaft 510. When the second drive shaft 512 is disengaged from the first drive shaft 510, the handle 502 only rotates the first drive shaft 510 and the second drive shaft 512 becomes inactive, thereby providing a second mode of operation in which, for example, the spinal implant device can be adjusted for tilt or lordosis. In fig. 50, the toggle switch 610 is disposed in a third position or "lock mode" position, which allows the second gear member 582 to engage with both the first gear member 581 and the gear lock 592. Because the second gear member 582 is engaged with the gear lock 592, rotation of the second gear member 582 is limited, and therefore, rotation of the first gear member 581 is also limited due to engagement with the second gear member 582. When the switch 610 is disposed in the third position or "lock mode" position, the instrument 500 is locked, wherein rotation of the first drive shaft 510 and the second drive shaft 512 is prevented.

FIG. 51 is a perspective view of an exemplary gear lock 592, according to an embodiment of the present disclosure. As shown, the gear lock 592 may include a tubular member 594, the tubular member 594 having an inner profile, such as a channel or slot, that may receive the first and

second gear members

581, 582. On the side that receives the second gear member 582, the inner surface of the gear lock 592 can be provided with a tooth configuration 596, the tooth configuration 596 being configured to mate with the teeth of the second gear member 582. The sides of the gear lock 592 may be open to allow the toggle switch 610 to slidably seat the second gear member 582 or displace the second gear member 582, allowing the teeth on the second gear member 582 to engage or disengage with the teeth 596 on the gear lock 592. The openings 598 may also allow the gear lock 592 to flex when positioned within a portion of the housing 565 of the chassis 560. The outer surface of gear lock 592 may have a profile configured to mate with the profile of the inner surface of chassis arm 564, such that gear lock 592 may fit with chassis arm 564 or with chassis arm 564 and not rotate upon application of a torque.

Referring to fig. 33-34, bearing lock assembly 630 operates to lock or unlock

drive shafts

510, 512 and

sleeves

520, 522 to or from chassis 560 in housing 540. Bearing lock assembly 630 is designed such that when bearing lock assembly 630 is in the locked mode, drive

shafts

510, 512 and

sleeves

520, 522 are not free to move in the axial direction, but are still free to rotate or spin. When bearing lock assembly 630 is in the unlocked mode,

sleeves

520, 522 and drive

shafts

510, 512 may be slid out of housing 540, while the components of bearing lock assembly 630 may remain in housing 540. The example bearing lock assembly 630 may include

bearings

632, 634, 642, 644, fasteners 633 and retaining plates 652, 654 (fig. 52).

Fig. 52 is a partial perspective view illustrating an exemplary bearing lock assembly 630 and other components of instrument 500 according to an embodiment of the present disclosure. In fig. 52, housing 540 and chassis 560 are removed to more clearly show the relationship of bearing lock assembly 630 to the other components of the instrument. As shown, bearing locking assembly 630 may include a pair of

drive shaft bearings

632, 634, the pair of

drive shaft bearings

632, 634 configured to lock or unlock

drive shafts

510, 512, respectively, to or from chassis 560. By way of example, the

drive shaft bearings

632, 634 may be in the form of a curved plate having a generally arcuate inner surface 635 (fig. 53). The

drive shaft bearings

632, 634 may each be configured to be flush with the chassis body 562 when assembled and tightened, thereby forming a pair of channels between the pair of

drive shaft bearings

632, 634 and the chassis body 562 to allow the pair of

drive shafts

510, 512 to fit therein. The

drive shaft bearings

632, 634 may each include a notch 636 (fig. 53) on the inner surface 635, the notch 636 being configured to fit into a groove of each drive shaft of the pair of

drive shafts

510, 512. When bearing lock assembly 630 is in the locked mode, notches 636 on

drive shaft bearings

632, 634 prevent

drive shafts

510, 512 from sliding out of housing 540 while allowing

drive shafts

510, 512 to freely rotate or turn. Each drive shaft bearing 632, 634 may include one or more ridges 638 on an inner surface 635. When the bearing lock assembly 630 is in the locked mode, the ridges 638 on the inner surface of the

drive shaft bearings

632, 634 and the ridges 569 on the inner surface of the chassis 560 press against the

drive shafts

510, 512, preventing the

drive shafts

510, 512 from moving freely in the axial direction.

