WO1999012485A1

WO1999012485A1 - Creating holes in bone via the medullary cavity

Info

Publication number: WO1999012485A1
Application number: PCT/US1998/017733
Authority: WO
Inventors: Chandra M. Agrawal; Kyriacos A. Athanasiou; Dan R. Lanctot
Original assignee: The Board Of Regents, The University Of Texas System
Priority date: 1997-09-05
Filing date: 1998-08-27
Publication date: 1999-03-18
Also published as: AU9122498A

Abstract

Disclosed are safe and accurate means of creating one or more holes in a bone. Specifically, devices and methods to produce one or more holes from the inside of the bone to the outside of the bone (i.e., from the endosteum of the bone to the periosteum of the bone) are disclosed. Additionally disclosed are uses of the instant methods and devices in various medical procedures, for example in setting a broken bone, and in anchoring or attaching a fixation device, exemplified by but not limited to an intramedullary nail, to a bone. The means comprise a drill with a flexible shaft within a sheath comprising a bend.

Description

DESCRIPTION

CREATING HOLES IN BONE VIA THE MEDULLARY CAVITY

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of medical devices and methods, and particularly concerns devices and methods for creating one or more holes in a bone from the inside of the bone (the endosteum) to the outside of the bone (the periosteum). More particularly, the invention relates to devices and methods for producing such holes using an apparatus to create holes in bone that match the holes in fixation systems, including, but not limited to, intramedullary nails.

2. Description of the Related Art

Generally accepted practice for the treatment of complicated bone fractures, particularly femoral and tibial fractures, includes the use of anchoring devices such as intramedullary (IM) nails. Tens of thousands of procedures involving IM nails are performed every year. IM nails are prosthetic devices that are surgically installed in the medullary canal of the bone and locked in place by means of fixation screws or pins driven through holes located at both the distal and proximal ends of the nail, thereby anchoring the nail in the surrounding bone. Anchoring the nail in place stops the broken ends of the fractured bone from rotating relative to one another, stabilizing the fracture and allowing it to heal properly.

A problem encountered in the use of IM nails is that once the nail is placed in the bone, the exact locations of the holes in the nail are not known, making it difficult to drill the matching holes in the bone. Often, this is done with the help of radiography, either continuous or discreet, while the nail is being inserted. This results in the repeated exposure of the surgeons and medical personnel to considerable amounts of radiation. Furthermore, these methods often involve inaccurate placement of the fixation holes as the X-ray information does not allow the surgeon to be certain about the axial orientation of the fixation holes.

In the attempt to alleviate the problems associated with drilling fixation holes for IM nails, various guide devices have been developed to allow the surgeon other means of deducing the position of the fixation holes in implanted IM nails. One such method, disclosed in U.S. Patent No. 4,667,664 involves an out-rigger device that attaches to the proximal end of the IM nail, but lies outside the patient. The device includes a moveable platform formed of radiolucent material with perpendicular cross-hairs formed of radiodense material. Movement of the platform near the distal fixation holes can be tracked through the use of X-ray equipment to detect when the cross-hairs are centered on the hidden hole. While this eliminates some of the inaccuracies involved with the drilling of IM fixation holes in bone, the device, of course, does not eliminate the problems of exposure to radiation.

An example of an IM nail guide device that does not rely on X-ray machines is found in U.S. Patent No. 4,877,019, which discloses a hollow hexagonally shaped intramedullary nail having one or more holes at its distal end and one or more slots at its proximal end. To obtain centering and positioning of the distal screws or pins in the holes, an insertable hexagonally shaped probe containing electronic microcircuits is used. An oscilloscope positioned outside the patient is able to locate the position of the probe due to the magnetic field generated by the electrical current caused by the microcircuit. External toroidal magnets are also used to insure that the true axis of fixation hole has been determined. Thus, although the device eliminates the use of potentially harmful x- rays, it still relies on the use of complex external devices. Flexible surgical tools are known in the art. U.S. Patent No. 5,464,407 concerns a flexible screwdriver, and U.S. Patent No. 5,041,119 concerns an angle frame bone drill. Additionally, Kϋntscher (1965) concerns an intramedullary saw with a flexible drive shaft for cutting bone from the medullary canal outward.

However, none of these references overcomes the limitations inherent in the art.

Thus devices and methods for accurately and safely creating one or more holes in a bone would represent a significant advance in the art.

