Objective To analyze the accuracy of prosthesis size selection in Naton robot-assisted medial unicondyle knee arthroplasty by comparing the actual prosthesis size used during operation and the preoperative planning. Methods The clinical data of 100 patients (110 knees) who underwent Naton robot-assisted medial unicondylar knee arthroplasty between June 2023 and July 2024 was retrospectively analyzed, including 47 knees on left side and 63 knees on right side. There were 37 males (40 knees) and 63 females (70 knees) with a mean age of 65.4 years (range, 59-71 years). Body mass index was 22.2-28.6 kg/m2 (mean, 25.4 kg/m2). The disease duration ranged from 1 to 8 years (mean, 3.4 years). Preoperative planning was performed by Naton robotic surgical system based on lower limb CT data. The final prosthesis size after osteotomy was recorded and compared with the preoperative plan to analyse whether it was consistent with the preoperative plan, as well as the situation of knee flexion and extension gaps (<0.5 mm, >2.0 mm) corresponding to the different models of prostheses. ResultsDuring operation, 5 patients (5 knees) were treated with traditional UKA due to mechanical arm failure, software obstacles, significant bone amputation bias, or loose reference frame, and were excluded from the final analysis. The remaining 95 patients (105 knees) successfully received Naton robot-assisted surgery, and no related complications occurred. The prosthesis size was consistent with the preoperative plan in 101 knees (96.2%) on the femur side, 100 knees (95.2%) on the tibia side, and 97 knees (92.4%) on both femur and tibia sides. The prosthesis size was inconsistent in 3 cases (2.86%) on the femur side alone, 4 cases (3.81%) on the tibial side alone, and 1 case (0.95%) on both femur and tibial sides. Among the prostheses with different models, the flexion and extension gaps were less than 0.5 mm in 3 knees, the flexion gap was less than 0.5 mm and the extension gap was more than 2.0 mm in 3 knees, and the flexion gap was more than 2.0 mm and the extension gap was less than 0.5 mm in 2 knees. Conclusion The accuracy of prosthesis size selection for Naton robot-assisted medial unicondylar knee arthroplasty is relatively high.
Objective To compare the safety and early effectiveness between conventional manual technique and domestic robot-assisted simultaneous bilateral medial unicompartmental knee arthroplasty (UKA). Methods Clinical data of 59 patients who underwent simultaneous bilateral UKA and met the selection criteria between January 2023 and June 2024 were retrospectively analyzed. Among them, 30 patients received bilateral UKA via conventional surgery with Oxford mobile-bearing unicompartmental knee prosthesis (conventional group); another 29 patients underwent bilateral UKA with LINK SLED fixed-bearing unicompartmental knee prosthesis assisted by the domestic NATON robotic surgical system (robotic group). Baseline data including gender, age, body mass index, disease duration, Kellgren-Lawrence grade, and preoperative American Knee Society Score (KSS) and Oxford Knee Score (OKS) showed no significant intergroup differences (P>0.05). Intraoperative and perioperative indicators including operation time, length of hospital stay, perioperative hemoglobin (Hb) drop (preoperative vs immediate postoperative), and incidence of complications were recorded and compared. KSS and OKS scores were adopted to assess knee functional recovery preoperatively, at 3 months postoperatively, and at last follow-up. KSS satisfaction score was used to evaluate patient satisfaction at 3 months postoperatively and at last follow-up. Radiographic measurements of tibial prosthesis varus-valgus angle and the change in joint line height before and after surgery were performed to evaluate the accuracy of prosthesis implantation. ResultsThe conventional group had significantly shorter operation time than the robotic group (P<0.05). There was no significant difference in length of hospital stay and perioperative Hb drop between the two groups (P>0.05), and no patient required blood transfusion. All patients completed follow-up, the follow-up duration was (12.3±2.3) months for the conventional group and (12.1±2.4) months for the robotic group, with no significant difference (t=0.324, P=0.752). No severe complication including prosthesis loosening, periprosthetic infection, periprosthetic fracture, deep vein thrombosis of lower extremities, pulmonary embolism, knee stiffness, or knee instability occurred in either group. The tibial prosthesis varus-valgus angle and the change in joint line height in the robotic group were significantly smaller than those in the conventional group (P<0.05). No significant intergroup difference was observed in patient satisfaction scores at 3 months postoperatively and at last follow-up (P>0.05). Both KSS and OKS scores significantly improved at 3 months postoperatively and at last follow-up when compared with preoperative scores, with further improvement over time (P<0.05); no significant intergroup difference in these scores was found at any postoperative time point (P>0.05). Conclusion Although robot-assisted simultaneous bilateral UKA requires longer operation time, it achieves comparable early effectiveness and safety to conventional manual simultaneous bilateral UKA, with superior accuracy of prosthesis implantation. The domestic robot-assisted system demonstrates promising clinical application value in simultaneous bilateral UKA.