The value of preoperative planning for total hip arthroplasty

Abstract

To analyse the value and accuracy of preoperative planning for total hip replacement (THR) we digitised electronically and compared the hand-sketched preoperative plans with the pre- and postoperative radiographs of 100 consecutive primary THRs. The correct type of prosthesis was planned in 98%; the agreement between planned and actually used components was 92% on the femoral side and 90% on the acetabular side. The mean (+/- SD) absolute difference between the planned and actual position of the centre of rotation of the hip was 2.5 +/- 1.1 mm vertically and 4.4 +/- 2.1 mm horizontally. On average, the inclination of the acetabular component differed by 7 +/- 2 degrees and anteversion by 9 +/- 3 degrees from the preoperative plans. The mean postoperative leg-length difference was 0.3 +/- 0.1 cm clinically and 0.2 +/- 0.1 cm radiologically. More than 80% of intraoperative difficulties were anticipated. Preoperative planning is of significant value for the successful performance of THR.