Distal Femur Allograft Prosthetic Composite Reconstruction for Short Proximal Femur Segments following Tumor Resection

Bryan S Moon,Patrick P Lin,Nathan F Gilbert,Christopher P Cannon,Valerae O Lewis

doi:10.1155/2013/397456

Abstract

Short metaphyseal segments remaining after distal femoral tumor resection pose a unique challenge. Limb sparing options include a short stemmed modular prosthesis, total endoprosthetic replacement, cross-pin fixation to a custom implant, and allograft prosthetic composite reconstruction (APC). A series of patients with APC reconstruction were evaluated to determine functional and radiologic outcome and complication rates. Twelve patients were retrospectively identified who had a distal femoral APC reconstruction between 1994 and 2007 to salvage an extremity with a segment of remaining bone that was less than 20 centimeters in length. Seventeen APC reconstructions were performed in twelve patients. Eight were primary procedures and nine were revision procedures. Average f/u was 89 months. Twelve APC reconstructions (71%) united and five (29%) were persistent nonunions. At most recent followup 10 patients (83%) had a healed APC which allowed WBAT. One pt (8%) had an amputation and one pt (8%) died prior to union. Average time to union was 19 months. Four pts (33%) or five APC reconstructions (29%) required further surgery to obtain a united reconstruction. Although Distal Femoral APC reconstruction has a high complication rate, a stable reconstruction was obtained in 83% of patients.

Highlights

Resection of large skeletal tumors can result in short metaphyseal juxtaarticular segments of host bone which can pose a reconstructive challenge to the musculoskeletal tumor surgeon
Aseptic loosening or fracture around a standard reconstruction can lead to loss of bone stock so that only a short metaphyseal segment of host bone remains for fixation in revision surgery
Limb salvage reconstructive options in this scenario include the use of a standard endoprosthesis with fixation of the stem into the short segment of host bone, use of custom implants allowing for crosspin fixation of the endoprosthesis to the host bone, use of an endoprosthesis to replace the entire bone, and use of a composite of an allograft and an endoprosthesis [1,2,3]

Summary

Introduction

Resection of large skeletal tumors can result in short metaphyseal juxtaarticular segments of host bone which can pose a reconstructive challenge to the musculoskeletal tumor surgeon. Limb salvage reconstructive options in this scenario include the use of a standard endoprosthesis with fixation of the stem into the short segment of host bone, use of custom implants allowing for crosspin fixation of the endoprosthesis to the host bone, use of an endoprosthesis to replace the entire bone, and use of a composite of an allograft and an endoprosthesis [1,2,3]. Use of cross-pin fixation of a custom prosthesis to host bone has been described previously with a low rate of aseptic loosening [1] (Figure 2). This technique is limited by decreasing intraoperative flexibility and adding extra time and cost.

Methods

Results

Conclusion