Outcome after femoral shaft fractures in the elderly: the effects of altitude.

Background: A paucity of knowledge currently exists surrounding the effects of altitude on femur fracture outcomes. The purpose of this study was to determine if altitude plays a significant role in determining the outcome of femoral shaft fractures in the elderly. The authors hypothesized that the additional cardiopulmonary stress of altitude would promote poorer outcomes of those individuals treated at high altitude, especially those individuals whose home residence was located at low altitude.

Methods: Medicare part A claims data between 1996 and 2000 were searched and patients with open or closed femoral shaft fractures were identified for the study. The treatment altitude and home residence altitude for each patient was recorded by cross-matching Zip Code information provided in the Medicare part A database with a database providing altitude data by Zip Code. The patients were grouped both by the altitude of treatment and by the difference between the altitude of residence and the altitude of treatment. The data was analyzed for outcome measurements.

Results: The claims data search identified 30,168 patients for the study. For the entire sample, the in-hospital mortality was 4.2%, 30-day mortality was 8.3%, 1-year mortality was 26.3%, and complication rate was 5.7%. Length of stay results demonstrated that patients treated at medium or high altitude had statistically shorter lengths of stay than those treated at low altitude (p < 0.01). Mortality rates and complications were not statistically different for those treated at high, medium, or low altitude with the exception of a slightly lower in-hospital mortality in the medium treatment altitude group (p = 0.04). Additionally, those patients who resided more than 1000 ft below the treatment altitude had shorter lengths of stay than those who resided more than 1000 ft above the treatment altitude (p < 0.01). Those patients who lived within 1000 ft of the treatment hospital or more than 1000 ft below the treatment hospital had fewer days in the intensive care unit (p < 0.01, p = 0.01; respectively).

Conclusions: Femoral shaft fractures treated at altitude were not associated with increased morbidity and mortality as compared to femoral shaft fractures treated at low altitude. Additionally, patients residing at low altitude and treated at high altitude did not suffer increased morbidity or mortality.