2019 COA/ICORS Annual Meeting: A Randomized Controlled Trial of Modular Versus Monoblock Cementless Acetabular Components in Primary Total Hip Arthroplasty

88 patients scheduled for a unilateral total hip arthroplasty were randomized to receive a modular cup or monoblock acetabular component. The outcomes of interest included the incidence of cup-acetabulum gap, shell-to-bone contact, correlation between patient reported outcome measures (WOMAC, mHHS, UCLA Hip Score) and the advent of lucent lines, and the incidence of adverse events. Results revealed significantly more gaps in the modular cup group compared to the monoblock group. Shell-to-bone contact without a radiolucent line was significantly less prevalent in the modular cup group. There was no observed correlation between patient reported outcomes and the advent of lucent lines. The modular cup group was found to be a statistically significant predictor of lucent lines. While no cases of revision surgery were observed, two cases of squeaking were reported in the monoblock group.