New Technology for Total Knee Arthroplasty Provides Excellent Patient-Reported Outcomes: A Minimum Two-Year Analysis

Robotic-assisted total knee arthroplasty has been demonstrated to help increase various patient-reported, clinical, and surgical outcome metrics (PROMs). However, the current literature is limited regarding PROMs data for longer follow-up periods beyond one year. Therefore, the purpose of this study was to 1) report multicenter patient-reported outcomes with multiple metrics, as well as 2) postoperative surgeon-specific outcomes at a minimum two-year follow-up.

Five fellowship-trained, high-volume surgeons performed a total of 188 total knee arthroplasty surgeries using the enhanced preoperative planning and real-time intraoperative feedback of a robotic-assisted device. Patients from all surgeons followed similar postoperative rehabilitation beginning on postoperative day one. Patients were evaluated based on the Short Form-12 Questionnaire (SF-12), the Forgotten Joint Score (FJS), and Knee Society total and subscores (KSS). The SF-12 was subdivided into two components: mental composite score (MCS) and physical composite score (PCS). The KSS was subdivided into functional and knee scores. Additionally, surgical outcomes from the latest follow-up visit were evaluated. All patients were evaluated at a minimum of two years follow-up time.

All patients reported excellent postoperative outcomes for all three PROMs. The mean postoperative SF-12 MCS and PCS scores were both 57 points, with 50 as the threshold for norm-based scoring (MCS range: 42 to 69 points; PCS range: 41 to 68 points). The mean FJS was 75 points (range: 14 to 100 points). The mean KSS functional score was 84 points (range: 20 to 100) while the mean Knee Score was 92 points (range: 40 to 100). Similarly, we found that the aseptic revision rates were low (n=2, 1.06%, one for unexplained pain, and another for a post-traumatic tibial fracture) with few other postoperative complications (n=7 patients [3.7%]) in our cohort.

Our analysis found that patients had excellent outcomes across multiple PROM metrics. Future work can build on these results with large patient populations over longer follow-up intervals. Nevertheless, these results provide the foundation and evidence to support the continued use of this innovative technology for total knee arthroplasties.