Complications of extensor mechanism surgery for patellar malalignment.

This review focuses on the complications of extensor mechanism surgery for symptomatic patellar malalignment and ways to avoid those complications. We combined a review of new and referred patients who had complications resulting from extensor mechanism surgery with a review of selected literature specifically addressing similar complications. By studying the pathologic anatomy at the time of arthrotomy, it was possible in many cases to determine the causes of adverse outcomes with this type of surgery. The complications of extensor mechanism surgery can be avoided by performing a thorough preoperative evaluation, determining each component of the malalignment, tailoring the procedure to correct each patient's unique pathomechanics, and respecting the functional anatomy of the extensor mechanism.