Femoral fracture through a previous pin site after computer-assisted total knee arthroplasty

Computer-assisted total knee arthroplasty has been gaining popularity given the proposed benefits of increased accuracy of the femoral and tibial cuts, quantitative feedback on soft tissue balancing, and the potential for performing the procedure through smaller incisions with decreased soft tissue trauma. Most navigation systems require femoral and tibial threaded pin insertion for placement of guidance trackers, which when removed leave behind defects in the bone that may act as stress risers. We present 2 cases of a femoral fracture through a previous pin site where a guidance tracker had been placed for computer-assisted total knee arthroplasty. Both patients were informed that data concerning the cases would be submitted for publication. To our knowledge, this complication has not previously been reported for this procedure.