SUMMARY OF THE INVENTION

The present invention overcomes these and other drawbacks currently in the art by providing a variety of safe and accurate means of creating one or more holes in a bone. Specifically, the present invention provides devices and methods to produce one or more holes from the inside of the bone to the outside of the bone (i.e., from the endosteum of the bone to the periosteum of the bone). Additionally provided are uses of the instant methods and devices in various medical procedures, for example in setting a broken bone, and in anchoring or attaching a fixation device, exemplified by but not limited to an intramedullary nail, to a bone.

The present invention provides a bone drill apparatus, comprising a drill comprising a flexible shaft and a sheath comprising a bend at or proximal to a drill- distal end, the flexible shaft being disposed within the sheath. The instant bone drill apparatus is adapted for use inside the medullary cavity of a bone, and thus can be used to drill from the inside of a prosthetic device, such as an intramedullary nail, to the outside. While this will typically be during a procedure where the prosthetic device is placed within a bone, and the drilling is from the inside of the device, to the endosteum and through the bone to the periosteum, this is not required in all applications. The invention also provides a method of creating a hole starting from the endosteum of a bone and progressing to the periosteum of the bone, comprising obtaining a bone drill apparatus comprising a drill comprising a flexible shaft and a sheath comprising a bend at a drill-distal end, the flexible shaft being disposed within the sheath, and employing the drill apparatus to drill a hole from the endosteum of the bone to the periosteum of the bone. The present invention also provides a bone drill apparatus, comprising a drill comprising a flexible shaft, a sheath, the flexible shaft being disposed within the sheath, and a curved guide, the guide operably attached to the sheath. In particular aspects of the present invention, the bone drill apparatus is designed for a single use.

In certain aspects of the invention, the bend in the sheath or the curved guide is rigid, while in other aspects the bend is adjustable. In preferred embodiments of the invention comprising the adjustable bend, the bend may be semi-flexible, in that once the angle of the bend is adjusted to a new angle, the bend stays at the new angle until readjusted. In particularly preferred embodiments, the angle of the bend may be adjusted while the sheath or curved guide is comprised within a bone or an intramedullary nail.

As used herein, the terms "drill apparatus" or "bone drill apparatus" will be understood to encompass any apparatus capable of forming a hole in a bone, and therefore is not limited to the dictionary definition of drill. In this regard, the term "drill", as used herein, will be understood to comprise any device that is capable of forming such a hole, as long as the device can be made flexible, is compatible with the size and material making up the bone or any bone setting devices used, and the use of the device does not produce undesired effects on the bone or any tissues surrounding the bone. Devices thus contemplated for use include, but are not limited to: mechanical devices such as a drill bit, a trephine, an awl, a vibrating probe or an ultrasound probe; electromechanical devices such as a laser; thermal devices such as a heat transfer probe or a cauterizing probe; or a fluid or chemical jet. Fluids contemplated for use in the fluid jet include, but are not limited to, water or an acid.

Thus, in particular embodiments of the invention, the drill comprises a drill bit operably joined to the flexible shaft, a trephine operably joined to the flexible shaft, an awl operably joined to the flexible shaft, a vibrating probe operably joined to the flexible shaft, an ultrasound probe operably joined to the flexible shaft, a laser comprised within the flexible shaft, a thermal, heat transfer or cauterizing probe operably joined to the flexible shaft or a fluid jet comprised within the flexible shaft.

The size of the hole created by the drill may vary, depending on the particular application desired. For example, the hole or holes created by the drill may be from about 0.1 mm in diameter to about 5 mm or more in diameter, or any intermediate value in between these values, including, but not limited to, about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5 mm, about 0.6 mm, about 0.7 mm, about 0.75 mm, about 0.8 mm, about 0.9 mm, about 1 mm, about 1.25 mm, about 1.5 mm, about 1.75 mm, about 2 mm, about 2.5 mm, about 3 mm, about 3.5 mm, about 4 mm, or about 4.5 mm and so on. Additionally, in certain applications, holes of different size may be formed in a single bone. In applications wherein an intramedullary nail is being fastened to a bone, the holes will be of appropriate size for the sizes of the fixation holes in the particular IM nail employed. Thus, holes of between about 1 mm and about 3 mm are typically preferred inmost procedures, with intermediate values such as those listed above also contemplated for use.

