WO2009100190A2 - Dynamic rod - Google Patents
Dynamic rod Download PDFInfo
- Publication number
- WO2009100190A2 WO2009100190A2 PCT/US2009/033174 US2009033174W WO2009100190A2 WO 2009100190 A2 WO2009100190 A2 WO 2009100190A2 US 2009033174 W US2009033174 W US 2009033174W WO 2009100190 A2 WO2009100190 A2 WO 2009100190A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- rod
- rod portion
- dynamic
- lock
- relative
- Prior art date
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Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
- A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
- A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
- A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
- A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
- A61B17/7002—Longitudinal elements, e.g. rods
- A61B17/7004—Longitudinal elements, e.g. rods with a cross-section which varies along its length
- A61B17/7005—Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit in the screw or hook heads
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
- A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
- A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
- A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
- A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
- A61B17/7002—Longitudinal elements, e.g. rods
- A61B17/7004—Longitudinal elements, e.g. rods with a cross-section which varies along its length
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
- A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
- A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
- A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
- A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
- A61B17/7002—Longitudinal elements, e.g. rods
- A61B17/7019—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other
- A61B17/7023—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other with a pivot joint
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
- A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
- A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
- A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
- A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
- A61B17/7002—Longitudinal elements, e.g. rods
- A61B17/7019—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other
- A61B17/7025—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other with a sliding joint
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
- A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
- A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
- A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
- A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
- A61B17/7002—Longitudinal elements, e.g. rods
- A61B17/7011—Longitudinal element being non-straight, e.g. curved, angled or branched
- A61B17/7013—Longitudinal element being non-straight, e.g. curved, angled or branched the shape of the element being adjustable before use
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
- A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
- A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
- A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
- A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
- A61B17/7002—Longitudinal elements, e.g. rods
- A61B17/7019—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other
- A61B17/7026—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other with a part that is flexible due to its form
- A61B17/7028—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other with a part that is flexible due to its form the flexible part being a coil spring
Definitions
- One end of the rigid link element is connected to an anchor inserted in the pedicle of the upper vertebra and the other end of the rod is connected to an anchor inserted in the pedicle of an adjacent lower vertebra.
- the rod ends are connected to the anchors via coupling constructs such that the adjacent vertebrae are supported and held apart in a relatively fixed position by the rods.
- two rods and two pairs of anchors are installed each in the manner described above such that two rods are employed to fix two adjacent vertebrae, with one rod positioned on each side of adjacent vertebrae.
- fixation accompanies a fusion procedure in which bone growth is encouraged to bridge the intervertebral body disc space to thereby fuse adjacent vertebrae together. Fusion involves removal of a damaged intervertebral disc and introduction of an interbody spacer along with bone graft material into the intervertebral disc space.
- fixation accompanies fusion excessively rigid spinal fixation is not helpful to the promotion of the fusion process due to load shielding away from the fixed series. Without the stresses and strains, bone does not have loads to adapt to and as bone loads decrease, the bone becomes weaker.
- fixation devices that permit load sharing and assist the bone fusion process are desired in cases where fusion accompanies fixation.
- the dynamic rod in the fixation system plays an important role in recreating the biomechanical organization of the functional unit made up of two fixed vertebrae together with the intervertebral disc.
- a doctor may determine that it is best for the patient to substitute a rigid rod for a dynamic one or vice versa.
- No device currently on the market allows for the change without replacing the already imlanted rod.
- the present invention advantageously provides the doctor with an option to convert the same rod from a dynamic one to a rigid one and vice versa through a unique reversible locking mechanism that may be engaged percutaneously in a minimially invasive manner.
- a dynamic rod implantable in a spine, comprises a first rod portion having a first engaging portion at a first end and a second rod portion having a second engaging portion at a first end.
- the first and second rod portions are connected to each other at the first and second engaging portions such that the first rod portion and second rod portion are capable of relative motion.
- the dynamic rod further includes a lock configured to lock said relative motion.
- the lock is reversible.
- a bias element such as a spring is disposed between the first rod portion and the second rod portion to bias the movement of one rod portion relative to the other rod portion.
- the dynamic rod is configured such that the relative motion is angulation of the first rod portion relative to the second rod portion. In another variation, the dynamic rod is configured such that the relative motion is longitudinal translation of the first rod portion relative to the second rod portion. In another variation, the dynamic rod is configured such that the relative motion is angulation of the first rod portion relative to the second rod portion and longtudinal translation of the first rod portion relative to the second rod portion.
