Patent ID: 12232787

DETAILED DESCRIPTION

The present disclosure is related to a patella bone plate and methods of with fixing the bone plate to the patella. It has been discovered that the bone plate and associated methods of fixation provide for stability across multiple fracture fragments. The bone plate and associated methods can also address inferior pole comminution. Further, the bone plate can be fixed to the patella without compromising a vascular supply to the patella. The vascular supply that is avoided is currently believed to be the primary vascular supply to the patella.

A bone plate20will now be described with reference toFIGS.1A-1C, it being appreciated that the description of the bone plate20illustrated inFIGS.1A-1Calso applies to the bone plate20illustrated inFIGS.2A-2Cunless otherwise indicated. The bone plate20is configured for fixation to the patella bone. In one example, the bone plate20can be configured as a mesh cage22that is configured to surround the lateral end of the circumferential or peripheral rim of the patella as well as a portion of the anterior cortex of the patella. Thus, as will be appreciated from the description below, the bone plate20is configured to provide fixation of a patella after fracture reduction so as to maintain alignment of the articular surface.

The bone plate20includes a bone plate body24that defines an inner surface24aconfigured to face the patella, and an outer surface24bopposite the inner surface24a. The bone plate20further includes a plurality of fixation holes26that extend through the bone plate body24from the outer surface24bto the inner surface24a. In one example, the bone plate body24includes a plurality of eyelets28and links30that are connected between adjacent ones of the eyelets28. The fixation holes26can extend through the eyelets28from the outer surface24bto the inner surface24a. In particular, the fixation holes26can extend through the eyelets28along respective central axes25. One or more up to all of the links30can extend linearly from and to adjacent ones of the eyelets28. Alternatively or additionally, one or more up to all of the links30can define bent regions between adjacent ones of the eyelets28so as to provide for linear distance adjustment between the corresponding adjacent ones of the eyelets28. The links30and the eyelets28can be monolithic with each other. Alternatively, the links30and the eyelets28can be secured to each other using any attachment technique as desired. The bone plate20can be a titanium bone plate, a stainless steel bone plate, or any alternative suitable biocompatible made as desired that possesses the requisite strength for patella fixation.

As is described in more detail below with respect toFIGS.4A-4G, the fixation holes26are configured to receive a respective fixation element that is configured for insertion through the fixation hole26and into the underlying patella so as to fix the bone plate20to the patella. Thus, a fixation system can include the bone plate20and the fixation elements. It should be appreciated, of course, that the bone plate20can be alternatively configured as desired so as to define the bone plate body and a plurality of fixation holes26that extend through the bone plate body24from the outer surface24bto the inner surface24a.

The plate body24can include any number of eyelets28as desired, it being appreciated that a greater number of eyelets allows for greater flexibility in the positioning of fixation elements to be driven into the patella. In this regard, it is recognized that patella fractures can be significantly comminuted, and that it may be desirable to drive the fixation elements into select ones of the bone fragments. By including a large number of eyelets28, the fixation element can be aligned with a desired bone fragment.

With continuing reference toFIGS.1A-1C, the bone plate20has a length that extends along a longitudinal direction L, a height that extends along a lateral direction A that is oriented substantially perpendicular with respect to the longitudinal direction L, and a thickness that extends along a transverse direction T that is oriented substantially perpendicular to each of longitudinal direction L and the lateral direction A. Unless otherwise indicated, the longitudinal direction as used herein can include the longitudinal direction L and directions within 45 degrees of the longitudinal direction L. Similarly, unless otherwise indicated, the lateral direction as used herein can include the lateral direction A and directions within 45 degrees of the lateral direction A. Similarly, unless otherwise indicated, the transverse direction as used herein can include the transverse direction T and directions within 45 degrees of the transverse direction T.

When the bone plate20is in a flat configuration illustrated inFIG.1A, the length and the height can be coplanar with each other. When the bone plate20is in a contoured configuration illustrated inFIGS.1B-1C, the length and thus the longitudinal direction L can be curved in a first respective direction of curvature such that the inner surface24adefines a concavity. Similarly, and the height and thus the lateral direction A can be curved in a second respective direction of curvature that is different than the first respective direction of curvature such that the inner surface24adefines a concavity. The first and second directions of curvature can be substantially perpendicular to each other. In one example, the curvatures of the length and the height can be linear and thus can lie in respective first and second planes. The first and second planes can be substantially orthogonal to each other. In another example, the curvatures can be non-linear from eyelet to eyelet. It should thus be appreciated that the curvatures of the length and height can be shaped as desired such that the inner surface24ais contoured to substantially match the contour of the patella.

The bone plate body24, and thus the bone plate20, can include a base32that extends along the longitudinal direction L. The base32is configured to attach to a peripheral rim of a patella, as will be described in more detail below. Thus, the bone plate can also be referred to as a patella peripheral rim bone plate. The bone plate body24, and thus the bone plate20, includes a plurality of bone fixation holes26that extend through the base32along the transverse direction T from the outer surface24bto the inner surface24a. For instance, the base32can include a plurality of eyelets28and links30connected between adjacent ones of the eyelets28. In particular, the base32can include at least one row34of eyelets28that are spaced from each other along the longitudinal direction L. Thus, the at least one row34can be said to be oriented along the longitudinal direction L. The base32can define an intermediate section32a, a first outer section32bthat extends out from a first side of the intermediate section32a, and a second outer section32cthat extends out from a second side of the intermediate section32athat is opposite the first side. Thus, the intermediate section32acan be disposed between the first outer section32band the second outer section32c. The first outer section32bis configured to be fixed to the patella on the boney edge of the superior pole of the patella under (or posterior of) the quadriceps tendon. The second outer section32bis configured to be secured to the non-articulating inferior pole of the patella under (or posterior of) the patellar tendon. Thus, the first outer section32bcan define a superior extension of the bone plate20when the bone plate20is configured and aligned for attachment to the patella. Similarly, the second outer section32ccan define an inferior extension of the bone plate when the bone plate20is configured and aligned for attachment to the patella.

The fixation holes26of the at least one row34can be at least partially aligned with each other along the longitudinal direction L. For instance, the fixation holes26of the at least one row34can be partially aligned with each other along the longitudinal direction L. In one example, the fixation holes26of the at least one row34can be aligned with each other along the longitudinal direction L. The central axes25of the fixation holes26that are said to be aligned along a direction can be inline with each other along that direction. Alternatively or additionally, the link30that is connected between the eyelets28of adjacent fixation holes26that are said to be aligned along a direction can extend along the direction from and to adjacent ones of the eyelets28that are said to be aligned with each other. Alternatively or additionally still, the link30that is connected between the eyelets28of adjacent fixation holes26that are said to be aligned along a direction can extend along the direction from and to adjacent ones of the eyelets28that are said to be aligned with each other. Alternatively or additionally still, the link30that is connected between the eyelets28of adjacent fixation holes26that are said to be aligned along a direction can extend from one location of a first one of the eyelets28at a first location, and can extend from a second location of a second one of the eyelets28. The first and second locations can be aligned with each other along the direction.

