Are porous tantalum cups superior to conventional reinforcement rings

Background and purpose — Porous tantalum cups have been introduced as an alternative to various reinforcement rings in revision hip surgery. We hypothesized that porous tantalum cups would be superior to Muller acetabular roof reinforcement rings (MARRs) in revision hip surgery with re-revision for aseptic loosening as the primary outcome measure.Patients and methods — 207 hips operated with either a porous tantalum cup (TM cup, n = 111) or a MARR (n = 96) at index procedure were identified in our local arthroplasty register. Acetabular defects were classified according to Paprosky. There were 96 men and 111 women with a median age of 71 (35–95) years, presenting acetabular defect size type I in 39 cases, IIA in 22, IIB in 27, IIC in 43, IIIA in 32, and IIIB in 37 cases. Analysis of medical records identified all patients with subsequent re-revision and reasons for re-revisions. Kaplan-Meier survival functions were used to estimate implant survival.Results — With re-revision for aseptic loosening as the e...