Kidney function, bone health, and vascular calcifications in patients with CKD II - IV: A 2 - 3 year prospective study with bone biopsies.

Background: Patients with chronic kidney disease (CKD) have serum, bone, and vascular abnormalities presenting as chronic kidney disease-mineral bone disorder (CKD-MBD) syndrome. This study sought to identify the parameters with the greatest relative impact on progression of CKD-MBD abnormalities.

Materials And Methods: This prospective study measured 237 parameters including serum markers, clinical variables, dual-energy X-ray absorptiometry (DXA) measurements, vascular calcifications, and histomorphometric results from bone samples obtained at baseline and after 2 - 3 years.

Trabecular bone microcrack accumulation in patients treated with bisphosphonates for durations up to 16 years.

This study quantified the length, number, and density of microcracks in bone from patients treated with bisphosphonates as a function of duration. Anterior iliac crest bone samples from 51 osteoporotic Caucasian females continuously treated with oral bisphosphonates for 1-16 years were obtained by bone biopsy. Samples were histologically processed and analyzed for bone area, microcrack number, and microcrack length.

Bone Quality and Fractures in Women With Osteoporosis Treated With Bisphosphonates for 1 to 14 Years.

Oral bisphosphonates are the primary medication for osteoporosis, but concerns exist regarding potential bone-quality changes or low-energy fractures. This cross-sectional study used artificial intelligence methods to analyze relationships among bisphosphonate treatment duration, a wide variety of bone-quality parameters, and low-energy fractures. Fourier transform infrared spectroscopy and histomorphometry quantified bone-quality parameters in 67 osteoporotic women treated with oral bisphosphonates for 1 to 14 years.

Muscle activity during maximal isometric forearm rotation using a power grip.

This study aimed to provide quantitative activation data for muscles of the forearm during pronation and supination while using a power grip. Electromyographic data was collected from 15 forearm muscles in 11 subjects while they performed maximal isometric pronating and supinating efforts in nine positions of forearm rotation. Biceps brachii was the only muscle with substantial activation in only one effort direction.

Evaluating bone quality in patients with chronic kidney disease.

Bone of normal quality and quantity can successfully endure physiologically imposed mechanical loads. Chronic kidney disease-mineral and bone disorder (CKD-MBD) adversely affects bone quality through alterations in bone turnover and mineralization, whereas bone quantity is affected through changes in bone volume. Changes in bone quality can be associated with altered bone material, structure, or microdamage, which can result in an elevated rate of fracture in patients with CKD-MBD.

Low-energy fractures without low T-scores characteristic of osteoporosis: a possible bone matrix disorder.

Background: Osteoporotic fractures commonly occur after low-energy trauma in postmenopausal women with reduced bone quantity documented by low bone mineral density (BMD). Low-energy fractures, however, have also been reported to occur in premenopausal women with normal or near-normal BMD, suggesting the existence of a bone quality abnormality.

Methods: Bone quality and quantity were evaluated in a cross-sectional study of three groups of premenopausal white females: (1) twenty-five subjects with low-energy fracture(s) and BMD in the normal range (t-scores > -2.

Effect of age and activity level on lower extremity gait dynamics: an introductory study.

Elderly adults should perform exercises that maintain or improve balance to reduce risk of injury from falls. Bone fractures secondary to falls in the elderly, particularly sedentary females, continue to pose a major health and economic problem. A greater understanding of the processes that contribute to the propensity for falling may be obtained by considering changes in gait biodynamics with age and activity level.

Differences in bone quality in low- and high-turnover renal osteodystrophy.

Abnormal bone turnover is common in CKD, but its effects on bone quality remain unclear. We qualitatively screened iliac crest bone specimens from patients on dialysis to identify those patients with low (n=18) or high (n=17) bone turnover. In addition, we obtained control bone specimens from 12 healthy volunteers with normal kidney function.

Plank fence penetration into automobiles-implications for prevention initiatives.

The wooden plank fence presents a deadly but unrecognized hazard to motorists. We hypothesize that fence plank injury is prevalent and results in significant morbidity and mortality. Databases of the University of Kentucky's Level I Trauma Center and the Fayette County Coroner were retrospectively analyzed over a 12-year period (1995-2006).

Pediatric anthropometrics are inconsistent with current guidelines for assessing rider fit on all-terrain vehicles.

Background/purpose: This study sought to establish objective anthropometric measures of fit or misfit for young riders on adult and youth-sized all-terrain vehicles and use these metrics to test the unproved historical reasoning that age alone is a sufficient measure of rider-ATV fit.

Methods: Male children (6-11 years, n=8; and 12-15 years, n=11) were selected by convenience sampling. Rider-ATV fit was quantified by five measures adapted from published recommendations: (1) standing-seat clearance, (2) hand size, (3) foot vs.

Novel three-dimensional MRI technique for study of cartilaginous hip surfaces in Legg-Calvé-Perthes disease.

Treatment of Legg-Calvé-Perthes disease (LCPD) may improve if new knowledge can be obtained regarding how articular cartilage changes shape during the course of this disorder. A new technique is presented showing how analyses of magnetic resonance images can be used to quantify the three-dimensional changes in the femoral and acetabular articulating cartilage surfaces of children with LCPD. Ten male subjects (8 +/- 1 years) with unilateral LCPD were enrolled in this IRB approved study.

Bone engineering of the rabbit ulna.

Purpose: The purpose of the present preliminary study is to show that a novel 3-dimensional porous silica-calcium phosphate nanocomposite (SCPC) can provide a controlled release of rhBMP-2 and regenerate bone in a load-bearing segmental defect.

