Contribution of trochanteric soft tissues to fall force estimates, the factor of risk, and prediction of hip fracture risk
Contribution of trochanteric soft tissues to fall force estimates, the factor of risk, and prediction of hip fracture risk
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DOI：
10.1359/jbmr.070309
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发表时间：
2007-06-01
影响因子：
6.2
通讯作者：
Delmas, Pierre D.
中科院分区：
文献类型：
--
作者：
Bouxsein, Mary L.;Szulc, Pawel;Delmas, Pierre D.
我们比较了21名发生髋部骨折的绝经后妇女和42名年龄匹配的对照组的股骨粗隆软组织厚度、股骨骨密度和坠落力与股骨力量的比率(即危险因素)。股骨粗隆软组织厚度减少、股骨aBMD低、坠落力与股骨力量之比增大(即风险系数)与髋部骨折风险增加相关。简介：粗隆软组织厚度对髋部骨折风险的贡献尚未完全了解。一种评估髋部骨折风险的生物力学方法可以通过结合股骨粗隆软组织的力衰减效应来改进，该方法比较侧向跌倒时施加在髋关节上的力与股骨力量。材料和方法：我们在49具53-99岁的人体身体标本中确定了股骨面积骨密度(ABMD)和股骨失效负荷之间的关系。我们比较了21名发生髋部骨折的绝经后妇女和42名年龄匹配的对照组的股骨骨密度、股骨粗隆软组织厚度和坠落力与骨骼强度的比率(即髋部骨折的危险因素，Phi)，并考虑了股骨粗隆软组织的力量衰减特性。(0.92+/-0.44比0.65+/-0.50；P=0.04)。结果：股骨骨密度与股骨失效载荷密切相关(r(2)=0.73-0.83)。年龄、身高和体重没有差异；然而，髋部骨折女性的股骨全骨密度(OR=2.06；95%CI，1.19-3.56)和粗隆间软组织厚度(OR=1.82；95%CI，1.01，3.31)较低。合并粗隆间软组织厚度测量使坠落力的估计值降低了50%。在考虑了股骨粗隆软组织的力量衰减特性后，病例组跌倒力量与股骨强度的比率比对照组高50%(分别为0.92+/-0.44和0.65+/-0.50；p=0.04)。结论：通过结合基于股骨aBMD和身体股骨骨强度之间的经验关系对股骨强度的估计，以及在侧向跌倒时施加于髋关节的载荷(考虑了股骨粗隆间软组织的厚度)，可以计算基于生物力学的髋部骨折风险估计。我们的研究结果表明，粗隆软组织厚度可能通过减弱侧向跌倒时施加在股骨上的力来影响髋部骨折的风险，并为改进粗隆软组织的测量和研究更大范围的队列以确定粗隆软组织厚度是否独立于骨密度而影响髋部骨折风险提供了理论基础。
We compared trochanteric soft tissue thickness, femoral aBMD, and the ratio of fall force to femoral strength (i.e., factor of risk) in 21 postmenopausal women with incident hip fracture and 42 age-matched controls. Reduced trochanteric soft tissue thickness, low femoral aBMD, and increased ratio of fall force to femoral strength (i.e., factor of risk) were associated with increased risk of hip fracture.Introduction: The contribution of trochanteric soft tissue thickness to hip fracture risk is incompletely understood. A biomechanical approach to assessing hip fracture risk that compares forces applied to the hip during a sideways fall to femoral strength may by improved by incorporating the force-attenuating effects of trochanteric soft tissues.Materials and Methods: We determined the relationship between femoral areal BMD (aBMD) and femoral failure load in 49 human cadaveric specimens, 53-99 yr of age. We compared femoral aBMD, trochanteric soft tissue thickness, and the ratio of fall forces to bone strength (i.e., the factor of risk for hip fracture, Phi), before and after accounting for the force-attenuating properties of trochanteric soft tissue in 21 postmenopausal women with incident hip fracture and 42 age-matched controls. (0.92 +/- 0.44 versus 0.65 +/- 0.50, respectively; p = 0.04).Results: Femoral aBMD correlated strongly with femoral failure load (r(2) = 0.73-0.83). Age, height, and weight did not differ; however, women with hip fracture had lower total femur aBMD (OR = 2.06; 95% CI, 1.19-3.56) and trochanteric soft tissue thickness (OR = 1.82; 95% CI, 1.01, 3.31). Incorporation of trochanteric soft tissue thickness measurements reduced the estimates of fall forces by -50%. After accounting for force-attenuating properties of trochanteric soft tissue, the ratio of fall forces to femoral strength was 50% higher in cases than controls (0.92 +/- 0.44 versus 0.65 +/- 0.50, respectively; p = 0.04).Conclusions: It is possible to compute a biomechanically based estimate of hip fracture risk by combining estimates of femoral strength based on an empirical relationship between femoral aBMD and bone strength in cadaveric femora, along with estimates of loads applied to the hip during a sideways fall that account for thickness of trochanteric soft tissues. Our findings suggest that trochanteric soft tissue thickness may influence hip fracture risk by attenuating forces applied to the femur during a sideways fall and provide rationale for developing improved measurements of trochanteric soft tissue and for studying a larger cohort to determine whether trochanteric soft tissue thickness contributes to hip fracture risk independently of aBMD.