Recurrent dislocation of the patella treated by the modified Roux-Goldthwait procedure. A prospective study of forty-seven knees.

We studied the results in forty-seven knees in thirty-seven patients - ten male and twenty-seven female - who had recurrent dislocation of the patella and were treated by a modified Roux-Goldthwait procedure (lateral retinacular release, medial transfer of the lateral patellar tendon without advancement, plication of the medial retinaculum, and advancement of the vastus medialis). Ten of the female patients had bilateral dislocation. The results were analyzed after follow-ups ranging from 3.0 to 16.3 years (average, 5.8 years). The study confirmed that a tangential radiograph of the patellofemoral joint, made with the knee in 20 degrees of flexion, is reliable in determining patellar displacement. The results were excellent in twelve knees, good in thirty-one, fair in one, and poor in three. The fair and poor ratings were due to pain caused by severe chondromalacia patellae. The patient with a fair result had had recurrent dislocations after the Roux-Goldthwait procedure due to a very lax synovial and capsular sac. Reoperation with tightening of the sac medially and laterally eliminated hypermobility of the patella in this patient and established straight patellar tracking. There was one serious complication, a large subcutaneous hematoma with necrosis of a skin flap. The patients with mild chondromalacia improved and showed no progressive patellofemoral arthritis after simple realignment, while those with severe chondromalacia were not improved by shaving, drilling, and realignment. Preliminary results indicated that a modified Maquet procedure, in addition to realignment, may be indicated for patients with severe chondromalacia. This study demonstrated that the modified Roux-Goldthwait procedure, without advancement of the tibial attachment of the patellar ligament, can stabilize the patella without increasing patellofemoral compression. The procedure does not relieve the symptoms of severe chondromalacia of the patella but realignment is the first step in treatment of any form of patellofemoral arthrosis.