Reconstruction of the medial patellofemoral ligament for patellar instability using a semitendinosus autograft.

Between 1999 and 2001 thirty knees underwent a semitendinosus tendon plasty to recreate the medial patellofemoral ligament for recurrent patellar dislocation. The mean follow-up was 38 months. The mean improvement of the patellofemoral congruence angle after surgery was 14 +/- 7 degrees. All patients ended up with a full range of motion, except one patient, whose flexion was limited to 120 degrees due to superficial wound infections. Dislocation did not recur. According to the Larsen and Lauridsen outcome score the clinical results were excellent in 27 patients, good in 2 and fair in one. In conclusion this procedure is indicated for the chronic dislocation and cases of severe femoral dysplasia with marked laxity. The procedure assures the stabilisation of the patella, although it doesn't restore the patellofemoral congruence angle to normal values.