Patent Application
20110144694
The present disclosure generally relates to bone fixation assembly, and in particular to a bone fixation assembly configured to fix a bone fixation rod between two or more vertebrae, in order to stabilize a part of the spinal cord.
Conventional bone fixation elements can be provided as pedicle screws that screw in to the pedicles of vertebral boies. The pedicle screws can include a bone anchor retained within an anchor seat and captured by a collet. Pedicle screw assemblies include a plurality of pedicle screws joined by a bone fixation rod that extends through rod slots formed in the pedicle screws. It has been found that conventional pedicle screws can be oversized for the cervical vertebrae.
In accordance with one embodiment, bone fixation assembly includes a bone fixation element having a bone fixation member that is attachable to a bone, in particular to a lamina of a vertebra without affecting the bone or lamina of a vertebra and which is rigidly connectable to a bone fixation rod such that the rod is aligned in the direction of the spinal cord, and a connector assembly that is configured to connect the bone fixation member to the bone fixation rod. For instance, the connector assembly can be configured to releasably fix the bone fixation rod to the bone fixation member. The connector assembly can be polyaxially pivotably linked to the bone fixation member, or can be configured as a cable tie.
The bone fixation member can include a fixation body that includes a base and a pair of laterally spaced arms that extend from the base. The arms can be elastically spreadable, and configured to reversibly clamp onto a lamina of a vertebra. The bone fixation member can further include a connection interface attached to the fixation body, for instance at the base, and is configured to attach to the connector assembly so as to rigidly fix the bone fixation member the bone fixation rod.
In accordance with one embodiment, the bone fixation member can be made from a material with a Young's modulus greater than 30 GPa, preferably greater than 100 GPa. Suitable materials for the bone fixation member are metallic materials as stainless steel, cobalt-chromium alloys, e.g. Co28Cr6Mo with a Young's modulus of 241 GPa, and titanium alloys, e.g. TiNbTaZr with a Young's modulus of 30-100 GPa, Ti15Mo α+β with a Young's modulus of 105 GPa and Ti15Mo β with a Young's modulus of 78 GPa.
In another embodiment, the bone fixation member is made from a memory metal, preferably Nitinol with a Young's modulus of 30-75 GPa.
In a further embodiment the bone fixation member is made from reinforced PEEK with a Young's modulus of >30 GPA.
In another embodiment the bone fixation member has a closable form for enclosing the entire periphery of a longitudinal rod. Due to this configuration a longitudinal rod can be rigidly fixed to the bone fixation member. The longitudinal rod is secured against an unintended removal from the bone fixation member.
In a further embodiment the bone fixation member can be secured to a longitudinal rod with respect to relative translational and rotational movement.
In yet another embodiment the bone fixation member and the connector assembly are rigidly connected to each other. Therewith the advantage can be achieved that the longitudinal rod is securely retained in its position aligned with the spinal cord.
In a further embodiment the bone fixation member oriented such that the fixation rod extends substantially in the plane defined by the fixation body when the fixation rod is fixed to the fixation member.
In another embodiment of the bone fixation member the fixation member is formed as a cable tie. This configuration allows a configuration of the bone fixation member with a small volume of the fixation member.
In another embodiment of the bone fixation member the fixation member comprises a head fixedly arranged at the outer part of the base and a connector assembly linked to the head by a releasably fixable polyaxially pivotable joint and allowing to releasably fix a longitudinal rod to the bone fixation member. This configuration allows the advantage that the longitudinal rod must not necessarily be adapted to the position of each of the bone fixation members along the spinal column. The polyaxially pivotable joint offers the possibility to adjust the fixation member with regard to the position of longitudinal rod.
In a further embodiment, the fixation body of the bone fixation member substantially defines an elliptical C-shape having a first dimension and a second dimension that is less than the first dimension. The substantial arc of the fixation body can extend along a distance within a range that is greater than approximately 240°, for instance greater than approximately 260°, and can be less than approximately 290°, for instance less than approximately 280° measured on a circumcircle of the arc. In accordance with one embodiment, the substantial arc of the fixation body can extend along a distance that is approximately 270° measured on the circumcircle of the arc.
In yet another embodiment the bone fixation member includes more than two arms, preferably four arms that can be arranged in an X-shape or any alternative shape, and can form a passage with an ellipse-like or elliptical C-form or any alternative form as desired.
In another embodiment the base of the fixation body of the bone fixation member has an inner surface the defines a first radius of curvature, and at least one or both of the arms has an inner surface that defines a second radius of curvature that is less than the first radius of curvature.
