Focal cortical thinning is associated with lower thigh muscle area in hip fractures and controls.
Sarcopenia, Muscle and Falls
Biomechanics and Bone Quality
Poster Sessions, Presentation Number: MO0398
Session: Poster Session III
Monday, October 12, 2015 12:30 PM - 2:30 PM, Washington State Convention Center, Discovery Hall - Hall 4BC
* , UNITED KINGDOM, Graham Treece, Engineering Division of the Department of Engineering, University of Cambridge, Fjola Johannesdottir, Department of Medicine, Kenneth Poole, Department of Medicine
Low muscle strength and focal osteoporosis are known risk factors for hip fracture. However, associations between thigh muscle compartment size and proximal femur 3D bone mass distribution in hip fracture are less clear.
SUBJECTS AND METHODS.
A total of 84 CT scans consisting of age matched hip fractured patients (n=40) and non-hip fracture controls (n=43) were analyzed (Mean age 78 years, range 61-92). Fracture cases were age matched with patients undergoing routine CT. Age, height and weight were recorded. The thigh muscle compartment was determined just below lesser trochanter using 10 x 1mm slice mean tissue values. Muscle and fat tissue separation and areal bone density (BMD) analysis were done using QCT Pro (5.1.3). Proximal femur bone mass characteristics were measured with Stradwin 5.0 software. Significant associations between muscle cross sectional area and bone parameters, including cortical mass (CM) and endocortical trabecular density (ECTD), were color mapped using SurfStat Matlab toolbox. An independent-samples t-test was conducted to compare the groups.
A lower thigh muscle cross-sectional area (cm2) was seen in fractures (Mean=91.7, Standard deviation=13.9) compared to controls (97.8, 12.7); t(81)=-2.1, p<0.05. Across all patients, higher thigh muscle area was associated with more cortical mass in patches of bone known to associate with hip fracture (Picture). Fracture patients had lower body mass index (22.8, 4.4) than control (26.1, 4.9) group; t(81)=-3.21, p<0.01.
A lower areal BMD (g/cm2) was seen in fractures (0.624, 0.162) versus controls (0.698, 0.10) in total hip;t(81)=-2.57, p=0.01 and in femoral neck ((0.539, 0.120) vs. (0.651, 0.81)), respectively; t(81)=-5.0, p<0.001. There was no difference in the amount of intramuscular fat between the groups. Adjusting muscle and fat areas for height2, did not change the results. The association persisted after adjusting for age and volumetric bone size.
Femoral cortical bone distribution is associated with thigh muscle cross-sectional area, in fracture critical zones. In addition, the muscle compartment size and bone mass are significantly lower in hip fracture patients. Smaller muscle area is a modifiable risk factor suggested to contribute towards weaker bone characteristics and hip fractures.
* Presenting Authors(s):
, UNITED KINGDOM