Follow-up study after treatment of knee flexion contractures in spina bifida patients.

Knee flexion contractures in spina bifida patients are seen in all levels of paralysis. The majority is encountered in children with thoracolumbar lesions. Positional deformation, spinal reflex activity, fractures around the knee joint and a weak quadriceps are the main causes of the flexion deformity of the knee. One hundred and forty-five knee flexion contractures in 80 children have been treated between 1980 and 1995; 15 with unilateral contracture, 65 with bilateral involvement. The age at the time of correction in 38 patients with thoracolumbar lesions was between 24 months and 11 years (average, 7.7 years). In 42 patients with sacral or lumbosacral lesions, the age at the time of correction was between 10 and 19 years (average, 16.3 years). Associated surgery was mainly carried out on hip flexors, adductors and triceps surae. Complete posterior release was practiced in thoracolumbar lesions including posterior capsulotomy and release of the posterior cruciate ligament. In lumbosacral lesions, the lengthened tendons are sutured to prevent flexor weakness in the postoperative course. Vascular and neurologic structures are spared. Postoperative serial casts are helpful to achieve full extension without vascular or skin troubles. The long-term results were very good in 59 patients with 106 knees, good in 16 patients with 29 knees, and unsatisfactory in 5 patients with 10 knees. Slow deterioration years after surgery can be anticipated. The main causes are lack of personal initiative to stand and to walk, and obesity.