@article{GroteNoeldekeBlauthetal.2013,
  author    = {Grote, Stefan and Noeldeke, Tatjana and Blauth, Michael and Mutschler, Wolf and B{\"u}rklein, Dominik},
  title     = {Mechanical torque measurement in the proximal femur correlates to failure load and bone mineral density ex vivo},
  series = {Orthopedic Reviews (Pavia)},
  volume    = {5},
  journal   = {Orthopedic Reviews (Pavia)},
  number    = {e16},
  doi       = {10.4081/or.2013.e16},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132358},
  year      = {2013},
  abstract  = {Knowledge of local bone quality is essential for surgeons to determine operation techniques. A device for intraoperative measurement of local bone quality has been developed by the AO-Research Foundation (DensiProbe®). We used this device to experimentally measure peak breakaway torque of trabecular bone in the proximal femur and correlated this with local bone mineral density (BMD) and failure load. Bone mineral density of 160 cadaver femurs was measured by ex situ dual-energy X-ray absorptiometry. The failure load of all femurs was analyzed by side-impact analysis. Femur fractures were fixed and mechanical peak torque was measured with the DensiProbe® device. Correlation was calculated whereas correlation coefficient and significance was calculated by Fisher's Z-transformation. Moreover, linear regression analysis was carried out. The unpaired Student's t-test was used to assess the significance of differences. The Ward triangle region had the lowest BMD with 0.511 g/cm2 (±0.17 g/cm2), followed by the upper neck region with 0.546 g/cm2 (±0.16 g/cm2), trochanteric region with 0.685 g/cm2 (±0.19 g/cm2) and the femoral neck with 0.813 g/cm2 (±0.2 g/cm2). Peak torque of DensiProbe® in the femoral head was 3.48 Nm (±2.34 Nm). Load to failure was 4050.2 N (±1586.7 N). The highest correlation of peak torque measured by Densi Probe® and load to failure was found in the femoral neck (r=0.64, P<0.001). The overall correlation of mechanical peak torque with T-score was r=0.60 (P<0.001). A correlation was found between mechanical peak torque, load to failure of bone and BMD in vitro. Trabecular strength of bone and bone mineral density are different aspects of bone strength, but a correlation was found between them. Mechanical peak torque as measured may contribute additional information about bone strength, especially in the perioperative testing.},
  language  = {en}
}
@article{HaringPettingerBeaetal.2013,
  author    = {Haring, Bernhard and Pettinger, Mary and Bea, Jennifer W. and Wactawski-Wende, Jean and Carnahan, Ryan M. and Ockene, Judith K. and Wyler von Ballmoos, Moritz and Wallace, Robert B. and Wassertheil-Smoller, Sylvia},
  title     = {Laxative use and incident falls, fractures and change in bone mineral density in postmenopausal women: results from the Women's Health Initiative},
  series = {BMC Geriatrics},
  journal   = {BMC Geriatrics},
  doi       = {10.1186/1471-2318-13-38},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-95960},
  year      = {2013},
  abstract  = {Background Laxatives are among the most widely used over-the-counter medications in the United States but studies examining their potential hazardous side effects are sparse. Associations between laxative use and risk for fractures and change in bone mineral density [BMD] have not previously been investigated. Methods This prospective analysis included 161,808 postmenopausal women (8907 users and 151,497 nonusers of laxatives) enrolled in the WHI Observational Study and Clinical Trials. Women were recruited from October 1, 1993, to December 31, 1998, at 40 clinical centers in the United States and were eligible if they were 50 to 79 years old and were postmenopausal at the time of enrollment. Medication inventories were obtained during in-person interviews at baseline and at the 3-year follow-up visit on everyone. Data on self-reported falls (≥2), fractures (hip and total fractures) were used. BMD was determined at baseline and year 3 at 3 of the 40 clinical centers of the WHI. Results Age-adjusted rates of hip fractures and total fractures, but not for falls were similar between laxative users and non-users regardless of duration of laxative use. The multivariate-adjusted hazard ratios for any laxative use were 1.06 (95\% confidence interval [CI], 1.03-1.10) for falls, 1.02 (95\% CI, 0.85-1.22) for hip fractures and 1.01 (95\% CI, 0.96-1.07) for total fractures. The BMD levels did not statistically differ between laxative users and nonusers at any skeletal site after 3-years intake. Conclusion These findings support a modest association between laxative use and increase in the risk of falls but not for fractures. Its use did not decrease bone mineral density levels in postmenopausal women. Maintaining physical functioning, and providing adequate treatment of comorbidities that predispose individuals for falls should be considered as first measures to avoid potential negative consequences associated with laxative use.},
  language  = {en}
}