In another embodiment of the bone fixation member each of the two arms has a free end opposite the base so that between the two free ends an opening remains with a first initial width measured in an unloaded or unflexed state, and can be expanded by an expansion force so as to define a second flexed width that is greater than the first initial width. When the expansion force is released, the fixation body can be firmly fixed on the lamina. The first and second widths can be dimensioned as follows, in accordance with various embodiments.
The first initial width can be within a range that is greater than approximately 12 mm, for instance greater than approximately 13 mm, and less than approximately 16 mm, for instance less than approximately 15 mm. In accordance with one embodiment, the first initial width can be approximately 14 mm. The second flexed width can be within a range that is greater than approximately 16 mm, for instance greater than approximately 18 mm, and less than approximately 22 mm, for instance less than approximately 20 mm. In accordance with one embodiment, the second flexed width can be approximately 19 mm. Thus, the difference between the first initial width and the second flexed width can be within a range that is greater than approximately 3 mm, for instance greater than approximately 4 mm, and less than approximately 7 mm, for instance less than approximately 6 mm. In accordance with one embodiment, the difference between the first initial width and the second flexed width can be approximately 5 mm.
The bone fixation member, for instance the fixation body, can define a relative spreadability that is defined by the ratio of the first initial width/the second flexed width. In accordance with one embodiment, the relative spreadability can be within a range that is greater than approximately 0.6, for instance greater than approximately 0.7, and less than approximately 0.8, for instance less than approximately 0.75. In accordance with one embodiment, the relative spreadability can be approximately 0.74. Otherwise stated, the bone fixation member, for instance the fixation body, can define a ratio of the second flexed width/the first initial width that is within a range greater than approximately 1.25, for instance greater than approximately 1.3, and less than approximately 1.5, for instance less than approximately 1.4. In accordance with one embodiment, the ratio of the second flexed width/the first initial width is approximately 1.36.
the base of the bone fixation member can comprise two recesses arranged symmetrically at equal distances from the short axis in the inner side of the base.
In again a further embodiment of the bone fixation member the each of the two arms comprises an engagement member configured to engage an insertion instrument, preferably in the form of a projection or of a recess.
In another embodiment the arms of the bone fixation member has an inner surface which is coated with hydroxylapatite, a polymer or titanium. The coating allows the advantage that the friction between the arms of the arc-shaped element and the bone can be reduced.
In accordance with another aspect, a method is provided for stabilizing a part of the spinal cord, particularly in the area of the cervical spine by using at least two bone fixation elements comprising the following steps:
In accordance with a further aspect, an insertion instrument is provided for clipping a bone fixation member on a lamina of a vertebral body. the insertion instrument comprises:
Several embodiments will be described in the following by way of example and with reference to the accompanying drawings in which:
Referring initially to
Unless otherwise specified herein, the terms “lateral,” “longitudinal,” and “transverse” are used to describe the directional components of the bone fixation assembly 20. In the orientation illustrated in
The words “inward,” “outward,” “upper,” “lower,” “distal,” and “proximal,” can refer to directions toward or away from, respectively, the geometric center of the bone fixation assembly 20 and its components. The words, “anterior”, “posterior”, “superior,” “inferior” and related words and/or phrases designate preferred positions and orientations in the human body to which reference is made and are not meant to be limiting. It should further be appreciated that while round structures define diameters as described herein, the round structures could be replaced with alternative (e.g., polygonal) structures which would define alternative cross-sectional dimensions opposed to diameters. The term “diameter” as used herein is intended to include all such alternatives unless otherwise specified. The terminology includes the above-listed words, derivatives thereof and words of similar import.
With continuing reference to
Unless otherwise specified, the bone fixation assembly 20 and its components can be made from titanium-aluminum-niobium alloy (TAN), implant-grade 316L stainless steel, or any suitable alternative implant-grade material. The bone fixation elements 22A-D can be generally implanted in any region of the spine, for instance at lumbar, thoracic, or cervical regions. In this regard, when the bone fixation elements 22A-D are joined by the fixation rod 24, the bone fixation assembly 20 fixes the relative position of the vertebrae 23A-D. Accordingly, the bone fixation elements 22A-D can be referred to as spine fixation elements, the fixation rod 24 can be referred to as a spinal fixation rod, and the bone fixation assembly 20 can be referred to as a spine fixation assembly. However, it should be appreciated that the bone fixation assembly 20 can also be used for fixation of other parts of the body, such as joints, long bones, or bones in the hands, face, feet, extremities, cranium, and the like. The fixation rod 24 can be substantialy cylindrical or tubular in shape, and can be substantially rigid or flexible as desired. The fixation rod may include, but is not limited to, a solid body, a non-solid body, a flexible or dynamic body, or the like, and can assume any alternative shape as desired.
