The treatment of established non-union of the proximal humerus using the Polarus locking intramedullary nail

INTRODUCTION: Non-union following fracture of the proximal humerus is not uncommon, particularly in the elderly. This can be associated with significant morbidity due to pain, instability and functional impairment. The Polarus device (Acumed) is a locked, antegrade intramedullary nail designed to stabilize displaced 2-, 3- and 4-part fractures of the proximal humerus. We report our experience with the Polarus nail for the treatment of established non-union of the proximal humerus. MATERIALS AND METHODS: A total of 7 Polarus nails were inserted for the treatment of non-union of the proximal humerus between June 2000 and July 2007. Each fracture site was opened, debrided, stabilized with a Polarus nail and then grafted with autologous cancellous iliac crest bone. The time between injury and surgery ranged from 6 to 102 months. One patient had undergone previous fixation of her fracture using Rush intramedullary rods. All patients were females, and mean age at surgery was 63.6 years (range, 49-78 years). A retrospective review of notes and radiographs was carried out. Patients were reviewed at varying intervals postoperatively (range, 13-68 months) and assessed using the Constant shoulder-scoring system. RESULTS: All un-united fractures progressed to union. There were no wound complications and no postoperative nerve palsies. Functional outcome was good, even in those cases with a long interval between injury and surgery. The mean Constant score was 63 (range, 54-81). Migration of a single proximal locking screw was seen in 2 patients, and these screws required removal at 5 and 12 months, respectively, postoperatively. CONCLUSION: In our experience, a locked proximal humeral nail used in conjunction with autologous bone grafting is an excellent device for the treatment of proximal humerus non-unions.