Further, central axes25of the fixation holes26that are said to be at least partially aligned along one of the longitudinal direction L and the lateral direction A can be offset from each other along the other of the lateral direction A and the longitudinal direction L such that a plane defined by the transverse direction T and the one of the longitudinal direction L and the lateral direction A can pass through the fixation holes26of adjacent eyelets that are said to be partially aligned along the one of the longitudinal direction L and the lateral direction A. Alternatively or additionally, the link30that is connected between the eyelets28of adjacent fixation holes26that are said to be partially aligned along a direction can extend along a second direction that defines an angle with respect to the direction of partial alignment that is 45 degrees or less. Alternatively or additionally still, the link30that is connected between the eyelets28of adjacent fixation holes26that are said to be partially aligned along a direction can extend along a second direction that defines an angle with respect to the direction of partial alignment that is 45 degrees or less from and to adjacent ones of the eyelets28that are said to be partially aligned with each other. Alternatively or additionally still, the link30that is connected between the eyelets28of adjacent fixation holes26that are said to be partially aligned along a direction can extend from one location of a first one of the eyelets28at a first location, and can extend from a second location of a second one of the eyelets28. The first and second locations can be aligned with each other along a second direction defines an angle with respect to the direction of partial alignment that is 45 degrees.

In one example, the at least one row34of the base32can include first and second rows34aand34bof eyelets28, the rows spaced from each other along the lateral direction A. In this regard, the longitudinal direction L can define a row direction, and the lateral direction A can define a column direction. In one example, the second row34bcan be spaced from the first row34ain a first select lateral direction. Thus, the first row34acan be spaced from the second row in a second select lateral direction that is opposite the first select lateral direction. When the plate20is oriented and configured for fixation to the patella, the first select lateral direction can be defined by one or both of the anatomical medial direction and the anatomical anterior direction. Thus, the second row34bcan be spaced one or both of medially and anteriorly from the first row34awhen the bone plate20is configured and aligned for attachment to the patella.

The first and second rows34aand34bcan be spaced from each other along the lateral direction A. The eyelets28of the first row34acan be at least partially aligned with respective ones of the eyelets28of the second row34balong the lateral direction A. For instance, the eyelets28of the first row34acan be partially aligned with respective ones of the eyelets28of the second row34balong the lateral direction A. In one example, the eyelets28of the first row34acan be aligned with respective ones of the eyelets28of the second row34balong the lateral direction A. In another example, the eyelets of the first and second row34aand34bcan be staggered with respect to each other along the longitudinal direction L. The first and second rows34aand34bof eyelets can be oriented substantially parallel to each other. It is recognized that first and second rows34aand34bof eyelets28allow for positional flexibility along both the longitudinal direction L and the lateral direction A of bone fixation elements that pass through the eyelets28of the base32and into the anterior rim of the patella, as will be described in more detail below. Thus, the base32is configured to be fixed to the lateral rim of the patella at locations that are offset from each other both along the longitudinal direction L and the lateral direction A. For instance, selection of one of the first and second rows34aand34ballows for positional flexibility along the lateral direction A. Selection of one of the plurality of fixation holes26of a given one of the rows34aand34ballows for positional flexibility along the longitudinal direction L. Further, one or both of the rows34aand34bcan be angulated along the superior and inferior portions of the rim of the patella so as to provide for additional positional flexibility along the lateral direction A.

The first and second rows34aand34bcan include the same number of eyelets28or a different number of eyelets28. In one example, the first row34ahas a greater number of eyelets than the second row34b. The eyelets28of the first row34acan be equidistantly spaced from each other along the longitudinal direction L a first distance. Further, the eyelets28of the second row34bcan be equidistantly spaced from each other along the longitudinal direction L a second distance. The second distance can be equal to the first distance. Alternatively, the second distance can be greater than or less than the first distance. The eyelets28of the second row34bcan be offset from the eyelets28of the first row34aa respective distance along the lateral direction A that can be equal to one or both of the first and second distances. Alternatively, the eyelets28of the second row34bcan be offset from the eyelets28of the first row34aa respective distance along the lateral direction A that can be different than each of the first and second distances.

The first row34acan define a first longitudinal end37a, a second longitudinal end37bthat is opposite the first longitudinal end37a, and a middle segment37cdisposed between the first and second longitudinal ends37aand37b. The first longitudinal end37acan be said to be spaced from the second longitudinal end37bin a first select longitudinal direction. Similarly, the second longitudinal end37bcan be said to be spaced from the first longitudinal end37ain a second select longitudinal direction opposite the first select longitudinal direction. The first longitudinal end37acan be defined by the first outer section32b. The second longitudinal end37bcan be defined by the second outer section32c. The middle segment37ccan be defined by the intermediate section32a. When the bone plate20is oriented and configured for fixation to the patella, the first select longitudinal direction can be at least partially defined by the superior direction. Thus, when the bone plate20is oriented and configured for fixation to the patella, the first select longitudinal direction can be at least partially defined by the inferior direction.

Similarly, the second row34bcan define a first longitudinal end38a, and a second or middle segment38bdisposed adjacent the first longitudinal end38a. It is also envisioned that the second row can include a second longitudinal end that is opposite the first longitudinal end38a, such that the middle segment38bdisposed between the first longitudinal end38aand the second longitudinal end. The first longitudinal end38acan be spaced from the second longitudinal end in the first select longitudinal direction. The second longitudinal end can be spaced from the first longitudinal end38ain the second select longitudinal direction. The first longitudinal end38acan be defined by the first outer section32b. The second longitudinal end can be defined by the second outer section32c. The middle segment38bcan be defined by the intermediate section32a.

The first row34adefines a first longitudinal length from longitudinally outermost ends of the first row34a. The second row34bdefines a second longitudinal length that can extend from longitudinally opposed outermost end of the second row34b. The first longitudinal length can be greater than the second longitudinal length. Alternatively, the second longitudinal length can be greater than the first longitudinal length. Alternatively, the first longitudinal length can be substantially equal to the second longitudinal length. Accordingly, as will be appreciated from the description below, the first row34ais configured to reach further around the superior and inferior poles of the patella than the second row34b.

In one example, the first longitudinal end37aof the first row34acan be disposed outboard of the first longitudinal end38aof the second row34balong the longitudinal direction L, and in particular in the first select longitudinal direction. In particular, the first longitudinal end37acan be offset from the first longitudinal end38aa first offset distance. The second longitudinal end37bof the first row34acan be disposed outboard of the second row34balong the longitudinal direction L, and in particular in the second select longitudinal direction. In particular, the second longitudinal end37bcan be offset from the second row34ba second offset distance. In one example, the first offset distance can be less than the second offset distance. Thus, the first longitudinal end37acan include fewer eyelets28than the second longitudinal end37bthat are disposed longitudinally outboard of the second row34b. Alternatively, the first and second longitudinal ends37aand37bcan include an equal number of eyelets28that are disposed longitudinally outboard of the second row34b. Alternatively still, the second longitudinal end37bcan include fewer eyelets28than the first longitudinal end37athat are disposed longitudinally outboard of the second row34b. Thus, it should be appreciated, of course, that the first offset distance can be greater than the second offset distance. Alternatively still, the first offset distance can be substantially equal to the second offset distance.