- the lock includes a spacer movable to a locked position between the first and second rod portions to arrest said relative motion. In another variation, the lock includes a ramp portion configured to provide ramp surface for the spacer to move against into a locked position.
- the spacer and ramp portion are located in the first engaging portion and the second rod portion is nested inside the first engaging portion such that when in the locked position the ramp portion abuts the first end of the second rod portion and the spacer abuts the ramp portion.
- the dynamic rod includes an aperture for percutaneously engaging said lock.
- a dynamic rod implantable in a spine, comprises a first rod portion coupled to a second rod portion and configured such that movement of one rod portion with respect to the other rod portion is lockable in position by a lock.
- the movement is longitudinal translation or angulation of one rod portion with respect to the other rod portion.
- the movement of one rod portion with respect to the other rod portion is reversibly lockable in position by the lock.
- the longitudinal translation of the first rod portion with respect to the second rod portion is lockable by the lock while permitting the angulation of the first rod portion with respect to the second rod portion.
- the angulation of one rod portion with respect to the other rod portion is lockable whereas the relative longitudinal translation is permitted.
- the distance of the first rod portion from the second rod portion is lockable at any location within the range of motion.
- the rod is lockable in a position such that the first rod portion is fully extended from the second rod portion.
- the lock operates such that the rod is lockable in a position such that the first rod portion is angled with respect to the second rod portion.
- the lock operates such that the rod is lockable in a position such that the first rod portion is fully compressed towards the second rod portion.
- the lock comprises an element movable in a substantially transverse direction to the longitudinal axis of the rod to a locked position.
- the dynamic rod includes a spring disposed between the first and second rod portions.
- FIG. Ia illustrates a perspective view of two dynamic rods according to the present invention each spanning two bone anchors implanted in a spinal motion segment.
- FIG. Ib illustrates a perspective view of two dynamic rods according to the present invention each spanning two bone anchors and two non-dynamic rods each spanning two bone anchors; the bone anchors being implanted in three adjacent vertebral bodies.
- FIG. 2a illustrates a perspective view of a dynamic rod according to the present invention.
- FIG. 2b illustrates a perspective exploded view of a dynamic rod according to the present invention.
- FIG. 2c illustrates a perspective cross- sectional view of a dynamic rod according to the present invention.
- FIG. 3a illustrates a cross- sectional view of a first rod portion of a dynamic rod according to the present invention.
- FIG. 3b illustrates a perspective view of a first rod portion of a dynamic rod according to the present invention.
- FIG. 4a illustrates a cross- sectional view of a second rod portion of a dynamic rod according to the present invention.
- FIG. 4b illustrates a perspective view of a second rod portion of a dynamic rod according to the present invention.
- FIG. 5a illustrates a cross- sectional view of a retainer of a dynamic rod according to the present invention.
- FIG. 5a illustrates a cross- sectional view of a retainer of a dynamic rod according to the present invention.
- FIG. 5b illustrates a perspective view of a retainer of a dynamic rod according to the present invention.
- FIG. 6a illustrates a side view of a lock of a dynamic rod according to the present invention.
- FIG. 6b illustrates a perspective view of a lock of a dynamic rod according to the present invention.
- FIG. 7a illustrates a perspective view of a slide of a dynamic rod according to the present invention.
- FIG. 7b illustrates a top view of a slide of a dynamic rod according to the present invention.
- FIG. 7c illustrates a cross- sectional view taken along line B-B of FIG. 7b of a slide of a dynamic rod according to the present invention.
- FIG. 6a illustrates a side view of a lock of a dynamic rod according to the present invention.
- FIG. 6b illustrates a perspective view of a lock of a dynamic rod according to the present invention.
- FIG. 7a illustrates a perspective view of a slide of a dynamic rod according to the present
- FIG. 8a illustrates a side cross-sectional view of a dynamic rod in a fully extended position according to the present invention.
- FIG. 8b illustrates a side cross-sectional view of a dynamic rod in a fully compressed position according to the present invention.
- FIG. 8c illustrates a side cross-sectional view of a dynamic rod with phantom depictions of polyaxial displacement of the second rod portion relative to the first rod portion according to the present invention.
- FIG. 8d illustrates a side view of a dynamic rod with phantom depictions of polyaxial displacement of the second rod portion relative to the first rod portion with the second rod portion fully extended relative to the first rod portion according to the present invention.
- FIG. 8b illustrates a side cross-sectional view of a dynamic rod in a fully extended position according to the present invention.
