Popliteal pterygium knee contracture: treatment with the Ilizarov technique.

INTRODUCTION Various treatment options are in use to address severe knee flexion contractures in children. Their success depends on an adequate selection of the proper one applying to each individual anatomical situation. HYPOTHESIS Applied to limb deformity, the Ilizarov technique combines progressive correction, to joint structures flexibility restitution in case of severe knee flexion contracture. We review a continuous series of popliteal pterygium syndrome patients managed with this technique. PATIENTS AND METHODS Medical records of eight children (11 knees), consecutively treated between 1986 and 2007, were reviewed. Knee flexion ranged from 40 to 120 degrees. Contracture (> 90 degrees) was extremely severe in 10 cases. Progressive correction was gained by Ilizarov external fixation. Complications during and following articular chain distraction-lengthening were noted. Follow-up ranged from 1 to 21 years. RESULTS Surgical realignment was rendered particularly complex by the popliteal cutaneous band itself, partly responsible of the joint stiffness and sciatic nerve shortening. Deformities were corrected by the Ilizarov technique. Complete extension was obtained in all cases. In six cases, flexion contracture reccurrence required to repeat the correction, using the same technique, at a mean interval of 3-4 years. During follow-up, four evolutive partial posterior tibial dislocations and one complete dislocation were diagnosed, all associated with recurrence of the flexion contracture. LEVEL OF EVIDENCE Level IV. Therapeutic Study.