Effects of surgeon experience and patient characteristics on accuracy of digital pre-operative planning in total hip arthroplasty

Background The effect of surgeon experience on accuracy of digital pre-operative planning for total hip arthroplasty (THA) remains unclear. The aims of our study were to compare pre-operative planning accuracy between fellow-trained orthopaedic surgeons and residents and to explore whether surgery indication effects the prediction accuracy. Methods We prospectively reviewed 101 patients who underwent pre-operative digital templating for THA in our center from January 2019 to January 2020 with King Mark device. Extracted data included baseline characteristics and indication for primary arthroplasty. Pre-operative digital templating was performed separately by both a fellow-trained surgeon and a resident. Accuracy of each group was compared with the implanted components. Results The overall adequate pre-operative planning of the acetabular cup (exact or +/-1 size match) by the fellow-trained group was higher compared with the resident's group (77.2 and 64.3% respectively,p= 0.037), whereas the overall adequate pre-operative planning of the femoral stem (exact or +/-1 size match) was higher in the resident's group compared with the fellow-trained group (83.2 and 61.4% respectively,p< =0.001). The fellow-trained group showed better pre-operative planning of complex cases (developmental dysplasia of the hip and avascular necrosis of femoral head) than the resident's group. Conclusions The experience of the planner does not significantly affect the accuracy of correctly predicting component sizes. However, in complex cases, fellow-trained surgeons should assist residents in digital pre-operative templating for THA.