Thigh Muscle Composition and Its Relationship to Functional Recovery Post Hip Fracture Over Time and Between Sexes
Marty Eastlack, Ram R. Miller, Gregory E. Hicks, Ann L. Gruber‐Baldini, Denise Orwig, Jay Magaziner, Alice S. Ryan
Abstract
BACKGROUND: Computed tomography (CT)-scan measures of muscle composition may be associated with recovery post hip fracture. METHODS: In an ancillary study to Baltimore Hip Studies Seventh cohort, older adults were evaluated at 2 and 6 months post hip fracture. CT-scan measures of muscle were acquired at 2 months. Short Physical Performance Battery (SPPB) was measured at 2 and 6 months. Generalized estimating equations were used to model the association of muscle measures and physical function, adjusting for age, sex, body mass index, and time postfracture. RESULTS: Seventy-one older adults (52% males, age 79.6 ± 7.3 years) were included. At 2-months, males had greater thigh cross-sectional area (CSA, p < .0001) and less low-density muscle (p = .047), and intermuscular adipose tissue (p = .007) than females on the side of the fracture, while females performed better on the SPPB (p = .05). Muscle measures on the fractured side were associated with function at 2 months in both sexes. Participants with the lowest tertile of muscle CSA difference at 2-months, indicating greater symmetry in CSA between limbs, performed better than the other 2 tertiles at 6-months. Males performed worse in functional measures at baseline and did not recover as well as females (p = .02). CONCLUSION: CT-scan measures of muscle CSA and fatty infiltration were associated with function at 2-months post hip fracture and with improvement in function by 6 months. Observed sex differences in these associations suggest that rehabilitation strategies may need to be adapted by sex after hip fracture.