The learning curve of a novel seven-axis robot-assisted total hip arthroplasty system: a randomized controlled trial

Abstract

Bacground The aim of this study was to assess the learning curve of a novel seven-axis robot-assisted total hip arthroplasty (RaTHA) system. Methods A total of 59 patients who underwent unilateral total hip arthroplasty at our institution from June 2022 to September 2022 were prospectively included in the study. In this randomized controlled clinical trial, robot-assisted THA (RaTHA) and Conventional THA (CoTHA) were performed using cumulative sum (CUSUM) analysis to evaluate the learning curve of the RaTHA system. The demographic data, preopera1tive clinical data, duration of operation, postoperative Harris Hip Score (HHS), postoperative Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, and duration of operation between the learning stage and the proficiency stage of the RaTHA group were compared between the two groups. Results The average duration of operation of the RaTHA group was increased by 34.73 min compared with the CoTHA group (104.26 ± 19.33 vs. 69.53 ± 18.38 min, p < 0.01). The learning curve of the RaTHA system can be divided into learning stage and proficiency stage, and the former consists of the first 13 cases by CUSUM analysis. In the RaTHA group, the duration of operation decreased by 29.75 min in the proficiency stage compared to the learning stage (121.12 ± 12.84 vs.91.37 ± 12.92, p < 0.01). Conclusions This study demonstrated that the surgical team required a learning curve of 13 cases to become proficient using the RaTHA system. The duration of operation, total blood loss, and drainage gradually shortened (decreased) with the learning curve stage, and the differences were statistically significant. Trial registration Number: ChiCTR2200061630, Date: 29/06/2022.

A new seven-axis robotic-assisted total hip arthroplasty system improves component positioning: a prospective, randomized, multicenter study

“…Current evidence suggests that the application of traditional six-axis robotic-assist systems leads to increased accuracy in positioning the prosthesis, especially the inclination and anteversion of the acetabular cup 22 , 23 . In the present study, the RAS group demonstrated 80.85% of the inclination and anteversion within the safe zone, which was significantly higher than that in the CON group, similar to the conclusion reported by Kong et al 13 , 24 . Notably, when compared with the preoperative planning component position, the postoperative deviation was small.…”

“…People have tried to solve these problems by improving the degree of freedom of the robot. Haocheng Sun et al reported a seven-axis robot assistance system 13 . In there study the duration of operation, total blood loss, and drainage gradually decreased with the learning curve stage.…”

“…Increasing the freedom of robotic-assisted systems promises to solve these problems. Sun et al 13 showed that a seven-axis robot-assisted total hip arthroplasty system could be mastered with a learning curve of only 13 cases, which is better than the traditional six-axis robot (14–35 cases) 14 . However, There is currently a lack of large multicenter studies assessing it’s effectiveness, safety and clinical outcomes after a seven-axis robot-assisted THA system.…”