Precision of robotic guided instrumentation for acetabular component positioning

Area of Science:

• Orthopedic Surgery
• Medical Robotics
• Biomechanical Engineering

Background:

• Total hip arthroplasty (THA) aims to restore joint function and alleviate pain.
• Accurate placement of the acetabular cup is crucial for long-term implant survival and optimal patient outcomes.
• Traditional THA relies on surgeon's skill, leading to variability in cup positioning.

Purpose of the Study:

• To evaluate the accuracy and precision of a robotic computerized instrumentation system for guiding bone preparation and acetabular cup implantation in THA.
• To compare intraoperative robotic guidance with postoperative CT scan measurements for cup inclination and anteversion.
• To assess the robotic system's ability to achieve the planned center of rotation (COR).

Main Methods:

• A prospective study involving 38 patients (43 hips) undergoing THA.
• Utilized robotic computerized instrumentation for bone preparation and acetabular cup implantation.
• Validated intraoperative cup inclination and anteversion against postoperative CT scans.

Main Results:

• Robotic instrumentation achieved high precision: 88% for inclination, 84% for anteversion, and 81.5% for COR.
• Intraoperative measurements showed minimal deviation from planned values.
• Postoperative CT scans revealed a low percentage of outliers (12% for inclination, 16% for anteversion) exceeding 5°.
• The center of rotation was positioned slightly superiorly (0.9±4.2 mm) and medially (2.7±2.9 mm).

Conclusions:

• Robotic-assisted THA demonstrates significant precision in achieving target acetabular cup positioning.
• The system offers a reliable method for improving accuracy in inclination, anteversion, and COR placement.
• This technology holds promise for enhancing surgical consistency and potentially improving patient outcomes in total hip arthroplasty.