Fragmentation of the distal pole of the patella in spastic cerebral palsy.

Of eighty-five consecutive patients, thirteen to twenty years old, with spastic cerebral palsy involving one or both extremities (thirty-five patients seen at one institution and fifty, at another), four had roentgenographic evidence of fragmentation of the distal pole of the patella. In addition, three other patients with six spastic lower extremities, four of them with patellar fragmentation, were also included. In these seven patients, there were nine knees with patellar fragmentation, twelve knees with patella alta, nine with a flexion contracture, five that were painful, and four with changes in the tibial tubercle resembling those found in Osgood-Schlatter disease. Excessive tension in the quadriceps mechanism, usually in the presence of a flexion contracture, appeared to cause the lesions. Four of the fragmented patellae healed after hamstring release and correction of the flexion deformity.