Extensile Lateral Approach with Radial Nerve Release in the Semi-Lateral Position for Humeral Shaft and Periprosthetic Fractures: A Technical Note

Background Identification and protection of the radial nerve remain major challenges during surgical treatment of humeral shaft fractures (HSFs) and periprosthetic humeral fractures (PHFs). Conventional anterolateral and posterior approaches may limit reliable radial nerve visualization or restrict anterior or posterior exposure. Here, we describe an extensile lateral approach performed in the semi-lateral position that facilitates early identification and protection of the radial nerve while exposing the anterior, lateral, and posterior aspects of the humerus to manage HSFs and PHFs. Methods The patient is positioned in the semi-lateral position with the affected side elevated approximately 30°–45°, facilitating gravity-assisted retraction of the posterior musculature and enabling visualization of the anterior and posterior aspects of the humerus. First, the inferior lateral cutaneous nerve of the arm is identified and traced proximally to expose the radial nerve. Subsequently, the radial nerve is released from the lateral intermuscular septum to increase its mobility and reduce tension during fracture reduction and plate fixation. Subperiosteal dissection provides circumferential exposure of the humeral shaft. This approach can be extended proximally toward the axillary nerve, allowing exposure of almost the entire humeral shaft when required. Results We applied this technique in the 78-year-old female patient with a periprosthetic humeral fracture. Stable fixation and uneventful bone union without radial nerve palsy were achieved. Conclusion Our extensile lateral technique combines preoperative ultrasonographic mapping of the radial nerve, semi-lateral positioning, release of the lateral intermuscular septum with preservation of the cutaneous perforators of the posterior radial collateral artery, and elevation of the lateral head of the triceps. This technique may enable early identification and reliable protection of the radial nerve while providing wide exposure of the anterior, lateral, and posterior aspects of the humerus through a single approach, making it a useful surgical option for HSFs and PHFs.