All cups showed stable fixation as demonstrated by bone ingrowth with an average postoperative period of 48 months. The minimum 3D coverage was 61.2%, with a mean value of 77.1% ± 6.7% and maximum value of 97.6%. We found a significant positive but poor relationship between 3D and 2D coverage (bone coverage index; r = 0.30). Consequently, the 2D-3D discrepancy varied greatly, with a mean value of −1.6% ± 12.3% (range, −36.5% to 32.2%). Multiple linear regression analyses confirmed that lower cup center and anterior tilt of the pelvis relative to the computed tomography table were independent factors associated with increasing 2D-3D discrepancy.