Forty-nine patients with hip osteoarthritis were randomized to receive MoM resurfacing via an anterolateral approach (n=25) or a posterior approach (n=24). The primary outcome of interest was the anatomical location, grade, and prevalence of pseudotumors and muscle atrophy on MARS-MRI. Secondary outcomes of interest included acetabular component position (inclination/anteversion), femoral neck narrowing, radiolucencies, serum cobalt/chromium concentrations, and HHS/OHS. Outcomes were assessed at a mean of 5.3 years (range 3.2–7.7). Overall, the results of the study revealed that pseudotumor location and muscle-atrophy patterns followed the surgical approach (anterolateral lesions with the anterolateral approach; posterolateral with the posterior approach), while overall prevalence, metal-ion levels, and clinical scores were similar between groups. These findings suggest many cystic pseudotumors and specific atrophy patterns may represent expected postoperative appearances rather than “MoM disease.”