The results of internal fixation of three- and four-part proximal humeral fractures with the Polarus nail.

Twenty-three patients with acute displaced three- and four-part fractures of the proximal humerus, including seven patients with associated shaft involvement, were treated with the Polarus intramedullary interlocking nail using a closed technique. At the 1-year follow up, the median Neer scores were 89 and 60 for the three- and four-part fractures, respectively. Three patients (13%), all of whom were in the four-part group, continued to have significant pain at final review. We found the implant to be extremely satisfactory and particularly useful in the treatment of combined neck and shaft fractures of the humerus.