Treatment of knee flexion contracture due to central nervous system disorders in adults.
BACKGROUND: Studies concerning adult patients with spastic flexion contracture of the knee are rare. Such patients frequently have cutaneous and vascular complications as well as recurrence of the contracture after treatment. We present a strategy consisting of simultaneous correction of all deformities of both lower limbs, distal hamstring releases, and application of femorotibial external fixation when extension of the knee is limited by excessive posterior soft-tissue tension. METHODS: A consecutive series of fifty-nine patients (ninety-seven knees) between the ages of twenty-one and seventy-seven years received surgical treatment for a flexion contracture of the knee secondary to neurological impairment. The flexion contracture was bilateral in thirty-eight patients. Preoperatively, the mean flexion contracture angle was 69 degrees and the mean passive range of motion was 61 degrees. The contracture was corrected, through medial and lateral approaches, with distal hamstring lengthening. A posterior capsulotomy was performed in thirty-five knees. Full extension of thirty-four knees was achieved intraoperatively. In seventy-seven knees, partial correction was maintained with a unilateral external fixator, and passive and active mobilization was performed four times daily after temporary removal of the spanning external fixator rod. RESULTS: At the time of final follow-up, ranging from one to five years postoperatively, the mean residual flexion contracture was 6.2 degrees. Forty-five knees had complete extension, and thirty-nine knees had a residual flexion contracture of <10 degrees. No recurrence of the flexion contracture or instability was noted in any knee at the time of follow-up. There were four cutaneous complications but no vascular or neurological complications. CONCLUSIONS: We believe that our surgical strategy for correction of fixed knee flexion contracture in adult patients is safe and effective. The correction improves nursing care and sitting posture, facilitating the upright position of patients who are unable to walk, and improves walking ability for patients who are able to walk.