Minimally invasive plate osteosynthesis of proximal humerus fractures through a modified anterior subacromial approach

Abstract

Purpose Proximal humeral fractures are usually treated through the deltopectoral approach and direct lateral deltoid-split approach. ​The direct lateral deltoid-split technique has a minor incisional injury but restricted exposure, whereas the deltopectoral approach has a somewhat significant incisional injury but greater exposure is possible. ​To combine the advantages of a less invasive incision with enough exposure, this study's objectives was to propose a modified anterior subacromial (MAS) approach for treating proximal humerus fractures and to assess its radiological and clinical results. Methods A retrospective analysis was performed on 35 patients with proximal humerus fractures treated with a MAS approach, including 15 males and 20 females, with an average age of 61.7 years. According to the Neer classification, seven patients had 2-part fractures, 10 patients had 3-part fractures, and 18 patients had 4-part fractures. Quantitative variables including operative time, incision length, follow-up time, and Constant-Murley score for shoulder function, fracture union time, and neck-shaft angle (NSA) were recorded. Qualitative variables including intraoperative and postoperative complications were assessed. Results All cases achieved bony union, and the average healing time was 11.8±1.4 weeks (range, 10–15 weeks). During a mean follow-up of 22.1±5.8 months (range, 14-31 months), the mean incision length was 80.7±2.5 mm (range, 76–90 mm). The pain score at the last follow-up was 1.63±0.7 (range, 1–3). The Constant-Murley score of shoulder joint function at the last follow-up was 89.6±2.9 (range, 84–95). The complications such as ischemic necrosis of the humeral head and varus collapse at the fracture site, as well as sensory deficits in the distribution of the axillary nerve or anterior deltoid paralysis, were not observed. The mean NSA at the last follow-up was 133.4±3.1° (range, 128°-138°). In terms of statistical significance, there was no difference between fractures of Neer types 2, 3, and 4. Conclusion The MAS approach has the properties of minimally invasive incision and effective exposure, which has advantages in reduction, plate placement, and inferomedial calcar screw (IMCS) placement of proximal humeral fractures. This approach is a useful alternative to the deltopectoral approach or direct lateral deltoid-split approach in the treatment of proximal humeral fractures.