Trochleoplasty in dysplastic knee trochlea.

In patients complaining of recurrent patellar dislocations or persistent retropatellar pain due to a dysplastic femoral trochlea, we perform a Henri Dejour trochleoplasty. In this technique the femoral trochlea is deepened by removing the subchondral trochlear bone followed by incision, impaction and fixation of the cartilage flange along the trochlear groove. Between 1996 and 1999, 13 procedures were performed in 12 patients. Strictly lateral X-rays showed dysplasia of the trochlea, as defined by the "crossing sign", whether or not in combination with patella alta. Patients were assessed using the Larsen-Lauridsen score considering pain, stiffness, osteopatellar crepitus, flexion and loss of function. Although the majority of patients scored fair and poor on an objective scoring system, we achieved 77% good to very good subjective results. Although the result was not perfect, the patients were satisfied with the procedure. This technique might be a valuable alternative in cases of frank trochlear dysplasia associated with persistent retropatellar pain or recurrent patellar dislocations.