Templating in uncemented THA. On accuracy and postoperative leg length discrepancy

Area of Science:

• Orthopedic Surgery
• Medical Imaging
• Arthroplasty Design

Background:

• Digital templating is increasingly used for preoperative planning in total hip arthroplasty (THA).
• Accurate component selection is crucial for successful surgical outcomes and patient satisfaction.
• Assessing the precision of digital templating against actual surgical implantation is essential for refining surgical techniques.

Purpose of the Study:

• To evaluate the accuracy of digital templating for uncemented total hip arthroplasty (THA) components.
• To determine if templated component sizes correlate with surgically implanted components.
• To assess the impact of digital templating accuracy on postoperative limb length equality.

Main Methods:

• Retrospective analysis of digital X-rays from 41 patients undergoing uncemented THA.
• Comparison of digitally templated component sizes with actual intraoperative implant choices.
• Evaluation of postoperative limb length equality using radiographic measurements.
• Statistical analysis to quantify templating accuracy and its correlation with outcomes.

Main Results:

• Acetabular component templating accuracy was 7.3% (within +/-2 sizes: 73%).
• Femoral stem templating accuracy was 34% (within +/-2 sizes: 90%).
• Neck length templating accuracy was 29% (within +/-2 sizes: 100%).
• Postoperative limb length equalization within +/- 5mm occurred in 54% of patients, and within +/- 10mm in 85%.

Conclusions:

• Digital templating accuracy is acceptable for femoral stems in uncemented THA.
• Accuracy is inferior for acetabular shells and poor for neck length.
• While valuable for preoperative planning, digital templating should not be considered a rigid surgical blueprint.