Robotic Unicompartmental Knee Arthroplasty Demonstrates Improved Recovery During the First 90 Postoperative Days Compared With Robotic Total Knee Arthroplasty: A Prospective Remote Monitoring Study.

BACKGROUND

Unicompartmental knee arthroplasty (UKA) and total knee arthroplasty have been extensively compared; however, prior studies have largely relied on manual surgical techniques and patient-reported outcomes collected at discrete time points, limiting characterization of recovery during the initial postoperative period. With increasing adoption of robotic assistance and wearable technology, higher-resolution assessment of recovery is possible. This study compared recovery following robotic-assisted UKA (rUKA) and robotic-assisted TKA (rTKA) using continuous remote patient monitoring during the first 90 postoperative days.

METHODS

We prospectively enrolled 80 patients undergoing rUKA and 94 patients undergoing rTKA for isolated medial compartment osteoarthritis. Patients utilized wearable activity monitors and a smartphone app for two weeks preoperatively and 90 days postoperatively. Outcomes included daily visual analog scale (VAS) pain scores, daily opioid consumption, step counts, patient-reported outcome measures, and time to walking-aid cessation. Pain trajectories were analyzed using linear mixed-effects models adjusting for baseline pain, demographic variables, comorbidity burden, and surgeon.

RESULTS

Preoperative VAS pain was higher in the rUKA cohort. Adjusted pain trajectories differed between groups, with lower pain in the rUKA cohort during early recovery; however, absolute VAS pain scores were similar by approximately 90 days. The rUKA cohort demonstrated lower opioid consumption through postoperative day 21, higher daily step counts throughout the 90 days with fewer declines from baseline, superior 30-day patient-reported outcome scores, and earlier discontinuation of walking aids than rTKA patients.

CONCLUSIONS

Patients who underwent rUKA demonstrated improved recovery during the first 90 postoperative days and reduced opioid requirements compared with rTKA. Although pain trajectories favored rUKA during the initial postoperative weeks, pain levels converged by 90 days, suggesting that differences during this period are primarily functional rather than reflective of sustained differences in pain intensity.