FEMORAL RECONSTRUCTION USING IMPACTED CANCELLOUS ALLOGRAFTS PROTECTED WITH A METAL MESH FOR REVISION TOTAL HIP ARTHROPLASTY: 23 HIPS WITH MEAN 12.5 YEARS FOLLOW-UP (RANGE 8–20 YEARS)

Abstract

Purpose of the study: The incidence of revision hip arthroplasty is increasing. In order to overcome certain problems related to loss of femoral bone stock, an original technique was developed combining fragmented allograft material and a metallic mesh with a non filling stem cemented distally in a healthy zone to ensure stability.

Materials and Methods: The clinical data (Postel-Merle-d’Aubigné, PMA score) and radiographic findings (implant migration, loss of bone stock using the SOFCOT and PAPROSKY classification, quality of cementing, filling, and graft aspect, graft lysis, periprosthetic lucency, final aspect of the graft) were collected retrospectively. The operation and the technical difficulties and intraoperative complications were noted.

Results: We report a series of 32 hips treated with this technique and having a mean follow-up of 12.5 years (range 8–20 years). The population studied had particularly significant bone loss (78.2% SOFCOT stage 3 and4). These hips underwent revision for aseptic loosening. The implantation technique required a femoral window in 39.1%. Preventive cerclage was often used (39.1%) but did not prevent fracture or missinsertion in 30.4%. The PMA score improved significantly from 10.6 (7–18) preoperatively to 17 (12–18) at last follow-up. Radiologically, femoral bone regeneration at last follow-up had an aspect of corticalisation in 63.6% of hips, and of cancellous trabeculation in 36.4%. Femoral implant survival was 100% at eight years, and 92.8±6.88% at mean follow-up of 12.5 years. There was only one revision at eleven years for secondary osteolysis related to polyethylene wear in a very active subject implanted before the age of 50 years.

Discussion: The clinical and radiographic results are very satisfactory for this series of femoral revisions using an impacted fragmented graft material and with the longest follow-up reported in the literature. Distal fixation limited migration observed when the stem is entirely cemented in the graft, but did not affect reconstruction which demonstrated long-term stability. This technique, initiated in 1986 without a specific instrument set, had now demonstrated its long-term reliability. The only problem is the length of the operation and the complications related to femoral preparation.