Proximal femoral osteochondroma excision aided by computer navigation: surgical technique and case series

Abstract

Purpose:Surgical excision is frequently indicated for symptomatic osteochondroma of the proximal femur. The purpose of this study was to describe our experience with computer-navigation aided excision of osteochondromata in the proximal femur and the outcomes of this technique.Methods:Seven patients who underwent computer-navigation aided excision of proximal femoral osteochondromata were studied. Computed tomography images of each patient's proximal femur and a size-matched normal proximal femur were fused on a commercially available navigation planning software. The intended resection margins were then plotted using the normal proximal femur as a template, and the plan executed using intra-operative navigation guidance. Patients were followed clinically, radiographically and with functional scoring using the Musculoskeletal Tumor Society (MSTS) score.Results:Five patients had isolated exostoses, while two had tumors associated with multiple hereditary exostoses. A posterolateral approach was used for tumors projecting posteriorly or posteromedially, while an anterior approach was used for anteriorly and medially based tumors. Prophylactic fixation was performed in the four patients that required anterior approaches. Mean duration of surgery was 196 minutes. No intraoperative fractures or post-operative complications occurred, and no secondary procedures were necessary. The mean MSTS score at a mean follow up of 13.1 months was 28.8 (out of a maximum of 30).Conclusions:This series is the first report of this novel application of computer-navigation, and demonstrates favorable post-operative functional scores and a low complication rate. It demonstrates the applicability, safety and efficacy of this technique, and is particularly applicable in resections involving particularly large tumors that obscure anatomical landmarks and in patients with associated proximal femoral deformity.