The accuracy and inter-observer reliability of acetate templating in total hip arthroplasty

AIM The accuracy and inter-observer reliability (IOR) of acetate templating on hard copy X-rays in 33 primary total hip arthroplasties as measured by consultant and trainee surgeons was analyzed to find out how accurate are junior surgeons undertaking specialty training. METHODS The study was questionnaire-based using a prospective cohort over a 4 weeks period. The Surgeon measurements of acetabular cup, femoral stem and femoral offset sizes were noted following acetate measurements and then compared with the final implant chosen during surgery. RESULTS Prediction of sizing to within one size of the final match size was 75% accurate for cup and 91% accurate for femoral stem. Prediction of exact femoral offset sizes was 91% accurate. Templating showed strong IOR between senior consultant surgeon and junior trainee registrar within one size for cup (83%) and stem (100%) and for exact hip offset prediction (92%). CONCLUSION We conclude that acetate templating on hard copy X-rays is beneficial to surgeons to gauge acetabular cup and femoral stem size to within one size range. This further helps in predicting nearly exact femoral offset size.