Can a simple iPad app improve C-arm based component position in anterior THA?

Area of Science:

• Orthopedic Surgery
• Medical Imaging Technology
• Biomechanical Engineering

Background:

• Accurate acetabular component positioning is crucial for optimal hip biomechanics and reducing dislocation risk in total hip arthroplasty (THA).
• C-arm imaging is a cost-effective tool for THA but can present parallax challenges for evaluating component placement.
• Direct anterior THA offers potential benefits, necessitating precise intraoperative control of component positioning and leg length.

Purpose of the Study:

• To evaluate the efficacy of a software app-based measurement technique for controlling acetabular component position and leg length during direct anterior THA.
• To assess the accuracy of intraoperative measurements obtained via the software app compared to standard postoperative radiographs.

Main Methods:

• Prospective study involving 93 patients undergoing direct anterior THA.
• Utilized C-arm imaging and an iPad software app for intraoperative measurement of acetabular anteversion, inclination, and leg length discrepancy.
• Compared intraoperative app measurements with standard postoperative AP-pelvis radiographs.

Main Results:

• Strong correlations were found between intraoperative and postoperative measurements for anteversion (r=0.701), inclination (r=0.816), and leg length discrepancy (r=0.542).
• Mean intraoperative anteversion was 20.5° vs. 20.9° postoperatively; inclination was 40.5° vs. 40.7°.
• Mean intraoperative leg length discrepancy was 0.9 mm vs. 0.6 mm postoperatively, demonstrating high accuracy.

Conclusions:

• The evaluated software app provides a simple and accurate method for measuring intraoperative acetabular cup position in direct anterior THA.
• This technology aids in achieving precise leg length equalization during the procedure.
• The app-based approach enhances intraoperative decision-making and can contribute to improved patient outcomes.