Influence of Conscious Sedation Versus Spinal Anesthesia on Range of Motion and Pain Scores Following Manipulation Under Anesthesia After Total Knee Arthroplasty.

BACKGROUND

Manipulation under anesthesia (MUA) is a common intervention for postoperative stiffness following total knee arthroplasty (TKA). While monitored anesthesia care (MAC) is most frequently used, short-acting spinal anesthesia (SA) is increasing in popularity. There is limited research comparing outcomes of these anesthetics, specifically functional and patient-reported outcomes. This study aimed to compare the impact of MAC versus SA on postoperative range of motion (ROM) and Patient-Reported Outcome Measure Information System (PROMIS) scores following MUA.

METHODS

This retrospective cohort study included 197 patients who underwent MUA after TKA. Patients were grouped by anesthesia type: MAC (n = 138) and SA (n = 59). Knee ROM measurements, PROMIS scores, and medication requirements, including opioids, muscle relaxants, and corticosteroid use, were collected. These measures were compared using Kruskal-Wallis tests.

RESULTS

Patients receiving MAC had significantly greater improvements in knee ROM (change in ROM = 30.8° ± 19.2) at two months following MUA compared with those receiving SA (change in ROM = 20.0° ± 20.1, P = 0.0021) after MUA. There was greater improvement in both flexion (change in flexion = 27.8° ± 18.3 for MAC versus 18.4° ± 18.4 for SA, P = 0.0037) and extension (change in extension = -3.0° ± 4.7 for MAC versus -1.6° ± 5.0 for SA, P = 0.013). Additionally, MAC demonstrated lower PROMIS Pain Interference scores compared with SA, indicating lower pain levels (P = 0.047). There was no difference in morphine equivalent requirements between groups (P = 0.078).

CONCLUSIONS

The MAC with conscious sedation was associated with significantly greater improvements in knee flexion, extension, and total ROM following MUA after TKA when compared with SA. Patients in the MAC group also reported significantly lower PROMIS Pain Interference scores, with a trend toward reduced opioid requirements.

LEVEL OF EVIDENCE: Level III, retrospective cohort study.