1. Field of the Invention
The present invention relates to a bone fixation system. More particularly, the present invention relates to a bone peg utilized to provide stable, accurate, and repeatable fixation with a bone fixation device.
2. Description of the Related Art
Conventional methods used to fixate a patient's anatomy, for example, a bone, and prevent movement thereof during a surgical procedure typically involve screws driven directly into the bone. These screws may be used to secure a bone fixation device to the bone. The screws used in such a manner typically extend into the cancellous portion of the bone. The bone fixation device is then secured to an operating table or other fixed structure in the operating room to provide a stable fixation construct which prevents movement of the bone during the procedure.
The present invention provides a bone peg which provides stable, accurate, and repeatable fixation with a bone fixation device to provide a system of fixation between a patient's anatomy, for example, a bone, and the bone fixation device. The fixation system advantageously prevents the bone from moving during a surgical procedure.
In one form thereof, the present invention provides a bone fixation system including a bone peg for implantation in a bone including an anchor portion, the anchor portion including a cannulated portion; and a head portion, the head portion including an aperture generally aligned with the cannulated portion; and a surgical instrument, the surgical instrument releasably engageable with the cannulated portion and with a support structure.
In another form thereof, the present invention provides a bone fixation system for fixating a bone including a bone fixation device; and fixation means for accurately coupling, decoupling, and recoupling the bone fixation device to the bone.
In yet another form thereof, the present invention provides a method for securing a bone to a bone fixation device including the steps of providing a bone peg, the bone peg including an anchor portion, the anchor portion including a cannulated portion; and a head portion, the head portion including an aperture generally aligned with the cannulated portion; implanting the bone peg in the bone; and releasably coupling the bone fixation device and the bone peg.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
The present invention generally provides a bone peg which is inserted or implanted in a patient's anatomy, for example, a bone. The bone peg provides stable, accurate, rigid, and repeatable fixation to a bone fixation device which fixates the bone relative to an operating table or other structure used in a surgical procedure. Advantageously, the bone fixation device may be coupled to the bone peg to permit fixation of the bone relative to the operating table. Furthermore, the bone peg also permits repeatable decoupling and recoupling of the bone fixation device to the bone peg throughout the surgical procedure without increasing the risk of potential damage to the bone, thereby removing the potential for decreased accuracy of the surgical procedure.
Referring now to
Referring now to
In an alternative embodiment, bone peg 20 has no threads and may include a spike at a distal end thereof, similar to that shown in
In an alternative embodiment, bone peg 20 has no threads and may include a substantially smooth exterior portion which engages with a pre-drilled hole in tibia bone 36 via an interference fit.
In yet another alternative embodiment, bone peg 20 has no threads and, upon engagement with a fixation instrument, for example, bone peg insertion device 38 or a fixation dowel or element of bone fixation device 32, is radially expanded to be secured in a pre-drilled hole in tibia bone 36. In this embodiment, bone peg 20 may include a radially expandable fixation portion. Several examples of radially expandable fixation devices are described in U.S. patent application Ser. No. 11/243,789, titled EXPANDABLE FIXATION DEVICES FOR MINIMALLY INVASIVE SURGERY, published on Mar. 9, 2006 as U.S. Patent Application Publication No. 2006/0052788, assigned to the assignee of the present application, the disclosure of which is expressly incorporated herein by reference.
Referring now to
Referring now to
Head engaging portion 42 includes bottom surface 43 which, when insertion device 38 is fully inserted into bone peg 20, abuts impaction surface 29 of aperture 28 to facilitate transfer of force from the rotation-imparting or impaction tool to bone peg 20. Furthermore, the abutting of bottom surface 43 and impaction surface 29 facilitates increased accuracy when decoupling and recoupling bone peg insertion device 38 and bone peg 20 because the surface abutment provides a repeatable landmark to the surgeon to facilitate returning bone fixation device 32 to the same location every time bone fixation device 32 is coupled to bone peg 20.
Bone peg 20 may be formed of any biocompatible material. In one embodiment, bone peg 20 may be made out of a bioresorbable material, thereby allowing bone peg 20 to be left in the body after the surgical procedure is completed. Alternatively, bone peg 20 could be made of a polymeric or metallic material. In a further alternative embodiment, bone peg 20 may be made of a radiopaque material which may facilitate determining relative implant position over time.
In operation and referring to
Bone peg 20 may include a securement mechanism to secure the fixation dowel or bone peg insertion device 38 to bone peg 20. In one embodiment, the fixation dowel and/or bone peg insertion device 38 may include threads which engage a threaded cannulated portion 26 to provide fixation between bone fixation device 32 and bone peg 20. In yet another embodiment, the fixation dowel and/or bone peg insertion device 38 may include a groove configured to mate with a keyway provided in cannulated portion 26 to provide fixation between bone fixation device 32 and bone peg 20. In still another embodiment, the fixation dowel and/or bone peg insertion device 38 may include a retractable protrusion which mates with a groove or recess located within cannulated portion 26, e.g., a snap-fit engagement, to provide fixation between bone fixation device 32 and bone peg 20. In any of the embodiments described above for the securement mechanism, bone peg insertion device 38 may be formed without head engaging portion 42.
Advantageously, bone fixation device 32 is readily releasably coupled to bone peg 20 to provide stable fixation of tibia bone 36 relative to operating table 33. The readily releasable coupling permits bone fixation device 32 to be decoupled from tibia bone 36 without requiring removal of bone peg 20 from tibia bone 36 and without requiring substantial effort to decouple bone fixation device 32 from bone peg 20. Bone peg 20 provides a repeatable and accurate landmark where fixation between bone fixation device 32 and tibia bone 36 may repeatedly occur. Advantageously, eliminating the removal of bone peg 20 every time that bone fixation device 32 is decoupled from tibia bone 36 prevents potential damage to the cancellous portion of tibia bone 36 due to the repeated engagement of threads 50 with the cancellous bone. Moreover, bone peg 20 provides a repeatable and stable fixation location to facilitate better fixation and greater accuracy in repeatedly fixing tibia bone 36 relative to operating table 33. During a surgical procedure, a surgeon may advantageously decouple and recouple bone fixation device 32 with bone peg 20 in a predictable manner.
In an alternative embodiment, a plurality of bone pegs 20 may be used in an external fixation system. For example, two bone pegs 20 may be positioned in a bone, or multiple bones, at two separate locations and then connected with a rod or other connection device for use in a trauma application, for example.
While this invention has been described as having exemplary designs, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.