It should be appreciated that while the base32has been described in accordance with one embodiment, and that numerous alternative designs are envisioned suitable for implantation as described in more detail below. For instance, while the base32has been described as including first and second rows34aand34b, the base32can include any number of rows as desired, greater than or equal to one. The first row34acan define an outer boundary of the bone plate with respect to the second select lateral direction. It is further envisioned that the base32can be constructed without any rows but still including the first outer section32bconfigured for fixation to the superior boney edge of the superior patella under (or posterior of) the quadriceps tendon, and the second outer section32bconfigured to be secured to the non-articulating distal pole of the patella under (or posterior of) the patellar tendon.

With continuing reference toFIGS.1A-1C, the bone plate body24, and thus the bone plate20, can further include an outer portion40that extends from the base32along the lateral direction A. The outer portion40can be monolithic with the base32. Alternatively, the outer portion40can be fastened to the base32in any manner as desired. During use, when the base32surrounds a portion of the patella rim, the outer portion40is configured to extend medially over the anterior cortical surface of the patella. For instance, the base32can at least partially surround the lateral half of the patella rim. Thus, it should be appreciated that the base32can be contoured to fit against the patella rim, and the outer portion40can be contoured to fit against the anterior cortical surface of the patella. The bone plate body24, and thus the bone plate20includes a plurality of bone fixation holes26that extend through the outer portion along the transverse direction from the outer surface24bto the inner surface24a. Thus, the patella peripheral rim bone plate20can be further configured to be fastened to the anterior surface of the patella.

For instance, the outer portion40can include a plurality of eyelets28and links30connected between adjacent ones of the eyelets28. In particular, the outer portion40can include at least one column42of eyelets28that are spaced from each other along the lateral direction A. Thus, the at least one column42can be said to be oriented along the longitudinal direction A. The outer portion40can define an outer proximal end40a, an outer intermediate section40b, and an outer distal end40c. The outer intermediate section40bcan be disposed between the outer proximal end40aand the outer distal end40c. The outer proximal end40acan extend out from the base32. The outer portion40can terminate at the outer distal end40cwhich can be a free end. The outer portion40can thus be cantilevered from the base32. The outer portion40is configured to be fixed to the patella at the anterior wall. In particular, the outer intermediate section40band the outer distal end40ccan be configured to receive fixation elements that extend through the anterior cortical surface and into the patella. Thus, the outer intermediate section40bcan extend medially from the outer proximal end40a, and the outer distal end40ccan extend medially from the outer intermediate section40b.

Whether the bone plate is in the flat configuration or the curved configuration, the base32can be elongate substantially along a first plane, and the outer portion40can extend from the base32substantially along a second plane, it being understood that each of the base32and the outer portion40can be contoured as desired to deviate from a plane. The first and second substantial planes can be substantially orthogonal with respect to to each other.

The fixation holes26of the at least one column42can be at least partially aligned with each other along the longitudinal direction A. For instance, the fixation holes26of the at least one column42can be partially aligned with each other along the lateral direction A. In one example, the fixation holes26of the at least one column42can be aligned with each other along the lateral direction A.

In one example, the at least one column42of the outer portion40can include first and second limbs that extend out from the base32. The first and second limbs can be defined by respective first and second columns42aand42bof eyelets28, the columns spaced from each other along the longitudinal direction L. In one example, the first column42acan be spaced from the second column42bin the first select longitudinal direction. Thus, the second column42bcan be spaced from the first column42ain the second select longitudinal direction. Thus, the first column42acan be spaced superior with respect to the second column42bwhen the bone plate20is oriented and configured for attachment to the patella.

The first and second columns42aand42bcan be spaced from each other along the longitudinal direction L. The eyelets28of the first column42acan be at least partially aligned with respective ones of the eyelets28of the second row34balong the longitudinal direction L. For instance, the eyelets28of the first column42acan be partially aligned with respective ones of the eyelets28of the second column42balong the longitudinal direction L. In one example, the eyelets28of the first column42acan be aligned with respective ones of the eyelets28of the second column42balong the longitudinal direction L. In another example, the eyelets28of the first and second columns42aand42bcan be staggered with respect to each other along the lateral direction A. The first and second columns42aand42bof eyelets28can be oriented substantially parallel to each other.

It is appreciated that first and second columns42aand42bof eyelets28allow for positional flexibility along both the longitudinal direction L and the lateral direction A of bone fixation elements that pass through the eyelets28of the base32and into the anterior wall of the patella, as will be described in more detail below. Thus, the outer portion40is configured to be fixed to the anterior wall of the patella at locations that are offset from each other both along the longitudinal direction L and the lateral direction A. In this regard, the first and second columns42aand42bcan define first and second anterior extensions of the bone plate20when the bone plate20is configured and aligned for attachment to the patella60. Thus, the outer portion40of the bone plate20can be referred to as an anterior portion of the bone plate20when the bone plate is aligned and configured for fixation to the patella.

Selection of one of the first and second columns42aand42bfor fixation allows for positional flexibility along the longitudinal direction L. Selection of one of the plurality of fixation holes26of a given one of the columns42aand42bfor fixation allows for positional flexibility along the lateral direction A. Further, one or both of the columns42aand42bcan be angulated along the anterior wall so as to provide for additional positional flexibility along the longitudinal direction L. The application of the base32to the lateral half of the peripheral rim of the patella along with the fixation of the first and second columns42aand42bto the anterior wall of the patella permits fixation of the bone plate20to the patella in multiple planes of fixation.

The first column42acan define a first lateral end46a, a second lateral end46bthat is opposite the first lateral end46a, and a middle segment46cdisposed between the first and second lateral ends46aand46b. The second lateral end46bcan be said to be spaced from the first lateral end46ain the first select lateral direction. Similarly, the first lateral end46acan be said to be spaced from the second lateral end46bin the second select longitudinal direction. Thus, the second lateral end46bcan be spaced from the first lateral end46ain at least the medial direction when the bone plate20is oriented and configured for fixation to the patella. The first lateral end46acan be defined by the outer proximal end40a. When the bone plate20is placed against the patella, the first lateral end46acan extend anteriorly and medially, such that the first middle segment46cand the second lateral end46bcan face the anterior surface of the patella. The second lateral end46bcan be defined by the second outer distal end40c. The middle segment46ccan be defined by the outer intermediate section40b.

Similarly, the second column42bcan define a first lateral end48a, a second lateral end48bthat is opposite the first lateral end48a, and a middle segment48cdisposed between the first lateral end48aand the second lateral end48b. The second lateral end48bcan be spaced from the first lateral end48ain the first select lateral direction. The first lateral end48acan be spaced from the second lateral end48bin the second select lateral direction. The first lateral end48acan be defined by the outer proximal end40a. When the bone plate20is placed against the patella, the first lateral end48acan extend anteriorly and medially, such that the first middle segment48cand the second lateral end48bcan face the anterior surface of the patella. The second column42bcan be spaced from the first column42ain the inferior direction. Thus, the first column42acan be spaced from the second column42bin the superior direction. The second lateral end48bcan be defined by the outer distal end40c. The middle segment48ccan be defined by the outer intermediate section40b.

