Hybrid deltopectoral and Minimally Invasive Plating for complex proximal humeral fractures extending into the shaft: A prospective case series

Proximal humerus fractures with diaphyseal extension present a unique surgical dilemma. While the deltopectoral approach allows for anatomic reconstruction of the articular segment, and Minimally Invasive Plate Osteosynthesis (MIPO) is advocated for humeral shaft fractures, textbook guidelines caution against MIPO for fractures extending into metaphyseal regions. This study evaluates a combined protocol for these complex injuries. A prospective case series of 20 consecutive patients with OTA/AO 11-C or 12-C fractures treated between 2021-2023. The technique involved: 1) Anatomical reduction and provisional K-wire fixation of the proximal fragment via a standard deltopectoral approach. 2) Submuscular tunneling along the anterolateral humerus. 3) A 3-4 cm distal anterolateral incision for radial nerve exploration/visualization and plate insertion. 4) Submuscular passage and percutaneous fixation of a long PHILOS plate, utilizing the preoperative contralateral arm rotational profile for alignment. All patients completed 24-month follow-up. The union rate was 100% at a mean of 14.2 weeks. Complications included one transient radial nerve neuropraxia (5%, resolved by 6 months), one case of Complex Regional Pain Syndrome Type I (5%, resolved after a single stellate ganglion block), and one plate fracture (5%) in a non-compliant patient who returned to heavy hammering prematurely, successfully revised. There were no infections, nonunions, or symptomatic malunions. Mean final Constant-Murley and DASH scores were 84 and 18, respectively. The combined deltopectoral and MIPO technique using a PHILOS plate is a safe and effective strategy for complex proximal-shaft humeral fractures. It allows direct articular reconstruction while providing biological fixation for the shaft. Meticulous preoperative planning, selective radial nerve management, and adherence to rehabilitation are critical for success. This method challenges the conventional restriction of MIPO to pure diaphyseal fractures. 4