Patients Undergoing Manipulation Under Anesthesia Recover Mobility, but Have Worse Functional Outcomes.

Abstract

To regain range of motion (ROM) after total knee arthroplasty (TKA), manipulation under anesthesia (MUA) may be recommended; however, restoration of gait following MUA requires clarification. The purpose of this study was to compare gait quality metrics, function, and ROM between stiff-kneed patients who underwent and did not undergo MUA. This study was a secondary data analysis of a large multicenter, observational cohort study in which patients used a digital care management platform with a smartwatch before and after TKA. Patients who had active flexion less than 90° at one month postoperatively were divided by occurrence of MUA (MUA: n = 52; non-MUA: n = 218). Patient recovery following MUA was evaluated via active flexion ROM, Knee Osteoarthritis and Outcomes Scale for Joint Replacement (KOOS JR), and objective gait metrics. On average, gait metrics of participants who received an MUA decreased 1 to 8 percentiles compared to non-MUA patients immediately post-MUA, with significant differences between cohorts at five days post-MUA for walking speed (P = 0.02) and step count (P = 0.05), but not walking asymmetry (P = 0.09). All gait metrics were similar between cohorts at 10- through 30-days post-MUA (P = 0.05). There were no significant (P = 0.09) differences in preoperative ROM between the MUA and non-MUA cohort, but ROM was reduced in the MUA cohort at one (75.0 versus 80°, P = 0.002) and three months (105 versus 115°, P = 0.048) postoperative. Similarly, KOOS JR did not differ significantly between cohorts preoperatively (P = 0.960), but was significantly (P = 0.0021) lower in the MUA cohort at three-, six-, and 12-months postoperative. Gait metrics normalized within five to 10 days after MUA, whereas KOOS JR scores remained lower in the MUA cohort for up to one year, highlighting a disconnect between objective and patient-reported outcomes. These findings underscore the importance of surgeon awareness when counseling patients about the expected recovery trajectory after MUA.