The first column42adefines a first lateral length from the first lateral end46ato the second lateral end46b. The second column42bdefines a second lateral length from the first lateral end48ato the second lateral end48b. The first lateral length can be substantially equal to the second lateral length. Thus, the second lateral ends46band48bcan be substantially aligned with each other along the longitudinal direction L. Alternatively, the first lateral length can be greater than the second length. Thus, the second lateral end46bcan be disposed laterally outboard, or medially during use, of the second lateral end48b. Alternatively still, the first lateral length can be less than the second lateral length. Thus, the second lateral ends48bcan be disposed laterally outboard, or medially during use, of the second lateral end46b. As will be appreciated from the description below, the first and second columns42aand42bare each configured to extend anteriorly from the base32to the anterior wall of the patella, and medially along the anterior wall of the patella.

The first and second columns42aand42bcan include the same number of eyelets28or a different number of eyelets28. The eyelets28of the first column42acan be equidistantly spaced from each other along the lateral direction A a respective first distance. Further, the eyelets28of the second column42bcan be equidistantly spaced from each other along the lateral direction A a respective second distance. The respective second distance can be equal to the respective first distance. Alternatively, the respective second distance can be greater than or less than the respective first distance. Further still, the respective first and second distances defined by the eyelets28of the first and second columns42aand42bcan be the same as or different than the first and second distances defined by the eyelets of the first and second rows34aand34b, respectively.

The eyelets28of the first column42acan be offset from the eyelets28of the second column42ba distance along the longitudinal direction L that can be greater than one or both of the respective first and second distances. Accordingly, the outer portion40can include at least one cross-beam50that extends between the first and second columns42aand42b, and is connected to each of the first and second columns42aand42b. The cross-beam50can be monolithic with one or both of the first and second columns42aand42b. Alternatively or additionally, the cross-beam50can be can be secured to one or both of the first and second columns42aand42busing any attachment technique as desired. The cross-beam50can include at least one eyelet28, and first and second links30that are joined to the first and second columns42aand42b, respectively. In particular, one or both of the links30can be joined to respective eyelets28of the first and second columns42aand42b, respectively. The at least one eyelet28of the cross-beam50can be spaced from the eyelets28of the first and second columns42aand42bany distance along the longitudinal direction L as desired. In particular, the at least one eyelet28of the cross-beam50can be spaced from the eyelets28of the first and second columns42aand42ba distance along the longitudinal direction L can be the equal to or different than the respective first and second distances that the eyelets28of the first and second columns42aand42bare spaced from each other along the lateral direction A.

The outer distal end40cof the outer portion40can be defined by the eyelets28of the outer portion40that are disposed outboard from the cross-beam in the first select lateral direction. Thus, the second lateral end46bof the first column42acan be defined by the at least one eyelet or eyelets28that are spaced from the cross-beam50in the first select lateral direction. The second lateral end46bof the first column42acan be defined by the at least one eyelet or eyelets28that are spaced from the cross-beam50in the first select lateral direction. The second lateral end46band48bcan include a single eyelet28. Alternatively, the second lateral end46band48bcan include a plurality of eyelets28as desired.

The first and second outer sections32band32cof the base32, and thus the first and second longitudinal ends37aand37bof the first row34acan be defined by those eyelets28of the first and second rows34aand34bthat are disposed longitudinally outboard with respect to the eyelets28of the outer portion40. For instance, the at least one eyelet28or eyelets28of the first longitudinal end37acan be spaced from the outer portion40in the first select longitudinal direction. Thus, in one example, the at least one eyelet28or eyelets28of the first longitudinal end37acan be spaced from the first column42ain the first select longitudinal direction L. Similarly, the at least one eyelet28or eyelets28of the second longitudinal end37bcan be spaced from the outer portion40in the second select longitudinal direction. Thus, in one example, the at least one eyelet28or eyelets28of the second longitudinal end37bcan be spaced from the second column42bin the second select longitudinal direction L.

Likewise, the first longitudinal end38aof the second row34bcan be defined by those eyelets28of the second row34bthat are disposed longitudinally outboard with respect to the eyelets28of the outer portion40in the first select longitudinal direction. Thus, in one example, the at least one eyelet28or eyelets28of the first longitudinal end38acan be spaced from the first column42ain the first select longitudinal direction L. Similarly, if the second row34bincludes a second longitudinal lend38b, the at least one eyelet28or eyelets28of the second longitudinal end38bcan be spaced from the outer portion40in the second select longitudinal direction. Thus, in one example, the at least one eyelet28or eyelets28of the second longitudinal end38bcan be spaced from the second column42bin the second select longitudinal direction L.

It should be appreciated that while the outer portion40has been described in accordance with one embodiment, and that numerous alternative designs are envisioned suitable for implantation as described in more detail below. For instance, while the outer portion40has been described as including first and second rows columns42aand42b, the outer portion40can include any number of columns as desired, greater than or equal to one. The first column42acan define an outer boundary of the outer portion40with respect to the first select longitudinal direction. The second column42acan define an outer boundary of the outer portion40with respect to the second select longitudinal direction. Additional columns can be disposed between the first and second columns42aand42bwith respect to the longitudinal direction.

Referring now toFIGS.1A-1C and2A-2C, the bone plate20can be provided in many different sizes as desired. In one non-limiting example, bone plates20having different longitudinal lengths are envisioned. As illustrated inFIGS.1A-1C, the cross-beam50includes first and second eyelets28that are disposed between the first and second columns42aand42b. Further, the middle segment37cof the first row34aincludes four eyelets28. The middle segment37cof the second row34balso includes four eyelets. It is recognized, however, that the various segments of the bone plate20can include any number of eyelets28as desired. As illustrated inFIGS.2A-2C, the cross-beam50includes a single eyelet28that is disposed between the first and second columns42aand42b. Further, the middle segment37cof the first row34aincludes three eyelets28. The middle segment37cof the second row34balso includes four three. It is recognized, however, that the various segments of the bone plate20can include any number of eyelets28as desired. It should be appreciated, however, that the intermediate section32aof the base of a first bone plate20as illustrated inFIGS.1A-1Ccan include a greater number eyelets28that extend along the longitudinal direction L compared to the eyelets28of the intermediate section32aof a second bone plate20illustrated inFIGS.2A-2C. Further, the cross-beam50of the first bone plate as illustrated inFIGS.1A-1Ccan include a greater number of eyelets28that extend along the longitudinal direction L compared to the eyelets of the cross-beam50of the second bone plate ofFIGS.2A-2C.

Thus, it should be appreciated that the surgical provider can be provided with a kit of bone plates20of different sizes. The different sizes can be defined by the eyelets28as described above with respect to the bone plate20illustrated inFIGS.1A-1C, and the bone plate20illustrated inFIGS.2A-2C. It is recognized that the different sizes may be achieved in any suitable alternative manner as desired. Further still, the kit can include bone plates of different shapes suitable for implantation using the method described below. For instance, the base32can include a single row, or can include more than two rows. Further, the outer portion40can include one cross-beam or a plurality of cross-beams. Further still, the outer portion40can include more than two columns. The surgical provider can select the bone plate20deemed to be most suitable for the patella to which the bone plate20is to be affixed. The selection can be based at least in part on one or both of the size of the patella, and the shape of the patella.

