What Is the Most Effective Strategy for Acute Postoperative Pain in Total Knee Arthroplasty-Retrospective Observational Study.

Background and

Objectives

Effective early postoperative pain control is essential for optimal recovery following total knee arthroplasty (TKA). In addition to pharmacological pain management, the choice of anesthetic agents and surgical technique can significantly impact postoperative outcomes. Remimazolam and robotic-assisted TKA (RA-TKA) have recently gained attention due to their potential advantages. This study aims to evaluate the effects of remimazolam and RA-TKA on acute postoperative pain compared with conventional TKA (C-TKA) and standard anesthetic protocols. Materials and

Methods

In this retrospective observational study, 460 patients undergoing elective unilateral TKA were divided in to four groups based on surgical technique and anesthetic agents; RA-TKA with remimazolam (Group RR, n = 115), C-TKA with remimazolam (Group CR, n = 134), RA-TKA with conventional anesthesia (Group RC, n = 79), and C-TKA with conventional anesthesia (Group CC, n = 152). Remimazolam was administered at 6 mg/kg/h for induction and 1 mg/kg/h for maintenance, whereas conventional anesthesia was induced with propofol (1.5 mg/kg) and maintained with sevoflurane (1.5~2.0 vol%). The primary endpoint was acute postoperative pain, assessed via patient-controlled analgesia (PCA) consumption and supplemental analgesic use on the day of surgery. Secondary endpoints included total PCA consumption and additional analgesic use during the first 72 h, recovery room stay, discharge scores, and the incidence of postoperative nausea and vomiting (PONV).

Results

Group RR required significantly fewer additional analgesics on the day of surgery than the other groups. Although group RR and group CR exhibited prolonged recovery room stay and lower discharge scores, these outcomes were not correlated with PCA consumption or supplementary analgesic use. RA-TKA was associated with approximately a 31% reduction in additional analgesic use compared with C-TKA, indicating a major contribution of the surgical technique to early postoperative pain control. Remimazolam alone did not demonstrate an independent effect on acute pain management.

Conclusions

RA-TKA combined with remimazolam significantly reduced the need for additional analgesics on the day of surgery, highlighting a synergistic effect of the anesthetic and surgical approach. These findings support RA-TKA with remimazolam as an effective strategy for managing early postoperative pain following TKA.