Displaced two-part surgical-neck fractures: surgical classification and results of third-generation percutaneous intramedullary nailing

Background: Locking plate and screw constructs are the primary fixation method for displaced two-part surgical neck fractures of the proximal humerus, yet they are associated with various clinical complications. While antegrade intramedullary (IM) nailing offers a potential alternative, early-generation nail designs frequently resulted in high rates of reoperation and morbidity, including rotator cuff irritation and hardware migration.

Objective: This study aims to evaluate the clinical and radiological outcomes of a third-generation, straight, locked IM nail using a percutaneous insertion technique and to establish a classification-based strategy for optimizing nail entry points.

Key Points: A retrospective analysis was conducted on 41 patients (mean age 57 years) with displaced two-part surgical neck fractures (AO/OTA Type 11A3). The third-generation nail design features a straight profile to minimize supraspinatus tendon injury, polyethylene bushings for angular-stable proximal fixation, and tuberosity-oriented screws to prevent glenoid erosion. Surgical neck fractures were classified into three types—valgus, translated, and varus—to guide the specific percutaneous entry portal. At a mean follow-up of 26 months, all fractures achieved union with a mean neck-shaft angle of 132°. The mean Constant-Murley score was 71, and the subjective shoulder value was 80%. Complications included one case of asymptomatic partial avascular necrosis and two reoperations (5%) for hardware-related irritation.

Conclusion: Percutaneous fixation using a third-generation IM nail is a viable alternative to locking plates for two-part surgical neck fractures. The technique provides stable biomechanical fixation and high union rates while minimizing soft-tissue dissection and hardware-related complications.