Structural adaptation to changing skeletal load in the progression toward hip fragility

The study of osteoporotic fractures

Thomas J. Beck, Tammy L. Oreskovic, Katie L. Stone, Christopher B Ruff, Kristine Ensrud, Michael C. Nevitt, Harry K. Genant, Steven R. Cummings

Research output: Contribution to journalArticle

Abstract

Longitudinal, dual-energy X-ray absorptiometry (DXA) hip data from 4187 mostly white, elderly women from the Study of Osteoporotic Fractures were studied with a structural analysis program. Cross-sectional geometry and bone mineral density (BMD) were measured in narrow regions across the femoral neck and proximal shaft. We hypothesized that altered skeletal load should stimulate adaptive increases or decreases in the section modulus (bending strength index) and that dimensional details would provide insight into hip fragility. Weight change in the ∼3.5 years between scan time points was used as the primary indicator of altered skeletal load. "Static" weight was defined as within 5% of baseline weight, whereas "gain" and "loss" were those who gained or lost >5%, respectively. In addition, we used a frailty index to better identify those subjects undergoing changing in skeletal loading. Subjects were classified as frail if unable to rise from a chair five times without using arm support. Subjects who were both frail and lost weight (reduced loading) were compared with those who were not frail and either maintained weight (unchanged loading) or gamed weight (increased loading). Sixty percent of subjects (n = 2559) with unchanged loads lost BMD at the neck but not at the shaft, while section moduli increased slightly at both regions. Subjects with increasing load (n = 580) lost neck BMD but gained shaft BMD; section moduli increased markedly at both locations. Those with declining skeletal loads (n = 105) showed the greatest loss of BMD at both neck and shaft; loss at the neck was caused by both increased loss of bone mass and greater subperiosteal expansion; loss in shaft BMD decline was only caused by greater loss of bone mass. This group also showed significant declines in section modulus at both sites. These results support the contention that mechanical homeostasis in the hip is evident in section moduli but not in bone mass or density. The adaptive response to declining skeletal loads, with greater rates of subperiosteal expansion and cortical thinning, may increase fragility beyond that expected from the reduction in section modulus or bone mass alone.

Original languageEnglish (US)
Pages (from-to)1108-1119
Number of pages12
JournalJournal of Bone and Mineral Research
Volume16
Issue number6
StatePublished - 2001
Externally publishedYes

Fingerprint

Osteoporotic Fractures
Bone Density
Hip
Weights and Measures
Neck
Bone and Bones
Femur Neck
Photon Absorptiometry
Weight Gain
Arm
Homeostasis

Keywords

  • Adaptation to skeletal loading
  • Dual-energy X-ray absorptiometry
  • Frost's mechanostat
  • Section modulus
  • Skeletal homeostasis
  • Structural geometry
  • Subperiosteal expansion
  • Wolff's law

ASJC Scopus subject areas

  • Surgery

Cite this

Beck, T. J., Oreskovic, T. L., Stone, K. L., Ruff, C. B., Ensrud, K., Nevitt, M. C., ... Cummings, S. R. (2001). Structural adaptation to changing skeletal load in the progression toward hip fragility: The study of osteoporotic fractures. Journal of Bone and Mineral Research, 16(6), 1108-1119.

Structural adaptation to changing skeletal load in the progression toward hip fragility : The study of osteoporotic fractures. / Beck, Thomas J.; Oreskovic, Tammy L.; Stone, Katie L.; Ruff, Christopher B; Ensrud, Kristine; Nevitt, Michael C.; Genant, Harry K.; Cummings, Steven R.

In: Journal of Bone and Mineral Research, Vol. 16, No. 6, 2001, p. 1108-1119.

