JOA - 2026-04-24 - Journal Article
Robotic Unicompartmental Knee Arthroplasty Demonstrates Improved Recovery During the First 90 Postoperative Days Compared With Robotic Total Knee Arthroplasty: A Prospective Remote Monitoring Study.
Schneider AM, Bendich I, Hannon CP, King J, Riegler V, Barrack RL, Nunley RM
Topics
Key Takeaway
Robotic UKA patients had lower opioid consumption through POD 21, higher daily step counts across all 90 days, and earlier walking-aid cessation compared to robotic TKA, though VAS pain scores converged by day 90.
Summary Depth
Choose how much analysis to show on this article page.
Summary
This prospective study compared recovery trajectories in robotic-assisted UKA versus robotic-assisted TKA for isolated medial compartment OA using continuous wearable monitoring and daily app-based reporting over 90 days. The rUKA cohort demonstrated lower adjusted VAS pain scores in early recovery, lower opioid consumption through POD 21, higher daily step counts throughout the entire 90-day period, superior 30-day PROMs, and earlier walking-aid discontinuation. Pain scores converged between groups by approximately day 90, suggesting the functional recovery advantage is not sustained as a pain differential at 3 months.
Key Limitation
Non-randomized allocation means unmeasured confounders—including surgeon preference, patient expectation, and disease severity beyond VAS pain—likely influenced procedure selection and recovery behavior despite statistical adjustment.
Original Abstract
INTRODUCTION
Unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) 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.
MATERIALS AND 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 less decline from baseline, superior 30-day patient-reported outcome scores, and earlier discontinuation of walking aids compared with rTKA patients.
DISCUSSION
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.