Osteonecrosis and Resorption of the Patella After Total Knee Replacement

A 54-year-old woman with a history of right total knee replacement had right knee pain and swelling for 6 months. Radiographs of the knee showed significant fragmentation and resorption of the patella consistent with osteonecrosis. Evidence of increased anteroposterior laxity was noted on physical examination. Revision surgery to a posterior stabilized prosthesis with excision of the patellar fragments resulted in a marked improvement in her …