Baltimore Hip Studies

Over the past 17 years, researchers in the Division of Gerontology have been conducting studies on recovery from hip fracture.

The goal of this work is to describe changes which occur post fracture and identify ways to optimize recovery. This work has extended from examination of changes in functional ability to changes in bone mineral density, and examination of markers of bone turnover, and the design and evaluation of interventions to enhance recovery from hip fracture. The attached figure shows the progression and direction of this work.

The first project, initiated in 1983, detailed mortality and changes in physical and instrumental activities of daily living for one year post fracture in a cohort of 982 admissions to seven Baltimore area hospitals (1984-86). The second project extended this description of recovery to examine changes in physical capacity (i.e., mobility and lower extremity neuromuscular functioning), cognition, affect and social activity. In this project, 804 hip fracture patients entering eight Baltimore area hospitals were enrolled (1990-91) and followed for two years post fracture. In this study, patients were observed performing a series of tasks which permit assessment of neuromuscular functioning. Changes in six important quality of life domains during the two years following a hip fracture have been described. In addition, this project was designed to identify potentially modifiable determinants of the quality of life domains.

The third study extends this work on recovery to a physiological level through an examination of changes in bone mineral density (BMD) and muscle mass and strength post fracture. In this project, 223 hip fracture patients entering two Baltimore area hospitals (1992-96) have been enrolled and followed for one year post fracture. These patients have had BMD and muscle mass assessed using dual energy x-ray bone densitometry. They also have had muscle strength tested and have been observed while performing neuromuscular tasks and activities of daily living. As part of this project, serum and urine from all surviving patients were collected and stored at five points following their hip fracture (3, 10, 60, 180, and 360 days). Post-fracture changes in insulin-like growth factor-I (IGF-I) and 11 markers of bone metabolism were described, and the association between these changes and changes in BMD, muscle mass and strength, as well as changes in neuromuscular functioning and physical activity are being evaluated. Data from these Baltimore Hip Studies projects are being used to chart the sequelae of hip fracture in terms of mortality, loss of function and changes in body composition. This work has recently been extended to design and implement interventions to improve recovery from hip fracture. The initial interventions being designed are the provision of medications to reduce bone loss and a home-based aerobic and strengthening exercise program to reduce losses in bone, muscle and function. This intervention research provides a foundation for future studies of other programs aimed at improving the well-being of older persons following a hip fracture.

Data currently exist on over 2000 hip fracture patients who have been identified at the time of their initial hospitalization and followed prospectively for one to two years post fracture. These data are being used as the basis for publications and to identify promising interventions for enhancing recovery from hip fracture.