- FIG. 8c illustrates a side cross-sectional view of a dynamic rod with phantom depictions of polyaxial displacement of the second rod portion relative to the first rod portion with the second rod portion fully extended
- FIG. 8e illustrates a side view of a dynamic rod with phantom depictions of polyaxial displacement of the second rod portion relative to the first rod portion with the second rod portion fully compressed relative to the first rod portion according to the present invention.
- FIG. 9a illustrates a side cross-sectional view of a dynamic rod according to the present invention.
- FIG. 9b illustrates a side cross-sectional view of a dynamic rod with a lock partially advanced according to the present invention.
- FIG. 9c illustrates a side cross-sectional view of a dynamic rod with a lock fully advanced according to the present invention.
- a spinal fixation system 12 generally includes a first set 14 of two bone anchor systems installed into the pedicles of a superior vertebral segment 18, a second set 16 of two bone anchor systems installed into the pedicles of an inferior vertebral segment 20, a first link element 10a connected between one of the pedicle bone anchor systems in the first set and one of the pedicle bone anchor systems in the second set along the same side of the inferior and superior vertebral segments, and a second link element 10b connected between the other of the pedicle bone anchor systems in the first set and the other of the pedicle bone anchor systems in the second set along the same side of the inferior and superior vertebral segments.
- a typical anchor system comprises, but is not limited to, a spinal bone screw
- the seat 24 is designed to receive the link element 10a, 20b in a channel 26 in the seat 24.
- the link element 10a, 10b is typically a rod or rod-like member.
- the seat 24 typically has two upstanding arms that are on opposite sides of the channel that receives the rod member 10a, 10b.
- the rod 10a, 10b is laid in the open channel which is then closed with a closure member 28 to both capture the rod 10a, 10b in the channel 26 and lock it in the seat 24 to prevent relative movement between the seat 24 and the rod 10a, 10b.
- a multi-level installation is shown in FIG.
- Non-dynamic link elements 34a, 34b are shown extending between the second set 16 and the third set 30 of bone anchor systems.
- the dynamic rod 10 of the present invention may be selectively employed by the surgeon in any multi-level, fully dynamic or semi-rigid spinal fixation system 12.
- a rod 10 according to the present invention comprises a first rod portion 12, a second rod portion 14, a bias element 16, a retainer 17 or other connecting means, a locking slide 100 and a dynamic lock or spacer 102.
- the first rod portion 12 is connected to the second rod portion 14 via the retainer 17.
- the locking slide 100 and the dynamic lock 102 are disposed inside the first rod portion 12 and the bias element 16 is disposed within and between the first and second rod portions 12, 14, and, in particular, the bias element 16 is disposed within the locking slide 100 as shown in FIG. 2c which illustrates a cross-section of the assembled rod 10.
- the first rod portion 12 includes a first end 18 and a second end 20.
- the first rod portion 12 is generally cylindrical, elongate and rod-like in shape.
- An anchor connecting portion 22, shown in FIG. 3b, is formed at the first end 18 and configured for attachment to an anchor system.
- the anchor connecting portion 22 is partially spherical in shape and includes oppositely disposed outwardly extending pins 26 for engaging slots formed in the anchor to allow the dynamic rod 10 to pivot about the pins 26 when connected to the anchor.
- the anchor connecting portion 22 also includes oppositely disposed flat areas 28. When the dynamic rod 10 is connected to the anchor and pivoted into a substantially horizontal position, the flat areas 28 face upwardly and downwardly and as a result, provide a lower profile for the rod within the seat of the anchor.
- the flat areas 28 provide a flat contact surface for a closure member on the upper surface of the rod and a flat contact surface on the bottom surface when seated in the anchor.
- FIGs. 3a and 3b show the rod having an anchor connecting portion 22 configured for a pin-to-slot engagement, any suitable anchor connecting portion configuration is within the scope of the present invention.
- the first rod portion 12 includes an engaging portion 24 at a slightly enlarged and bulbous second end 20.
- the engaging portion 24 is configured to engage the second rod portion 14 of the dynamic rod 10.
- the engaging portion 24 includes a first bore defining a receiving portion 30 for receiving the second rod portion 14.
- the engaging portion 24 also includes at least one abutment or ledge 31 formed within the first bore where there is a reduction in the bore diameter.
- the first bore also defines a locking slide receiving portion 104 configured for receiving the locking slide 100.
