Is analog preoperative planning still applicable?—comparison of accuracy of analog and computer preoperative planning methods in total hip arthroplasty

BACKGROUND: Preoperative planning is an integral part of total hip arthroplasty and has a significant impact on surgical technique and clinical outcome. The variety of types and sizes of endoprosthesis components makes the procedure more demanding and generates a need for accurate preoperative planning. The objective of this study was to analyze an analog method of preoperative planning of primary total hip arthroplasty based on templates overlaying on preoperative radiograms and compare its accuracy for predicting the size, both the stem and cup, with computer planning methods. METHODS: A retrospective cohort study based on 360 X-ray images of hip joints in 348 patients qualified for total hip arthroplasty between 2018 and 2019. The study group consisted of 136 men and 212 women, with an average age of 65 years (56 to 85 years). Material included both cementless and cemented endoprostheses. RESULTS: In the analyzed material, the accuracy of cup planning using the analog method was 85% (P<0.001) and 77% (P<0.001) in the planning of stem size. However, using the computer method, planning accuracy was 82% (P<0.001) for the cup and 72% (P<0.001) for the stem. CONCLUSIONS: Both methods of preoperative planning remain effective. The analog method of preoperative planning is simple, precise, and repeatable in choosing the type and size of endoprosthesis components with an accuracy of 85% and 77% for the cup and stem respectively. The accuracy of planning depends on the type of endoprosthesis and in the case of the cemented endoprosthesis, it is lower than in cementless.