Referring now to
The bone fixation member 30 can be made from any suitable material, for instance a material having a Young's modulus greater than 30 GPa, such as greater than 100 GPa. For instance, the bone fixation member 30 can be made from a metallic material such as stainless steel, cobalt-chromium alloys, e.g. Co28Cr6Mo which can have a Young's modulus of approximately 241 GPa, and titanium alloys, e.g. TiNbTaZr which can have a Young's modulus of between approximately 30 GPa and approximately 100 GPa, Ti15Mo α+β which can have a Young's modulus of approximately 105 GPa, and Ti15Mo β which can have a Young's modulus of approximately 78 GPa. In accordance with another embodiment, the bone fixation member 30 can be made from a shape memory material or metal, such as Nitinol which has a Young's modulus of between approximately 30 GPa and approximately 75 GPa. In accordance with yet another embodiment, the bone fixation member 30 can be made from reinforced PEEK with a Young's modulus greater than approximately 30 GPa.
The fixation body 34 includes a base 36 and a pair of longitudinally spaced arms 38 that extend from laterally opposed sides of the base 36. The arms 38 define respective inner surfaces that face each other, and opposed outer surfaces. The inner surfaces can be coated with hydroxylapatite, a polymer or titanium, so as to reduce friction between the arms 38 and the bone received in the arms 38. The arms 38 can define any suitable size and shape as desired, and are curved in accordance with the illustrated embodiment. For instance, the opposed arms 38 can be substantially concave with respect to each other. Thus, each arm 38 can define a proximal end 38a that curves away from the proximal end 38a of the opposed arm 38, and a free distal end 38b opposite the base that curves toward the free distal end 38b of the opposed arm 38. Thus, the fixation body 34 can be substantially arc-shaped in accordance with the illustrated embodiment, and for instance can define a substantially elliptical C-shape that can define a first longitudinal dimension that extends along a longitudinal axis L, and a second transverse dimension that extends along the transverse axis T and can be smaller than the first longitudinal dimension. The first longitudinal dimension can define the longest longitudinal dimension of the fixation body 34 between the arms 38, and the second transverse dimension can define the longest transverse dimension of the fixation body 34. Thus, the first longitudinal dimension is longer than the second transverse dimension. The base 36 defines an inner radius of curvature R1 and each of the two arms 38 has an inner radius of curvature R2 that is less than R1 as illustrated.
It should be appreciated, however, that the fixation body 34 can define any suitable alternative shape as desired. For instance, the arms 38 can alternatively comprise at least one segment, alone or in combination with at least one curved segment. Accordingly, when the fixation member 30 is in a first initial or unflexed position, the arms 38 can define a first distance that extends between the proximal ends 38a, a second distance that extends between a location between the proximal ends 38a and 38b that extends parallel to the first distance and is greater than the first distance, and a third distance that extends between the distal ends 38b parallel to the first and second distances and is less than the second distance.
In accordance with one embodiment, the fixation body 34 of the bone fixation member 30 can substantially defines the shape of a substantial arc that can extend along a distance within a range that is greater than approximately 240°, for instance greater than approximately 260°, and can be less than approximately 290°, for instance less than approximately 280° measured on a circumcircle of the arc. In accordance with one embodiment, the substantially arc of the fixation body can extend along a distance that is approximately 270° measured on the circumcircle of the arc.
The fixation body 34, and in particular the base 36 and arms 38 defines a bone-receiving space 42 having a mouth 44 that defines a width W between the disposed between the distal ends 38b of the opposed arms 38. The fixation body 34, and in particular the arms 38, can move between a first initial position such that the distal ends 38b of the arms 38 define a first initial width W1 and a second flexed position such that the distal ends 38b of the arms 38 define a second flexed width W2 (see
The first initial width W1 can be within a range that is greater than approximately 12 mm, for instance greater than approximately 13 mm, and less than approximately 16 mm, for instance less than approximately 15 mm. In accordance with one embodiment, the first initial width W1 can be approximately 14 mm. The second flexed width W2 can be within a range that is greater than approximately 16 mm, for instance greater than approximately 18 mm, and less than approximately 22 mm, for instance less than approximately 20 mm. In accordance with one embodiment, the second flexed width W2 can be approximately 19 mm. Thus, the difference between the first initial width W1 and the second flexed width W2 can be within a range that is greater than approximately 3 mm, for instance greater than approximately 4 mm, and less than approximately 7 mm, for instance less than approximately 6 mm. In accordance with one embodiment, the difference between the first initial width W1 and the second flexed width W2 can be approximately 5 mm.
