Megaprosthesis Reconstruction of the Proximal Femur following Bone Tumour Resection: When Do We Need the Cup?

PURPOSE

Reconstruction of the proximal femur after tumour resection can be performed with proximal femoral endopros-theses (PFE). Many studies have reported that bipolar hemiarthroplasty (BHA) reduce the risk of dislocation after oncological resections. However, progressive cotyloiditis which might require acetabular resurfacing (total hip arthroplasty [THA]) has been reported. The aim of this study is to compare the results of BHA and THA after proximal femur resection.

MATERIALS AND METHODS

A total of 104 consecutive patients affected by primary (n=52) and metastatic (n=52) bone tumours were included. Ninety patients underwent BHA and 14 patients underwent THA. Complications were recorded and classified according to the Henderson classification. At final follow-up, patients with the implant in site were functionally evaluated with modified Harris hip score (HHS).

RESULTS

The mean follow-up was 50 months (range, 2-171 months). Twenty-four (23.1%) patients developed major complications. Eleven (12.2%) BHA required acetabular resurfacing. Patients affected by primary bone tumours showed an increased risk of THA conversion (=0.042). A reduced risk was observed in patients younger than 35 years (=0.043) and in those older than 65 years (=0.033). Dislocation occurred in four case (3.8%), in particular after THA (=0.021). At final follow-up, 93 patients had the prosthesis in site (80 BHA and 13 THA). Mean postoperative HHS was 70 (range, 30-90).

CONCLUSION

The risk of dislocation is lower for bipolar endoprosthesis compared to THA. However cotyloiditis and acetabular resurfacing might occurred.