- the engaging portion 24 also includes a dynamic lock engaging aperture 106 and a dynamic lock release aperture 108 through the engaging portion 24 configured for accessing the dynamic lock 102 to engage or release it.
- the collar 34 has a slightly smaller outer diameter than the rest of the bulbous engaging portion 20. With the retainer 17 mated with the male member collar 34, the intersection of the first rod portion 12 and retainer 17 is flush.
- the outer surface of the first rod portion 12 further includes inserter notches 110 for an inserter instrument to grab the dynamic rod 10.
- the second rod portion 14 includes a first end 36 and a second end 38.
- the second rod portion 14 is generally cylindrical, elongate and rod-like in shape and includes an engaging portion 40 at the first end 36.
- the engaging portion 40 is configured to engage with the first rod portion 12 of the dynamic rod 10.
- the engaging portion 40 of the second rod portion 14 includes a spherical feature or collar 43 that allows the second rod portion 14 to angulate when placed inside the first rod portion 12.
- the first end 36 is shaped to form at least one abutment surface 45 (FIG. 4a) on the spherical collar 43 for contacting the receiving portion 30 wall of the first rod portion 12.
- At least a portion of the engaging portion 40 of the second rod portion 14 is configured and sized to fit within the receiving portion 30 of the first rod portion 14.
- the second rod portion 14 further includes a bore opening at the first end 36 defining a bias element receiving portion 112 configured and sized to receive at least a portion of the bias element 16 therein.
- the 14 includes an anchor connecting portion 44 configured to be connected to an anchor.
- the anchor connecting portion 44 is sized and configured to be seated in a channel of a seat of a bone screw anchor for example.
- Any configuration for the second end 38 that is suitable for connection to an anchor is within the scope of the present invention and, for example, may include a rotatable pin-and-slot or other configuration similar to that shown in FIG. 3b.
- the bias element 16 is a coil or spring.
- the bias element 16 is made from any suitable material such as surgical steel, titanium or PEEK.
- the bias element 16 is sized to be received inside the bias element receiving portion 112 and inside the locking slide 100 between the first rod portion 12 and the second rod portion 14.
- a coiled spring is employed.
- any suitable type of effective bias element known to a person of ordinary skill in the art may be employed. Different types of biasing elements are discussed in greater detail in related application entitled “Dynamic rod” bearing application serial number 12/154,540 filed on May 23, 2008 and herein incorporated by reference in its entirety.
- FIGs. 5a and 5b there is shown a retainer 17 having a first end 46 and a second end 48 according to the present invention.
- the retainer 17 is generally cylindrical and sleeve-like in shape and has a bore opening to and extending between the first and second ends 46, 48.
- the retainer 17 is configured to encompass at least a portion of the first rod portion 12 and at least a portion of the second rod portion 14 as shown in FIG. 2c.
- the bore defines a first receiving portion 50 at the first end 46 configured to receive therein at least a portion of the first rod portion 12 and, in particular, configured to receive the collar 34 of the first rod portion 12 as shown in FIG. 2c.
- the bore also defines a second receiving portion 52 at the second end 48 that is configured to receive therein at least a portion of the second rod portion 14.
- the retainer 17 forms a constriction such that the second end 48 has a smaller diameter relative to the diameter of the retainer at the first end 46.
- the interior surface of the retainer 17 substantially corresponds to the geometry being received within the retainer 17 with an abutment created at the intersection of the first and second receiving portions 50 and 52.
- the retainer 17 also includes apertures or notches 140 for orienting the rod 10 with an insertion instrument during installation.
- the dynamic lock 102 includes a pusher 122 having a curved end 124 cantilevered to a spring lock portion 126 having a hook 128 at the end.
- the cantilevered end 124 is the end that engages an instrument configured to actuate the dynamic lock 102 through the dynamic lock engaging aperture 106.
- the dynamic slide 100 includes a first end 114 and a second end 116.
- a bore opening at the first end 114 defines a bias element receiving portion 118 configured to receive at least a portion of the bias element 16 therein.
- At the second end 116 there is a dynamic lock receiving portion 120 configured to engage with the dynamic lock 102.
- the dynamic lock receiving portion 120 includes an unlocked well 132 in which the hook 128 of the spring lock portion 126 resides when in an unlocked position and a locked well 134 in which the hook 128 of the spring lock portion 126 resides when in a locked position.
- the dynamic lock receiving portion 120 also includes a spring lock portion ramp 136 against which the spring lock portion 126 rides in going from the unlocked position to the locked position and vice versa.