Further, bone plates20can be provided to the surgical care provider as descried above with respect to either or both ofFIGS.1A-1CandFIGS.2A-2C. Thus, the bone plate20can be pre-formed in the manner described above, so as to be contoured to the shape of a patella prior to being sent to the surgical provider. It is appreciated that the pre-sized and pre-shaped implant can be further cut and shaped by the surgical care provider to define contour that further fits the patella to which the bone plate20is to be affixed. It is envisioned that a pre-sized and pre-shaped implant is contoured so as to substantially fit the patient's patella prior to any cutting or manipulation by the surgical provider.

In an alternative embodiment, the surgical provider can be provided with a flat mesh sheet having an array of eyelets28that are spaced from each other along the row direction and the column direction, and connected to each other by the links30as described above. The mesh sheet can be cut to a shape described herein so as to define the bone plate20, and contoured to the fractured patella to which the bone plate is to be fixed.

A method of fixation of the bone plate20to the patella to repair patella fractures will now be described. As will become appreciated from the description below, the bone plate20can provide a multiplanar fixation with the bone plate20that can provide a low profile fixation construct against the patella. The method of fixation can maintain anatomic reduction under direct visualization of complex articular injuries and of the articular reduction with compression plating and interfragmentary screw fixation, including inferior pole comminution, while minimizing or at least reducing disruption to the vascular supply to the patella compared to conventional plating techniques.

Referring now toFIG.3A, the patella60is an ovoid, triangular shape bone. The proximal roughly 75 percent of the patella60is composed of cortical-cancellous bone anteriorly with thick articular cartilage on the posterior surface. Distally near the inferior pole76, the patella60is composed of thinner cancellous bone. The patella60defines an articular surface66(seeFIG.3B) that is mainly divided by the major vertical ridge into the lateral and medial facets, with the lateral facet typically being the larger of the two. The patella60lies in a subcutaneous position with strong fascial attachments that compose the quadriceps tendon68proximally (quadriceps tendon68shown only inFIG.3Afor the purpose of simplicity), the retinaculum medially and laterally, and the patellar tendon72distally. These soft tissue structures together with the patella60comprise the extensor mechanism. The quadriceps tendon68originates from the superior pole74and is formed from a blending of the insertions of the four quadriceps muscles: rectus femoris, vastus medialis, vastus lateralis, vastus intermedius. The patellar tendon originates from the inferior pole76and inserts on the tibia tubercle. The patella retinaculum is formed from portions of the deep investing fascia lata with the vastus medialis and vastus lateralis aponeurotic fibers. It travels along the medial and lateral aspect of the patella60to insert on the proximal tibia and functions to assist with knee extension.

Historically, the intraosseous blood supply to the patella60was thought to originate from two main arterial systems that are the midpatellar vessels and the polar vessels. The midpatellar vessels penetrate the middle third of the patella, and the polar vessels penetrate the patella apex. However, more recent studies have demonstrated that the largest intraosseous arterial supply to the patella60in fact enters at the inferior or distal pole76and predominantly enters inferomedially. In addition, a deep peripatellar anastomotic ring has also been found that provides arterial blood supply. Because conventional understandings of the locations of primary blood supply to the patella60were inaccurate, conventional bone plates based on these conventional understandings risked a resulting avascular necrosis. The present method of fixation can avoid disruption of both the predominate inferomedial vessel and the peripatellar ring in order to preserve perfusion following the patella fracture fixation.

Two main surgical approaches for patella fractures include a midline longitudinal approach and a lateral parapatellar approach. The midline longitudinal approach includes creating a midline vertical incision down to the level of the retinaculum. Medial and lateral tissue flaps are raised to expose the extent of the retinacular tears. The present inventors have recognized the midline longitudinal approach creates difficulty visualizing the articular surface. Accordingly, the method of fixation includes a lateral parapatellar approach. The lateral parapatellar approach is believed to limit disruption to the patella vascularity, which as described above has been found to be primarily inferomedial. Thus, the method of fixation can include the step of creating a longitudinal skin incision75along the lateral border of the patella. The step of creating the incision75can further include creating the incision over the lateral edge of the patella down to the avascular subfascial layer. In one example, and the incision75can be made from the tibial tubercle to a location superior of the superior pole of the patella. For instance, the incision75can be made to a location between one and three inches above the superior pole of the patella. A limited lateral tissue flap can be raised to gain access to the articular capsule of the knee. It is appreciated that the incision along the lateral border of the patella can minimize the size of the lateral soft tissue flap for the lateral parapatellar arthrotomy. Prior to creating the incision, the knee is typically placed into approximately 20-30 degrees of flexion.

Once the incision has been created, the method of fixation can include the step of performing a lateral parapatellar arthrotomy. The lateral parapatellar arthrotomy can originate from the tear in the lateral retinaculum that is commonly present in patella fractures. The arthrotomy allows for direct visualization of the articular surface66, which significantly reduces the difficulty of obtaining an anatomic reduction compared to conventional techniques. In particular, as is described in more detail below, the access to the patella60through the lateral parapatellar arthrotomy can allow for angular manipulation of the patella to expose the articular surface and ensure continuity of the articular surface66after fracture reduction. Thus, the arthrotomy can allow for exposure and reduction of the articular fragments. Thus, the method can further include the step of directly visualizing the articular surface of the patella. The method can further include the step of exposing and reducing the articular fragments while directly visualizing the articular surface. Further, the direct visualization of the articular surface allows for visualization of the placement of the bone plate20on the patella60at locations that avoids interference with the articular surface. Thus, the method can further include the step of directly visualizing the articular surface while fixing the bone plate20to the patella60. The method can further include the step of fixing the bone plate20to the patella60while avoiding the inferomedial vascularity to the patella. In particular, the bone plate20can be placed against the bone plate20without causing the pate20to lie against the inferomedial vascularity to the patella. Once the lateral parapatellar arthrotomy has been completed, the method can include the step of irrigating the fracture site of the patella. The method can also include the step of removing the fracture hematoma. The method can further include the step of visually inspecting the patella60for loose bodies.

Referring now toFIGS.3B, the method of fixation can include the step of reducing the at least one fracture or fractures of the patella60. In particular, the reducing step can be performed after the arthrotomy has been completed. The patella60can be everted so as to expose the articular surface66, such that the method can include the step of directly visualizing the articular surface66. For instance, the patella can be angulated between 75 degrees and 180 degrees substantially about a superior-inferior axis to gain visual access to the articular surface66, and in particular to gain access to the at least one fracture location or fracture locations of the articular surface66. The angular manipulation of the patella can also allow for easy removal of hematomas at fracture locations of the articular surface66. In one example, during bone plate fixation, the patella can be angulated less than 180 degrees so as to simultaneously allow for access to the lateral aspect of the peripheral rim78of the patella60. Thus, the bone plate20can be fixed to a lateral aspect of the rim78while visualizing the articular surface to ensure integrity and continuity of the articular surface. At certain times during the surgical procedure, the patella60can be angulated more or less as desired so as to gain the desired visual access to the articular surface while allowing for fixation of the bone plate20to the patella60.