The

drive shaft bearings

632, 634 may each be provided with a bore 639 having an internal thread. The fastener 633, which may be in the form of a shoulder bolt or the like, may be externally threaded to be received in the bore 639 of the

drive shaft bearings

632, 634. Upon twisting, the fastener 633 may rotate within the threaded aperture 639, thereby urging the

drive shaft bearings

632, 634 against the chassis 560, thereby tightening the

drive shafts

510, 512 to the chassis 560. Rotating the fastener 633 in the opposite direction will loosen the

drive shaft bearings

632, 634, thereby unlocking the

drive shafts

510, 512 from the chassis 560.

The bearing locking assembly 630 may include a pair of

sleeve bearings

642, 644 configured to lock the

sleeves

520, 522 to the chassis 560 or unlock the

sleeves

520, 522 from the chassis 560, respectively. Similar to the

drive shaft bearings

632, 634, the

sleeve bearings

642, 644 may be in the form of curved plates having a generally arcuate inner surface 635. The

sleeve bearings

642, 644 may each be configured to be flush with the chassis body 562 when assembled and tightened, thereby forming a pair of channels between the pair of

sleeve bearings

642, 644 and the chassis body 562 to allow the pair of

sleeves

520, 522 to fit therein.

The

sleeve bearings

642, 644 may each include a notch 636 on the inner surface 635, the notch 636 configured to fit into a groove of each sleeve of the pair of

sleeves

520, 522. When bearing lock assembly 630 is in the locked mode, notches 636 on

sleeve bearings

642, 644 prevent

sleeves

520, 522 from sliding away from housing 540 while allowing

sleeves

520, 522 to rotate. In some embodiments, the

grooves

520d, 522d in the

sleeves

520, 522 may be machined slightly wider than the notches on the

sleeve bearings

642, 644 to allow slight axial movement of the

sleeves

520, 522, as may be desired in connection with the instrument 500, for example, with an interbody fusion device. The

sleeve bearings

642, 644 may also include one or more ridges on the inner surface. When the bearing lock assembly 630 is in the locked mode, the

ridges

638, 569 on the inner surface of the

sleeve bearings

642, 644 and the inner surface of the chassis 560 press against the

sleeves

520, 522, preventing the

sleeves

520, 522 from moving freely in the axial direction. Such a dynamic locking system facilitates assembly and disassembly for cleaning and sterilization activities, such that instrument 500 can be reused for multiple procedures while providing a secure assembly connection during the procedure.

Similar to the

drive shaft bearings

632, 634, the

sleeve bearings

642, 644 may be provided with a bore 639, the bore 639 having internal threads for coupling with the fastener 633. The fastener 633, which may be a shoulder bolt or the like, may be externally threaded to be received in the bore of the sleeve bearing. Upon twisting, the fastener 633 may rotate within the threaded hole, thereby pushing the sleeve bearing flush with the chassis 560. Rotating the fastener in the opposite direction will loosen the

sleeve bearings

642, 644 from the chassis 560, thereby unlocking the

sleeves

520, 522.

Bearing lock assembly 630 may include a pair of retaining

plates

652, 654 for retaining fastener 633 within the housing. The

retainer plates

652, 654 include holes 656 that allow a torque application tool to access the fasteners 633 (fig. 54) when tightening or loosening the bearing. However, the retaining

plates

652, 654 limit outward movement or movement of the fastener 633 in the axial direction of the fastener, thereby preventing the fastener 633 from loosening from the entire assembly when the bearing is loosened after being torqued. The

retention plates

652, 654 allow the

sleeves

520, 522 and drive

shafts

510, 512 to be removed from the assembly for cleaning, sterilization, or replacement without having to completely remove the fastener 633 from the assembly. This provides further convenience for the medical staff when disassembly is required for replacement, cleaning and disinfection. The retaining plate may contain an O-ring of medical grade silicone to ensure that biological material or water does not enter the gap of the bearing lock assembly.