The bone fixation member 30, for instance the fixation body 34, can define a relative spreadability that is defined by the ratio of the first initial width W1/the second flexed width W2. In accordance with one embodiment, the relative spreadability can be within a range that is greater than approximately 0.6, for instance greater than approximately 0.7, and less than approximately 0.8, for instance less than approximately 0.75. In accordance with one embodiment, the relative spreadability can be approximately 0.74. Otherwise stated, the bone fixation member 30, for instance the fixation body 34, can define a ratio of the second flexed width W2/the first initial width W1 that is within a range greater than approximately 1.25, for instance greater than approximately 1.3, and less than approximately 1.5, for instance less than approximately 1.4. In accordance with one embodiment, the ratio of the second flexed width W2/the first initial width W1 is approximately 1.36.
The fixation body 34 further defines at least one engagement member configured to mate with a complementary engagement member of the insertion tool 40, such that the insertion tool 40 can apply an expansion force to the fixation body 34, and in particular to the arms 38 that causes the arms 38 to flex from their first initial or unflexed positions to their second flexed positions. The engagement member of the fixation body 34 can be configured as desired, such as a projection or a recess, and is illustrated as a recess that forms a groove 48 that extends into each arm and is configured to receive a respective engagement member in the form of an engagement tooth 44 of the insertion instrument 40 (see
The fixation body 34 further defines a pair of recesses 50 that extend into the inner surface of the respective pair of arms 38 at a location that can be arranged symmetrically at substantially equal distances from the second transverse dimension of the fixation body 34. Each recess 50 defines a thinned region of the arms 38 that increase the elasticity, or flexibility, of the arms 38. Thus, the arms 38 can define respective hinges 53 at the recesses 50 that facilitate flexing of the arms between the first initial or unflexed position and the second flexed position. Furthermore, the fixation body 34 defines a central section 54 disposed adjacent and proximal to the recesses 50 (e.g., at the base 36) that is thicker than the hinges 53 and defines a rigid anchorage that is configured to connect to the connector assembly 32 and facilitate fixation of the bone fixation member 30 to the fixation rod 24. The fixation body 34 defines a distal section 56 of the arms 38 disposed adjacent and distal to the recesses 50 (e.g., at the base 36) that is thicker than the hinges 53 and defines a rigid anchorage that is configured to connect to a bone (e.g., lamina) that is received in the bone-receiving space 42.
Referring now to
The connector assembly 32 can be configured as desired, as is well known in the field of pedicle screws or hooks. For instance, the connector assembly 32 can include a hollow cylindrical sleeve 62 that defines a central bore hole 61 elongate along a central transverse axis 33. The central bore 61 defines an internal channel 64 having an upper (e.g., outer transverse) open end 63 that is configured to receive the fixation rod 24 into the channel 64, for instance before a set screw 78, plug 80, and insert screw 82 are connected, either directly or indirectly, to the sleeve 62 so as to close the open end 63 of the channel 64. If desired, the channel 64 can also be open towards the side or be formed as an oval bore hole. The sleeve 62 defines a lower (e.g., inner transverse) end 66 that defines a recess 68 that can be substantially ring-shaped. The connector assembly 32 includes a fastener such as a spring chuck 70 that is inserted into the lower end 66 of the bore hole 61 of the sleeve 62. The spring chuck 70 includes an outer flange 72 that is inserted into the recess 68, so as to substantially fix the spring chuck 70 to the sleeve 62 with respect to translation along the central axis 33 of the bore hole 61. The outer flange 72 of the spring chuck 70 can be radially displaceable inside the recess 68.