- the dynamic lock receiving portion 120 also includes a pusher ramp 138 against which the pusher 122 rides in going from an unlocked position to a locked position.
- the dynamic lock 102 is placed in the dynamic lock receiving portion 120 of the locking slide 100 and inserted into the locking slide receiving portion 104 of the first rod portion 12.
- the bias element 16 is inserted into the bias element receiving portion 112 of the second rod portion 14.
- the second rod portion 14 together with the bias element 16 are inserted into the receiving portion 30 of the first rod portion 12 such that the bias element 16 is disposed inside the bias element receiving portion 118 of the locking slide 100.
- the retainer 17 placed over the shaft of the second rod portion 14 from the second end 38 and passed toward the first end 36 such that the engaging portion 40 resides in the first rod portion 12 and the collar 43 is received in the first receiving portion 50 of the retainer 17.
- the retainer 17 is connected to the first rod portion 12 by a laser weld or an e-beam weld or other suitable means such that the second rod portion 14 and bias element 16 are captured by the retainer 17 constriction and retained within the retainer 17 and the first rod portion 12 such that the second rod portion 14 is capable of movement relative to the retainer 17 and the first rod portion 12.
- the second rod portion 14 is capable of displacement from the longitudinal axis and/or movement along the longitudinal axis relative to the retainer 17 and the first rod portion 12.
- the bias element 16 may also be connected to locking slide 100 via a laser or e-beam weld.
- FIGs. 8a-8e movement of the second rod portion 14 relative to the first rod portion 12 will be discussed. Movement of the second rod portion 14 relative to the first rod portion 12 along the longitudinal axis such that the rod 10 is moving from a normal position into extension is shown in FIGs. 8a and 8b wherein FIG. 8a shows the rod 10 fully extended by a distance "d" and FIG. 8b shows the rod 10 in a fully compressed condition.
- Distance "d” is approximately 1 millimeter and preferably approximately between 0 and 10 millimeters and more preferably between 0 and 5 millimeters.
- Travel of the second rod portion 14 relative to the first rod portion 12 is biased by the bias element 16 in extension in one variation of the invention, in compression in another variation of the invention and in both extension and compression in a yet another variation of the invention.
- the bias element 16 exerts a force inwardly to return the second rod portion 14 into a normal position.
- the bias element 16 exerts a force outwardly to return the second rod 14 portion relative to the first rod portion 12 when compressed to a distance less than the maximum distance "d".
- the second rod portion 14 defines a distance "d" between the end of the first end 36 of the second rod portion 14 and the first end 114 of the locking slide 100.
- This distance “d” defines in part the extent of movement along the longitudinal axis of the second rod portion 14 relative to the first rod portion 12. In one variation, the distance “d” is approximately one or two millimeters. Distance “d” may be customized according to surgeon preference or be selected to be a suitable distance.
- the dynamic rod 10 After the dynamic rod 10 is assembled, it is ready to be implanted within a patient and be connected to anchors planted in pedicles of adjacent vertebral bodies preferably in a manner such that the first rod portion 12 of the dynamic rod 10 is oriented cephalad and connected to the upper anchor and the second rod portion 14 is placed caudad and connected to the lower anchor. Because the first rod portion 12 includes an anchor connecting portion 22 configured such that connection with the anchor does not result in the rod extending cephalad beyond the anchor, this orientation and configuration of the dynamic rod is advantageous particularly because it avoids impingement of adjacent anatomy in flexion or in extension of the spine of the patient.
- the dynamic rod 10 is implanted into the patient such that the first rod portion 12 is oriented caudad and the second rod portion 14 is oriented cephalad.
- the second rod portion 14 includes an anchor connecting portion 44 that is partially spherical in shape and includes oppositely disposed outwardly extending pins 54 for engaging slots formed in the upper anchor to allow the dynamic rod 10 to pivot about pins 54 when connected to the anchor.
- the anchor connecting portion 44 may also include oppositely disposed flat areas 56 as described above.
- the second rod portion 14 of the dynamic rod 10 is oriented cephalad and connected to the upper anchor and the first rod portion 12 is placed caudad and connected to the lower anchor.
- the second rod portion 14 includes an anchor connecting portion 44 configured such that connection with the anchor does not result in excessive rod extending cephalad beyond the anchor, this orientation and configuration of the dynamic rod is advantageous particularly because it avoids impingement of adjacent anatomy in flexion or in extension of the spine of the patient.
