Case report: Patella baja after retrograde femoral nail insertion.

Patella baja is a rare condition that can result from conditions involving trauma around the knee. Risk factors are believed to include scar tissue formation in the retropatellar fat pad, extensor mechanism dysfunction, and immobilization in extension. Early recognition and aggressive treatment are critical components in minimizing long-term disability. We present a case report of a woman with a fracture of the femoral diaphysis who underwent retrograde placement of an intramedullary nail. Subsequent followup revealed development of patella baja with resultant disability. The diagnosis was made late and the treatment was ineffective. Although patella baja has been reported in trauma around the knee, causative factors include retrograde femoral nailing. We believe early recognition and institution of treatment are important.