Abstract / Summary
Background/Objectives: Prosthetic anteversion (PA) is generally considered to be constrained by three-point fixation in the sagittal plane. However, previous studies have reported inconsistent changes from native femoral anteversion (NFA) to prosthetic anteversion (PA), ranging from no appreciable change to a mean increase of approximately 8°, suggesting that PA may not be determined by femoral anatomy alone. This study aimed to evaluate whether femoral stem anteversion can be intentionally adjusted towards a target angle and to identify factors associated with failure to achieve the intended correction. Methods: We retrospectively reviewed 142 hips in 133 patients who underwent total hip arthroplasty with a target PA of 30°. Hips were divided into increased-anteversion (Group 1) and decreased-anteversion (Group 2) groups according to the intended correction relative to NFA. Correlations between targeted and actual correction angles and factors associated with correction failure were analyzed separately for each group. Results: Of 142 hips, 126 were classified as Group 1 and 16 as Group 2. PA significantly increased from NFA in Group 1 (12.72 ± 9.24° vs. 25.17 ± 7.13°; p < 0.001) but not in Group 2 (39.13 ± 6.73° vs. 37.84 ± 7.88°; p = 0.513). A lower CCR and intended decrease in anteversion were associated with correction failure. In Group 1, targeted and actual correction angles were significantly correlated (r = 0.633, p < 0.001). Conclusions: Femoral stem anteversion can be intentionally increased using a single-wedge tapered stem, particularly in femora with a high CCR. However, the feasibility of intentionally decreasing anteversion requires further investigation.