The

retention plates

652, 654 may be configured to snap into the sub-housings 554a, 554b (fig. 54) by press-fitting or other suitable means. A groove may be provided in the area adjacent to the aperture 656 for sealing gaskets, O-rings, etc., to prevent water, debris, or biological material from entering the housing through the aperture. The

retainer plates

652, 654 can be easily removed for further cleaning and sterilization, if desired. Fig. 54 is a partial cross-sectional view of the operating instrument showing the

retainer plates

652, 654, which may be snapped into and out of the sub-housings 554a, 554 b.

Returning to fig. 33-34, the operating instrument 500 may include a first dial 506 and a second dial 508, the first dial 506 and the second dial 508 configured to provide information to a user regarding operation of the instrument. The first dial 506 may be coupled to a first drive shaft 510. The second dial 508 may be coupled to a second drive shaft 512. By way of example, the first dial 506 may be provided with an aperture configured to allow the first drive shaft 510 or adapter 504 to fit therein. The second dial 508 may be provided with a channel configured to receive the second drive shaft 512 or to couple with the second drive shaft 512.

In use, the first dial 506 rotates with the first drive shaft 510, and indicia on the first dial 506 provide information to the user regarding the rotation of the first drive shaft 510. The second dial 508 rotates with the second drive shaft 512, and indicia on the second dial 508 provide information to the user regarding the rotation of the second drive shaft 512. As described above, when the second drive shaft 512 is coupled with the first drive shaft 510 via the gear assembly 580, the handle 502 rotates both the first drive shaft 510 and the second drive shaft 512, and thus both the first dial 506 and the second dial 508, thereby providing the user with an indication of the first mode of operation of the instrument 500 or an indication of the level of the expanded height. When the second drive shaft 512 is disengaged from the first drive shaft 510 via the gear assembly 580, the handle 502 rotates only the first drive shaft 510, and thus, only the first dial 506 coupled to the first drive shaft 510, thereby providing the user with an indication of the second operating mode of the instrument 500. When the first drive shaft and the second drive shaft are driven unequally, the indication of the first dial and the second dial when separated is considered an increasing angle of lordosis or kyphosis.

In embodiments of the present disclosure, the instrument 500 operates an interbody fusion implant device during surgery, and the markings provided on the first and

second dials

506, 508 may be configured to allow a user to measure the amount of increased expansion, contraction, and/or lordotic adjustment of the patient's intervertebral disc space. For example, markings may be provided on the first dial 506 to indicate or allow the user to measure the increased lordosis. As an example, four (4) degrees may correspond to a full turn of the dial 506, or two (2) degrees may correspond to a half turn of the dial 506. Markings may also be provided on the first dial 506 and/or the second dial 508 to indicate or allow the user to measure the increased height or expansion. As an example, 2.2mm may correspond to a full turn of the first dial 506 and the second dial 508, or 1.1mm may correspond to a half turn of the

dials

506, 508.

Referring to fig. 33-34, in use, instrument 500 can be coupled to a workpiece, such as a spinal implant device, via

sleeves

520, 522. The user may, for example, turn or rotate

sleeves

520, 522 inwardly to screw instrument 500 onto the implant device. Prior to connection of the instrument 500 with the implant device, the user may first set the instrument 500 in the locked mode (fig. 50), for example, by positioning the switch 610 in an intermediate position in the switch guide, such that the first and second gear members are locked and rotation of the

drive shafts

510, 512 is prevented. An anterior force may be required in some instances when placing the implant device into a vertebral space of a patient. If desired, the handle 502 of the instrument 500 may be temporarily removed and replaced with the impaction cap 503 or hammer 670. A forward force may then be applied by instrument 500 by striking impact cap 503 using, for example, a mallet. Once the implant device is properly positioned in the patient's vertebral space, the impaction cap 503 can be removed and replaced with the handle 502 for manipulation of the implant device. In some embodiments, the handle 502 or impact cap 503 may be removed and the hammer 670 may be attached to an instrument, such as to the top of the adapter 504 or housing 540. If the surgeon desires to move the implant out of the disc space after insertion, clapper 670 acts as an attachment to provide a removal or pulling force on the implant.

