Abstract:

Objective：To discuss the result of treating valgus or varus knee deformity with fixator assist nailing (FAN) technique and distal femur osteotomy(DFO). Methods: In this retrospective study, 14 patients with 17 limbs, 12 valgus and 5 varus knee deformity were treated with DFO and FAN. The average age of the patients was 23 (17-44) years . The unilateral external fixator was mounted on the lateral side of femur, the minimal invasive distal femoral osteotomy was performed. After the deformity was corrected, the intramedully nail was inserted to fix the femur. None of the patients need bone autograft. The preoperation and postoperation lateral distal femur angle (LDFA), mechanical axis deviation (MAD) and range of motion (ROM) were measured and analyzed. Results: All the 14 patients were followed-up for 12-72 months (average 34 months). The osteotomy site united in 3-5 months (average 3.5 months) post-operatively. According to Paley’s functional scores, 12 patients were excellent, 2 patients were good. We achieved desired postoperative MAD ( from medial 15 mm to lateral 10 mm) in 15 limbs of 12 patients. The LDFA in 11 limbs was corrected to normal (84°-90°). The ROM was not significantly changed before and after operation in the both groups. No infection or neuro-vascular injury occurred. Conclusion: The FAN technique is an effective method to treat valgus knee or varus knee deformity in young patients with DFO.

Key words: External fixators, Bone nails, Deformities, acquired joint, Osteotomy