Instability of the patellofemoral joint in Rubinstein-Taybi syndrome.

Twenty-five (3.4%) of 732 individuals with Rubinstein-Taybi syndrome were noted to have instability of the patellofemoral joint. We believe that this is in fact an underrepresentation of the true incidence, as we were able to identify only those patients whose symptoms were most severe. These individuals typically had symptoms before or during their adolescent growth spurt, had bilateral involvement, and in some instances, ceased to ambulate because of their patellofemoral problems. A subset of these individuals underwent patellar realignment surgery, with those whose treatment did not include extensive quadriceps mobilization/quadricepsplasty having a 2.7 times higher risk of requiring revision patellar surgery. Patellofemoral instability associated with Rubinstein-Taybi syndrome demands early recognition and treatment to prevent potentially catastrophic gait disturbances.