To effect expansion of the implant device, the user may position switch 610 in a proximal position, allowing the first and second gear members to disengage from the locked position and engage to couple first and

second drive shafts

510, 512. The user may then rotate the handle 502 in, for example, a clockwise direction to apply a torque to the first drive shaft 502. Rotation of the first drive shaft 512 simultaneously causes rotation of the second drive shaft 51 to effect expansion of the implant device in minute increments. If desired, the user may rotate the handle 502 in the opposite direction, e.g., counterclockwise, to retract or fine-tune the level of expansion of the implant device. The gear assembly 580 may be configured such that rotation of the first drive shaft 510 in a first direction, e.g., clockwise, causes rotation of the second drive shaft 512 in a second direction, e.g., counterclockwise, opposite the first direction. Alternatively, the gear assembly 580 may be configured such that rotating the handle 502 causes the first drive shaft 510 and the second drive shaft 512 to rotate in the same direction.

To achieve lordosis, the user may position switch 610 in a distal position, allowing the first and second gear members to disengage, thereby disengaging second drive shaft 512 from first drive shaft 510. The user may then rotate the handle 502 in, for example, a clockwise direction, applying torque only to the first drive shaft 510 as the second drive shaft 512 becomes inactive. Rotation of only the first drive shaft 510 causes the implant device to tilt, thereby achieving lordosis. If desired, the user may rotate the handle 502 in the opposite direction, e.g., counterclockwise, to adjust or remove the level of lordosis while maintaining the first drive shaft 510 and the second drive shaft 512 restricted from rotation. This restriction ensures that the drive shaft cannot retract the implant when the instrument is disconnected from the implant.

To disconnect the surgical instrument 500 from the implant device, the user may position the switch 610 in the neutral position to set the instrument in the locked mode and then rotate the

sleeves

520, 522 outward, for example, to unscrew the instrument 500 from the implant device.

Various embodiments of the operating instrument have been described. It should be understood that the disclosure is not limited to the particular embodiments described. Aspects described in connection with a particular embodiment are not necessarily limited to that embodiment and may be practiced in any other embodiment.

Various embodiments are described with reference to the accompanying drawings. It should be emphasized that some of the figures are not necessarily to scale. The drawings are intended to facilitate the description of the embodiments only and are not intended as an exhaustive description or as a limitation on the scope of the disclosure. Furthermore, in the drawings and description, specific details may be set forth in order to provide a thorough understanding of the present disclosure. It will be apparent to one of ordinary skill in the art that some of these specific details may not be used to practice embodiments of the present disclosure. In other instances, well-known components may not have been shown or described in detail to avoid unnecessarily obscuring embodiments of the disclosure.

Unless specifically defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. As used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. The term "or" refers to a non-exclusive "or" unless the context clearly dictates otherwise.

Those skilled in the art will appreciate that various other modifications may be made. All such and other variations and modifications are contemplated by the inventors and are within the scope of the invention.

Claims

1. An operating instrument, comprising:

a handle;

a first drive shaft operably connected to the handle;

a second drive shaft; and

a gear assembly comprising a first gear member received on the first drive shaft, a second gear member slidably received on the second drive shaft, and a lever member operable to position the second gear member in engagement with the first gear member to couple the second drive shaft with the first drive shaft to provide a first mode of operation in which the handle is operated to rotate both the first drive shaft and the second drive shaft, or to position the second gear member out of engagement with the first gear member to decouple the second drive shaft from the first drive shaft to provide a second mode of operation in which, the handle is operable to rotate only the first drive shaft.

2. The operating device of claim 1, further comprising a housing provided with a cavity configured to receive the gear assembly and the first portion of the first drive shaft and the first portion of the second drive shaft, wherein the second portion of the first drive shaft and the second portion of the second drive shaft extend from the housing.

3. The operating device of claim 2, wherein the first and second drive shafts are each rotatably secured to the housing to prevent axial movement of the first and second drive shafts away from the housing while allowing rotation of the first and second drive shafts.

4. The operating instrument according to claim 2, further comprising:

a first tubular shaft surrounding the second portion of the first drive shaft and a second tubular shaft surrounding the second portion of the second drive shaft,

wherein the first and second tubular shafts each include a first end portion rotatably fixed to the housing to prevent axial movement of the first and second tubular shafts away from the housing while allowing the first and second tubular shafts to rotate independently of rotation of the first and second drive shafts, respectively.

