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.