Acetabular Revision with a Roof Reinforcement Ring and Impacted Allograft Bone

A series of 43 acetabular revisions treated with impacted allograft bone and a roof reinforcement ring were reviewed. The average follow-up was 5 years (2–15). The mean age was 70 years. The position of the hip center, and the orientation of the ring and cup were digitized and measured. The average inclination of the roof ring with respect to the horizontal was 44° (22°-60°) early post-operatively. The cup inclination was 33° (21°- 49°). These figures did not change significantly at the latest follow-up. Definite loosening was defined as migration of the components or breakage of the screws. Four components were definitely loose. Two other patients had continuous radiolucent lines, but no migration of the components at the bone-implant interface. The radiographic success rate was 86%. Pre- and post-operative Harris Hip Score were 34.1 (18 – 65) and 71.6 (36 – 90) respectively. The study supports the use of impacted morsellized allograft bone and a roof reinforcement ring for cavitary acetabular defects.