5. The operating instrument according to claim 4, wherein the first and second tubular shafts each include a workpiece connecting end portion provided with an internal thread configured to connect with a workpiece having a corresponding external thread.

6. The operating instrument of claim 4, wherein at least one of the first tubular shaft and the second tubular shaft includes a finger grip.

7. The operating instrument of claim 2, wherein the lever member is further operable to dispose the second gear member in the housing in a locked position in which rotation of the second drive shaft and the first drive shaft by the handle is prevented.

8. The operating instrument of claim 7, wherein an inner surface of the housing is provided with a tooth configuration configured to mate with at least a portion of the second gear member in the locked position.

9. The operating instrument of claim 2, further comprising a first dial operably coupled to the first drive shaft indicating rotation of the first drive shaft.

10. The operating instrument of claim 9, further comprising a second dial operably coupled to the second drive shaft indicating rotation of the second drive shaft.

11. The operating device of claim 1, further comprising an adapter connecting the first drive shaft and the handle.

12. The operating device of claim 11, wherein the first and second drive shafts have substantially the same length and substantially the same cross-sectional geometry along the length.

13. The operating instrument of claim 1, wherein the first and second gear members are configured such that: when the first and second gear members are operatively engaged, rotation of the first drive shaft in a first direction by the handle causes rotation of the second drive shaft in a second direction opposite the first direction.

14. An operating instrument, comprising:

a handle;

a housing;

a first drive shaft operatively connected with the handle, the first drive shaft rotatably secured to the housing and including a first portion received in the housing and a second portion extending from the housing;

a second drive shaft rotatably secured to the housing and including a first portion received in the housing and a second portion extending from the housing;

a first tubular shaft surrounding the second portion of the first drive shaft and rotatably fixed to the housing;

a second tubular shaft surrounding the second portion of the second drive shaft and rotatably fixed to the housing; and

a gear assembly received in the housing, the gear assembly operable to couple the second drive shaft with the first drive shaft to provide a first operating mode in which the handle is operated to rotate both the first drive shaft and the second drive shaft, or the gear assembly operable to decouple the second drive shaft from the first drive shaft to provide a second operating mode in which the handle is operated to rotate only the first drive shaft.

15. The operating device of claim 14, further comprising an adapter connecting the first drive shaft and the handle.

16. The operating device of claim 15, wherein the first and second drive shafts have substantially the same length and substantially the same cross-sectional geometry along the length.

17. The operating instrument of claim 14, further comprising a first dial operably coupled to the first drive shaft indicating rotation of the first drive shaft.

18. The operating instrument of claim 17, further comprising a second dial operably coupled to the second drive shaft indicating rotation of the second drive shaft.

19. The operating device of claim 14, wherein the gear assembly is further operable to lock the second drive shaft and the first drive shaft, thereby preventing rotation of the second drive shaft and the first drive shaft.

20. The operating instrument of claim 19, wherein an inner surface of the housing is provided with a tooth configuration configured to cooperate with a portion of the gear assembly to lock the second drive shaft and the first drive shaft.

21. The operating device of claim 20, wherein the gear assembly is configured such that in the first operating mode, rotation of the first drive shaft in a first direction by the handle causes rotation of the second drive shaft in a second direction opposite the first direction.

22. An operating instrument, comprising:

a housing;

a chassis;

a first drive shaft and a second drive shaft each having a first portion supported by the chassis in the housing and a second portion extending from the housing;

a gear assembly including a first gear member fixedly received on the first portion of the first drive shaft and a second gear member slidably received on the first portion of the second drive shaft;

a switching assembly operable to place the second gear member in engagement with the first gear member to couple the second drive shaft with the first drive shaft to provide a first mode of operation in which the second drive shaft is rotatable with the first drive shaft or to displace the second drive shaft out of engagement with the first gear member to disengage the second drive shaft from the first drive shaft to provide a second mode of operation in which the second drive shaft is not rotatable with the first drive shaft; and

a bearing locking assembly operable to lock the first and second drive shafts to the chassis whereby the first and second drive shafts are restricted from sliding out of the housing and are free to rotate, or operable to unlock the first and second drive shafts from the chassis to allow the first and second drive shafts to slide out of the housing.

