[Patella alta in cerebral palsy patients]

The absence of active knee extension in cerebral palsy patients is often due to elevation of the patellar ligament causing the patella to run outside the intercondylar groove. Distal patellar realignment can be achieved by either patellar ligament shortening or transposition of the patellar ligament distally.

In the 1992-2008 period we indicated 95 knees for the distal realignment procedure involving a bone block in children 12 to 18 years old, and 46 knees in children aged between 8 and 16 years for shortening of the patellar ligament using the method of rafage in the early period, and modified plication from 2003.

Clinical and radiographic findings were evaluated pre-operatively and at 6 weeks, 6 months and 1 year after surgery. In the cases treated by patellar ligament shortening, the Insall-Salvati index was assessed post-operatively. Physical examination included local findings and the patient's ability to change locomotion.

Improved locomotion and maintenance of knee extension during standing and walking were recorded in 89 of the 95 knees with distal patellar realignment (93.68%) and in 40 of the 46 kness with patellar ligament shortening (86.96%).

Distal realignment of the patellar ligament or its shortening should be indicated as a follow-up treatment after muscular balance has been gained at persistent knee joint flexion during standing and walking, and the inability of active extension. The distal realignment procedure with a bone block should be indicated only after growth cessation because otherwise genu recurvatum may develop. Concurrently with this procedure, it is necessary to carry out distal realignment of the proximal ligament of the rectus femoris muscle.

Shortening of the patellar ligament using modified plication or its distal realignment involving a bone block are two options for the treatment of patella alta that is indicated in the absence of active knee extension in cerebral palsy patients.