The flexible shaft contains any necessary wiring, electronic circuitry and/or equipment required to control and power the hole forming device. Suitable wiring schemes and power requirements will be known or apparent to one of skill in the art in view of the disclosure of this specification. In preferred aspects of the invention, the flexible shaft is comprised of an appropriate material, including, but not limited to, stainless steel, graphite, a woven mesh, a plastic, a composite material, Teflon , titanium, a polymer, silicone rubber, cobalt chromium or other materials commonly used in invasive procedures. In particularly preferred embodiments, the flexible shaft is comprised of surgical grade stainless steel, and in more particularly preferred embodiments, the flexible shaft is comprised of surgical grade, corrosion resistant stainless steel, such as 317 stainless steel.

Suitable materials contemplated for use for the bend portion of the sheath include, but are not limited to, stainless steel, graphite, plastic, titanium, Teflon , ceramics, cobalt chromium, polymers, composites and other materials commonly used in invasive procedures. In preferred embodiments of the invention, the bend in the sheath is about a 90° bend, because this is the most angle used in most procedures. In other preferred embodiments, the bend in the sheath is between about 1° and about 179°, including, but not limited to, about a 5° bend, about a 10° bend, about a 20° bend, about a 30° bend, about a 40° bend, about a 45° bend, about a 50° bend, about a 60° bend, about a 70° bend, about a 80° bend, about a 100° bend, about a 110° bend, about a 120° bend, about a 130° bend, about a 135° bend, about a 140° bend, about a 150° bend, about a 160° bend, about a 170° bend, or about a 175° bend, or any intermediate angle, in relation to the plane of the length of the bone, depending on the desired angle of the hole in the bone.

In some particular aspects of the invention, the sheath further comprises a flexible section. In certain aspects, the majority of the sheath is flexible, for example to allow for easy insertion and a wider range of motion inside the bone or a bone setting device. In various aspects of the present invention, the portion of the sheath that is flexible or semi-flexible is between about 0% and about 100%, including, but not limited to, about 5%, about 10%, about 15%, about 20%, about 25%o, about 30%, about 33%, about 40%, about 50%, about 60%, about 67%, about 70%, about 75%, about 80%, about 90%, or about 95%, or any intermediate value. In other aspects, the part of the sheath located from the proximal end of the bend to the proximal end of the entire apparatus is flexible, allowing the drill the widest possible range of motion, for example when locating the fixation holes in an IM nail.

In preferred aspects of the invention, the flexible section of the sheath is comprised of an appropriate material, including, but not limited to, stainless steel, graphite, a woven mesh, a plastic, a composite material, Teflon , titanium, a polymer, silicone rubber, cobalt chromium or other materials commonly used in invasive procedures. In additional embodiments of the invention, the sheath further comprises at least a first operably positioned hole locator. In yet other embodiments, the sheath further comprises at least a first and at least a second operably positioned hole locator. In further embodiments of the invention, the hole locator or locators is/are positioned adjacent the drill-distal end of the sheath.

The present invention provides a drill apparatus for use in creating a hole from the endosteum of a bone to the periosteum of the bone, in anchoring an intramedullary nail to a bone or in setting a broken bone. Therefore, the use of the instant drill apparatus in the creation of a hole from the endosteum of a bone to the periosteum of said bone, to anchor an intramedullary nail to a bone or to set a broken bone is provided.

In certain aspects of the invention, the methods further comprise obtaining an intramedullary nail and positioning the intramedullary nail in a suitable orientation within the intramedullary cavity of the bone. In other aspects, the methods may be characterized as comprising inserting the flexible shaft into a lumen of the intramedullary nail, positioning the flexible shaft adjacent a first attachment or fixation hole in the intramedullary nail, and drilling through the attachment or fixation hole, into the endosteum and out to the periosteum of the bone to form a hole in the bone. In these aspects of the invention, the bend may ensure that the drill will be located in the correct orientation with respect to the fixation hole so that the axis of the fixation hole and the axis of the hole formed by the drill in the bone will be in agreement. After the holes have been properly oriented and drilled so that they can be detected from the periosteum side of the bone, the holes can be enlarged as needed, for example with a larger, cannulated drill from the outside of the bone surface. Thus, in certain aspects of the invention, the methods further comprise counter-drilling through the hole in the bone into the periosteum of the bone and out to the endosteum of the bone.

