Background Pre-operative templating is an important aspect of THR. Templating helps determine the size of prosthesis, and increases accuracy. Templating is only as good as information provided by radiographs. We investigated the quality of planning radiographs at our trust, and assessed templating accuracy. Methods The most recently operated 101 primary THR patients’ radiographs were reviewed. Pre-operative radiographs were checked if within 6 months of surgery, included a scaling ball, and whether sufficient proximal femur was visible. Saved templates were then further assessed for accuracy, by comparing to prosthesis size from op-notes. Results 96% of radiographs were within 6months of surgery. 39% had a scaling ball present. The position and apparent size of the 25mm scaling ball varied; average apparent size of 32.3mm (magnified by a factor of 1.3). An average of 68mm of femur was visible below the lesser trochanter. 62/101 patients had saved templates. 10(16%), showed enough femur to include the templated stem tip. 18 templated stems, and 15 cups, matched those implanted. Average cup discrepancy was 2.6mm (1.02× templated). The average stem discrepancy was one size. Conclusion This study shows planning radiograph quality varies. Overall templating was not accurate to that implanted. It is noted that templates were produced by both consultants and juniors. Presence and position of scaling ball varied, affecting magnification estimates. We propose to use a protocol to enhance local radiograph quality. This study shows how radiograph and templating quality varies, and that ongoing review is important to ensure use in THR planning is optimal.
Woodward et al. (2025) studied this question.