- the preferred implantation method and preferred orientation of the dynamic rod 10 is such that there is minimal or substantially no "overhanging" rod extending cephalad beyond the upper anchor.
- Such orientation is achieved by the orientation of the rod during implantation as well as by the configuration of the anchor connecting portion 22, 44 of either one or both of the first rod portion 12 and second rod portion 14 such that the anchor connecting portion 22, 44 is configured such that there is substantially no or little overhang beyond the anchor.
- FIGs. 8c and 8d illustrate displacement from the longitudinal axis of the second rod portion 14 relative to the first rod portion 14 by an angle "A" while the second rod portion 14 is also longitudinally in extension relative to the first rod portion 12 by a distance "d".
- Angle "A” is approximately between zero and ten degrees, preferably approximately five degrees with respect to the longitudinal axis "x" in a polyaxial direction from the longitudinal axis "x”.
- FIGs. 8a-8e illustrate that the dynamic rod allows for movement described by a polyaxial displacement from the longitudinal axis as well as movement along the longitudinal axis in extension or compression alone or in combination with polyaxial motion allowing the rod to carry some of the natural flexion and extension moments that the spine is subjected to.
- Substantial polyaxial rotation of the second rod portion relative to the first rod portion is within the scope of motion of the dynamic rod.
- rotation of the second rod portion 14 relative to the first rod portion 12 may be constrained by a squared first end 36 of the second rod portion 14 inserted into a conformance formed by the bias element receiving portion 118 of the locking slide 100. This feature controls rotation and provides torsional strength and resistance.
- the bias element 16 is a compression spring that becomes shorter when axially loaded and acts as an extension mechanism such that when disposed in the assembled dynamic rod 10 and axially loaded, the bias element 16 exerts a biasing force pushing the first rod portion 12 and the second rod portion 14 apart.
- the bias element 16 is configured such that it exerts a biasing force pushing the first rod portion 12 and second rod portion 14 apart by the maximum degree permitted by the dynamic rod configuration such that when longitudinally loaded the second rod portion 14 will move inwardly towards the first rod portion 12 and the bias element will tend to push the second rod portion 14 outwardly.
- the bias element 16 is a coil configured to not exhibit spring-like characteristics when loaded along the longitudinal axis. Instead, the coil serves a stabilizer for loads having a lateral force component, in which case the lateral biasing is provided by the bias element.
- FIG. 9a illustrates the rod 10 in an unlocked configuration in which the second rod portion 14 is free to translate longitudinally as well as angulate polyaxially.
- FIG. 9b illustrates the rod 10 in an unlocked configuration in which the second rod portion 14 is free to translate longitudinally as well as angulate polyaxially.
- the dynamic lock 102 is engaged through the dynamic lock engaging aperture 106 by an instrument (not shown) such that the pusher 122 of the dynamic lock 102 contacts the pusher ramp 138 of the locking slide 100 and further advancement of the dynamic lock 102 results in the pusher 102 riding the pusher ramp 138 pushing the locking slide 100 away from the first rod portion 12.
- the spring lock portion 126 of the dynamic lock contacts the spring lock portion ramp 136 and further advancement of the dynamic lock 102 results in the spring lock portion 126 riding the spring lock portion ramp 136 until the hook 128 springs into the locked well 134 into a locked configuration as shown in FIG. 9c.
- the second rod portion 14 is fully extended and hence, incapable of further extension along the longitudinal axis.
- the second rod portion 14 when in the locked configuration, the second rod portion 14 is permitted to angulate and in another variation, the second rod portion 14 is also locked from angulation as shown in FIG. 9c.
- the locked position is the fully extended and non-angulated position.
- the locked position is an angulated position.
- the distance of the first rod portion from the second rod portion is locked in place.
- the first and second rod portions are lockable in a fully compressed orientation.
- the first and second rod portions are lockable in a fully compressed orientation or extended configuration or at any distance of longitudinal extension which still permitting angulation to take place and in another variation the angulation is also locked.
- the dynamic rod 10 may be unlocked by insertion of an instrument into the dynamic lock release aperture 108 to push the dynamic lock 102 into an unlocked configuration.
- this invention sets forth a dynamic rod 10 that is capable of being locked and unlocked according to surgeon preference.
- individual rods in a spinal fixation system require individual adjustment to fine-tune the installation based on patient anatomy or surgeon preference and the present invention addresses this need.
- the disclosed devices or any of their components can be made of any biologically adaptable or compatible materials including PEEK, PEK, PAEK, PEKEKK or other polyetherketones.
