Radiographic abnormalities and clinical symptoms associated with patella alta in ambulatory children with cerebral palsy.

One hundred seventeen randomly selected, skeletally immature, ambulatory children with spastic cerebral palsy were evaluated with clinical examination and lateral radiographs of the knee. Radiographic abnormalities within either the patella or the proximal tibia were present in 21% (41 knees) of the 193 affected knees. The most common radiographic findings were elevation of the tibial tubercle in 34 knees and fragmentation of one pole of the patella in seven knees. Clinical symptoms including pain, swelling, and tenderness were present in 32% of those children with radiographic findings (13 of 41 knees). Patella alta was seen in nearly all children in the study. The radiographic findings appeared to be chronic, were usually asymptomatic, and have required no treatment to date.