The spring chuck 70 defines an inner engagement surface 73 that defines an internal cavity 74, which can be shaped as a portion of a hollow sphere. Thus, the inner engagement surface 73 can likewise be substantially spherical. The spring chuck 70 further defines a plurality of slots 74 that allow the spring chuck 70 to be substantially homogeneously expanded and compressed as the connector assembly 32 iterates between its first unlocked configuration and its second locked configuration. Because the outer flange 72 of the spring chuck can be radially displaced when connected to the outer sleeve 62, the head 52 of the bone fixation member 30 can be snapped into the spring chuck 70, such that the head is disposed in the internal cavity 74, and can further be snapped out of the spring chuck 70 as desired while the connector assembly 32 is in the first unlocked configuration. When the head 52 is disposed inside the internal cavity 74, the outer engagement surface 58 can abut the complementary inner engagement surface 73 of the spring chuck 70 such that the connector assembly 32 and the fixation member 30 can pivot polyaxially with respect to each other while the connector assembly 32 is in the first unlocked configuration, prior to tightening the set screw 78 which causes the connector assembly 32 to assume the second locked configuration.
The spring chuck 70 further defines an outer surface 76 that tapers conically inward along a direction toward its upper end. The connector assembly 32 further includes a hollow cylindrical insert 84 that is shaped complementarily conical to the outer surface 76 of the spring chuck 70, and can slide down (or transversely inward) within the bore hole 61 at its lower end between the spring chuck 70 and the sleeve 62, thereby providing a radial compressive force onto the outer surface 76 as the conical surfaces ride along each other, thereby causing the inner engagement surface 73 to bear against the outer engagement surface 58 of the head 52. For instance, the set screw 78 can be tightened against the plug 80, which has at least one leg 81 such as a pair of legs 81 that can bear against a shoulder 88 of the insert 84, that causes the insert to translate downward (or transversely inward). Furthermore, the plug 80, which can alternatively be integral with the set screw 78, defines an inner surface 90 that can be substantially spherical so as to tighten the fixation rod 24 that is disposed in the internal channel 64 against the sleeve 62, thereby locking the fixation rod 24 with respect to movement relative to the connector assembly 32, and thus also relative to the bone fixation member 30 when the connector assembly is in its second locked configuration. The bone fixation member 30 can be oriented such that the fixation rod 24 extends substantially in a plane defined by the fixation body 34 when the fixation rod 24 is fixed to the fixation member 30.
As the set screw 78 is tightened, the plug 80 can press the fixation rod 24 onto the insert 84, for instance at the shoulder 88, which can also cause the insert 84 to translate downward. As the insert 84 translates downward, the insert 84 applies a radial compressive force onto the spring chuck 70 that can be sufficient so as to frictionally lock the spring chuck 70 onto the head 52 disposed in the internal cavity 74. The radial compressive force can be released so as to iterate the connector assembly 32 from the second locked configuration to the first unlocked configuration.
The insert screw 82 can essentially alter the inner thread in the sleeve 62 that mates with the set screw 78. It is appreciated that the inner thread is interrupted by the channel 64, and the insert screw 82 can alter the inner thread so as to define a peripherally closed inner thread such that the set screw 78 can advance unhinderedly. Because the bore hole 61 in the sleeve 62 is penetrated by the channel 64 which is open at the upper end 63 of the sleeve 62 and the sleeve 62 can be weakened at this location, the insert screw 82 includes a ring shaped groove 92 that receives the upper end 63 of the sleeve 62 so as to prevent the sleeve 62 from widening as the set screw 78 is tightened.
The connector assembly 32 can also be iterated from the second locked configuration to the first unlocked configuration by loosening the set screw 78, which relieves the pressure of the plug 80 on the shoulder 88 of the insert 84, thereby removing the radial compressive force onto the spring chuck 70.
It should be appreciated that while the connector assembly 32 has been described in accordance with one embodiment, various embodiments of a device that connect a fixation rod with a pedicle screw including a polyaxially pivotable coupling between the device and a pedicle screw are described, for instance in U.S. Pat. No. 6,248,105, the disclosure of which is hereby incorporated by reference as if set forth in its entirety herein.
Referring now to
The clamp 94 includes a pair of longitudinally opposed spreader arms 100 that project obliquely out from the distal end 95 of the shaft 96 at an angle with respect to the longitudinal axis 41. The free ends of the spreader arms 100 each carry an engagement member that is configured to mate with the engagement member of the fixation body 34 so as to apply an expansion force onto the arms 38. For instance, the engagement member of each of the spreader arms 100 can be provided as a tooth that is carried on an inner surface of the spreader arms 100 at a location proximate to the free end of the spreader arms 100. Each tooth 44 each projects inwardly toward the opposed tooth 44, and is configured to be received in a complementary one of the grooves 48 that extend into the arms 38 as described above.