Research output: Contribution to journalArticle

Beck, TJ, Oreskovic, TL, Stone, KL, Ruff, CB, Ensrud, K, Nevitt, MC, Genant, HK & Cummings, SR 2001, 'Structural adaptation to changing skeletal load in the progression toward hip fragility: The study of osteoporotic fractures', Journal of Bone and Mineral Research, vol. 16, no. 6, pp. 1108-1119.
Beck, Thomas J. ; Oreskovic, Tammy L. ; Stone, Katie L. ; Ruff, Christopher B ; Ensrud, Kristine ; Nevitt, Michael C. ; Genant, Harry K. ; Cummings, Steven R. / Structural adaptation to changing skeletal load in the progression toward hip fragility : The study of osteoporotic fractures. In: Journal of Bone and Mineral Research. 2001 ; Vol. 16, No. 6. pp. 1108-1119.
@article{0a6ac26ff5b54bbda67a558b28aee9fd,
title = "Structural adaptation to changing skeletal load in the progression toward hip fragility: The study of osteoporotic fractures",
abstract = "Longitudinal, dual-energy X-ray absorptiometry (DXA) hip data from 4187 mostly white, elderly women from the Study of Osteoporotic Fractures were studied with a structural analysis program. Cross-sectional geometry and bone mineral density (BMD) were measured in narrow regions across the femoral neck and proximal shaft. We hypothesized that altered skeletal load should stimulate adaptive increases or decreases in the section modulus (bending strength index) and that dimensional details would provide insight into hip fragility. Weight change in the ∼3.5 years between scan time points was used as the primary indicator of altered skeletal load. {"}Static{"} weight was defined as within 5{\%} of baseline weight, whereas {"}gain{"} and {"}loss{"} were those who gained or lost >5{\%}, respectively. In addition, we used a frailty index to better identify those subjects undergoing changing in skeletal loading. Subjects were classified as frail if unable to rise from a chair five times without using arm support. Subjects who were both frail and lost weight (reduced loading) were compared with those who were not frail and either maintained weight (unchanged loading) or gamed weight (increased loading). Sixty percent of subjects (n = 2559) with unchanged loads lost BMD at the neck but not at the shaft, while section moduli increased slightly at both regions. Subjects with increasing load (n = 580) lost neck BMD but gained shaft BMD; section moduli increased markedly at both locations. Those with declining skeletal loads (n = 105) showed the greatest loss of BMD at both neck and shaft; loss at the neck was caused by both increased loss of bone mass and greater subperiosteal expansion; loss in shaft BMD decline was only caused by greater loss of bone mass. This group also showed significant declines in section modulus at both sites. These results support the contention that mechanical homeostasis in the hip is evident in section moduli but not in bone mass or density. The adaptive response to declining skeletal loads, with greater rates of subperiosteal expansion and cortical thinning, may increase fragility beyond that expected from the reduction in section modulus or bone mass alone.",
keywords = "Adaptation to skeletal loading, Dual-energy X-ray absorptiometry, Frost's mechanostat, Section modulus, Skeletal homeostasis, Structural geometry, Subperiosteal expansion, Wolff's law",
author = "Beck, {Thomas J.} and Oreskovic, {Tammy L.} and Stone, {Katie L.} and Ruff, {Christopher B} and Kristine Ensrud and Nevitt, {Michael C.} and Genant, {Harry K.} and Cummings, {Steven R.}",
year = "2001",
language = "English (US)",
volume = "16",
pages = "1108--1119",
journal = "Journal of Bone and Mineral Research",
issn = "0884-0431",
publisher = "Wiley-Blackwell",
number = "6",

}

TY - JOUR

T1 - Structural adaptation to changing skeletal load in the progression toward hip fragility

T2 - The study of osteoporotic fractures

AU - Beck, Thomas J.

AU - Oreskovic, Tammy L.

AU - Stone, Katie L.

AU - Ruff, Christopher B

AU - Ensrud, Kristine

AU - Nevitt, Michael C.

AU - Genant, Harry K.

AU - Cummings, Steven R.

