Comparison of porous-threaded and smooth-threaded acetabular components of identical design. Two- to four-year results.
Between April 1985 and April 1987, 82 smooth-threaded and 62 porous-threaded acetabular components of identical design were implanted without structural bone grafting as primary acetabular replacements. At a minimum two year follow-up examination, statistically significant differences were found in the roentgenographic and clinical results between the two matched groups. Twenty-nine percent of the smooth-threaded cups and none of the porous-threaded acetabular components were classified as roentgenographically unstable. Clinically, groin or buttock pain was present in 25% of patients with smooth-threaded cups and in only 7.5% of the patients with the porous-threaded components. Six smooth-threaded components and none of the porous-threaded components have been revised to date. Because of the unacceptable high incidence of instability at short-term follow-up, the smooth-threaded acetabular component is no longer being used at this institution. The addition of the porous coating was associated with the superior results noted in this group.
Anderson Orthopaedic Research Institute, Arlington, Virginia 22206.
F
F
Pupparo
C A
CA
Engh
D000077:Acetabulum / Q000000981:diagnostic imaging; D001178:Arthroplasty / Q000379:methods; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging; D006622:Hip Prosthesis / Q000009:adverse effects; D006801:Humans; D010146:Pain / Q000209:etiology; D011859:Radiography