Periprosthetic fracture repair

#The use of fixation plates to treat periprosthetic fractures has been limited by the interference of a prosthetic within the medullary canal poses to the insertion of screws, pegs, nails or other fixation devices therethrough.

#The present invention is directed to a device for treating fractures, comprising a plate receiving structure including on a bone facing side thereof a recess sized and shaped to receive a fixation plate and a mating structure sized and located to engage a corresponding structure of the fixation plate to prevent relative movement between the fixation plate and the device in combination with one or more legs projecting laterally away from the recess, at least a first one of the legs including a fixation element receiving hole extending therethrough, the first leg being positioned and oriented so that, when the device is received on a fixation plate anchored to the bone, the fixation element receiving hole is aligned to pass a fixation element inserted therethrough into the bone without passing through a longitudinal axis of the medullary canal. Those skilled in the art will understand that medullary canals are generally neither straight nor concentric with the bone. Thus the axis of the medullary canal, as that term is used in this application, refers to a curve connecting points in the center of the medullary canal along the length of the bone.

#The present invention is further directed to a method for treating fractures, comprising coupling a first end of a longitudinal fixation device to a bone on a first side of a fracture so that the longitudinal fixation device extends along the bone substantially parallel to a longitudinal axis of the medullary canal and coupling a first lateral fixation device to a portion of the longitudinal fixation device extending over a portion of the bone on a second side of the fracture by mating the longitudinal fixation device within a recess of the first lateral fixation device in combination with coupling the first lateral fixation device to the bone by inserting a fixation element through a hole formed in a portion thereof separated from the longitudinal fixation device by a selected distance around a portion of a circumference of the bone.

#FIG. 1 is a side view of a fracture located on a distal end of a hip prosthesis;

#FIG. 2 is a side view of a fracture located distal to a hip prosthesis;

#FIG. 3 is a side view of a fracture located near to a knee prosthesis;

#The present invention may be further understood with reference to the following description and to the appended drawings, wherein like elements are referred to with the same reference numerals. The present invention relates to devices for treatment of fractures. In particular, the invention relates to improved methods and systems for repairing periprosthetic fractures. Although exemplary embodiments of the present invention will be discussed with reference to knee and hip prostheses, the present invention may be successfully implemented in any long bone including a prosthetic device inserted into its medullary canal. In addition, as would be understood by those skilled in the art, the present invention may be used for the treatment of fractures around nails and for “conventional” fractures in patients with poor bone quality. The present invention allows the user to apply standard fixation plates while placing screws and/or pins therethrough into the bone along paths selected to: 1) avoid any prosthesis in the medullary canal; 2) align the screws/pins non-parallel to one another to improve purchase in the bone; and/or 3) maximize the length of cancellous bone through which the screws/pins pass.

#Periprosthetic fractures may occur intraoperatively (during implantation or replacement of a prosthetic), or postoperatively (e.g., as a result of stress or trauma to the bone in which the prosthetic was previously implanted). As would be understood by those skilled in the art, fractures have been effectively treated by stabilizing the bone using fixation plates (e.g., dynamic compression plates (DCPs), locking compression plates (LCPs), etc.), which typically comprise a metal plate including a plurality of holes through which anchoring of screws or other fixation devices are inserted into underlying bone tissue. Periprosthetic fractures are more difficult to treat than ordinary fractures because a prosthesis extending within the medullary canal may interfere with the proper coupling of a fixation plate across the fracture by preventing the fixation devices from being inserted through the bone across the medullary canal. For example, hip prostheses may interfere with certain fractures of the femur. These hip prostheses often include a ball joint and a stem which is inserted into the medullary canal of the femur. As the femur absorbs significant stresses with each step, to adequately couple a fixation plate thereto, it is desired to maximize the purchase of the fixation devices in the femur.

#In determining a course of treatment, the needs of the patient must be considered. For example, an active 55 year old with a periprosthetic fracture will likely have functional demands different from those of a sedentary 85 year old. Important factors to consider include the location of the fracture, how well-fixed the prosthesis is, and the quality of the femoral bone stock. The Vancouver classification divides periprosthetic hip fractures into three categories: Type A fractures are trochanteric (i.e., disposed at or near the greater or lesser trochanters); Type B fractures occur around the stem of the prosthesis; and Type C fractures occur so far from the stem that the fracture may be treated as a general fracture (i.e., the prosthesis may be ignored). Of these fractures, Type B is the most common. As used in the following descriptions of exemplary embodiments of the invention, the term “distal” refers to a direction away from the end of the bone through which the prosthesis is inserted into the medullary canal. Thus, the distal end of a hip prosthesis is that which is located furthest from the pelvis and the proximal end is that which is nearest to the pelvis. FIG. 1 shows an example of a Type B fracture 50 located along a distal portion 110 of a hip prosthesis 100. As discussed above, the present invention may also be used to treat general fractures (e.g., Type C fractures). An example of a Type C fracture is shown in FIG. 2. In particular, FIG. 2 shows a fracture 52 located distal of the hip prosthetic 100. However, those skilled in the art will understand that the apparatus according to the present invention may also be used to treat Type A fractures as well as similar fractures of other bones. For example, FIG. 3 shows a treatable fracture 54 located near a knee prosthetic 130.