Search results for "Bone Density"
showing 10 items of 339 documents
Preventing bone loss during androgen deprivation therapy for prostate cancer: Early experience with neridronate
2005
Abstract Objective: Androgen-deprivation therapy (ADT) is the usual treatment for locally advanced or metastatic prostate cancer. Osteoporosis is a common complication of ADT. The aim of our study was to evaluate the efficacy of neridronate, a relatively new bisphosphonate to prevent bone loss during androgen ablation. Methods: Sixty patients with prostate cancer and osteoporosis were enrolled and randomly assigned to 2 different treatment regimes: group A (30 patients) treated with maximum androgenic blockage (MAB), and group B (30 patients) treated with bicalutamide 150mg. Each group was divided in 2 subgroups A1–A2 and B1–B2. All patients received calcium and cholecalciferol supplements …
Calcaneal Bone Mineral Density Predicts Fracture Occurrence: A Five-Year Follow-up Study in Elderly People
1997
A 5-year follow-up study investigated calcaneal bone mineral density (BMD) and changes in BMD in relation to fracture occurrence. The subjects comprised two cohorts born in 1914 and 1910 living in the city of Jyväskylä in central Finland. One hundred and three men (82%) and 188 women (73%), aged 75, and 57 men (74%) and 136 women (65%), aged 80, of the eligible population participated in the baseline bone measurements. The follow-up bone measurements were obtained for 59 men (68%) and 119 women (66%), aged 80 years, and for 21 men (53%) and 61 women (48%), aged 85 years. During the follow-up period, 8 men and 36 women from the younger and 11 men and 24 women from the older cohort sustained …
Hip fractures and femoral bone mineral density in male former elite athletes
2009
We studied whether vigorous physical activity in young adulthood is associated with higher femoral bone density and lower risk of hip fracture at older age in men.A cohort of former male elite athletes (n=2147) and matched control subjects (n=1467) were studied for their leisure physical activity, and for fragility fractures at the hip (proximal femur) by Cox regression. Areal bone mineral densities (aBMD) at femoral neck and trochanter region were measured using dual-energy X-ray absorptiometry in a subgroup of the former athletes (n=87; median age 59 years) and in a population-based control group (n=194) and compared by general linear models.After their active sporting careers, the former…
Quantification of Bone Density of the Proximal Femur After Hip Resurfacing Arthroplasty—Comparison of Different DXA Acquisition Modes
2010
Total hip arthroplasty (THA) is a traditional operative procedure in the treatment of osteoarthritis. The hip resurfacing arthroplasty (HRA) provides an alternative to the THA for young active patients. HRA is a bone-preserving procedure eliminating the problem of proximal femoral stress shielding and osteolysis associated to THA. Unfortunately, there is no standardized methodology to monitor the quality of bone after HRA. In this study, areal bone mineral density (BMD) in the operated hip (10 regions of interests [ROIs] of 34 volunteered HRA patients) was measured using Lunar Prodigy dual-energy X-ray absorptiometry, and the agreement of a standard (dual femur) and an orthopedic (orthopedi…
Influence of Different DXA Acquisition Modes on Monitoring the Changes in Bone Mineral Density After Hip Resurfacing Arthroplasty
2011
Dual-energy X-ray absorptiometry (DXA) is a technique enabling the measurement of bone mineral density (BMD) around prostheses after hip resurfacing arthroplasty (HRA). In this study, we evaluated the consistency of different DXA acquisition modes with 33 patients who had undergone HRA. Patients were scanned with DXA immediately after surgery and at 3-, 6-, and 12-mo time points. All the patients were scanned with dual femur and orthopedic hip acquisition modes and analyzed using 10-region ROI model. With both acquisition modes, a statistically significant decrease (p0.05, Wilcoxon's test) in BMD at 3mo was revealed in 3 ROIs, located to upper and lateral upper femur. Both acquisition modes…
Characterization of C4-2 Prostate Cancer Bone Metastases and Their Response to Castration
2003
New well-characterized preclinical models of prostate cancer (CaP) bone metastases are needed to improve our understanding of the development of CaP-related bone disease in patients. Here we describe characterization of a model consisting of direct injection of C4–2 cells into tibias. Introduction: Prostate cancer (CaP) has a high proclivity to metastasize to bone. Development and characterization of preclinical models of CaP bone metastases are of high interest. The objective of this study was to characterize C4–2 bone metastases and their response to castration. Materials and Methods: Cell suspensions of C4-2, a subline of LNCaP, were injected directly into the tibias of intact male mice.…
Photo-acoustic excitation and optical detection of fundamental flexural guided wave in coated bone phantoms.
2013
Abstract Photo-acoustic (PA) imaging was combined with skeletal quantitative ultrasound (QUS) for assessment of human long bones. This approach permitted low-frequency excitation and detection of ultrasound so as to efficiently receive the thickness-sensitive fundamental flexural guided wave (FFGW) through a coating of soft tissue. The method was tested on seven axisymmetric bone phantoms, whose 1- to 5-mm wall thickness and 16-mm diameter mimicked those of the human radius. Phantoms were made of a composite material and coated with a 2.5- to 7.5-mm layer of soft material that mimicked soft tissue. Ultrasound was excited with a pulsed Nd:YAG laser at 1064-nm wavelength and received on the s…
Assessment of the cortical bone thickness using ultrasonic guided waves: Modelling and in vitro study
2007
Determination of cortical bone thickness is warranted, e.g., for assessing the level of endosteal resorption in osteoporosis or other bone pathologies. We have shown previously that the velocity of the fundamental antisymmetric (or flexural) guided wave, measured for bone phantoms and bones in vitro, correlates with the cortical thickness significantly better than those by other axial ultrasound methods. In addition, we have introduced an inversion scheme based on guided wave theory, group velocity filtering and 2-D fast Fourier transform, for determination of cortical thickness from the measured velocity of guided waves. In this study, the method was validated for tubular structures by usi…
Elastic wave propagation in bone in vivo: methodology.
1995
The purpose of this study was to investigate the usefulness of elastic wave propagation (EWP) in estimating the mechanical properties (elasticity) of human tibia. The test group was composed of 78-yr-old women assigned to high (n = 19) and low (n = 17) bone mineral density (BMD) groups as measured at the calcaneus by the 125I-photon absorption method. The EWP apparatus consisted of an impact-producing hammer with a force strain gauge and two accelerometers positioned on the bone. Results for nylon and acrylic were used to calibrate the apparatus. Polyvinyl chloride (PVC) solid rods and tubes of various diameters were used to evaluate the relationship between the elastic wave velocity and cr…
Biomechanical evaluation of oversized drilling technique on primary implant stability measured by insertion torque and resonance frequency analysis
2015
Background This study evaluated the influence of implant site preparation depth on primary stability measured by insertion torque and resonance frequency analysis (RFA). Material and Methods Thirty-two implant sites were prepared in eight veal rib blocks. Sixteen sites were prepared using the conventional drilling sequence recommended by the manufacturer to a working depth of 10mm. The remaining 16 sites were prepared using an oversize drilling technique (overpreparation) to a working depth of 12mm. Bone density was determined using cone beam computerized tomography (CBCT). The implants were placed and primary stability was measured by two methods: insertion torque (Ncm), and RFA (implant s…