Acetabular component thickness does not affect mid-term clinical results in hip resurfacing.
BACKGROUND
The benefits of using thin acetabular components for hip resurfacing have been shown in terms of bone conservation, but there currently are little data available in the literature addressing the mid-term clinical results of these devices.


OBJECTIVE
We aimed to determine whether thinner acetabular components altered mid-term postoperative clinical scores, complication rates, survivorship, radiographic appearance, and metal ion levels.


METHODS
Two hundred eighty-one patients with unilateral disease received a 5-mm thick acetabular shell and 223 received a 3.5-mm shell. The femoral component implanted in both groups was identical. We compared clinical scores, complication rates, survivorship, radiographic results, and ion levels between these two groups.


RESULTS
UCLA hip scores were similar (pain, p = 0.0976; walking, p = 0.9571; function, p = 0.9316; activity, p = 0.2085). Complications were higher in the 5-mm group (6.4% versus 1.8%, p = 0.0431). Both groups were similar regarding survivorship (p = 0.3181), cup radiolucency at 5 years (p = 0.107), and metal ion levels (cobalt p = 0.404, chromium p = 0.250).


CONCLUSIONS
With comparable mid-term clinical results, there is no tangible reason to abstain from using the 3.5-mm acetabular component.


METHODS
Level III, retrospective comparative study. See the Guidelines for Authors for a complete description of levels of evidence.
Joint Replacement Institute, 2200 West Third Street, Suite 400, Los Angeles, CA, 90057, USA.
Mariam
M
Al-Hamad
Michel J
MJ
Le Duff
Karren M
KM
Takamura
Harlan C
HC
Amstutz
D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation*; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D061825:Metal-on-Metal Joint Prostheses; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult