Interventions
knee arthroplasty
Based on the estimated results, we included 144 patients who underwent TKA. The patients were randomly divided into two groups: the CON group (72 patients) included patients who underwent conventional TKA, with the operation process performed as described in the technique manual provided by the manufacturer; the RAS group (72 patients) included patients who underwent robotic-assisted knee arthroplasty using the robotic-assisted system developed by Hangzhou Jianjia Robot Co. Ltd. This robot is a semiactive surgical robot, which can generate a 3D bone model based on the patient’s preoperative computed tomography scan, help doctors determine the most appropriate prosthesis model and size before operation, and improve prosthesis placement. The same prosthesis (Zimmer Biomet, Warsaw, Indiana, USA) was used in all surgeries. The patient was operated under general anesthesia unless there was a clear contraindication. A lower limb tourniquet was used in all patients, and the tourniquet pressure was 300 mm Hg. The anterior median approach was followed in all surgeries, and the incision was ~14 cm long.In the RAS group, when the robotic‑assisted system was applied for TKA, two 3.0 mm steel needles were inserted perpendicular to the femur at ~5 cm above the front articular line of the femur. Following this, the guide plate was fixed and connected with the femoral reflex ball to adjust the position of the receiver and make the receiving signal stable. After the registration of the femur was completed and verified, the robotic arm was positioned, and the cutting guide was inserted. The distal femur cut was performed after verifying that the amount of cutting matched with preoperative planning, and the robotic arm was adjusted again. After determining the osteotomy volume of the anterior and posterior femoral condyles and verifying it again, the robotic arm was positioned and the osteotomy guide was inserted to complete the osteotomy of the femur. Subsequently, two 3.0 mm steel needles were inserted vertically to the tibia at about 5 cm below the joint line of the tibia. After the registration of the tibia was completed and verified by the positioning needle with a reflex ball, the robotic arm was positioned, fixed after the positioning was confirmed, and the cutting guide was inserted to verify that the cutting matched with preoperative planning (Figs The distal femur osteotomy procedure using the Jianjia robot-assisted total knee arthroplasty system.Tibial osteotomy procedure using the Jianjia robot-assisted total knee arthroplasty system.