Proximal femoral reconstruction with a constrained acetabulum in oncologic patients

Metallic endoprostheses are used for oncological reconstruction around the proximal femur and hip joint. Common modes of failure with hemiarthroplasty or standard hip arthroplasty after proximal femoral replacement include dislocation, late hip pain, and infection. The authors reviewed hospital records to identify patients undergoing constrained tripolar hip arthroplasty for oncological reasons between 2002 and 2012. Inclusion criterion was at least 12-cm proximal femoral resection, including patients with total femur reconstruction. A total of 33 patients were reviewed. Information regarding demographics, length of follow-up, treatment characteristics, and patient outcomes was extracted. Average follow-up for all patients was 912.33 days (30.4 months). Average follow-up was 1396.1 days for living patients and 428.6 days for deceased patients. Average estimated blood loss was 462.12 cc: an average of 1080 cc for patients undergoing total femoral resection and replacement and 315.8 cc for patients undergoing proximal femoral resection and replacement. Average operative time was 137.7 minutes: an average of 205 minutes for patients undergoing total femoral resection and replacement and 119.1 minutes for patients undergoing proximal femoral resection and replacement. Average Musculoskeletal Tumor Society score was 21.7. There were no dislocations in the cohort. A constrained tripolar device can be safely used for oncological proximal femoral reconstructions while minimizing the risk of dislocation. Positioning of the acetabular implant in neutral anatomic version in conjunction with a neutral-placed femoral component provides the greatest range of motion, reduction of liner impingement, and improved hip stability.