Suitable IM nails contemplated for use in conjunction with the present invention should be hollow and composed of a biocompatible material such as titanium, stainless steel or other material with proper tensile strength capable of being used in invasive procedures. The IM nail may have a variety of shapes. For example nails with circular, tri-flangiate and hexagonal cross sections are known. The exact shape, length and material composition of the nail will depend upon the type and size of bone in which the nail is being used.

The intramedullary nails are hollow and typically contain fixation holes near both the distal and proximal ends. During use in this aspect of the invention, the drill apparatus may be inserted at either the proximal or distal end as may be conveniently accessible. The flexible shaft may be of a suitable size for exiting through the fixation holes in the IM nail, as detailed herein above, to facilitate boring the hole in the surrounding bone. The fixation hole allows the drill bit access to the bone beyond the IM nail. Thus, when the hole locator finds a hole in the side of the IM nail, the drill bit is positioned over the hole opening and can drill a matching hole in the surrounding bone from the inside of the bone out. By containing the apparatus inside the IM nail, finding the position of the fixation holes in the IM nail is a safe and precise process. No additional awkward or potentially harmful external devices are needed during the procedure. In certain preferred aspects of the present invention, the instant devices and methods are used in the reduction of fractures in long bones. Such bones include, but are not limited to, the femur, the tibia, the fibula, the radius, the ulna, carpi, tarsi and the humerus. In preferred aspects of the present invention, the bone is comprised within a mammal, and in particularly preferred aspects, the mammal is a human subject or patient.

The present invention also provides a method of anchoring an intramedullary nail to a bone, comprising, in any suitable order obtaining an intramedullary nail, comprising a lumen, the nail having at least a first attachment hole and at least a second attachment hole, inserting the intramedullary nail into the intramedullary cavity of the bone, obtaining a drill apparatus comprising, a drill comprising a flexible shaft and a sheath comprising a bend at a drill-distal end, the flexible shaft being disposed within the sheath, inserting the flexible shaft into the lumen of the intramedullary nail, positioning the flexible shaft adjacent the first attachment hole in the intramedullary nail, drilling through the first attachment hole, into the endosteum and out to the periosteum of the bone to form a first hole in the bone, placing a first nail attachment through the first hole in the bone into the first attachment hole in the intramedullary nail, repositioning the flexible shaft adjacent the second attachment hole in the intramedullary nail, drilling through the second attachment hole, into the endosteum and out to the periosteum of the bone to form a second hole in the bone, and placing a second nail attachment through the second hole in the bone into the second attachment hole in the intramedullary nail, thereby anchoring the intramedullary nail to the bone.

In particular embodiments of the invention, the first nail attachment and the second nail attachment are bone screws. In other embodiments of the invention, the first nail attachment and the second nail attachment are pins. In yet other embodiments, the first nail attachment and the second nail attachment are rivets. Of course, any suitable attachments may be used, limited only by the requirements of any particular procedure.

The present invention further provides a method of setting a broken bone, which may be characterized as comprising, in any suitable order, creating a hole from the endosteum of the broken bone to the periosteum of the broken bone comprising obtaining a drill apparatus comprising a drill comprising a flexible shaft and a sheath comprising a bend at a drill-distal end, the flexible shaft being disposed within the sheath, and employing the drill apparatus to drill a hole from the endosteum of the broken bone to the periosteum of the broken bone, obtaining a bone setting device having an attachment hole therein, and placing a bone setting device attachment through the attachment hole of the bone setting device into the hole in the broken bone. In certain preferred embodiments, the bone setting device is an intramedullary nail. In other preferred embodiments, the bone setting device is a plate.

Additionally, the present invention provides a method of setting a bone, the bone comprising a break therein, which may be characterized as comprising, in any suitable order, obtaining an intramedullary nail, comprising a lumen, a first attachment hole and a second attachment hole, inserting the intramedullary nail into the intramedullary cavity of the bone, the first attachment hole and the second attachment hole being located on opposite sides of the break in the bone, obtaining a drill apparatus comprising a drill comprising a flexible shaft and a sheath comprising a bend at a drill-distal end, the flexible shaft being disposed within the sheath, inserting the flexible shaft into the lumen of the intramedullary nail, positioning the flexible shaft adjacent the first attachment hole in the intramedullary nail, drilling through the first attachment hole, into the endosteum and out to the periosteum of the bone to form a first hole in the bone, placing a first nail attachment through the first hole in the bone into the first attachment hole in the intramedullary nail, repositioning the flexible shaft adjacent the second attachment hole in the intramedullary nail, drilling through the second attachment hole, into the endosteum and out to the periosteum of the bone to form a second hole in the bone, and placing a second nail attachment through the second hole in the bone into the second attachment hole in the intramedullary nail, thereby setting the bone.

