Survival of the GAP II cage in the management of metastatic disease of the acetabulum

Abstract

Aims The aim of this study was to assess the clinical and radiological outcomes of an antiprotrusio acetabular cage (APC) when used in the surgical treatment of periacetabular bone metastases. Methods This retrospective cohort study using a prospectively collected database involved 56 patients who underwent acetabular reconstruction for periacetabular bone metastases or haematological malignancy using a single APC between January 2009 and 2020. The mean follow-up was 20 months (1 to 143). The primary outcome measure was implant survival. Postoperative radiographs were analyzed for loosening and failure. Patient and implant survival were assessed using a competing risk analysis. Secondary parameters included primary malignancy, oncological treatment, surgical factors, length of stay in hospital, and postoperative complications. Results A total of 33 patients (59%) died during the study period at a mean of 15 months postoperatively (1 to 63). No patient had radiological evidence of loosening or failure. Acetabular component survival was 100%. Three patients (5.4%) had further surgery; one (1.8%) underwent revision of the femoral component for dislocation, one required debridement with implant retention for periprosthetic joint infection, and one required closed reduction for dislocation. Using death as a competing risk, at 100 months, the probability of revision was 0.036 and the risk of death was 0.84. Conclusion With appropriate patient selection, the antiprotrusio cage offers good implant survival, with a reasonable perioperative complication rate in this high-risk group of patients when managing metastatic disease or haematological malignancy around the acetabulum. Cite this article: Bone Joint J 2022;104-B(4):504–509.

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“…Table III shows some recent studies evaluating patients with metastatic bone disease [66][67][68][69][70][71][72][73][74][75][76] .…”

“…In patients with disease progression requiring arthroplasty, conversion was uncomplicated. For larger osseous defects, Kennedy et al reported on the survival of an antiprotrusio acetabular cage in patients with periacetabular bone metastases 72 . They demonstrated 100% acetabular component survival at the final follow-up and concluded that antiprotrusio cages are a viable option in patients with periacetabular metastatic bone disease.…”

“…Surgical techniques for the management of periacetabular metastatic bone disease continue to evolve 68,72 . English et al reported on a cohort of patients with acetabular metastases treated with minimally invasive stabilization with percutaneous screw placement and cementoplasty and compared the outcomes between those who underwent adjunct ablation treatments and those who did not 68 .…”