Intraoperative estimation of femoral anteversion in cementless total hip arthroplasty using the lesser trochanter

Introduction

The intraoperative estimation of the anteversion of the femoral component of a total hip arthroplasty is generally made by the surgeon’s visual assessment of the stem position relative to the condylar plane of the femur.

Aim

The aim of this study was to evaluate the femoral component anteversion relative to lesser trochanter during cementless total hip arthroplasty. The intraoperative estimation of the anteversion of the femoral component of a total hip arthroplasty is generally made by the surgeon’s visual assessment of the stem position relative to the condylar plane of the femur. The aim of this study was to evaluate the femoral component anteversion relative to lesser trochanter during cementless total hip arthroplasty.

Method

The authors investigated the version of the lesser trochanter (LTV) relative to the posterior femoral condyles. Fifty-seven patients (59 hips) scheduled for primary cementless total hip arthroplasty underwent preoperative computed tomography and it was measured the LTV and collo-femoral version at the level of the proximal-most portion of the inferior neck, with respect to the lesser trochanter (native collo-trochanteric angle, NCTA). During surgery, the operative collo-trochanteric angle (OCTA) was measured.

Results

The mean LTV was 34.1 ± 3.0°, the mean NCTA was 49.1 ± 5.6°, and the mean OCTA was 48.8 ± 6.0°, which did not differ significantly from the NCTA (p = 0.495); the correlation coefficient was 0.872 (p < 0.0001). Based on the data, there was a constant relationship between the lesser trochanter and posterior femoral condyles and a good correlation between NCTA and OCTA.

Conclusion

The authors recommend first estimating the anteversion of the femoral component relative to lesser trochanter and then adjusting the position of the acetabular component to that anteversion of the femoral component to improve stability and reduce impingement.