In accordance with long standing patent law convention, the words "a" and "an" when used in this application, including the claims, denotes "one or more".

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.

FIG. 1 is a perspective view of a broken bone showing an IM nail positioned therein.

FIG. 2 is a view of an embodiment of one of the devices of the present invention comprising a drill apparatus positioned near a fixation hole inside the IM nail.

FIG. 3 is a detailed view of the embodiment of the device comprising a drill apparatus shown in FIG. 2.

FIG. 4 is a perspective view of an alternate drill apparatus of the present invention. DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In a most general aspect, the present invention provides safe and accurate means of creating one or more holes in a bone from the endosteum of the bone to the periosteum of the bone. Some presently preferred embodiments are shown in FIG. 1, FIG. 2 and FIG. 3. The figures depict a preferred method of using the instant devices in setting a broken bone, by anchoring or attaching a fixation device, in this case an intramedullary nail, to a bone, as well as a preferred embodiment of a device used to create one or more holes from the inside of the bone to the outside of the bone.

Referring to FIG. 1, bone 11 is shown with fracture site 13. Intramedullary nail 30 is positioned in medullary cavity 12 of bone 11. Intramedullary nail 30 has two pairs of fixation or attachment holes. One pair of fixation holes, 34 and 35, is located at the distal or first end of the nail, and the second pair of fixation holes, 36 and 37, is located at the proximal or second end of the nail. As generally employed, the distal end of the IM nail is situated at the distal end of the bone, the end that is furthest away from the attachment point of the bone to the torso of the body, whereas the proximal end of the IM nail is situated at the proximal end of the bone, the end that is closest to the point of attachment. When the IM nail is inserted into the proximal end of the bone, a bone fixation hole forming apparatus can be inserted at the proximal end of the nail in order to locate the distal fixation holes hidden from view upon insertion of the IM nail into the medullary cavity of the bone.

As shown in FIG. 2, the distal end of drill apparatus, 40, is disposed within lumen 38 of IM nail 30. When drill bit 47 is positioned over hole, 34, hole locator pieces, 49 and 50, let the surgeon or drill operator know that one of the fixation holes has been found. When the drill is then put into operation, a hole may be drilled into the bone matter located outside the fixation hole in the IM nail. The drill can then be retracted or pushed further into the IM nail to find remaining fixation holes until all of the fixation holes have been found. Then the drill apparatus can be fully retracted from the IM nail. When reducing a fracture in a long bone of a patient, the hole made for insertion of the nail can then be closed.

FIG. 3 shows a section of drill apparatus, 40, including the distal end with hole locator pieces 49 and 50, and drill bit 47. The drill apparatus has two main parts, a hollow outer sheath, 51, and, inside the sheath, a flexible inner shaft, 53, which attaches to drill bit, 47. The inner shaft contains the wiring required to power the drill bit. The outer sheath, 51, contains two major sections. A flexible section, 55, comprises a majority of the proximal end of the sheath. At the distal end of the outer sheath is located a curved section, 57, including a bend 58; in the embodiment depicted, the bend is about 90°. At the extreme distal end of this curved section are an opening for drill bit, 59, and hole locator pieces, 49 and 50.

FIG. 4 shows an alternate embodiment of drill apparatus 40. Motor 60 is operably connected to flexible inner shaft 53, which operably positioned with respect to handle 62 and outer sheath 51. Handle 62 is operably attached to outer sheath 51. Curved guide 64 is operably attached at its proximal end to the distal end of outer sheath 51, and at its proximal end to drill bit/hole locator 66. Drill bit 59 is operably positioned with respect to drill bit/Tiole locator 66 and curved guide 64, and is operably attached to flexible inner shaft 53.

The following example is included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the example which follows represent techniques discovered by the inventors to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.

