[Ilizarov technique for correcting flexion deformity of the knee of arthrogryposis multiplex congenita].

Objective: To study the methods and effects of Ilizarov distraction technique in treating the flexion deformity of the knee of arthrogryposis multiplex congenita.

Methods: Between August 1998 and February 2003, 6 patients (10 knees) with the arthrogryposis multiplex congenita were treated, 4 patients in double knees, 5 males, 1 female, mean age 8 years and 2 months, ranged from 3 years and 7 months to 13 years. The preoperative flexion degree was averagely 51 degrees. The patients accompanied 13 other parts malformation of limbs. The modified Ilizarov distraction apparatus of the knee was used. While installing the apparatus in the operation, the knees should be kept in the of location of maximum extension, the center of joint hinges on the apparatus should be placed towards the rotatory center of the knee, two groups of 2 mm K-wires were passed through the femur and tibia around the knee, who were fixed on the proximal and distal rings. Distraction was started after the surgical procedure 5 days via rotating the threaded rods at the posterior of the knee, at an average of 2 to 3 mm per day, at the first week, after 2 weeks with the rate modified to 2 mm per day, up to the knee extended to 0 degrees. The accompanied deformities of the hip and/or the foot might be corrected at the same time or next time. The average duration of the distraction was 37 days (23-48 days). During the correction all limbs might undergo weight. After 2 weeks at the end of distraction the fixator was removed and the patients could walk by a long-leg brace.

Results: Ten knees with the flexion contracture were sufficiently corrected without severe complications. Nine knees of all were followed up at an average time of 1 years and 3 mouths, no recurrence of the deformity was seen in all patients, their function of walk was significantly improved.

Conclusions: Ilizarov technique is a simply, safe and effective method for managing the flexion deformity of the knee of the arthrogryposis multiplex congentia. The procedure is conformable to the biological theories and microsurgical principles.