In one example, the step of reducing the patella can include the step of driving Kirschner wires (K-wires)79into select ones of the patella bone fragments80, and manipulating the K-wires to adjust the position of the bone fragment or fragments80. The K-wires can have any suitable diameter as desired. In one example, the K-wires can have a diameter between and including 1.5 mm and 2 mm. Thus, the K-wires can be used as joysticks that can translate and angulate the bone fragments to thereby reduce the at least one fracture or fractures. Reduction can further be performed using interfragmentary small fragment compression screws that can adjoin small fragments of the patellar fracture to each other, and reduce the fragments. During reduction, the patella60can be angulated as described above so as to provide visual access to the articular surface. The angulation can provide both direct visualization of fracture fragments and direct visualization of the articular surface. If further exposure or inversion is desired, the arthrotomy can be extended superiorly with a cuff of quadriceps tendon left on the vastus lateral left for later repair. Thus, the method can include the step of angulating the patella, and directly visualizing both at least a portion up to all of the fracture fragments and the articular surface. Alternatively, the patella60can be angulated intermittently after completion of a reduction operation to inspect the articular surface, to therefore assess whether additional reduction is to be performed. The reduction can be performed until the articular surface is aligned and the extensor mechanism is restored.

Referring now toFIG.3C, fracture can further be performed by capturing bone fragments80to be reduced between the arms82of reduction clamps84, and bringing the arms together so as to thereby urge the captured bone fragments80toward each other. The reduction clamps84can be used alone or in combination with either or both of the K-wires79and interfragmentary small fragment compression screws. Similarly, the K-wires79can be used alone or in combination with either or both of the reduction clamps84and the interfragmentary small fragment compression screws.

In one example, the K-wires79alone or in combination with the interfragmentary small fragment compression screws can be used to reduce the at least one fracture or fractures, and the reduction clamps can hold the fracture fragments in their reduced state while the bone plate20is fixed to the patella60. In one example, smaller fragments are held together with the threaded K-wires79alone or in combination with the interfragmentary small fragment compression screws so as to construct larger fragments that can then be reduced to one another under pressure provided by the reduction clamps. The bone plate20can then be applied to the patella60. In this regard, it should be appreciated that the K-wires79should be driven into the respective bone fragments at locations that do not interfere with placement of the bone plate20onto the patella60. Depending on the nature of the fracture, the reducing step can reduce fractures at the articular surface so as to achieve realignment and continuity of the articular surface.

Referring now toFIGS.4A-4Hgenerally, once the fractured patella60has been reduced, the bone plate20can be fixed to the patella60. InFIGS.4A-4H, the K-wires79and reduction clamps84are not shown in order to more clearly illustrate the bone plate20, but it is appreciated that the K-wires79and reduction clamps84can remain in place until fixation of the bone plate20to the patella60has stabilized the reduced fragments, at which point the K-wires79and reduction clamps84can be removed.

After the patella60has been reduced, the method can include the step of inserting the bone plate20through the lateral parapatellar incision75, and positioning the bone plate around at least a portion of the patella60. For instance, the plate20can be positioned such that the inner surface24afaces the patella60. A first portion of the plate20, which can be defined by the base32, can face a lateral side of the peripheral rim78. A second portion of the plate20, which can be defined by the outer portion40, can face the anterior surface86of the patella60. A first end of the first portion, which can be defined by the first outer section32bof the base32, can face the superior pole74of the patella. A second end of the first portion, which can be defined by the second outer section32cof the base32, can face the inferior pole76of the patella60. The plate20can be configured to be in alignment with the patella60beneath the patellar tendon and quadriceps tendon while also extending over the anterior wall of the patella60. Thus, the plate20can span half or more of the perimeter of the patella. For instance, the bone plate can span a lateral half of the perimeter. As described above, the plate size can be selected based on patient size and the shape of the patella.

In particular, the plate20can be contoured to fit around the peripheral rim78of the reduced patella and the cortical anterior surface86of the patella60. For instance, the bone plate20can be positioned such that the intermediate section32aof the base32faces the lateral end of the peripheral rim78of the patella60, and the outer portion40faces the anterior surface86of the patella60. The first outer section32bof the base32can define a first extension that faces the patella60at a location superior of the intermediate section32a. For instance, the first outer section32bof the base32can define a first extension that faces a bony surface of the superior patella at a location posterior of (beneath) the quadriceps tendon. The second outer section32cof the base32can define a second extension that is configured to face the patella60at a location inferior of the intermediate section32a. For instance, the second outer section32cof the base32can define a second extension that faces the non-articulating distal pole of the patella60at a location posterior of (beneath) the patellar tendon. The plate20is fashioned to achieve fixation to the patella60at each major fracture fragment without encroachment on the quadriceps and patellar tendinous insertions on the superior and inferior pole of the patella60. This avoids releasing the quadriceps and patellar, which can already be compromised by the injury that caused the patella fracture, from the patella60. It is recognized that the shape and contour of the plate20can be modified to adapt to various different fracture patterns.

As described above a fixation system can include the bone plate20and a plurality of fixation elements88. The fixation element88can include a head90and a shaft92that extends out with respect to the head90. At least a portion of the shaft92can be threaded. For instance, an entirety of the shaft can be threaded. In another example, the fixation element can be configured as a lag screw wherein the distal end of the shaft92is threaded, but the shaft remains unthreaded between the head and the threaded distal end. The shaft92can have a length sufficient so as to extend through a cortical wall of the rim78at a first location, extend through the patella, and be embedded in a cortical wall of the rim at a second location. The second location can be substantially opposite the first location. Thus, in one example, the shaft92can have a length sufficient so as to extend through the lateral side of the rim78, extend through the patella60, and embed in the cortical wall at the medial side of the rim78. In another example, the shaft92can have a length sufficient so as to extend through the proximal pole of the rim78, through the patella60, and embed in the cortical wall at the superior pole of the rim78. In this regard, the fixation element88can be referred to as a bicortical screw. Alternatively, the shaft92can be configured as a unicortical screw whose shaft has a length suitable to threadedly purchase with the cortical wall at the location of the bone through which the fixation element88extends. The fixation elements88can include shafts92having different diameters. For instance, while certain ones of the shafts can have a diameter of 2.4 mm and certain others of the shafts can have a diameter of 2.7 mm are envisioned, shafts of any suitable alternative diameter are contemplated by the present disclosure.

Further, one or more of the fixation elements88can be configured as compression screws. In particular, at least one or both of the external surface of the head90and the internal surface of the eyelet28that defines the fixation hole26can be unthreaded. Accordingly, as the head90is brought into the fixation hole26while the shaft is driven into the patella60, the head90is configured to compress the bone plate20against the patella60as the shaft92is driven into bone. In other examples described below (seeFIG.4G), one or more of the fixation elements88can be configured as a locking screw, whereby the external surface of the head90is threaded. Further, the internal surface of the eyelet28that defines the fixation hole26can also be threaded. Thus, as the head90is brought into the fixation hole26while the shaft is driven into the patella60, the head90is configured to threadedly mate with the bone plate20in the fixation hole26. While certain steps of fixing the bone plate20to the patella60are described in connection with certain types of fixation elements, it should be appreciated that the disclosure is not limited to the particular type of fixation element described, and that any suitable alternative type of fixation element could instead be used as desired. Further, the number of fixation elements inserted through the bone plate20and into the patella60, and size of screws can often be determined by fracture pattern and bone quality of the patella60.

