The Analgesic Effect of Infraspinatus Teres Minor Block in Scapular Fracture Surgery: A Randomized Controlled Trial

The purpose of this study was to evaluate the analgesic effect of infraspinatus teres minor (ITM) block in scapular fracture (SFs) surgery.

A prospective, randomized, controlled trial was carried out on patients undergoing SFs surgery. These patients were randomly allocated to either receive an ultrasound-guided ITM block in conjunction with general anesthesia (ITM group) or a sham intervention along with general anesthesia (Sham group). The primary outcome measure was the postoperative pain intensity evaluated by the visual analog scale (VAS) at 0.5, 2, 6, 12, 24, and 48 hours after surgery. Secondary outcome measures included intraoperative opioid utilization, postoperative analgesic needs, the time to the first rescue analgesia, QoR-15 scores, and alterations in diaphragmatic activity.

The ITM group showed significantly lower VAS_pain AUC within 48 hours postoperatively than the Sham group (P = 0.009). Repeated-measures two-way ANOVA revealed a significant group × time interaction for VAS_pain changes (F _5,350 = 10.39, P < 0.001). VAS_pain was significantly lower in the ITM group at 0.5, 2, 6, 12, and 24 hours (all P < 0.001), but not at 48 hours (P = 0.232). Intraoperative sufentanil consumption was significantly lower in the ITM group (P < 0.001). Rescue analgesic use was also reduced in the ITM group within 24 hours (P = 0.007) and 48 hours (P = 0.012). The time to first rescue analgesia request was longer in the ITM group (log-rank, HR = 1.629; 95% CI: 1.104-2.583; P = 0.005). QoR-15 scores were higher in the ITM group at 24 hours (P = 0.025) and 48 hours (P < 0.001). No significant difference was observed in ipsilateral diaphragm function between groups (P = 0.113).

The ITM block demonstrates significant analgesic effectiveness in scapular surgery and holds promise for broader application.

The study was registered with the Chinese Clinical Trial Registry (www.chictr.org.cn) on December 9, 2024, under registration number ChiCTR2400093589.