title: Asymmetry in CT Scan Measures of Thigh Muscle 2 Months After Hip Fracture: The Baltimore Hip Studies.
abstract: BACKGROUND
  Hip fracture is an important problem for older adults with significant functional consequences. After hip fracture, reduced muscle loading can result in muscle atrophy.
  
  
  METHODS
  We compared thigh muscle characteristics in the fractured leg with those in the nonfractured leg in participants from the Baltimore Hip Studies 7th cohort using computed tomography (CT) scan imaging.
  
  
  RESULTS
  At 2 months postfracture, a single 10-mm axial CT scan was obtained at the midthigh level in 47 participants (26 men and 21 women) with a mean age of 80.4 years (range 65-96), and thigh muscle cross-sectional area (CSA), CSA of intermuscular adipose tissue (IMAT), as well as mean radiological attenuation were measured. Total thigh muscle CSA was less on the side of the fracture by 9.2 cm(2) (95% CI: 5.9, 12.4 cm(2)), whereas the CSA of IMAT was greater by 2.8 cm(2) (95% CI: 1.9, 3.8 cm(2)) on the fractured side. Mean muscle attenuation was lower on the side of the fracture by 3.61 HU (95% CI: 2.99, 4.24 HU).
  
  
  CONCLUSIONS
  The observed asymmetry is consistent with the effect of disuse and inflammation in the affected limb along with training effects in the unaffected limb due to the favoring of this leg with ambulation during the postfracture period.
authors.affiliation: GlaxoSmithKline, Research Triangle Park, North Carolina Division of Gerontology, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore ram.6.miller@gsk.com.
authors.forename: Ram R
authors.initials: RR
authors.lastname: Miller
authors.affiliation: Department of Physical Therapy, Arcadia University, Glenside, Pennsylvania.
authors.forename: Marty
authors.initials: M
authors.lastname: Eastlack
authors.affiliation: Department of Physical Therapy, University of Delaware, Newark.
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Hicks
authors.affiliation: Division of Gerontology, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore.
authors.forename: Dawn E
authors.initials: DE
authors.lastname: Alley
authors.affiliation: Division of Biostatistics and Bioinformatics, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore.
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Shardell
authors.affiliation: Division of Gerontology, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore.
authors.forename: Denise L
authors.initials: DL
authors.lastname: Orwig
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pennsylvania.
authors.forename: Bret H
authors.initials: BH
authors.lastname: Goodpaster
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pennsylvania.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Chomentowski
authors.affiliation: Division of Gerontology, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore.
authors.forename: William G
authors.initials: WG
authors.lastname: Hawkes
authors.affiliation: Department of Medicine, University of Maryland School of Medicine, Baltimore.
authors.forename: Marc C
authors.initials: MC
authors.lastname: Hochberg
authors.affiliation: Longitudinal Studies Section, National Institute on Aging, Baltimore, Maryland.
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.affiliation: Division of Gerontology, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore.
authors.forename: Jay
authors.initials: J
authors.lastname: Magaziner
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging; D000368:Aged; D000369:Aged, 80 and over; D015142:Baltimore / Q000453:epidemiology; D005260:Female; D006620:Hip Fractures / Q000453:epidemiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
keywords: Computed tomography; Hip fracture; Muscle composition; aged.