[Domestic ROPA surgical robot for total hip arthroplasty: An artificial bone experiments]

To evaluate the effectiveness and precision of the domestic total hip arthroplasty (THA)-assisted robotic system ROPA through artificial bone experiments.

Robot-assisted THA was performed on 16 artificial bone models (8 left hips and 8 right hips) using the ROPA system. Preoperative CT scans were imported into the ROPA system for three-dimensional reconstruction and preoperative planning. Component size, acetabular cup position (anteversion and abduction angles), and osteotomy parameters (femoral neck osteotomy distance, offset, leg length discrepancy, and acetabular reaming bone volume) were recorded. Intraoperative probe verification accuracy, matching accuracy, remaining reaming distance, and remaining press-fit distance were documented. Postoperative three-dimensional scanning was performed to measure actual parameters, which were compared with planned values to calculate deviations.

Osteotomy experiments were successfully completed on all 16 hip models. Component sizes were consistent with the preoperative plan in all 16 hip models. Deviations between actual and planned values were as follows: Anteversion angle was (0.79±1.69)° and abduction angle was (0.19±2.23)°. According to the initial position of acetabular cup, abduction angle was 40° and anteversion angle was 20°. The deviation of acetabular cup anteversion angle was (40.79±1.69)° and abduction angle was (20.19±2.23)°. All acetabular cups were implanted in the Lewinnek safe zone. The femoral neck osteotomy distance was (0.31±0.38) mm, the leg length discrepancy was (0.79±1.16) mm, the hip offset was (0.69±2.21) mm, and the acetabular fossa reaming bone volume was (0.03±0.06) mm, all of which met the acceptance criteria. The probe verification accuracy was (0.18±0.16) mm, the intraoperative registration accuracy was (0.50±0.22) mm, the remaining reaming distance was (-0.19±1.05) mm, and the remaining press-fit distance was (1.88±0.89) mm, all of which were in line with the expected design error range.

The domestic THA-assisted robotic system ROPA demonstrated favorable osteotomy accuracy, operational performance, effectiveness, and precision in artificial bone experiments. However, its long-term efficacy still requires further verification through clinical trials.