FIXATION OF DISPLACED FRACTURES OF THE PROXIMAL HUMERUS WITH THE POLARUS NAIL

Abstract

Displaced proximal humeral fractures are notoriously difficult to treat. We performed internal fixation of 55 such fractures with the Polarus locked intramedullary nail. 43 (78%) were women; the mean age was 74 (range 15–91). The mechanism of injury was RTA in four, sporting injury in a further four and a simple fall in 47 (85%). According to Neer’s classification, 25 were two part fractures, 20 three part and 10 four part. 47 fractures were fixed acutely (within seven days).

The average operative time, including patient positioning was 60 minutes. In 43 cases the standard size nail was used (11mm diameter, 150mm length). In the majority of cases (80%) either two or three proximal locking screws were used. In 15 cases (27%) open reduction was necessary.

Patients were followed up for an average of eight months. Three patients needed removal of backed out proximal screws under local anaesthetic. In one patient the nail migrated superiorly and was removed once the fracture had united. One patient developed symptomatic avascular necrosis of the humeral head, successfully treated by removing the proximal screws. Two patients developed fracture malunion and underwent conversion to hemiarthroplasty. One patient required arthroscopic release of a secondary frozen shoulder.

Patients completed an Oxford Shoulder questionnaire at an average of 18 months postoperatively (range 5–42 months). The median Oxford Shoulder score was 33 (95% CI 25–38) with a mean score of 34.6

Previous studies of Polarus nailing have reported satisfactory results, but with limited follow up of a small number of patients. Our study of 55 cases with an average 18 month follow up confirms good functional rapid recovery in the majority of patients. Only five patients required removal of the metalwork and only two patients required conversion to hemiarthroplasty. We recommend the Polarus nail as a useful addition to the shoulder trauma surgeon’s armamentarium.