The surgeon's eye: a prospective analysis of the anteversion in the placement of hemiarthroplasties after a femoral neck fracture.

Introduction: Hip dislocation after hemiarthroplasty performed in elderly patients with a femoral neck fracture is associated with severe morbidity and costs. Optimal anteversion during the placement of the hemiarthroplasty might reduce the dislocation rate. We assessed the surgeons' intraoperative visual estimations of the femoral anteversion.

Methods: The postoperative femoral anteversion of 20 consecutively performed hemiarthroplasties was measured on computer tomography and compared to the intraoperative visual estimations of the surgeon. Furthermore, the femoral anteversion of the contralateral non-fractured hip, which was considered the 'ideal' anatomical reference, was recorded.

Results: The mean postoperative anteversion of the hemiarthroplasty was 20° (SD 8.7°). The mean femoral anteversion of the contralateral non operated femur was 14° (SD 9.5°).The average difference between the anteversion angle estimated by the surgeon and the CT-measured is 9° (1° to 18°). In 14 (70%) cases the measured angle was greater than desired.

Conclusions: The current operation technique in which the anteversion angle is estimated by the surgeon's eye shows relatively good intraoperative precision.