Pelvic height planning versus conventional templating in preoperative planning of acetabulum cup size for THA.

This study aimed to compare the accuracy of pelvic height planning vs. the conventional templating method for acetabulum cup measurement. A total of 200 consecutive patients undergoing primary total hip arthroplasty (THA) were randomly grouped as follows: group A, accepting conventional templating; group B, accepting pelvic height planning. Preoperative measurement of the acetabular cup was performed with conventional templating and pelvic height planning, respectively. There were 57 cases with the same size or with one type size discrepancy, 49 with two type size discrepancies, and 14 with three type size discrepancies in group A. There were 145 cases with the same size or one type size discrepancy, 20 with two type size discrepancies, and 3 type size discrepancies in group B. The mean difference between the planned size and actual cup size was 2.58 ± 0.89 mm (group A) vs. 1.38 ± 1.22 mm (group B). Therefore, pelvic height planning is reliable for use in preoperative planning compared with conventional templating.