Is the contralateral lesser trochanter a reliable reference for planning of total hip arthroplasty – a 3-dimensional analysis

Abstract Background Preoperative templating in total hip arthroplasty (THA) is mandatory to achieve appropriate offset and leg length equality. However, methods using the contralateral might be susceptible errors resulting from side-differences femoral morphology. The distance of lesser trochanter head center (LTFHD) a frequently used reference parameter for preoperative planning intraoperative validation during THA. currently no three-dimensional (3D) analysis side differences LTFHD exists. Methods Using Computer tomography (CT)-based surface models 100 paired femora (50 cadavers), side-to-side asymmetry LTFHD, length, diameter (FHD) antetorsion were analyzed. Univariate linear regression established evaluate potential associations between sides regarding FHD as well correlation these parameters with each other. Results Statistically significant found ( p = 0.02) 0.03) mean absolute side-difference 1.6 ± 1.4mm (range 0.1–5.5mm) 0.4mm 0.6mm 0–3mm), respectively. ratio was consistent an average value 1.16 0.08 reliable coefficient (r) 0.72 < 0.01). Conclusions THA high r 0.93, 8 % investigated specimens revealed more than 4mm, which should anticipated avoid unsatisfiable results.