Accuracy of computer navigation for acetabular component placement in THA.

Area of Science:

• Orthopedic Surgery
• Medical Imaging
• Surgical Navigation Technologies

Background:

• Computer-aided surgical devices require high accuracy and precision for effective clinical use.
• Evaluating the reliability of imageless computer navigation systems is crucial for their adoption in total hip arthroplasty (THA).

Purpose of the Study:

• To compare the accuracy and precision of acetabular component positioning measured by an imageless computer navigation system against postoperative CT scans.
• To assess the agreement between the navigation system and CT scans for inclination and anteversion measurements.

Main Methods:

• Twenty-five patients (26 hips) undergoing primary THA utilized an imageless computer navigation system for acetabular component placement.
• Measurements of inclination and anteversion were taken in the operative coordinate system.
• Accuracy, precision, bias, and limits of agreement were calculated using Bland-Altman analysis.

Main Results:

• The accuracy for inclination was 1.8 +/- 1.2 degrees and for anteversion was 2.0 +/- 2.0 degrees.
• Precision was 3.4 degrees for inclination and 5.5 degrees for anteversion.
• Bias was minimal (0.52 degrees for inclination, 0.35 degrees for anteversion), with limits of agreement within acceptable surgical ranges.

Conclusions:

• Imageless computer navigation systems demonstrate high precision in determining acetabular cup position during THA.
• The system's measurements show good agreement with postoperative CT scans, supporting its clinical utility.