PY - 2001

Y1 - 2001

N2 - Longitudinal, dual-energy X-ray absorptiometry (DXA) hip data from 4187 mostly white, elderly women from the Study of Osteoporotic Fractures were studied with a structural analysis program. Cross-sectional geometry and bone mineral density (BMD) were measured in narrow regions across the femoral neck and proximal shaft. We hypothesized that altered skeletal load should stimulate adaptive increases or decreases in the section modulus (bending strength index) and that dimensional details would provide insight into hip fragility. Weight change in the ∼3.5 years between scan time points was used as the primary indicator of altered skeletal load. "Static" weight was defined as within 5% of baseline weight, whereas "gain" and "loss" were those who gained or lost >5%, respectively. In addition, we used a frailty index to better identify those subjects undergoing changing in skeletal loading. Subjects were classified as frail if unable to rise from a chair five times without using arm support. Subjects who were both frail and lost weight (reduced loading) were compared with those who were not frail and either maintained weight (unchanged loading) or gamed weight (increased loading). Sixty percent of subjects (n = 2559) with unchanged loads lost BMD at the neck but not at the shaft, while section moduli increased slightly at both regions. Subjects with increasing load (n = 580) lost neck BMD but gained shaft BMD; section moduli increased markedly at both locations. Those with declining skeletal loads (n = 105) showed the greatest loss of BMD at both neck and shaft; loss at the neck was caused by both increased loss of bone mass and greater subperiosteal expansion; loss in shaft BMD decline was only caused by greater loss of bone mass. This group also showed significant declines in section modulus at both sites. These results support the contention that mechanical homeostasis in the hip is evident in section moduli but not in bone mass or density. The adaptive response to declining skeletal loads, with greater rates of subperiosteal expansion and cortical thinning, may increase fragility beyond that expected from the reduction in section modulus or bone mass alone.

AB - Longitudinal, dual-energy X-ray absorptiometry (DXA) hip data from 4187 mostly white, elderly women from the Study of Osteoporotic Fractures were studied with a structural analysis program. Cross-sectional geometry and bone mineral density (BMD) were measured in narrow regions across the femoral neck and proximal shaft. We hypothesized that altered skeletal load should stimulate adaptive increases or decreases in the section modulus (bending strength index) and that dimensional details would provide insight into hip fragility. Weight change in the ∼3.5 years between scan time points was used as the primary indicator of altered skeletal load. "Static" weight was defined as within 5% of baseline weight, whereas "gain" and "loss" were those who gained or lost >5%, respectively. In addition, we used a frailty index to better identify those subjects undergoing changing in skeletal loading. Subjects were classified as frail if unable to rise from a chair five times without using arm support. Subjects who were both frail and lost weight (reduced loading) were compared with those who were not frail and either maintained weight (unchanged loading) or gamed weight (increased loading). Sixty percent of subjects (n = 2559) with unchanged loads lost BMD at the neck but not at the shaft, while section moduli increased slightly at both regions. Subjects with increasing load (n = 580) lost neck BMD but gained shaft BMD; section moduli increased markedly at both locations. Those with declining skeletal loads (n = 105) showed the greatest loss of BMD at both neck and shaft; loss at the neck was caused by both increased loss of bone mass and greater subperiosteal expansion; loss in shaft BMD decline was only caused by greater loss of bone mass. This group also showed significant declines in section modulus at both sites. These results support the contention that mechanical homeostasis in the hip is evident in section moduli but not in bone mass or density. The adaptive response to declining skeletal loads, with greater rates of subperiosteal expansion and cortical thinning, may increase fragility beyond that expected from the reduction in section modulus or bone mass alone.

KW - Adaptation to skeletal loading

KW - Dual-energy X-ray absorptiometry

KW - Frost's mechanostat

KW - Section modulus

KW - Skeletal homeostasis

KW - Structural geometry

KW - Subperiosteal expansion

KW - Wolff's law

UR - http://www.scopus.com/inward/record.url?scp=0034996540&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034996540&partnerID=8YFLogxK

M3 - Article

VL - 16

SP - 1108

EP - 1119

JO - Journal of Bone and Mineral Research

JF - Journal of Bone and Mineral Research

SN - 0884-0431

IS - 6

ER -