Bone fixation plate with complex suture anchor locations

[0001] This application claims the benefit of U.S. Ser. No. 60/718,356, filed Sep. 19, 2005, which is hereby incorporated by reference herein.

[0002] 1. Field of the Invention

[0003] This invention relates broadly to surgical devices. More particularly, this invention relates to orthopedic bone plates, particularly for fracture fixation, which include suture holes.

[0004] 2. State of the Art

[0005] The proximal humerus comprises the upper portion of the humerus, i.e. upper arm of the human body, and forms a portion of the shoulder joint. Fractures of the proximal humerus typically result from traumatic injuries such as sporting accidents and can be more frequent with age due to bone loss. Fractures of the proximal humerus are treated by exposing the fracture site and reducing the bone fracture and then placing a plate onto the bone to fixate the fracture for healing in the reduced position. Reducing the fracture includes realigning and positioning the fractured portions of the bone to their original position or similar stable position. Fixating the fracture includes positioning a plate over the fractured portions and securing the plate onto the fractured bones and adjacent non-fractured bones with bone screws. Commonly, after a fracture there exist disassociated tuberosities at the proximal portion of the humerus. Tuberosities are pieces of bone with tendons attached. The bone is weak but the insertion points of the tendons are very strong. The accepted way to reattach the bone for healing is to use suture material to stitch into the insertion point of the tendon and pull down to anchor the bone with the suture.

[0006] Humeral plates often include suture holes at which suture material, e.g., braided cord or wire suture, can secure the tuberosities to the plate. The suture holes are generally circular holes extending transverse to the longitudinal axis of the plate. For example, the Philos™ plate by Synthes includes multiple suture holes displaced around the plate which extend between the bone contacting and lower plate surfaces. Because one opening of each suture hole is even with the bone contacting surface, access to or egress from the holes with a suture needle is impeded. In addition, U.S. Pat. No. 6,468,278 to Mückter describes a narrow humeral plate having only two suture holes which extend parallel to the bone contacting and upper surfaces. One hole is located at the proximal end of the plate and the other holes is located substantially distal. Given the orientation and location of the holes, the holes present limited approaches for tissue attachment. U.S. Pub. No. 20050182405 A1 to Orbay describes several humeral plates having individual suture holes arranged about the proximal end of the plate in a manner which permits easy access to the holes. However, the arrangement of holes causes the proximal head portion of the plate to be rather elongate. It is desirable to reduce the extension of the head portion as much as possible to prevent any impingement of the plate against the acromium.

[0007] A fracture fixation system includes a plate having head and shaft portions, wherein the head portion has two suture anchor locations occupying a relatively small space on the plate. A first suture anchor location has an opening at the upper surface of the plate, an opening at the proximal end of the plate, and an opening at the anterior side of the plate and defines first and second suture paths which cross within the plate. Moreover, the first and second suture paths include a common opening. A second suture anchor location has an opening at the upper surface of the plate, an opening at the proximal end of the plate, and an opening at the posterior side of the plate which defines third and fourth suture paths which cross within the plate. The third and fourth suture paths also share a common opening. Thus, each suture anchor location is capable of providing a hold for suture from multiple approaches to secure tuberosities relative to the plate.

[0008] Similar suture anchor holes may be provided on plates for fixation of other bones. Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.

[0016] Turning now to FIGS. 1 and 2, a humeral fracture fixation plate 10 includes a head portion 16 and shaft portion 18. The head portion 16 of plate includes a central alignment hole 30 for closely receiving a K-wire (not shown), and may also include other alignment holes such as distal alignment hole 34, to hold K-wires at a fixed angle to facilitate alignment of the plate 10 relative to the humerus, as described in detail in co-pending U.S. Ser. Nos. 11/040,732, filed Jan. 21, 2005, and 11/134,247, filed May 20, 2005.