The insertion instrument 40 further includes a carrier 106 that can be tubular and is mounted onto the shaft 96, for instance proximate to the distal end 95 of the shaft 96. The carrier 106 can carry an outer textured grip surface 108. The insertion instrument 40 further includes a bushing 104 that is fixedly disposed in the distal portion of the carrier 106. Each of the spreader arms 100 defines a fixed end 102 that is fixedly connected to the bushing 104. The bushing 104 defines an internal thread 107 which is coaxial to the longitudinal axis 41 of the insertion instrument 40. The front part of the shaft 96 is provided with an outer thread which engages the internal thread 107 of the bushing 104.
The insertion instrument 40 can be coupled to the bone fixation member by placing the engagement teeth 44 into the complementary engagement grooves 48 that extend into the arms 38, such that a surface of the teeth 44 abut the steep flank 49 (see
Referring now to
1) establishing an incision each for a posterior approach to each vertebral body 23 to be treated;
2) attaching a first bone fixation member 30A of the first bone fixation element 22A to the insertion instrument 40;
3) actuating the insertion instrument so as to apply an expansion or spreading force to the first bone fixation member 30A that causes the respective arms 38 to flex outward;
4) inserting and positioning the bone fixation member 30 over the lamina 43 of a first vertebral body 23a to be treated;
5) releasing the bone fixation member 30 by reversing the shaft 96 so that the bone fixation member 30 is clipped over the lamina 24 as illustrated in
6) repeating steps 2) to 5) for a second bone fixation member 30b of a second bone fixation element 22b and second vertebral body 23b, and as many subsequent fixation members associated with each vertebral body 23 to be treated;
7) snapping a connector assembly 32 onto the connection interface 37 of each bone fixation member 30 attached to the vertebral bodies 23, as illustrated in
8) positioning a longitudinal rod 24 in the channels 64 of the connector assemblies 32 attached to the vertebral bodies 23 as illustrated in
9) mounting an insert screw 82 on each connector assembly 32;
10) fastening the insert screws 82; and
11) fastening the set screws 78 in each connector assembly 32 in order to fix the longitudinal rod 24 to the bone fixation members 30 as illustrated in
Referring now to
The fastener 112 can be configured as a cable tie that provides rigid fixation of the fixation rod 24 to the bone fixation member 30. In accordance with the illustrated embodiment, the tension-stable fastener 112 includes a substantially belt-shaped body 116 that can be looped and closed by a closing piece 118 having teeth that engage complementary teeth of the body 116, such that the free end of the body 116 is movable only in one direction, i.e. in a direction to make the fastener and the defined channel 64 smaller. By tightening the body 116, the bone fixation member 30 is drawn closer to the longitudinal rod 24, for instance to a degree such that the bone fixation member 30 abuts the fixation rod 24. The head 52 can define a concave abutment surface 120 that is configured to receive the longitudinal rod 24, and matches the convex outer surface of the longitudinal rod 24. The channel 16 can be elongate along a direction that is parallel to the first longitudinal axis 7 of the fixation body 34, such that the fixation rod 24 can extend along the plane defined by the fixation body 34.
In accordance with another alternative embodiment, the head 52 can widen out to admit two separate apertures 114, and the head 52 can be tipped down relative to the second transverse axis of the fixation body 34 in order to bring it closer to the longitudinal rod 24.
It should be appreciated that while various connection interfaces have been illustrated that are configured to rigidly fix a pedicle screw or hook to a fixation rod are described, for instance, in U.S. Pat. No. 6,325,802, the disclosure of which is hereby incorporated by reference as if set forth in its entirety herein.
It should be appreciated that a kit can include at least one such as a plurality of bone fixation elements 22 or components thereof, such as the bone fixation member 30 alone or in combination with a connector assembly 32, at least one such as a plurality of bone fixation rods 24, and at least one such as a plurality of insertion instruments 40.
Although the invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, and composition of matter, structure, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, composition of matter, structure, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention.
It will be appreciated by those skilled in the art that various modifications and alterations of the invention can be made without departing from the broad scope of the appended claims. Some of these have been discussed above and others will be apparent to those skilled in the art.
This claims the benefit of U.S. Patent Application Ser. No. 61/285,728, filed Dec. 11, 2009, the disclosure of which is hereby incorporated by reference as if set forth in its entirety herein.
| Number | Date | Country | |
|---|---|---|---|
| 61285728 | Dec 2009 | US |
