Medial submuscular plating of the femur after limb lengthening and correction with frame in patients with limb length discrepancy and/or angular deformity

Objective To evaluate the medial submuscular plating of the femur after limb lengthening and correction with frame in patients with limb length discrepancy and/or angular deformity. Methods A retrospective study was conducted involving 12 patients who had been referred to Department of Orthopaedic Trauma, Beijing Jishuitan Hospital from December 2009 to November 2016 for limb length discrepancy and/or angular deformity. They were 3 males and 9 females, with an average age of 23 years (from 14 to 32 years). Altogether 4 left and 8 right sides were involved. Of them, 11 got their length discrepancy and/or angular deformity secondary to injury to distal femoral epiphyseal plate caused by trauma in their childhood and one had length discrepancy and angular deformity following unsuccessful conservative treatment of superior condylar fracture of the femur. The femoral shortening ranged from 3 to 11 cm (average, 6.7 cm), and the varus or valgus deformity of the knee ranged from 8° to 18° (average, 12°). First, a monolateral fixator was installed on the lateral femur. The limb was lengthened from 7 to 14 days after diaphysis osteotomy. Femoral supracondylar osteotomy was conducted again in patients with knee angular deformity after the lengthening reached the expected length and the deformity was corrected with the aid of external fixator. After medial submuscular plating via the femoral lateral approach using minimally invasive techniques, the external frames were removed. The time for plate removal, limb lengthening and correction of the varus or valgus deformity were documented. Results The mean follow-up was 31 months (from 23 to 43 months) for the 9 patients who had their plates still in situ, and 6.5 months (from 2 to 14 months) for the 3 patients who had subsequently their plates removed. None had blood transfusion. All underwent distraction osteogenesis of the femur to their preoperatively expected length, ranging from 3 to 9 cm (mean, 6.2 cm). Both varus and valgus deformities were corrected. None developed a deep infection. The range of motion of the knee joint was similar to that before operation in all but one patient who had a range of motion 40° less than the pre-operative one. The time for external fixation averaged 91 days (from 46 to 113 days), with an external index of 22 d/cm. All patients were satisfied with their outcomes. Conclusion Medial femoral submuscular plating after limb lengthening and angular deformity correction with the external fixator on the lateral side is a useful technique for patients with femoral limb length discrepancy and/or angular deformity, significantly shortening the time for external fixation. Key words: Femur; External fixators; Bone plates; Surgical procedures, minimally; Abnormalities