MRI does not detect acetabular osteolysis around metal-on-metal Birmingham THA.
OBJECTIVE
Osteolysis has not been recognized as a common failure mode of the Birmingham modular metal-on-metal (MoM) total hip arthroplasty (THA). The clinical value of metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) to assess the periprosthetic soft tissue is well documented; however, the appropriate image modalities to detect periacetabular osteolysis remain unclear. Eleven patients with periacetabular osteolysis within 3-6 years after uncemented Birmingham modular MoM THA with a synergy stem are presented. All 11 patients received corresponding standardized AP pelvis radiographs, high-quality MARS MRIs and CT scans with a metal artifact reduction sequence. While periacetabular osteolysis around MoM THA was not detected on MARS MRI in ten patients, CT imaging identified osteolysis in all patients. Periacetabular osteolysis appears to be a failure mechanism of the Smith & Nephew Birmingham MoM THA.


CONCLUSIONS
There is no evidence in the literature to support the effectiveness of MARS MRI to detect periacetabular osteolysis around cobalt chromium alloy metal-on-metal total hip arthroplasties. Osteolysis due to corrosion-related particles seems to be one of the primary modes of failure in modular MoM THA.


CONCLUSIONS
MRI is not a sensitive test to identify periacetabular osteolysis. The authors recommend CT for the screening of implants with this failure mode. Our study suggests that patients with a Birmingham modular MoM THA are at increased risk to develop acetabular osteolysis and should be carefully monitored for this failure mode.
Adult Reconstruction and Joint Replacement Division, Hospital for Special Surgery, Weill Medical College of Cornell University, 535 East 70th Street, New York, NY, 10021, USA, WaldsteinW@hss.edu.
Wenzel
W
Waldstein
Tom
T
Schmidt-Braekling
Friedrich
F
Boettner
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D016477:Artifacts; D005260:Female; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D061825:Metal-on-Metal Joint Prostheses / Q000009:adverse effects*; D008875:Middle Aged; D010014:Osteolysis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D011475:Prosthesis Failure; D014057:Tomography, X-Ray Computed