The use of reinforcement rings to reconstruct deficient acetabula.
We reviewed 64 patients in whom 66 acetabula had been reconstructed with either the Müller ring (46) or the Burch-Schneider anti-protrusio cage (20) at a mean follow-up of five years. Five hips had been revised a second time for loosening, all after a Müller ring had been used for a medial segmental defect (2), ungrafted cavitary defects (2) or after resorption of a block graft (1). The use of bone grafts with the implants reduced the incidence of failure from 13% to 6% and of circumferential radiolucent lines at the bone-implant interface from 39% to 2%. The Müller ring is indicated for acetabula with isolated peripheral segmental defects or cavitary defects confined to one or two sectors. The Burch-Schneider cage should be used for medial segmental defects, extensive cavitary defects and combined deficiencies. Defects should be reconstituted with bone graft rather than cement.
Rosson
J
J
Sunnybrook Health Science Centre, Toronto, Ontario, Canada.
Schatzker
J
J
D000077:Acetabulum / Q000601:surgery*; D000328:Adult; D000368:Aged; D001863:Bone Screws; D016025:Bone Transplantation; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging; D006622:Hip Prosthesis / Q000295:instrumentation* / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation / Q000706:statistics & numerical data