- Materials considered acceptable for biological implantation include, but are not limited to, stainless steel, titanium, tantalum, combination metallic alloys, various plastics, polymers, resins, ceramics, biologically absorbable materials and the like. Any components may be also coated with various coatings or made with osteo-conductive (such as deminerized bone matrix, hydroxyapatite, and the like) and/or osteo-inductive (such as Transforming Growth Factor "TGF-B,” Platelet-Derived Growth Factor “PDGF,” Bone-Morphogenic Protein “BMP,” and the like) bio-active materials that promote bone formation as well as with anti-microbial materials.
- osteo-conductive such as deminerized bone matrix, hydroxyapatite, and the like
- osteo-inductive such as Transforming Growth Factor "TGF-B,” Platelet-Derived Growth Factor "PDGF,” Bone-Morphogenic Protein “BMP,” and the like
- a surface of any of the implants may be made with a porous ingrowth surface (such as titanium wire mesh, plasma-sprayed titanium, tantalum, porous CoCr, and the like), provided with a bioactive coating, made using tantalum, and/or helical rosette carbon nanotubes (or other carbon nanotube-based coating) in order to promote bone ingrowth or establish a mineralized connection between the bone and the implant, and reduce the likelihood of implant loosening.
- a surface of any of the implants may be made with a porous ingrowth surface (such as titanium wire mesh, plasma-sprayed titanium, tantalum, porous CoCr, and the like), provided with a bioactive coating, made using tantalum, and/or helical rosette carbon nanotubes (or other carbon nanotube-based coating) in order to promote bone ingrowth or establish a mineralized connection between the bone and the implant, and reduce the likelihood of implant loosening.
- any assembly or its components can also be entirely or partially made of a shape memory material or other deform
- the present invention can be used to relieve pain caused by spinal stenosis in the form of, by way of example only, central canal stenosis or foraminal stenosis, degenerative disc disease, spondylolisthesis, spinal deformaties, fracture, pseudarthrosis and tumors.
Landscapes
- Health & Medical Sciences (AREA)
- Orthopedic Medicine & Surgery (AREA)
- Life Sciences & Earth Sciences (AREA)
- Neurology (AREA)
- Surgery (AREA)
- Heart & Thoracic Surgery (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Surgical Instruments (AREA)
- Prostheses (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2009212432A AU2009212432A1 (en) | 2008-02-06 | 2009-02-05 | Dynamic rod |
EP09708744A EP2249727A4 (en) | 2008-02-06 | 2009-02-05 | Dynamic rod |
CA2714096A CA2714096A1 (en) | 2008-02-06 | 2009-02-05 | Dynamic rod |
IL207327A IL207327A0 (en) | 2008-02-06 | 2010-08-01 | Dynamic rod |
Applications Claiming Priority (11)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/970,366 US8162985B2 (en) | 2004-10-20 | 2004-10-20 | Systems and methods for posterior dynamic stabilization of the spine |
US11/006,495 US8075595B2 (en) | 2004-10-20 | 2004-12-06 | Systems and methods for posterior dynamic stabilization of the spine |
US11/033,452 US7998175B2 (en) | 2004-10-20 | 2005-01-10 | Systems and methods for posterior dynamic stabilization of the spine |
US11/436,407 US8025680B2 (en) | 2004-10-20 | 2006-05-17 | Systems and methods for posterior dynamic stabilization of the spine |
US11/427,738 US7935134B2 (en) | 2004-10-20 | 2006-06-29 | Systems and methods for stabilization of bone structures |
US93181107P | 2007-05-25 | 2007-05-25 | |
US99489907P | 2007-09-21 | 2007-09-21 | |
US6387808P | 2008-02-06 | 2008-02-06 | |
US61/063,878 | 2008-02-06 | ||
US12/154,540 US20080262554A1 (en) | 2004-10-20 | 2008-05-23 | Dyanamic rod |
US12/233,212 US20090030465A1 (en) | 2004-10-20 | 2008-09-18 | Dynamic rod |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2009100190A2 true WO2009100190A2 (en) | 2009-08-13 |
WO2009100190A3 WO2009100190A3 (en) | 2009-10-22 |
Family
ID=42727266
