Abstract
OBJECTIVE: To evaluate the effects of irrigation fluid temperature on postoperative swelling, pain, complications, and functional recovery in patients undergoing arthroscopic rotator cuff repair. METHODS: This retrospective study analyzed clinical data from 410 patients who underwent arthroscopic rotator cuff repair at Putuo Hospital between April 2020 and November 2024. Patients were divided into two groups according to irrigation fluid temperature: isothermic (37°C, n = 178) and room temperature (22-24°C, n = 232). Propensity score matching (PSM) was applied to balance baseline characteristics, yielding 164 patients per group. Primary outcomes included shoulder circumference at 7 and 14 days postoperatively, Visual Analog Scale (VAS) scores at 2, 12, and 24 hours postoperatively, incidence of postoperative hypothermia and shivering, and University of California, Los Angeles (UCLA; ≥ 26) and American Shoulder and Elbow Surgeons (ASES; ≥ 85) scores at 6 months. Logistic regression was used to compare outcomes between groups and identify prognostic factors. RESULTS: After PSM, the isothermic group had significantly smaller shoulder circumference at both 7 and 14 days postoperatively compared with the room temperature group (both P < 0.001). VAS scores at 12 hours postoperatively were also significantly lower in the isothermic group (P < 0.001). No significant between-group differences were found in postoperative hypothermia (P = 0.077) or shivering (P = 0.448). UCLA and ASES scores at 3 and 6 months showed no significant differences (all P > 0.05). Multivariate logistic regression identified body mass index (BMI) as an independent prognostic factor (OR = 0.592, 95% CI: 0.354-0.978, P = 0.043). CONCLUSIONS: Isothermic irrigation fluid significantly reduces early postoperative swelling and pain but does not appear to influence long-term functional recovery. Its effect on postoperative hypothermia and shivering is minimal. BMI was identified as an independent prognostic factor.