Pre-operative templating for knee arthroplasty shows low accuracy with standard X-rays

Area of Science:

• Orthopedic surgery
• Medical imaging analysis

Background:

• Pre-operative templating is crucial for planning orthopedic procedures, particularly knee replacements.
• Accurate templating of femoral and tibial components ensures optimal implant fit and patient outcomes.
• The influence of coronal deformity on templating precision remains an area of investigation.

Purpose of the Study:

• To assess the accuracy and reliability of pre-operative templating in predicting femoral and tibial component sizes.
• To determine the impact of coronal deformity on the precision of pre-operative templating.

Main Methods:

• Retrospective analysis of 39 pre-operative templates from three surgeons.
• Evaluation of accuracy and reliability using kappa coefficients of agreement.
• Spearman's correlation test to analyze the effect of coronal deformity on templating accuracy.

Main Results:

• Femoral component templating accuracy was low (28.21% AP, 35.90% lateral) with poor agreement (Kappa < 0.4).
• Tibial component templating showed slightly better accuracy (37.61% AP, 47.01% lateral) but still poor to slight agreement (Kappa < 0.32).
• Accuracy improved with a ±1 size margin, especially for tibial components; no correlation was found between coronal deformity and templating accuracy.

Conclusions:

• Pre-operative templating is an unreliable and inaccurate method for predicting component sizes in knee replacement surgery.
• The study found no relationship between coronal deformity and the accuracy of pre-operative templating.
• Findings suggest limitations in the current utility of templating for surgical planning.