Patellofemoral dysplasia in infantile cerebral palsy.
The authors have studied the biomechanical basis of functional alterations in the extensor apparatus of the knee in cases of infantile cerebral palsy. Several interesting aspects of the problem, some of which are controversial, have emerged from this study and from a review of patients with flexion contracture of the knee treated surgically: 1. The neurological pathology of the motor system leads to problems of posture and dysplastic conditions of the hip (coxa valgus, etc.) which favour the development of patellofemoral pathology. 2. By contrast, the early clinical manifestations of this pathology are relatively insignificant and completely overshadowed by the major problems of adaptation and compensation imposed by the more serious overall disabilities which face the patient in order to stand and walk. The knee plays a prevalently static role at this stage and is not particularly stressed during joint movement. 3. The clinical manifestations of patellofemoral pathology are thus paradoxically brought into focus by surgery on the flexor apparatus to deal with contracture. Although on the one hand this improves function, on the other it brings to light the more complex functional mechanisms of the knee, thus emphasizing any deficit in the extensor apparatus.