[0017] The head portion 16 of the plate is provided with a plurality of threaded holes 40a-f. The threaded holes 40a-f have defined axes. More particularly, proximal and distal threaded holes 40a, 40b have axes which are in the same plane and converge toward a point substantially defined by central alignment hole 30. The axes of holes 40a, 40b are directed substantially perpendicular to the central portion of the articular surface of the humeral head. Axes through holes 40c, 40d are directed substantially perpendicular to the upper portion of the articular surface, but diverge to provide support. Axes through holes 40e, 40f are directed substantially perpendicular to the lower portion of the articular surface, and also diverge to provide support; however the divergence angle between the axes through 40e, 40f is smaller than between the axes of 40c, 40d. In addition, the axes through 40e, 40f are also angled relatively further away from the ‘centerline’ defined by alignment hole 30, placing the axes therethrough, and thus any pegs therethrough, close to the lowermost part of the articular surface, but orienting such pegs to provide support to prevent the humeral head from going into varus (i.e., in which the lower pegs could protrude through the cortex). Thus, there is an optimal asymmetry to the orientation of the axes (and pegs inserted therethrough).

[0018] Suture anchor locations 50, 52 are provided at the metaphyseal end of the head portion of the plate. For the humeral plate 10, locations 50, 52 are at the proximal anterior and posterior locations of the head portion 16 of the plate.

[0019] Referring to FIGS. 1 through 6, a first suture anchor location 50 includes an opening 54a at the upper surface of the plate, an opening 54b at the anterior side of the plate, and an opening 54c at the proximal end of the plate. A curved suture needle and suture can be passed between openings 54a and 54c along a pathway or path A₁. In an exemplar embodiment, Path A₁ has a diameter of approximately 0.08 inch. Path A₁ defines an axis angled in rotation approximately −9° relative to the straight anterior side 58 of the plate, and angled in inclination approximately 38°. Path A₁ (and all suture paths described herein) is of sufficient diameter and sufficiently short to permit a curved needle of an approximately 6.5 mm radius to be passed therethrough. It is understood that needles of other dimensions and radiuses will also pass through the defined paths, but that the 6.5 mm radiused needle referenced is a standard sized needle used in tendon repair at the proximal humerus. A curved suture needle can also be passed between openings 54b and 54c along a path A₂, which has a diameter of approximately 0.08 inch and defines an axis angled in rotation approximately 38° relative to anterior side 58 of the plate and angled in inclination approximately −3°. Even as paths A₁ and A₂ are obliquely angled relative to each other in two dimensions, the paths are in communication within the plate. Opening 54c serves as a common exit (or entrance) to both of openings 54a and 54b, such that within the plate paths A₁ and A₂ define a forked pathway relative to opening 54c. It is noted that corner 60 provides a boundary to both paths A₁ and A₂ which is shorter than the opposite wall of the respective paths. This facilitates insertion of the curved suture needle therethrough. As shown with respect to FIGS. 4 through 6, the paths A₁ and A₂ have a smaller diameter than holes 40a-f.

[0020] A second suture anchor location 52 has an opening 56a at the upper surface of the plate, an opening 56b at the posterior side of the plate, and an opening 56c at the proximal end of the plate. The curved suture needle and suture can be passed between openings 56a and 56c along a path A₃. Path A₃ has a diameter of approximately 0.08 inch and defines an axis angled in rotation approximately 4° relative to the anterior side 58 of the plate and angled in inclination approximately 39°. The curved suture needle can also be passed between openings 56b and 56c along a path A₄, which has a diameter of approximately 0.08 inch and defines an axis angled approximately −38° in rotation relative to anterior side 58 of the plate and angled approximately −7° in inclination. Even as paths A₃ and A₄ are obliquely angled relative to each other in two dimensions, the paths are in communication within the plate. Opening 56c serves as a common exit (or entrance) to both of openings 56a and 56b, such that within the plate paths A₃ and A₄ are forked relative to opening 56c. It is noted that corner 62 provides a boundary to both paths A₃ and A₄ which is shorter than the opposite wall of the respective paths. This facilitates insertion of the curved suture needle therethrough.

[0021] All of the openings 54a-c, 56a-c about which suture will be tied have rounded edges to prevent cutting or otherwise damaging the suture when the suture is under tension; e.g. the edges have a radius of 0.012-0.040 inch. Recesses 64, 66 are provided on the top of the plate between openings 54a and 56a on either side of peg hole 40a for receiving exposed suture materials in a low profile manner; i.e., recessed below the upper surface of the plate.

