Patellectomy: a clinical study and biomechanical evaluation.

This study presents a long-term follow-up and evaluation of a single technique of patellectomy involving a cruciform repair of the extensor mechanism. The techniques of evaluation, namely: clinical observation, instant center analysis and an acoustical method of cartilage evaluation provide a more thorough and objective basis for clinical study than previously reported. Cruciform repair produced results comparable to conventional methods of surgical repairs. Patellectomized knees function well in people with patellofemoral disease but not in those with panarticular disease. Patellectomy substantially alters normal joint mechanics as evidenced by persistent changes in instant center analysis. Degenerative changes caused by the patellectomy are progressive. In view of newer concepts of the function of the patella in normal joint mechanics and improved designs of total knee arthroplasty, the indications for patellectomy are now more questionable than ever before in the history of orthopedics.