Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

BACKGROUND: The role of radiographs in the follow-up of patients with metal-on-metal hip resurfacing (MoMHR) implants is unclear. We investigated whether a combination of patient and radiographic factors predicted MoMHRs with evidence of a pseudotumor. METHODS: We performed a retrospective single-center case-control study of 384 MoMHRs. The pseudotumor group of 130 hips all had evidence of a symptomatic pseudotumor on cross-sectional imaging, with the diagnosis confirmed at revision. The nonpseudotumor group of 254 hips (a subgroup of these hips were previously reported on) all had normal findings on cross-sectional imaging. Radiographs taken immediately prior to revision were assessed in the pseudotumor group and were compared with radiographs taken at the time of normal cross-sectional imaging in the nonpseudotumor group. Two blinded independent observers analyzed the radiographs for signs of failure, with excellent interobserver agreement. Logistic regression modeling identified the patient and radiographic predictors of revision for pseudotumor. RESULTS: Hips with a pseudotumor more commonly had abnormal findings on radiographs compared to hips without a pseudotumor (80.0% compared with 63.4%; p = 0.001). Patient and radiographic factors predictive of revision for pseudotumor in the multivariable model were female sex (odds ratio [OR], 3.14; 95% confidence interval [CI], 1.85 to 5.35; p < 0.001), high inclination (OR, 1.04 per degree; 95% CI, 1.01 to 1.07 per degree; p = 0.006), acetabular osteolysis (OR, 5.06; 95% CI, 2.14 to 12.0; p < 0.001), femoral osteolysis (OR, 17.8; 95% CI, 5.09 to 62.2; p < 0.001), and acetabular loosening (OR, 3.35; 95% CI, 1.34 to 8.35; p = 0.009). Factors predictive of not having a pseudotumor were anteversion of ≥5° (5° to <10°: OR, 0.31; 95% CI, 0.12 to 0.77; p = 0.012; and ≥10°: OR, 0.32; 95% CI, 0.15 to 0.70; p = 0.004) and heterotopic ossification (OR, 0.19; 95% CI, 0.05 to 0.72; p = 0.015). The final multivariable model was well calibrated (p = 0.589), with good discriminatory ability (area under the curve = 0.801; sensitivity = 74.4%; specificity = 71.7%). CONCLUSIONS: A combination of patient and radiographic factors provided useful information for distinguishing between MoMHRs with and without evidence of a pseudotumor. Surgeons may wish to consider these specific patient and radiographic factors before proceeding with cross-sectional imaging. Radiographs are important when assessing patients with MoMHR implants and should be included in all follow-up protocols. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Original publication




Journal article


J bone joint surg am

Publication Date





214 - 222


Adult, Aged, Aged, 80 and over, Arthroplasty, Replacement, Hip, Case-Control Studies, Female, Granuloma, Plasma Cell, Hip Prosthesis, Humans, Male, Metal-on-Metal Joint Prostheses, Middle Aged, Prosthesis Design, Prosthesis Failure, Reoperation, Retrospective Studies, Risk Factors, Surface Properties