Femur bone mineral density is independently associated with functional recovery after hip fracture in elderly women

Abstract

Objective: To evaluate the association between femur bone mineral density (BMD) and functional recovery after hip fracture.

Design: Cross-sectional study.

Setting: Rehabilitation hospital in Italy.

Participants: A total of 233 of 263 white women with hip fracture consecutively admitted to a rehabilitation hospital.

Interventions: Not applicable.

Main outcome measures: Patients underwent BMD assessment by dual-energy x-ray absorptiometry (DXA) at the proximal femur (5 sites) on admission. Functional recovery was evaluated by using Barthel Index scores.

Results: A positive correlation was found between BMD and Barthel Index scores assessed on both admission and discharge (r range,.16-.24, depending on the site of BMD measurement). Linear multiple regression showed that the association between BMD and Barthel Index score was independent of 10 confounding variables: age, body mass index, fracture type, pressure ulcers, cognitive impairment, neurologic diseases, total lymphocyte count as a nutritional index, time between fracture occurrence and DXA assessment, comorbidity, and surgical procedure. Conversely, no significant associations were found between BMD and the change in Barthel Index score attributable to rehabilitation.

Conclusions: In the study population, femur BMD was an independent predictor of the functional recovery assessed by Barthel Index score after hip fracture, but not of the change in the functional score resulting from rehabilitation.