Referring now toFIGS.1A-2C and4A-4B, after the plate20has been positioned around the patella60, at least one first or lateral fixation element94of the plurality of fixation elements88can be driven through one of the fixation holes26of the eyelets28in a lateral-to-medial direction. The at least one lateral fixation element94can thus be configured to achieve initial fixation of the plate20to the patella60. Fixation of the bone plate20to the patella with the at least one lateral fixation element94can achieve stable compression and absolute stability of the major fracture fragments.

The at least one lateral fixation element94can be configured as a bicortical compression screw, though as described above any one or more up to all of the at least one lateral fixation element94can be configured as any suitable type of alternative fixation element as described above. In one example, the lateral fixation element94can be driven through one of the fixation holes26of the intermediate section32aand at least into the lateral aspect of the rim78. The threaded shaft92can threadedly purchase with cortical bone at the anterior aspect of the rim78. Further, the lateral fixation element94can be driven into the reduced patella60until the threaded shaft92extends across the patella60and can threadedly purchase in cortical bone on the medial side of the patella60.

The at least one lateral fixation element94can include a plurality of lateral fixation elements94that can be driven into respective fixation holes26of the intermediate section32a. While a pair of lateral fixation elements94are shown, any suitable number of fixation elements88can be driven through the respective fixation holes26of the intermediate section32ainto the patella60, with care taken so that the fixation elements88inserted through the intermediate section32ado not interfere with insertion of other fixation elements88to be inserted through other locations of the bone plate20and into the patella. The lateral fixation elements94can be inserted into different ones of the first and second rows34aand34b, or can be inserted into the same row as desired. For instance, the at least one lateral fixation element94can be driven through a bone fixation hole26defined by the middle segment37cof the first row34a. Alternatively or additionally, the at least one lateral fixation element94can be driven through a bone fixation hole26defined by the middle segment38bof the second row34b. The lateral fixation elements94can, for instance, be driven in the medial direction into the superior and inferior poles of the patella60to seat the plate20against the patella60. It should also be appreciated that the bicortical fixation of the plate20to the patella60in the lateral-to-medial direction can be multiplanar.

Referring now toFIGS.4C-4Hgenerally, after initial fixation of the plate20to the patella60, the contour of the plate20with respect to the patella60can be inspected, and additional contouring of at least one or more up to all of the first and second outer sections32band32cof the base, and the first and second columns42aand42bcan be performed. Advantageously, the plate20can achieve the fixation described herein without overlapping the articular surface of the patella. The contouring of the first and second columns42aand42bcan also achieve a low profile of the plate20on the anterior surface86of the patella60.

Referring toFIGS.1A-2C and4C-4D, at least one second or superior fixation element96can be driven through the plate20and into the patella60in the distal (or superior-to-inferior) direction so as to thereby fix a superior end of the plate20to the patella60. In particular, the at least one superior fixation element96can be driven through a respective at least one of the bone fixation holes26of the first outer section32bof the base32and into a bony surface of the patella60at the superior or proximal end of the patella60. For example, the at least one superior fixation element96can be driven through the peripheral rim78of the patella60at the superior pole of the patella60. Because the first outer section32bof the base32is disposed posterior of the quadriceps tendon, the at least one superior fixation element96can likewise be driven through the plate20and into the patella60at a location posterior of the quadriceps tendon. Thus, it can be said that the at least one superior fixation element96can be driven through an extension of the bone plate20that is disposed against a bony surface of the superior patella at a location posterior of the quadriceps tendon. The at least one fixation hole26that receives the at least one superior fixation element96can be an inferior-most hole26of the bone plate20, though it should be appreciated that any fixation hole26of the plate20aligned with the superior end of the patella60can be used.

In one example the at least one superior bone fixation element96can be driven through a bone fixation hole26defined by the first longitudinal end37aof the first row34a. Alternatively or additionally, the at least one superior bone fixation element96can be driven through a bone fixation hole26defined by the first longitudinal end38aof the second row34b.

The at least one superior fixation element96can be configured as a bicortical compression screw, though as described above one or more up to all of the at least one superior fixation element96can be configured as any suitable alternative type of fixation element described above. For instance, the at least one superior fixation element96can be configured as a unicortical compression screw. In one example, the at least one superior fixation element96can be driven through one of the fixation holes26of the first outer section32band at least into the superior aspect of the rim78. The threaded shaft92can threadedly purchase with cortical bone at the superior end of the patella. Further, the at least one superior fixation element96can be driven into the reduced patella60until the threaded shaft92extends across the patella60and can threadedly purchase in cortical bone at the inferior end of the patella60.

Alternatively, if the at least one superior fixation element96is a unicortical screw, the shaft92threadedly purchases with the cortical wall at the superior end of the patella60, but does not extend across the patella60a sufficient distance so as to threadedly purchase with the cortical wall at the inferior end of the patella60. It is recognized that the superior end of the patella60has dense bone that can be suitable for reliable threaded purchase by the at least one superior fixation element96, and thus the superior fixation element96can be a unicortical fixation element.

Because the at least one superior fixation element96can be a compression screw, the head90of the at least one superior fixation element96can compress the plate20against the superior end of the patella60at a location posterior of the quadriceps tendon. Any number of superior fixation elements96can be driven through respective fixation holes26of the plate20and into the patella60so as to provide fixation of the plate20to the patella as desired. For instance, the fixation of the plate20to the superior end of the patella60can occur along more than one plane, thereby enhancing fixation.

Referring now toFIGS.1A-2C and4E-4F, at least one third or inferior fixation element98can be driven through the plate20and into the patella60in the proximal (or inferior-to-superior) direction so as to thereby fix an inferior end of the plate20to the patella60. In particular, the at least one inferior fixation element98can be driven through a respective at least one of the bone fixation holes26of the second outer section32cof the base32and into a bony surface of the patella60at the inferior or distal end of the patella60. For example, the at least one inferior fixation element98can be driven through the peripheral rim78of the patella60at the inferior pole of the patella60. In particular, the at least one inferior fixation element98can be driven into the non-articulating inferior pole of the patella60. Because the second outer section32cof the base32is disposed posterior of the patellar tendon, the at least one inferior fixation element98can likewise be driven through the plate20and into the patella60at a location posterior of the patellar tendon. Thus, it can be said that the at least one inferior fixation element98can be driven through an extension of the bone plate20that is disposed against a bony surface of the inferior end of the patella60at a location posterior of the patellar tendon. The at least one fixation hole26that receives the at least one inferior fixation element98can be an inferior-most hole26of the bone plate20, though it should be appreciated that any fixation hole26of the plate20aligned with the inferior end of the patella60can be used

In one example the at least one inferior bone fixation element98can be driven through a bone fixation hole26defined by the second longitudinal end37bof the first row34a. Alternatively or additionally, the at least one superior bone fixation element98can be driven through a bone fixation hole26defined by a second longitudinal end of the second row34bin examples where the second row34bincludes a second longitudinal end.

It should be appreciated that the at least one second or superior fixation element96can be driven antegrade through the plate20in the distal direction, and the at least one third or inferior fixation element98can be driven retrograde through the plate20in the proximal direction, thereby provide interfragmentary compression across the fracture fragments of the patella60and correspondingly achieving stability of the fracture.

