title: Comparative 5-year results of short hip total hip arthroplasty with Ti- or CoCr-neck adapters.
abstract: This prospective study investigated revision after modular short stem implantation. Results are presented for 2 different types of neck adapters (titanium and cobalt-chromium [CoCr]). Eighty-five patients with titanium adapters and 87 patients with CoCr adapters underwent follow-up examination after an average of 5.7 and 5.2 years, respectively. Mean patient age was 57 years in both groups. Indications were primary osteoarthritis (80%), cup dysplasia (14%), and other (6%). Mean Harris Hip Scores were 98 and 99 points (titanium and CoCr groups, respectively). Ninety percent and 96% of patients were very satisfied or satisfied (titanium and CoCr groups, respectively); 3% of patients in both groups were dissatisfied. Pain decreased from visual analog scale score 7 and 6 preoperatively to 0.37 and 0.15 postoperatively for the titanium and CoCr groups, respectively. No joint dislocation occurred. Six patients needed revision within the first year (2 for infection, 1 for via falsa position, and 2 for aseptic loosening in the titanium group, and 1 for aseptic loosening in the CoCr group). Nine revisions occurred due to neck adapter failure (titanium group). Primary standard stems were used in all revisions. Excluding material-related adapter failures in the titanium group, the 5-year survival rate was 94.8% (95% confidence interval [CI], 88.9-97.6 for titanium) and 99% (95% CI, 93.7-99.8 for CoCr). No radiographic signs of loosening were seen at last follow-up. Fine sclerotic lines were detected in Gruen zones 1 (17.2%) and 2 (14%), hypertrophies in zone 3 (4.3%), and periprosthetic cancellous bone compressions in zone 6 (75.8%). No adapter fractures occurred for CoCr components. The treatment and anchoring system of the short stem studied yielded good results and allowed revision using standard stems in all patients.
authors.forename: Ralf H
authors.initials: RH
authors.lastname: Wittenberg
authors.forename: Reinhard
authors.initials: R
authors.lastname: Steffen
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D057068:Periprosthetic Fractures / Q000517:prevention & control*; D011446:Prospective Studies; D013997:Time Factors; D055815:Young Adult