New intramedullary nail for the surgical neck fracture of the proximal humerus in elderly patients

Background Fractures of the proximal humerus are common and the repair of displaced fractures generally requires an operative approach. In elderly patients, osteoporosis makes internal fixation problematic and frequently contributes to failed fixation and poor clinical results. We have developed a new intramedullary nail (pin lock nail) for the repair of surgical neck fractures of the proximal humerus in patients with osteoporotic bones. A retrospective review is presented of the cases of 19 elderly patients with two-part or three-part fractures of the proximal humerus treated using the pin lock nail. Methods We treated 19 elderly patients with a mean age of 70.5 years. There were 13 two-part surgical neck fractures, 3 two-part surgical neck fractures with non-displaced greater tuberosity fracture, and 3 three-part surgical neck fractures with greater tuberosity fracture. All fractures were treated using the pin lock nail. Clinical results were evaluated using the Japanese Orthopaedic Association score at the last follow-up examination. On radiographic evaluation, duration to bone union of the fracture, backing out of the pin and screw, penetration of the proximal pin, and varus angulations of the humeral neck were examined. Results Mean duration of follow-up was 14 months (range 6–54 months). All fractures had united at an average of 3.3 months after surgery. No backing out of the pin and screw or penetration of the proximal locking pin was seen at the time of last follow-up. Thirteen of the 16 patients had no or minimal varus angulations of the humeral neck (≤10°). The mean overall JOA score was 84.3 points (range 65.5–100). Conclusions Our data show that using the pin lock nail for the treatment of two-part and three-part humeral fractures is a reliable procedure, providing good results with careful postoperative management.