EXAMPLE 1 Typical Method of Use of One Embodiment of the Present Invention in a

Patient

Prior to insertion of the IM nail, reduction of the fracture may be required. Alternatively, the practitioner of the invention may insert the nail without reduction of the fracture, a procedure known as "blind nailing". The limb or portion of the body containing the fracture may need to be stabilized or braced in some fashion so that unnecessary motion of the fractured bone during the procedure is avoided. A local or general anesthesia may be administered to the patient prior to or during the procedure as is deemed necessary.

After preparation of the patient as described above, a cutaneous incision will be made at one end of the fractured bone. Then, using a drill, a hole may be drilled in the bone so that another device, such as a guide wire can be introduced into the medulla. The wire may be used to help realign the fracture. A sheath may then be inserted into the medulla to effectively bore a hole in the medulla large enough for the nail to be inserted.

An apparatus for creating holes in bone from the endosteum to the periosteum may be inserted into the IM nail prior to insertion of the nail into the bone or the apparatus may be inserted into the nail after the nail is in place. Using one or more hole locator devices on the end of the outer sheath of the apparatus, the practitioner of the invention can find one of the fixation holes in the nail and creates a hole in the bone surface aligned on the outside of the nail fixation hole. The holes made with the inserted flexible device may be used as guides for enlarging the hole using a drill or other tool. Further cutaneous incisions can be made so that nail attachments, such as screws, pins or rivets, may be introduced. The nail attachments will then be inserted through the holes in the bone and the IM nail.

Once all of the fixation holes have been located and the nail attachments fastened in place, the drill apparatus is removed from the nail. The opening for the apparatus is then closed. The incisions in the patient's skin and muscle are then appropriately closed. Surgical variations in the procedure used in inserting IM nails and closing the incisions when using the methods and devices of this invention will be well known to one of skill in the art.

EXAMPLE 2 Fabrication of One Embodiment of the Instant Drill Apparatus

This Example describes the fabrication of the embodiment of the drill apparatus shown in FIG. 4. While precise dimensions are given, variations in these dimensions are contemplated for use in the present invention.

The long end of a curved guide was inserted approximately 6.35 mm into an outer sheath and fixed with epoxy. The curved guide is preferably made from 304 stainless steel tube with an outer diameter of about 1.78 mm, an inner diameter of about 1.42 mm, a wall thickness of about 0.18 mm and a smooth bend of about 90°, with a radius at the outer curve of about 12.7 mm, and the two ends of the bend measuring about 12.7 mm and about 25.4 mm. The outer sheath is preferably made from 304 stainless steel tube with an outer diameter of about 3.18 mm, an inner diameter of about 2.29 mm and approximately 30.5 cm in length.

The blunt end of a drill bit was inserted into the end hole of a flexible inner shaft and fixed with epoxy. The drill bit is preferably made from a nickel-titanium wire about 0.56 mm in diameter and approximately 76.2 mm in length with one or more cutting surfaces, in this case three cutting surfaces that are centered at about 120° intervals around the wire and ground at approximately 35° to the long axis, intersecting at the point of the bit. The flexible inner shaft is preferably made from 304 stainless steel rod about 2.03 mm in diameter and about 41.9 cm in length, comprising an approximately 0.58 mm diameter hole drilled about 12.7 mm deep through the centerline of the long axis of the rod.

The outer sheath was inserted into the end hole of a handle and fixed with epoxy. The handle is preferably fabricated from an aluminum rod approximately 25.4 mm in diameter and approximately 10.2 cm in length, comprising a hole with a diameter of about 3.18 mm drilled through the center line of the long axis. The drill bit/flexible inner shaft assembly was inserted into the handle/sheath assembly until the drill bit passed through the curved guide and was flush with the distal end.

A drill bit/hole locator was inserted over the short end of the curved guide until the small diameter of the drill bit/hole locator was flush with the distal end of the guide and then fixed with epoxy. The drill bit locator is preferably made from 304 stainless steel that is machined to a conical shape with a base diameter of about 6.35 mm and a top diameter of about 3.0 mm, having a length of about 4.0 mm and comprising hole having a diameter of about 1.78 mm drilled through the center line. Finally, a drill motor, preferably a hand held 1000 rpm single speed drill, was attached to the flexible inner shaft.

All of the compositions, methods and devices disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions, methods and devices, and in the steps or in the sequence of steps of the methods described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents which are both chemically and physiologically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.

REFERENCES

The following references, to the extent that they provide exemplary procedural or other details supplementary to those set forth herein, are specifically incorporated herein by reference.

U.S. Patent No. 4,667,664.

