Acetabular Revision Surgery With Tantalum Trabecular Metal Acetabular Cup for Failed Acetabular Cage Reconstruction With Bone Allografts: a Retrospective Study With Mid- to Long-term Follow-up

Abstract

Abstract BackgroundThe acetabular cage reconstruction with bone allografts is one of the successful strategies to deal with the massive acetabular bone loss. However, the nonbiological fixation nature of cages can compromise long-term success. The tantalum trabecular metal acetabular cup (TM cup) has been used in acetabular revision surgery because of its increased initial stability and good bone ingrowth features. This study was to determine if the bone stock of acetabulum is enough to support the hemispheric TM cup after failed cage reconstruction with bone allografts.MethodsWe retrospectively reviewed our patients who received acetabular revision surgery with TM cups after failed cages reconstruction with bone allografts from 2006 to 2017. There were twelve patients (5 males and 7 females) including in this study at the mean age of 61.5 years (38 to 81) at re-revision surgery. The mean follow-up after re-revision surgery was 8.6 years (2.6 to 13.3). The endpoint was defined as the aseptic loosening of TM cup and reoperation for any causes. The change of bone stock of acetabulum between index revision and re-revision was assessed according to Gross classification for acetabular bone loss. ResultsOne patient died after eight years of follow-up with the cause not related to hip surgery. Two patients received two-stage revision arthroplasty due to PJI after 3.2- and 9.4-years follow-up. The bone stock of acetabulum was significantly improving between index revision and re-revision surgery (p < 0.0001). The Kaplan-Meier survivorship was 100% when aseptic loosening as the endpoint, and 90% and 75% at five- and ten-year when reoperation for any causes as the endpoint.Even the cage reconstruction with bone allografts will fail eventually, the bone stock of acetabulum will improve after union and incorporation between host bone and allografts. The restored bone stocks will facilitate further revision surgery with hemispheric TM cup. The biological fixation between host bone tantalum trabecular metal will provide longstanding stability of the TM cup.ConclusionsThe results of our study offered a viable option for patients with failed cage reconstruction with bone allografts.