Failure of a "screw-in" acetabular component: ten-year results, survivorship analysis, and the prediction of failure.
The Rotalok screw-in threaded acetabular component was prospectively reviewed with 10-year clinical and radiological follow-up for 60 patients. Nine patients died and 5 were lost to follow-up. Clinically, 28 patients were pain-free, 13 had mild pain, and 3 had moderate pain. Thirteen patients underwent revision for loosening and 3 required revision but were unfit. Superior migration, angular migration, and zone lucency were measured radiologically. Cumulative survival was 70.75% with revision surgery as the end point and 60% with combined clinical failure and revision as the end point. Angular migration of 3 degrees or more was a significant predictor of clinical failure and revision (P < .0001), with 5 degrees being very highly predictive with a sensitivity of 0.72 and a specificity of 1.00. Revision was associated with younger patients (P = .03) and autograft use without screw stabilization (P = .024). The high failure rate of the Rotalok necessitates careful clinical and radiological follow-up, with asymptomatic radiological angular migration often the first predictor of failure.
Sandhu
H
H
Royal United Hospital, Bath, England, UK.
Bankes
M J K
MJ
Youngman
J
J
Scott
G
G
D000077:Acetabulum / Q000601:surgery*; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D016009:Chi-Square Distribution; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D015996:Survival Rate; D014025:Titanium; D016896:Treatment Outcome
D014025:Titanium