U.S. Patent No. 4,877,019.

U. S. Patent No. 4,947,942.

U.S. Patent No. 5,041,119.

U.S. Patent No. 5,464,407.

Kϋntscher, The American Academy of Orthopedic Surgeons, Vol. 47- A, pp. 809- 818, 1965.

Claims

CLAIMS:

1. A bone drill apparatus, comprising:

a) a drill comprising a flexible shaft; and

b) a sheath comprising a bend at a drill-distal end, said flexible shaft being disposed within said sheath.

2. The bone drill apparatus of claim 1, wherein said drill comprises a drill bit operably joined to said flexible shaft.

3. The bone drill apparatus of any previous claim, wherein said flexible shaft is comprised of stainless steel.

4. The bone drill apparatus of any previous claim, wherein said bend in said sheath is rigid.

5. The bone drill apparatus of claim 4, wherein said bend in said sheath is a 90┬░ bend.

6. The bone drill apparatus of any one of claims 1-3, wherein said bend is adjustable.

7. The bone drill apparatus of any previous claim, wherein said sheath further comprises a flexible section.

8. The bone drill apparatus of any previous claim, further comprising a curved guide operably attached to said sheath.

9. The bone drill apparatus of any previous claim, wherein said sheath further comprises at least a first operably positioned hole locator.

10. The bone drill apparatus of claim 9, wherein said hole locator is positioned adjacent the drill-distal end of said sheath.

11. The bone drill apparatus of claim 9 or 10, wherein said sheath further comprises at least a second operably positioned hole locator.

12. A method of creating a hole from the endosteum of a bone to the periosteum of said bone comprising:

a) obtaining a bone drill apparatus as defined in any one of claims 1- 11; and

b) employing said drill apparatus to drill a hole starting from the endosteum of said bone and progressing to the periosteum of said bone.

13. The method of claim 12, further comprising obtaining an intramedullary nail and positioning said intramedullary nail in a suitable orientation within the intramedullary cavity of said bone.

14. The method of claim 13 , further comprising :

a) inserting the flexible shaft of the bone drill apparatus into a lumen of said intramedullary nail;

b) positioning said flexible shaft adjacent a first attachment hole in said intramedullary nail; and

c) drilling through said attachment hole, into the endosteum and out to the periosteum of said bone to form a hole in said bone.

15. The method of any one of claims 12-14, further comprising counter-drilling through said hole in said bone into the periosteum of said bone and out to the endosteum of said bone.

16. The method of any one of claims 12-15, wherein said bone is comprised within a mammal.

17. The method of claim 16, wherein said mammal is a human subject.

18. A method of anchoring an intramedullary nail to a bone, comprising, in any suitable order:

a) obtaining an intramedullary nail, comprising a lumen, said nail having at least a first attachment hole and at least a second attachment hole;

b) inserting said intramedullary nail into the intramedullary cavity of said bone;

c) obtaining a bone drill apparatus as defined in any one of claims 1-11;

d) inserting the flexible shaft of the bone drill apparatus into said lumen of said intramedullary nail;

e) positioning said flexible shaft adjacent said first attachment hole in said intramedullary nail;

f) drilling through said first attachment hole, into the endosteum and out to the periosteum of said bone to form a first hole in said bone;

g) placing a first nail attachment through said first hole in said bone into said first attachment hole in said intramedullary nail;

h) repositioning said flexible shaft adjacent said second attachment hole in said intramedullary nail; i) drilling through said second attachment hole, into the endosteum and out to the periosteum of said bone to form a second hole in said bone; and

j) placing a second nail attachment through said second hole in said bone into said second attachment hole in said intramedullary nail, thereby anchoring said intramedullary nail to said bone.

19. The method of claim 18, wherein said first nail attachment and said second nail attachment are bone screws.

20. A method of setting a broken bone, comprising, in any suitable order:

a) creating a hole from the endosteum of said broken bone to the periosteum of said broken bone comprising:

i) obtaining a bone drill apparatus as defined in any one of claims 1-11;

ii) employing said bone drill apparatus to drill a hole from the endosteum of said broken bone to the periosteum of said broken bone;

b) obtaining a bone setting device having an attachment hole therein; and

c) placing a bone setting device attachment through said attachment hole of said bone setting device into said hole in said broken bone.

21. The method of claim 20, wherein said bone setting device is an intramedullary nail.