Radiography versus Multidetector Computed Tomography in Assessing Graft Integration after Acetabular Reconstruction

Abstract

Purpose. To compare radiography with multidetector computed tomography (MDCT) in the evaluation of graft integration following acetabular reconstruction for failed total hip arthroplasty (THA). Methods. Records of 5 men and 6 women aged 60 to 78 (mean, 71.8) years who underwent acetabular reconstruction using structural allografts for severe acetabular deficiency secondary to aseptic loosening (n=9) or septic loosening (n=2) were reviewed. The mean survival time of the THA was 136.4 (range, 12–360) months. Acetabular defects were classified as IIC (n=2), IIIA (n=3), or IIIB (n=6). Structural allografts were fixed with impaction followed by a reinforcement ring (n=10), an antiprotrusio cage (n=2), and/or an oblong cup (n=1) with gentamicine-loaded cement. Cup loosening, graft integration, and graft resorption were evaluated using radiography. In addition, graft integration was evaluated using MDCT. Results. At a mean follow-up of 4.2 (range, 2–11) years, the survival of the acetabular reconstruction was 90.9%. No patient had any signs of infection. One patient underwent reoperation 22 months later for dislocation secondary to abductor deficiency caused by nonunion of the trochanteric fracture. According to radiography, all patients had graft integration. One patient had definitive and another had possible cup loosening. Four patients had minor graft resorption. According to MDCT, graft integration was complete in only one patient, partial >50% in 3, partial <50% in 4, and absent in 2. Conclusion. MDCT is more accurate than radiography in evaluating graft integration following acetabular reconstruction.