Increased correction of lateral centre edge angle after periacetabular osteotomy is associated with a reduction in hip flexion and internal rotation: A three‐dimensional computed tomography simulation study

Abstract Purpose Periacetabular osteotomy (PAO) is an established treatment for hip dysplasia, known to affect the hip range of motion (ROM). However, the quantitative relationship between PAO‐induced increase in lateral centre‐edge angle (LCEA) and postoperative ROM remains undefined. This study aimed to determine the precise influence of increased LCEA on hip ROM following PAO. Methods Fifty computed tomography (CT)‐based PAO simulations were performed on dysplastic hips, with corrections to LCEA values of 25° and 35°. Hip ROM was assessed in multiple planes using collision‐based simulation endpoints. Linear regression and subgroup analyses evaluated the relationship between ΔLCEA and ROM changes. Results Increased lateral acetabular coverage, as measured by the change in LCEA, showed significant negative correlations with hip flexion and internal rotation (both p 40° prior to PAO may be considered protective. To ensure residual ROM in hips at risk, the findings suggest accepting a lower target LCEA correction of 25°, on the lower end of the normal range. Level of Evidence Level III.