To assess the effectiveness of optimal treatment of proximal humeral fractures and humeral shaft fractures in elderly patients with osteoporosis using the Polarus nail.

Twenty-three patients with proximal humeral and humeral shaft fractures in elderly osteoporosis patients were treated using the Polarus intramedullary nail. Nine patients had proximal humeral fracture, 10 had humeral shaft fracture and 4 had the proximal humeral frac-ture extended diaphyseally. Radiological outcomes included the bone-union and the degree of re-sidual deformity. The residual deformities of the proximal humerus were assessed by the neck-shaft angle and the shaft angulation. Clinical outcome was assessed with the American Shoulder and Elbow Surgeons (ASES) score.

All cases had bony union and the mean union period was 16.5 weeks. The average neck/shaft alignment at the time of bone union was 135° and varus deformities of neck-shaft angle was not seen in all patients. Varus shaft angulation was seen in 5 patients. The mean ASES score after surgery was 86.7 points.

The Polarus intramedullary nail is effective for the treatment of proximal humeral and humeral shaft fractures in elderly patients with osteoporosis because it not only enables early postoperative mobilization, but also obtains bone-union without avascular necrosis and nonunion.