The mid-long term results of reconstructional cage and morselized allografts combined application for the Paprosky type III acetabular bone defects in revision hip arthroplasty

BACKGROUND: Severe acetabular bone defects is a complex problem in revision hip arthroplasty, cage is one of the reconstruction options. The purpose of this study is to report the mid-long term clinical and radiographic results of Paprosky type III acetabular bone defects revised with reconstructional cage and morselized allogeneic cancellous bone graft without impaction. METHODS: We retrospectively analyzed 28 patients who underwent revision hip arthroplasty with reconstructional cage and allogeneic cancellous bone graft between January 2007 and January 2016. There were 13 Paprosky type IIIA bone defect patients and 15 Paprosky type IIIB bone defect patients and 4 patients of the 15 were also with pelvic discontinuity. Clinical assessment included Harris Hip Score (HHS) and Short Form-12 (SF-12). Radiographic assessment included center of rotation, cage migration, and bone graft incorporation. RESULTS: All patients were followed up with a mean follow-up of 79.5 months (range 38–141), HHS improved from 31.4 (13–43) points preoperatively to 84.6 (55–94) points at last follow-up and SF-12 also improved significantly. There was 1 re-revision for the cage loosening and screw breakage at 61 months after surgery, and 2 patients had nonprogressive radiolucency in zone III and the junction of zone II and zone III at the bone implant interface. CONCLUSION: The reconstructional cage combining with morselized allografts without impaction achieves a good result with a high complete allograft incorporation rate in Paprosky type III acetabular bone defects.