[0022] The shaft portion 18 of the plate includes a plurality of screw holes 70, 72. Screw holes (and associated screws) may be of the non-threaded locking-type (as per screw hole 70, may be non-locking (as per screw hole 72), or may be threaded locking (e.g., similar to the type hole shown for the peg holes).

[0023] Referring to FIG. 7, in accord with one method of using the system of the invention shown with respect to a left arm humerus and respective humeral plate, a delto-pectoral approach is developed to expose and debride the fracture. Traction and direct manipulation are then used to reduce the fracture. The anatomical relationship between the articular surface 78 of the humeral head 80 and the humeral shaft 82 are reestablished by restoring both angular alignment and rotation. Tuberosities (insertion points of supraspinitus 84, subscapularus 86 and infraspinitus 88 tendons) are examined for assurance that they can be reduced to their proper position.

[0024] The position of the plate 10 is then located, preferably immediately lateral to the intertubercle groove and approximately 2.5 cm below the insertion of the supraspinatus 84. The plate is secured to the distal fragment using a cortical screw 90 inserted through the non-locking oblong screw hole 72 or via a plate-holding clamp. The reduction is then locked using a K-wire (e.g., 2.0 mm) (not shown) inserted through the central fixed angle k-wire hole 30 on the head portion 16 of the plate 10 and into the proximal fragment(s) of the humeral head. The K-wire fixes the fracture and anticipates the final position of the pegs. The reduced fracture, plate location and K-wire are then evaluated using fluoroscopy (preferably both AP and axillary views) and readjusted as necessary.

[0025] Holes are then drilled through the peg holes 40a-f (FIG. 2) in alignment with their respective axes. The holes are preferably drilled manually after penetrating the cortex under power. The appropriate length and type of pegs (smooth shaft and/or threaded shaft) are selected and inserted using a driver and secured to the fixation plate. The distal end of the pegs should be 3-6 mm below the subchondral bone.

[0026] After peg placement, radiographic confirmation of correct fracture reduction and peg placement is preferably obtained. Then using a drill bit, holes are drilled for the remaining cortical screws that will be used to fix the distal shaft portion 18 of the plate 10 to the shaft 82 of the humerus. Either multidirectional screws, e.g., of type 90, or fixed angle screws 92 can be used.

[0027] Then, as necessary, tuberosities are reduced and fixed to the plate at the suture anchor locations 50, 52 using suture material 94. The arrangement of the suture locations 50, 52 and the suture paths A₁, A₂, A₃, A₄ (FIGS. 3-4) is such that stitching the three main tuberosities of the proximal humerus (i.e., bone fragments and the insertion points of the respective supraspinitus, subscapularus and infraspinitus tendons) is facilitated. In accord with a preferred method, using suture paths A₁ and A₃, a stitch can be made to tie down the supraspinitus tendon, with the suture material knotted so that the knot 96 rests over peg hole 40a and/or recesses 64, 66. Using suture path A₂, a stitch can be made to tie down the subscapularis tendon 86. Using suture path A₄, a stitch can be made to tie down the infraspinitus tendon 88.

[0028] Finally, the surgical site is closed using appropriate surgical technique.

[0029] In addition, it is recognized that each of the suture anchor locations may define three paths, with an additional path, e.g. between 54a and 54b, and between 56a and 56b. That is, at one suture anchor location the additional path is inclined and extends from the upper surface to the anterior side of the plate and at the other suture anchor location the additional path is inclined and extends from the upper surface to the posterior side of the plate.

[0030] In addition to machining, any of the paths may be manufactured or refined using diamond wire to remove plate material and smooth edges of the plate surrounding the paths.

[0031] There have been described and illustrated herein embodiments of a humeral fracture fixation system and methods of implanting the fracture system on the humerus. While a particular embodiment of the invention has been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, the suture anchor system described can be applied to other orthopedic plates as well, particularly where such plates are intended to be used at or adjacent articulating surfaces where tuberosities may be present. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its scope as claimed.