Orthopedic surgery is among the fastest growing surgical specialties, with over 22 million orthopedic surgical procedures performed worldwide in 2017.1 Regional anesthesia has become a preferred anesthetic technique for many orthopedic operations, with studies showing that in many clinical circumstances, it has superior pain control, reduced opioid use and related side effects, earlier mobilization, shorter hospital stays, decreased intraoperative blood loss, and improved patient satisfaction compared to general anesthesia. There are several forms of regional anesthesia that are widely used for orthopedic surgery in the upper extremities.
By selectively interrupting nerve conduction, regional blocks can provide both intraoperative anesthesia and postoperative analgesia, making them particularly valuable in orthopedic practice, where postoperative pain is a major concern. Regional anesthesia is classified into neuraxial techniques (e.g., spinal, epidural, or combined spinal-epidural), which target spinal nerve roots and are commonly used for abdominal and lower extremity procedures, and peripheral nerve blocks (PNB), which involve injecting local anesthetic near specific nerves to provide surgical anesthesia or postoperative analgesia. While neuraxial anesthesia provides a more widespread blockade, PNBs offer more targeted anesthesia, often guided by ultrasound for precision and safety.
Orthopedic surgery in the upper extremities requires a detailed knowledge of the brachial plexus anatomy, which is where most of the muscular and cutaneous nerve supply in the upper extremities stems from, making it a major target for regional anesthesia for these procedures. This major network of nerve fibers is comprised of ventral nerve roots that give rise to trunks, divisions, cords, and terminal branches.2 These branches provide most of the sensory and motor innervation to the upper extremities, with additional contributions from the cervical plexus and the T2 nerve root. Clinically, the brachial plexus can be blocked at four levels: interscalene blocks can suppress the roots and/or the trunks, supraclavicular blocks can inhibit the trunks and/or divisions, infraclavicular blocks act on the cords, while axillary blocks intervene with the terminal branches.
The interscalene block anesthetizes the C5-C8 spinal cord roots and parts of the cervical plexus (C3-C4), making it especially effective for procedures involving the shoulder, clavicle, and proximal humerus.3 This block targets the brachial plexus between the anterior and middle scalene muscles, lateral to the carotid artery and the internal jugular vein. While generally safe, this block carries a high risk of phrenic nerve blockade and other complications such as Horner’s syndrome and recurrent laryngeal nerve blockade (which can result in temporary hoarseness). Rarer effects include pneumothorax, epidural injection, or spinal cord damage. As such, these blocks are contraindicated in patients with severe pulmonary disease. In otherwise healthy individuals, respiratory compromise is unlikely, and the block is well tolerated.
The supraclavicular block anesthetizes the brachial plexus at the trunks and divisions, providing dense anesthesia for the upper extremities, including the shoulder, arm, forearm, and hand. Due to this extensive coverage, this block is colloquially referred to as the “spinal of the arm.” Pneumothorax is a rare complication of this block (0.6% to 6.1%) but can be avoided with proper ultrasound usage.4 Other adverse events include phrenic nerve blockade (which can result in diaphragm weakness) and laryngeal nerve blockade (which can result in hoarseness).
The infraclavicular block targets the brachial plexus at the cords before the branching of the axillary and musculocutaneous nerves, which results in anesthesia of the arm, elbow, forearm, and hand. This block differs from the supraclavicular block since it features lower risk of pneumothorax and does not provide coverage of the shoulder.
Finally, the axillary block is performed at the terminal branches, providing anesthesia to the upper limb from the mid-arm distally to the elbow, forearm, and hand. Under ultrasound guidance, anesthesiologists may identify the axillary artery and the medial, ulnar, radial, and musculocutaneous nerves. This block carries risks of hematoma and intravascular injection due to its proximity to the axillary artery and vein.1
Regional anesthesia plays a crucial role in modern orthopedic surgery, offering targeted, effective, and safer alternatives to general anesthesia, particularly in procedures involving the upper extremities. A thorough understanding of the brachial plexus anatomy allows anesthesiologists to select the most appropriate block (i.e., interscalene, supraclavicular, infraclavicular, or axillary) based on the surgical site. Each approach provides distinct advantages and risk profiles, emphasizing the importance of individualized technique selection and ultrasound guidance to enhance efficacy and minimize complications. As regional anesthesia continues to evolve, its integration into orthopedic practice remains vital for optimizing perioperative outcomes, improving patient comfort, and advancing surgical care.
References
- Kamel I., Ahmed M.F., Sethi A., Regional Anesthesia for Orthopedic Procedures: What Orthopedic Surgeons Need to Know. World Journal of Orthopedics. 2022;13(1):11-35. https://doi.org/10.5312/wjo.v13.i1.11
- Bruce B., Green A.R., Blaine T.A., Wesner L.R., Brachial Plexus Blocks for Upper Extremity Orthopaedic Surgery. 2012;20(1):38-47. https://doi.org/10.5435/jaaos-20-01-038
- Srikumaran U., Stein B.E., Tan E.W., Freehill M.T., Wilckens J.H., Upper-Extremity Peripheral Nerve Blocks in the Perioperative Pain Management of Orthopaedic Patients. The Journal of Bone and Joint Surgery-American Volume. 2013;95(24):e197-113. https://doi.org/10.2106/jbjs.l.01745
- Perlas A., Lobo G., Lo N., Brull R., Chan V.W.S., Karkhanis R., Ultrasound-Guided Supraclavicular Block. Regional Anesthesia and Pain Medicine. 2009;34(2):171-176. https://doi.org/10.1097/aap.0b013e31819a3f81