Materials And Methods: A bone replica of the rabbit ulna was created from SCPC powder using rapid prototyping technology. The ceramic bone replica was coated with rhBMP-2 and then implanted into a 10-mm segmental defect created in a rabbit ulna and fixated with a 1-mm titanium adaptation plate.

Stress Reduction in Adjacent Level Discs via Dynamic Instrumentation: A Finite Element Analysis.

Background: Conventional (rigid) fusion instrumentation is believed to accelerate the degeneration of adjacent discs by increasing stresses caused by motion discontinuity. Fusion instrumentation that employs reduced rod stiffness and increased axial motion, or dynamic instrumentation, may partially alleviate this problem, but the effects of this instrumentation on the stresses in the adjacent disc are unknown. We used a finiteelement model to calculate and compare the stresses in the adjacent-level disc that are induced by rigid and dynamic posterior lumbar fusion instrumentation.

Tarsal shape, size, and articulating surface morphology in adolescent surgically treated clubfoot and their contralateral normal foot.

Despite the inability of radiographic measurements to quantify the 3-dimensional (3D) shape and size of the hindfoot bones affected by the clubfoot pathology, radiographs continue to be used to evaluate treatment efficacy. Advancements in imaging and image analysis allow new quantitative insights to be obtained into bone shape and size. Therefore, this study sought to quantify and compare the 3D size, shape, and articulating surface morphology of the tibia, talus, calcaneus, navicular, and cuboid bones in the adolescent surgically treated unilateral clubfoot and the contralateral normal foot.

Three-dimensional in vivo motion of adult hind foot bones.

Knowledge of hind foot bone motion is important for understanding gait as well as various foot pathologies, but the three-dimensional (3D) motion of these bones remains incompletely understood. The purpose of this study was to quantify the motion of the talus, calcaneus, navicular, and cuboid in normal adult feet during open chain quasi-static uniplanar plantar flexion motion. Magnetic resonance images of the right feet of six normal young adult males were taken from which 3D virtual models were made of each hind foot bone.

Augmentation of acrylic bone cement with multiwall carbon nanotubes.

Acrylic bone cement, based on polymethylmethacrylate (PMMA), is a proven polymer having important applications in medicine and dentistry, but this polymer continues to have less than ideal resistance to mechanical fatigue and impact. A variety of materials have been added to bone cement to augment its mechanical strength, but none of these augmentative materials has proven successful. Carbon nanotubes, a new hollow multiwalled tubular material 10-40 nm in diameter, 10-100 microm long, and 50-100 times the strength of steel at 1/6 the weight, have emerged as a viable augmentation candidate because of their large surface area to volume ratio.

Three-dimensional hindfoot motion in adolescents with surgically treated unilateral clubfoot.

Advances in imaging and computerized analyses have enabled three-dimensional bone motion in the treated clubfoot to be measured precisely. Three-dimensional translations and rotations of the talus, calcaneus, navicular, and cuboid of surgically treated clubfeet were less in magnitude and sometimes different in direction (or without motion in a specific plane) compared with the contralateral normal feet. Surgical techniques used for clubfoot treatment do not restore normal hindfoot bone motion when examined with high-resolution magnetic resonance imaging, computer reconstruction, and image analysis techniques.

Biomechanical evaluation of fixation techniques for bridging segmental mandibular defects.

Objective: To compare biomechanical properties of currently available plating systems used to reconstruct segmental mandibular defects.

Design: Controlled in vitro investigation.

Setting: Academic medical center laboratory.

Biomechanical superiority of plate fixation for proximal tibial osteotomy.

Proximal tibial osteotomies require secure and durable fixation to allow early range of motion; however, biomechanical data comparing commonly used fixation methods are lacking. The current study was done to quantify the dynamic biomechanical performance of blade staple fixation and plate fixation of simulated proximal tibial osteotomies. A 15 degrees proximal tibial osteotomy was done on each of 18 synthetic adult composite tibias.

Biomechanical comparison of the FasT-Fix meniscal repair suture system with vertical mattress sutures and meniscus arrows.

Background: A meniscal repair technique that combines the strength of vertical mattress sutures and the decreased tissue morbidity of an all-inside technique would be advantageous.

Hypothesis: The FasT-Fix Meniscal Repair Suture System will provide load at failure, stiffness, and displacement equivalent to that of vertical mattress sutures and superior to that of Meniscus Arrows.

Study Design: In vitro biomechanical study.

Complications of multilevel cervical corpectomies and reconstruction with titanium cages and anterior plating.

The ideal surgical treatment of multilevel cervical spondylosis remains unclear. This study analyzed the complications in using titanium cages and plating to reconstruct multilevel cervical corpectomies. This was a retrospective analysis of 21 consecutive patients who had multilevel cervical corpectomies and reconstruction with titanium cages and anterior plating.

Better treatment of vertebral osteomyelitis using posterior stabilization and titanium mesh cages.

There is no scientific consensus on the role of posterior instrumentation in vertebral osteomyelitis. No study has examined the use of titanium cages to reconstruct the anterior column of the spine with vertebral osteomyelitis. Here the authors evaluated the efficacy of using titanium mesh cages anteriorly and posterior instrumentation after anterior debridement in the surgical treatment of vertebral osteomyelitis.

Modified tibial nails for treating distal tibia fractures.

Objective: To determine the biomechanical consequences of cutting one centimeter off the tip of a tibial nail when treating distal tibia fractures with intramedullary nails.

Design: Randomized laboratory investigation using matched pairs of cadaveric tibias with osteotomies made to resemble distal tibia fractures extending to four and five centimeters from the tibiotalar joints.

Intervention: The smaller (four-centimeter) distal tibias were stabilized using ten-millimeter diameter tibial nails that had been modified by removing the distal one centimeter of the nail.