Complications of Femoral Lengthening using the Ilizarov Fixator

摘要

Objective: To report and evaluate the complications of femoral lengthening using the Ilizarov fixator.Method: Retrospective study of 10 patients who underwent femoral lengthening between 2001 and 2008. Demographics were collected by reviewing the medical records of each patient.Results: Of 10 patients, seven (70%) were females. Average age was 20 years (range 11 – 48 years). Equal limb lengths were achieved in six patients. Three patients had significant residual leg length discrepancies. Lengthening was discontinued in two patients due to marked restriction in knee flexion. In the other patient lengthening was discontinued due to subluxation of the hip. One patient developed mild subluxation of the knee. One patient sustained a fracture following fixator removal. The fracture healed with a mild leg length discrepancy. All patients developed knee stiffness following lengthening. Nine patients achieved full knee extension and flexion greater than 90?.Conclusion: Generally, the number of complications and failures of lengthening increase in proportion to the length of distraction and the severity of the preoperative problems. Introduction Limb-length discrepancy is not an uncommon problem. Discrepancies of less than 5 centimetre (cm) are conventionally treated by a shoe lift, epiphysiodesis or femoral shortening. Most patients are reluctant to wear a lift greater than 2cm. Discrepancies in excess of 5cm may warrant limb lengthening. With the introduction of more physiologic methods of lengthening pioneered by Ilizarov and based on the biology of bone and soft tissue regeneration under the conditions of tension stress, the bone healing problems have become less common (1, 2). However, the soft tissue problems of decreased joint motion, prolonged or permanent stiffness, joint subluxation, refracture, nerve palsy and infection after lengthening have remained (3 – 8).The author reports his complications following femoral lengthening using the Ilizarov Circular Fixator. Subjects And Methods This is a retrospective study of 10 patients who underwent femoral lengthening utilizing the Ilizarov fixator between 2001 and 2008. Demographics were collected by reviewing the medical records of each patient. The principles for optimization of the regenerate bone were as follows: low energy osteotomy utilizing osteotomes, stable external fixation, latency period of 7 – 10 days, distraction rate of 0.25mm four times per day and a period of consolidation.Physical therapy was started immediately and continued throughout the lengthening period to maintain ranges of motion of the hip and knee. Upon discharge from hospital, patients were given prescriptions for oral antibiotics which were to be taken only if a pin site infection developed. The signs and symptoms of a pin site infection were explained to the patient and relatives. Daily cleaning of pin sites with cotton swabs soaked in normal saline to remove crusts was recommended. Weekly follow-up with plain radiographs to ensure good quality of the regenerate bone was maintained for the first month and then at three-weekly intervals until distraction was complete. Once the distraction phase was complete, patients were usually seen monthly to assess bony consolidation. Rate of distraction was decreased in patients who had poor regenerate bone during the distraction periods. Normal rates of distraction were resumed when radiographs demonstrated good regenerate bone.Two patients (cases 3 and 9) had simultaneous lengthening with correction of angular deformities of the distal femora. Hinges were used to correct the angular deformities and the hinges were replaced by telescopic rods for the lengthening process. The Ilizarov frame was extended across the knee in four patients in whom lengthening greater than 7cm was contemplated. This was performed to prevent knee subluxation and reduce the compression of the articular cartilages.Apparatus removal was performed under general anaesthesia. Routine immobiliz