Miyakawa patellectomy.

A Miyakawa patellectomy was done in seventeen patients (twenty knees) for either osteoarthritis or chondromalacia of the patella, or both, secondary to malfunction of the extensor mechanism. Patients who had had a patellar fracture were not included in the series. The Miyakawa patellectomy realigns the extensor mechanism, with the proper tension, and centers the functional pull of the quadriceps tendon and patellar ligament. A superficial strip of the quadriceps tendon is pulled distally to fill the void that was left by removal of the patella and to maintain proper length. The musculotendinous portions of the vastus lateralis and vastus medialis are advanced over this defect in the midline and are sutured to the quadriceps tendon. The average length of follow-up was 13.8 years (range, 3.6 to 31.7 years). Nineteen of the twenty knees had a good or excellent subjective result and eighteen had a good or excellent objective result. No subsequent surgical treatment was needed for problems that were caused by malfunction of the extensor mechanism of the knee.