The present disclosure recognizes that the inferior pole of the patella60can be more osteoporotic than the superior pole of the patella60. Further, the fracture of the patella at the inferior pole can be more comminuted than at the superior pole. Accordingly, the at least one inferior fixation element98can be configured as a locking screw. Further, the at least one inferior fixation element98can be configured as a bicortical screw. It should be appreciated, however, as described above that one or more up to all of the at least one inferior fixation element98can be configured as any suitable alternative type of fixation element described above. In one example, the at least one inferior fixation element98can be driven through one of the fixation holes26of the second outer section32band at least into the inferior pole of the patella60. The threaded shaft92can threadedly purchase with cortical bone at the inferior pole. Further, the at least one inferior fixation element98can be driven into the reduced patella60until the threaded shaft92extends across the patella60and can threadedly purchase in cortical bone at the superior end of the patella60. As described above, the cortical bone at the superior end of the patella60is often more dense and strong than the cortical bone at the inferior end of the patella60. Accordingly, because the at least one inferior fixation element98can be bicortical, the at least one inferior fixation element98can reliably threadedly purchase with strong dense bone.

Because the at least one inferior fixation element98can be a locking screw, the head90of the at least one inferior fixation element98can threadedly mate with the plate20inside the fixation hole26. Thus, the fixation holes26at the second outer section32cof the base32can be configured as internally threaded locking holes. Because the at least one inferior fixation element98can be configured as a locking screw, the head90does not compress the plate against the patella60when the at least one inferior fixation element98is fully seated in the bone plate20and bicortically secured to the patella60. Any number of inferior fixation elements98can be driven through respective fixation holes26of the plate20and into the patella60so as to provide fixation of the plate20to the patella60as desired. For instance, the fixation of the plate20to the inferior end of the patella60can occur along more than one plane, thereby enhancing fixation.

Referring now toFIGS.1A-2C and4G-4H, at least one fourth or anterior fixation element100can be driven posteriorly through an anterior portion of the plate20into the anterior wall of the patella60that is opposite the articular surface66. The anterior wall defines the anterior surface86. As described above, the anterior portion of the plate20can be defined by the outer portion40. Thus, the at least one anterior fixation element100can be driven through a respective at least one fixation hole of the outer portion40of the bone plate20so as to fix the plate20to the anterior surface86of the patella60. In particular, the at least one anterior fixation element100can be driven through a respective at least one hole of the first column42a, the second column42b, or each of the first and second columns42aand42b. As described above, the anterior, superior, and inferior fixation elements can achieve multiplanar fixation of the bone plate20to the patella60. Fixation of the anterior portion of the plate20to the patella60provides an additional plane of fixation so as to further stabilize comminuted patella fractures, and to allow for fixation in the anteroposterior direction.

The at least one anterior fixation element100can be configured as a locking screw or a compression screw. Accordingly, the anterior fixation element100is driven posteriorly through the fixation holes26of the anterior portion of the plate20until fully seated in the plate20. If the anterior fixation element100is a compression screw, then the head90of the anterior fixation element100can compress the plate20against the anterior surface86of the patella60. Alternatively, if the anterior fixation element100is a locking screw, then the head90of the anterior fixation element100can threadedly purchase with a threaded locking hole26of the plate20at the anterior portion of the plate20.

Further, the at least one anterior fixation element100can be configured as a unicortical screw. Accordingly, when the at least one anterior fixation element100is fully seated in the respective at least one fixation hole26, the shaft92terminates anterior of the cortical bone at the anterior wall of the patella60. As a result, the shaft92can be configured so as to not interfere with the continuity of the articular surface66. Direct visualization of the articular surface achieved by the angulation of the patella60, as well as anteroposterior and lateral fluoroscopy, can be used to ensure that at least one anterior fixation element100has not violated the articular surface66. It is recognized that the at least one anterior fixation element100can include a single anterior fixation element100that is fixed to the plate20and the patella60through a respective fixation hole26, or a plurality of anterior fixation elements100fixed to the plate20and the patella60through a respective plurality of fixation holes26. For instance a first one of the plurality of anterior fixation elements100can be driven through the first column42a, and a second one of the plurality of anterior fixation elements100can be driven through the second column42b. In one example, a first one of the plurality of anterior fixation elements100can be driven through the second lateral end46bof the first column42a. A second one of the plurality of anterior fixation elements100can be driven through the second lateral end48bof the second column42b.

While the at least one superior fixation element96is described as being driven through the plate20and into the patella60prior to driving the at least one inferior fixation element98through the plate20and into the patella60, and the at least one inferior fixation element98is described as being driven through the plate20and into the patella60prior to driving the at least one anterior fixation element100through the plate20and into the patella60, fixation of the plate20to the patella60can occur in any order as desired. For instance, the at least one inferior fixation element98can be driven through the plate20and into the patella60prior to driving the at least one superior fixation element96through the plate20and into the patella60. It should be appreciated that the steps of fixing the plate20to the patella60allows fixation of each fragment of the patella60, for instance in situations where large pieces of articular comminution exist.

Referring now toFIGS.1A-2C and5, it is recognized that the inferior pole76of the patella60can often be comminuted, and can contain osteoporotic bone. In fact, inferior pole comminution has been observed in 88% of fractures of the patella60. Accordingly, fixation of the bone plate20to the patella60can be augmented by suture fixation. The method of fixation can further include the step of augmenting fixation of the plate20to the patella60by fixing at least one suture to the patellar tendon72and to the plate20. In one example, the sutures can be configured as FiberWire® sutures commercially available from Arthrex, having a place of business in Naples, Fla., though it should be appreciated that any suitable suture is envisioned. Thus, the method can include the step of attaching one or more sutures102to the patellar tendon72. The sutures102can thus be included in the fixation system. In one example, the sutures102can be passed beneath the anterior portion of the plate20, between the plate20and the patella60, and medially and laterally through the patellar tendon72in a Krackow configuration. The free end of the suture102can then be passed over the plate in the inferior direction, and tied to the plate20. For instance, the sutures102can be tied to at least one of the links30of the bone plate20. In one example, the sutures102can be passed through the fixation holes26of the anterior portion of the plate20and subsequently tied to the plate20. The fixation holes26can be defined by the second column42b. Thus, the suture102can further anchor the bone plate20to the patellar tendon72, which enhances the stability of the bone plate20at the inferior pole76. It is thus appreciated that the suture102can augmenting

It is desirable for the knee to be in extension during the suture fixation. The retinacular tears can be repaired with any suitable suture in a figure-eight pattern. The suture used for repairing retinacular tears can, for example, be a #2 Ethibond® suture commercially available from Ethicon, having a place of business in Somerville, NY, or #2 Fiberwire® sutures.

It should be noted that the illustrations and discussions of the embodiments shown in the figures are for exemplary purposes only, and should not be construed limiting the disclosure. One skilled in the art will appreciate that the present disclosure contemplates various embodiments. Additionally, it should be understood that the concepts described above with the above-described embodiments may be employed alone or in combination with any of the other embodiments described above. It should further be appreciated that the various alternative embodiments described above with respect to one illustrated embodiment can apply to all embodiments as described herein, unless otherwise indicated.