Search results for "Femur"
showing 10 items of 146 documents
Short-Term Precision Error of Bone Strain Index, a New DXA-Based Finite Element Analysis Software for Assessing Hip Strength
2020
Abstract Bone Strain Index (BSI) is a new finite element analysis tool applied to hip dual energy X-ray absorptiometry scans. The aim of this study was to assess the short-term precision error of BSI on the proximal femur, both on a phantom and patients. The International Society for Clinical Densitometry guidelines were followed for short-term precision error assessment. Dual energy X-ray absorptiometry measurements were performed on an anthropomorphic femur phantom that was scanned twice for 30 times, for a total of 60 scans. For the in vivo part, 30 subjects were scanned twice. BSI precision error was compared to that of bone mineral density (BMD). Both for the phantom and the in vivo st…
A new type of autosomal recessive spondyloepiphyseal dysplasia tarda
2004
Repeated occurrence of a hitherto unrecognized form of spondyloepiphyseal dysplasia tarda (SED tarda) has been studied in two independent families. Because parental consanguinity was also present in one family, autosomal recessive inheritance is proposed. The onset was in late childhood. The slowly evolving disorder shared several features of the already known types of SED tarda. The radiographic abnormalities were limited to the spine and proximal femora. The patients' hands were normal. The entity described is set apart not only from the X-linked and autosomal-dominant forms of SED tarda but also from the already delineated autosomal recessive types by significant clinical and radiographi…
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…
Der HEPFIEx-Simulator, eine Apparatur zur Bestimmung der Reibzahlen zwischen Hüftkopf-Prothesen und Knorpel / The HEPFlEx Simulator, a Device for Mea…
2002
We describe a device designed to investigate friction between various femoral head prostheses and human acetabula. It enables not only the determination of friction and the relevance of the play between the femoral head and acetabulum, but also the evaluation of the kinematic behaviour of bipolar prostheses. In the simulator, the various femoral head prostheses are placed on a special cone and tested against a human cadaveric acetabulum. The swiveling range of the device is uniaxial, and the swiveling angle is +/- 35 degrees. The maximum force produced pneumatically is 5kN. Testing of the simulator with a TEP was successful and friction-coefficients of < 0.1 were measured, as are reported i…
Osseous reaction to implantation of two endodontic cements : mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM)
2012
Aim: The aim of the present in vivo study was to determine bone tissue reaction to calcium enriched mixture (CEM) and mineral trioxide aggregate (MTA) using a rat femur model. Study Design: Sixty-three rats were selected and randomly divided into three groups of 21 each [experimental groups (n=15), control (n=6)]. Implantation cavities were prepared in each femoral bone and randomly filled with the biomaterials only in the experimental groups. The animals in three groups were sacrificed 1, 4, and 8 weeks postoperatively. Histologic evaluations comprising inflammation severity and new bone formation were blindly made on H&E-stained decalcified 6-µm sections. Results: At 1, 4, and 8 weeks aft…
Avoiding tunnel collisions between fibular collateral ligament and ACL posterolateral bundle reconstruction
2010
PURPOSE: The purpose of this study was to evaluate the risk of tunnel collisions of the fibular collateral ligament (FCL) and posterolateral bundle anterior cruciate ligament (PLB-ACL) tunnels during a combined FCL and double-dundle (DB) ACL reconstruction. METHODS: Thirty-six 4th-generation synthetic femurs (Sawbones, Pacific Research Laboratories, Vashon, WA) were utilized, and two different femur sizes were used. A FCL tunnel and a PLB-ACL tunnel were reamed on each femur. The tunnels of synthetic specimens that did not have a collision were filled with an epoxy resin augmented with BaSO(4) and radiographic evaluation, and Multidetector CT exams of the specimens were performed. RESULTS: …
How to avoid collision between PCL and MCL femoral tunnels during a simultaneous reconstruction.
2014
PURPOSE: The purpose of the present study was to assess the risk of femoral tunnel collisions between the medial collateral ligament (MCL) and the posterior cruciate ligament (PCL) tunnels during a simultaneous PCL and MCL reconstruction. METHODS: Fourth generation medium and large synthetic femur bones were used. On each femur, a MCL tunnel and a PCL tunnel were reamed. The MCL tunnel was drilled at 0°, 20° and 40° of axial and coronal angulations. The PCL femoral tunnel was reamed to simulate two different tunnel directions that could be obtained through an inside-out and outside-in technique. Tunnels were filled with epoxy resin augmented with BaSO4, and a multidetector CT examination of…
Influence of formalin fixation on the biomechanical properties of human diaphyseal bone.
2010
Owing to the lack of fresh human bones, formalin-fixed specimens are frequently used in biomechanical testing. However, formalin fixation is assumed to affect the biomechanical properties of bone. The aim of this study was to compare axial and torsional stiffness and bone mineral density in fresh and embalmed human bones. The subtrochanteric regions of 12 pairs of fresh human femora were randomised into two groups for paired comparison. After bone mineral density measurement, one group was preserved in 4% formalin. After 6 weeks, bone mineral density was remeasured and each specimen underwent axial and torsional loading. The formalin group showed significant higher stiffness values for tors…