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2009/033174 WO2009100190A2 (en) | 2004-10-20 | 2009-02-05 | Dynamic rod |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP2249727A4 (en) |
AU (1) | AU2009212432A1 (en) |
CA (1) | CA2714096A1 (en) |
IL (1) | IL207327A0 (en) |
WO (1) | WO2009100190A2 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7935134B2 (en) | 2004-10-20 | 2011-05-03 | Exactech, Inc. | Systems and methods for stabilization of bone structures |
US7998175B2 (en) | 2004-10-20 | 2011-08-16 | The Board Of Trustees Of The Leland Stanford Junior University | Systems and methods for posterior dynamic stabilization of the spine |
US8025680B2 (en) | 2004-10-20 | 2011-09-27 | Exactech, Inc. | Systems and methods for posterior dynamic stabilization of the spine |
CN105361936A (en) * | 2014-09-01 | 2016-03-02 | 圣美智财有限公司 | Spinal rod piece linking device |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8267969B2 (en) | 2004-10-20 | 2012-09-18 | Exactech, Inc. | Screw systems and methods for use in stabilization of bone structures |
US8226690B2 (en) | 2005-07-22 | 2012-07-24 | The Board Of Trustees Of The Leland Stanford Junior University | Systems and methods for stabilization of bone structures |
US8523865B2 (en) | 2005-07-22 | 2013-09-03 | Exactech, Inc. | Tissue splitter |
US8096996B2 (en) | 2007-03-20 | 2012-01-17 | Exactech, Inc. | Rod reducer |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4239716C1 (en) * | 1992-11-26 | 1994-08-04 | Kernforschungsz Karlsruhe | Elastic implant for stabilising degenerated spinal column segments |
US6986771B2 (en) * | 2003-05-23 | 2006-01-17 | Globus Medical, Inc. | Spine stabilization system |
US7854752B2 (en) * | 2004-08-09 | 2010-12-21 | Theken Spine, Llc | System and method for dynamic skeletal stabilization |
US7935134B2 (en) * | 2004-10-20 | 2011-05-03 | Exactech, Inc. | Systems and methods for stabilization of bone structures |
AU2006318673A1 (en) * | 2005-11-18 | 2007-05-31 | Life Spine, Inc. | Dynamic spinal stabilization devices and systems |
US7517359B2 (en) * | 2005-12-20 | 2009-04-14 | Sdgi Holdings, Inc. | Vertebral rod assemblies and methods |
DE102006003374A1 (en) * | 2006-01-24 | 2007-07-26 | Biedermann Motech Gmbh | Connecting rod with outer flexible element |
DE602006019939D1 (en) * | 2006-02-23 | 2011-03-17 | Eden Spine Europ Sa | Connecting element for bone parts |
-
2009
- 2009-02-05 EP EP09708744A patent/EP2249727A4/en not_active Withdrawn
- 2009-02-05 WO PCT/US2009/033174 patent/WO2009100190A2/en active Application Filing
- 2009-02-05 AU AU2009212432A patent/AU2009212432A1/en not_active Abandoned
- 2009-02-05 CA CA2714096A patent/CA2714096A1/en not_active Abandoned
-
2010
- 2010-08-01 IL IL207327A patent/IL207327A0/en unknown
Non-Patent Citations (1)
Title |
---|
See references of EP2249727A4 * |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7935134B2 (en) | 2004-10-20 | 2011-05-03 | Exactech, Inc. | Systems and methods for stabilization of bone structures |
US7998175B2 (en) | 2004-10-20 | 2011-08-16 | The Board Of Trustees Of The Leland Stanford Junior University | Systems and methods for posterior dynamic stabilization of the spine |
US8025680B2 (en) | 2004-10-20 | 2011-09-27 | Exactech, Inc. | Systems and methods for posterior dynamic stabilization of the spine |
US8075595B2 (en) | 2004-10-20 | 2011-12-13 | The Board Of Trustees Of The Leland Stanford Junior University | Systems and methods for posterior dynamic stabilization of the spine |
US8162985B2 (en) | 2004-10-20 | 2012-04-24 | The Board Of Trustees Of The Leland Stanford Junior University | Systems and methods for posterior dynamic stabilization of the spine |
CN105361936A (en) * | 2014-09-01 | 2016-03-02 | 圣美智财有限公司 | Spinal rod piece linking device |
Also Published As
Publication number | Publication date |
---|---|
IL207327A0 (en) | 2010-12-30 |
AU2009212432A1 (en) | 2009-08-13 |
EP2249727A2 (en) | 2010-11-17 |
CA2714096A1 (en) | 2009-08-13 |
EP2249727A4 (en) | 2013-01-23 |
WO2009100190A3 (en) | 2009-10-22 |
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