23. The operating device of claim 22, further comprising a handle connectable to the first drive shaft for applying torque.

24. The operating instrument of claim 22, further comprising an impact cap configured to seat on the housing for receiving an impact force.

25. The operating instrument according to claim 22, further comprising a clapper connectable to the operating instrument for applying a pulling force thereto.

26. The operating instrument of claim 22, further comprising a gear lock disposed in the chassis, wherein the switching assembly is further operable to place the second gear member in engagement with both the gear lock and the first gear member, thereby providing a third operating mode in which rotation of the second drive shaft and the first drive shaft is restricted.

27. The operating device of claim 26, wherein the shift assembly includes a pair of open ring structures that snap over or slide over the second drive shaft, thereby disposing the second gear member between the pair of open ring structures.

28. The operating instrument of claim 27, wherein the switching assembly further comprises a shield member configured to prevent debris or biological material from entering the housing.

29. The operating instrument of claim 22, wherein each of the first and second gear members includes a plurality of teeth each having two end surfaces and two side surfaces extending therebetween, wherein the two end surfaces are chamfered to allow the first and second gear members to be smoothly engaged or disengaged.

30. The operating device of claim 29, wherein the gear assembly is configured such that in the first operating mode, rotation of the first drive shaft in a first direction causes rotation of the second drive shaft in a second direction opposite the first direction.

31. The operating device of claim 22, wherein the chassis includes a first portion including a body supporting the first and second drive shafts and a second portion including spaced apart arms defining a partial housing for the gear assembly and the shift assembly, wherein the body is provided with a pair of elongated channels along opposite sides of the body configured to receive the first and second drive shafts.

32. The operating device of claim 31, wherein the body of the chassis further includes a base at an end of the body, the base being provided with a pair of openings allowing the first and second drive shafts to pass through the pair of openings in the base, be received in the pair of elongated channels, and enter the partial housing defined by the spaced apart arms.

33. The operating instrument of claim 32, wherein the body of the chassis further includes a divider that bifurcates the elongate channel, the divider being provided with a pair of openings that align with the pair of openings in the base of the body.

34. The operating instrument of claim 33, wherein the chassis is constructed of stainless steel or aluminum.

35. The operating instrument of claim 33, wherein the bearing locking assembly includes a pair of bearings configured to lock or secure the first and second drive shafts to the body of the chassis.

36. The operating device of claim 35, wherein the pair of bearings includes a circumferential notch on an inner surface of each of the pair of bearings, the circumferential notches configured to mate with grooves disposed in each of the first and second drive shafts to limit the first and second drive shafts from sliding out of the housing when locked or secured.

37. The operative device of claim 36, wherein each of the first and second pairs of bearings further comprises one or more circumferential ridges on an inner surface of the pair of bearings, the body of the chassis further comprising a plurality of ridges on an inner surface of each of the pair of elongated channels, wherein the ridges of the pair of bearings and the ridges of the body of the chassis are configured to limit free axial movement of the first and second drive shafts when locked or secured.

38. The operating instrument of claim 33, wherein the bearing lock assembly further comprises:

a first pair of fasteners configured to drive the pair of bearings, wherein rotation of the pair of fasteners allows the pair of bearings to tighten or loosen the first drive shaft and the second drive shaft in the pair of elongated channels of the chassis; and

a pair of retaining plates coupled to the housing, the pair of retaining plates configured to limit axial movement of the pair of fasteners.

39. The operating instrument of claim 22, wherein the housing includes a first end portion enclosing at least the gear assembly and a second end portion enclosing at least the bearing lock assembly, wherein the first end portion of the housing includes a pair of housing covers removably attached to the chassis, each housing cover of the pair of housing covers including a shoulder configured to support an impact cap.

40. The operating instrument of claim 39, wherein the housing comprises: a guide track providing guidance in operating the switching assembly in at least the first and second modes of operation; and a flag indicating at least the first and second modes of operation.

41. The operating instrument of claim 40, further comprising a guide washer constructed of silicone configured to smooth operation of the switch assembly in the guide track to help ensure that the switch assembly remains stationary in the selected operating mode and/or to prevent debris or biological material from entering the housing.