Total hip arthroplasty in severe segmental femoral bone loss situations: use of a reconstruction modular stem design (JVC IX). Retrospective study of 23 cases.

BACKGROUND

Management of extensive proximal femur bone loss secondary to tumor resection or major osteolysis remains controversial. The possible options include a composite allograft/stem prosthesis, a modular type megaprosthesis or a custom-made megaprosthesis. Modularity allows versatility at reconstruction and avoids the delay required manufacturing a custom-made implant. Hypothesis and type of study: A retrospective radiological and clinical study investigated whether a special reconstruction modular stem design (JVC IX) would provide medium term success in the treatment of severe proximal femur bone loss.

MATERIAL AND

METHODS

Between 1995 and 2005, 23 JVC IX hip replacements were performed for severe segmental proximal femur bone loss. Etiology was: 13 cases of tumor resection, eight of extensive osteolysis secondary to femoral implant loosening, and two traumatic situations. Follow-up was annual. Functional assessment used the Musculo-Skeletal Tumor Score (MSTS), and implant survival rates underwent Kaplan-Meier analysis, with surgical revision (to replace or remove the implant) as the end point.

RESULTS

All 23 patients (23 hips) were followed up for a mean 5.4 years (+/-3.7 yrs). Mean MSTS was 16.2 (max.=30). All stems demonstrated good fixation at radiological assessment, except for one case of probable loosening in contact with a metastatic osteolysis. Four implants had to be revised: two for non-controlled infection, one for tumor extension, and one for stem fatigue fracture. At 10 years' follow-up, implant survivorship was 81.5% (range: 62% to 100%).

DISCUSSION: Severe proximal femur bone loss is a difficult situation to deal with, offering no ideal treatment option. Modular megaprostheses are salvage procedures. Their results at a mean 5.4 years' follow-up are encouraging, and appear comparable to the ones obtained with alternative solutions (composite allograft/stem prostheses).

TYPE OF STUDY: Level IV retrospective, therapeutic study.