Efficacy of Ultrasound-Guided Superior Trunk Block for Postoperative Analgesia After Proximal Humerus Surgery: A Randomised Controlled Trial

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Korgün Ökmen, Gökberk Kürşat Ülker, Durdu Kahraman Yıldız, Aycan Kurtarangil Doğan

Volume 9 · Issue 2 · pp. 435–442

Published: 2026-06-30

Abstract

Aim: Moderate to severe pain is common after proximal humerus surgery, often requiring opioid-based analgesia. Superior trunk block (STB), a selective brachial plexus block, has been proposed as an alternative for postoperative pain control. This study aimed to evaluate the analgesic efficacy of STB compared with intravenous patient-controlled analgesia (PCA) following proximal humerus surgery. Methods: This prospective randomized controlled trial included 60 patients undergoing proximal humerus surgery who were randomly assigned to two groups. In the STB group (n = 30), patients received an ultrasound-guided superior trunk block with 10 mL of 0.25% bupivacaine in combination with intravenous PCA. The control group (n = 30) received intravenous PCA alone. The primary endpoint was pain level assessed using a visual analogue scale (VAS) at rest at 1, 2, 6, 12, and 24 hours postoperatively. Secondary endpoints included total tramadol consumption at 12 and 24 hours, subjective respiratory complaints, adverse effects, and the requirement for rescue analgesia. Results: The STB group had significantly lower VAS scores at all time points (p < 0.001). Tramadol consumption at 12 and 24 hours was also significantly lower in the STB group (p < 0.001). Paracetamol was required by 12% of control patients but by none in the STB group (p = 0.007). Adverse effects were similar; two STB patients developed Horner’s syndrome, and no respiratory complications were observed. Conclusion: Ultrasound-guided STB provided effective postoperative analgesia for the shoulder and upper arm after proximal humerus surgery, reducing opioid consumption with minimal respiratory side effects.

Keywords: Proximal humerus fracture; nerve block; superior trunk block; analgesia; brachial plexus

1. Introduction

Pain following proximal humerus fracture surgery is often moderate to severe. Ineffective postoperative pain management can hinder the initiation of physical therapy and early mobilization, ultimately affecting the shoulder joint and potentially contributing to the development of neuropathic pain features1.

The innervation of the shoulder and proximal humerus involves multiple nerve roots, making comprehensive analgesia challenging. A single brachial plexus block may be insufficient or may require large volumes of local anesthetic2,3. Several regional anesthesia techniques, including supraclavicular, interscalene, and axillary blocks, are commonly used for proximal humerus surgery. However, these approaches may have limitations related to inconsistent coverage of all relevant nerves and the potential for unwanted side effects2–4.

The superior trunk block (STB), performed proximal to the branching of the suprascapular nerve, has emerged as a more selective regional anesthesia technique. It has the potential to provide effective analgesia for both the shoulder and proximal arm while potentially reducing complications such as phrenic nerve paralysis, long thoracic nerve injury, and dorsal scapular nerve damage2–4. Therefore, this study aimed to evaluate the analgesic efficacy of ultrasound-guided STB compared with intravenous PCA for postoperative pain management following proximal humerus surgery.

2. Materials and Methods

2.1. Study Design and Setting

This prospective, randomized, controlled, single-blind clinical trial was conducted after obtaining approval from the institutional review board (Ethics Committee Approval No: 2022/06-12) and registration in the clinical trials registry (ClinicalTrials.gov Identifier: NCT05474014). The study adhered to the ethical principles of the Declaration of Helsinki. Written informed consent was obtained from all participants prior to enrollment.

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Cite this article

Korgün Ökmen, Gökberk Kürşat Ülker, Durdu Kahraman Yıldız, Aycan Kurtarangil Doğan. Efficacy of Ultrasound-Guided Superior Trunk Block for Postoperative Analgesia After Proximal Humerus Surgery: A Randomised Controlled Trial. Journal of Cukurova Anesthesia and Surgical Sciences. 9(2):435-442. https://doi.org/10.36516/jocass.1902544

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