"Internal fixation of proximal humeral fractures using the Polarus intramedullary nail: our institutional experience and review of the literature".

Background: The purpose of this study is to evaluate the functional outcome, union and complication rates after surgical treatment of unstable or displaced proximal humeral fractures using the Polarus intramedullary nail, by reviewing our institutional experience and the relevant current literature.

Methods: Twenty-seven patients were treated operatively for proximal humeral fracture using the Polarus nail. Fractures were classified according to Neer's classification. A number of parameters including patient demographics, mechanism of injury, operative time, time to union and complications were recorded. Functional outcome was evaluated using the Constant Shoulder Score. A comparison among functional outcomes in patients >60 years in relation to the younger ones was performed. Moreover, a review of the literature was carried out to evaluate the overall union and complication rates.

Results: Two patients lost to follow-up were excluded from the analysis. For the twenty-five patients (mean age: 61 years), the mean follow-up was 36 months. There were 7 complications (28%), including one fixation failure, four protruded screws, one superficial infection and one case of impingement. The union rate was 96% (mean time to union: 4.2 months). The mean Constant score was 74.5 (range: 48-89). Patients under the age of 60 had a better functional outcome compared to patients >60 years of age (p<0.05). From the literature review and from a total of 215 patients treated with a Polarus nail, the mean union rate was 95.8%, the overall reported complication rate, including both minor and major complications, ranged widely from 9.3% up to 70%.

Conclusions: The Polarus nail was found to be an effective implant for stabilisation of proximal humeral fractures. Functional outcome is for the vast majority of the cases excellent or good, but in elderly patients a lower Constant score can be expected.