Innovative intramedullary nail system with internally locking: A safe alternative fixation technique for humerus shaft fracture that reduces the risk of the iatrogenic radial nerve injury and surgical time.

PURPOSE: Humeral shaft fractures may be managed conservatively or operatively; however, increasing non-union and complications after non-operative treatment have renewed interest in intramedullary fixation. Innovative intramedullary nails with distal internally locking, requiring neither fluoroscopy nor external guidance, aim to reduce surgical time, simplify the procedure, and minimise the risk of iatrogenic radial nerve injury. This study evaluates the clinical and radiological outcomes of a humeral nail utilising distal internally locking.

MATERIAL AND METHOD: A retrospective review included 75 patients treated with antegrade intramedullary nailing for humeral shaft fractures between 2020 and 2025. Patients with pathological fractures, preoperative radial nerve palsy, concomitant upper-limb injuries, or insufficient follow-up were excluded. Operative parameters, complications, union time, hospital stay, and return to activity were recorded. Functional outcomes were assessed at final follow-up using the Constant-Murley score, QDASH, VAS, and shoulder range of motion.

RESULTS: Operative time was 46.4 ± 11.1 min, and hospital stay was 3.2 ± 0.8 days. Radiological union occurred at 13.0 ± 2.9 weeks, and patients returned to daily activities at 12.6 ± 2.5 weeks. No postoperative radial nerve palsy or infections were observed. One non-union required exchange nailing, and three cases of proximal screw irritation resolved after screw removal. Functional outcomes were excellent overall, with a Constant score of 93.4 ± 9.4, QDASH of 2.9 ± 6.0, VAS of 0.8 ± 1.3, and near-complete restoration of shoulder mobility.

CONCLUSION: Intramedullary nailing with an internally distal locking mechanism, without the need for fluoroscopy and an external guidance system, offers a safe and efficient treatment option for humeral shaft fractures. This technique significantly reduces surgical time and the risk of iatrogenic radial nerve injury, while maintaining excellent union rates and functional outcomes. This system represents a reliable alternative to traditional interlocking nails and plate fixation, particularly in clinical settings where minimising surgical time is essential.

CLINICAL TRIAL REGISTRATION: Not applicable.