Learning curve analysis of robotic-assisted total knee arthroplasty with a Chinese surgical system

PURPOSE: The aim of this study was to analyze the learning curve of total operative time, bone cutting accuracy, and limb alignment in total knee arthroplasty (TKA) using a Chinese image-based knee surgery robot known as HURWA. Additionally, a comparison was conducted with conventional TKA to ascertain the benefits of robotic-assisted TKA. METHODS: In this retrospective study, we analyzed a series of patients (n = 90) who underwent robotic-assisted total knee arthroplasty using the HURWA robot between December 2021 and October 2022. The procedures were performed by one of three orthopedic surgeons with varying levels of experience. As a control group, we selected the last 30 conventional TKA cases performed by each of these three surgeons. To determine the learning curve, we recorded the operative time, bone cutting error, and pre- and post-surgery radiographs. RESULTS: The study found no significant differences in total operative time, bone cutting accuracy, or limb alignment among the three surgeons. Of the three surgeons, surgeon 1, who had the most experience in joint arthroplasty, reached the learning curve in case 8, with the shortest bone cutting time and robot time. Surgeon 2 reached the learning curve in case 16, while surgeon 3 reached the learning curve in case 9. There was no observable learning curve effect for bone cutting accuracy and limb alignment. However, the percentage of cases where limb alignment differed from preoperative planning by 3° or less was higher in robotic-assisted TKA (77.97%) than in conventional TKA (47.19%). CONCLUSION: The study determined that the learning curve for robotic-assisted TKA using the HURWA knee surgery robot ranged from 8 to 20 cases. No observable learning curve effect was detected for bone cutting accuracy or limb alignment. Experienced surgeons using the HURWA robot for bone cutting took less time and reached the learning curve earlier. The HURWA robot achieved better limb alignment without depending on the experience of conventional TKA.