Intergenerational comparison of total and regional bone mineral density and soft tissue composition in Japanese women without vertebral fractures

We measured total and regional bone mineral density (BMD) and soft tissue mass in 115 healthy Japanese women without vertebral fractures. The subjects, aged 20 to 75 years, were divided into four age groups : 20’s to 40’s group (n=33), 50’s group (n=26), 60’s group (n=26), and 70’s group (n=30). BMD was measured by dual energy X-ray absorptiometry (DXA).The evaluated regions were the head, arms, legs, ribs, thoracic vertebrae, lumbar vertebrae and pelvis. The total and regional BMDs were the highest in the 20’s to 40’s group, and they decreased with age, and reached their respective lowest values in the 70’s group. The decrease in BMDs of the spine and pelvis was the most prominent of all regional BMDs. Total and regional lean mass and fat mass were the highest in the20’s to 40’s group, and they decreased to their respective lowest values in the 70’s group. The results showed that the decrease in BMD of the spine and pelvis was the most prominent of all regional BMDs associated with a decrease in the total and regional lean mass and total and regional fat mass

Effects of unilateral sciatic neurectomy on growing rat femur as assessed by peripheral quantitative computed tomography, Fourier transform infrared spectroscopy and bending test

We studied the effects of unilateral sciatic neurectomy (USN) on the development of the femoral shaft in the 30 growing Wistar-derived rats aged 5 weeks. Rats were allocated to three groups. One of these was immediately used for measurements, and the remaining 2 groups underwent USN of internal control. Specimens obtained from each group were divided into 2 subgroups : left femurs of each group served as the control subgroup (CONT) and right femurs from each group as the USN-operated subgroup (USN-OP). The bone mineral density (BMD), bone mineral content (BMC), bone area, periosteal circumference and endosteal circumference were measured by peripheral quantitative computed tomography (pQCT) and the mineral /matrix ratio was evaluated by Fourier transform infrared spectroscopy (FTIR). A three-point bending test was performed to analyze the biomechanical effects of sciatic neurectomy. USN-OP showed a significant decrease in cortical BMC, bone area, and periosteal circumference compared with CONT. The mineral /matrix ratio of cortical bone did not differ significantly between USN-OP and CONT. Strength and stiffness were significantly decreased in USN-OP compared with CONT. The results showed that USN inhibited periosteal bone formation, but has no significant effects on the mineral /matrix ratio of cortical bone in femurs

Effect of baseplate position on locking screws

Introduction : Superior screw insertion in reverse shoulder arthroplasty (RSA) carries the potential risk of suprascapular injury. The purpose of this study was to evaluate how the baseplate position affects the superior screw position and length in RSA. Methods : Three-dimensional (3D) computer simulation models of RSA were established using computed tomography data of baseplates with superior and inferior screws and 3D scapular models from 10 fresh cadavers. Superior screw position, the distance from the superior screw hole to the suprascapular notch, and the screw lengths were measured and compared among various baseplate positions with two inferior tilts (0 and 10 degrees) and three rotational patterns (11–5, 12–6, and 1–7 o’clock in the right shoulder). Results : For the 1–7 o’clock / inferior tilt 0 degrees baseplate, the superior screw located anterior to the SS notch in all shoulders, the distance to the SS notch was the longest (12.8 mm), and the inferior screw length was the shortest (23.1 mm). Conclusion : Although there is a concern of a short inferior screw length, initial fixation using a baseplate with 1–7 o’clock rotation and an inferior tilt of 0 degrees appears preferable for SS nerve injury prevention during superior screw insertion

Differences of therapeutic effects on regional bone mineral density and markers of bone mineral metabolism between alendronate and alfacalcidol in Japanese osteoporotic women

We studied the differences of therapeutic effects on regional bone mineral density (BMD) and markers of bone mineral metabolism between alendronate and alfacalcidol in Japanese osteoporotic women. Ninety-two Japanese women suffering from primary osteoporosis without osteoporotic fractures, aged 55 to 81 years, were divided into two groups : women treated orally with alendronate for one-year (5mg/day)(alendronate group, n=35) and women treated orally with alfacalcidol for one year (0.5μg/ day) (alfacalcidol group, n=57). The mean BMD of the 2nd to 4th lumbar vertebrae (L2-4 BMD) and regional BMD were measured using dual energy X-ray absorptiometry. In the alendronate group, the percentage changes of L2-4BMD, lumbar spine BMD, thoracic spine BMD, pelvis BMD in the alendronate group were 106.3±4.6%, 104.2±6.6%, 107.1± 10.4%, 107.1±10.5%, respectively. The percentage changes of L2-4BMD and regional BMD except for head BMD in the alendronate group were significantly greater than those in the alfacalcidol group. In the alfacalcidol group, L2-4BMD, thoracic spine BMD and lumbar spine BMD were maintained at respective pretreatment levels, whereas other regional BMD were decreased. Both serum bone-specific alkaline phosphatase and urinary type I collagen cross-linked N-telopeptide of the alendronate group were decreased, whereas these markers of bone mineral metabolism of alfacalcidol group were increased compared with the respective pre-treatment levels. The results suggest that one-year treatment with alendronate increased L2-4BMD, lumbar spine BMD, thoracic spine BMD and pelvis BMD, and that markers of both bone formation and bone resorption were decreased following one-year treatment with alendronate

Femoral neck fracture with osteoporosis in Tokushima Prefecture

The numbers and features of occurrence, causes, treatments and prognosis of femoral neck fracture with osteoporosis in Tokushima prefecture were investigated in the 10th fiscal year of Heisei. 634 patients (154 males and 480 females) suffered from the femoral neck fracture. Females were 3.1 times as many as males. In females, the occurrence of the fracture had a tendency to increase to 85-years-old population. In fracture types, 253 cases were intracapsular type and 381 cases extracapsular type. Extracapsular type of the femoral neck fracture increased in proportion to aging. 384 cases were treated with osteosynthesis, 207 cases with femoral prosthesis and 43 cases with othermethods. The main cause of the fracture was trivial fall (79%). 288 cases returned to home and 258 cases still admitted in the secondary hospitals. 69 cases entered to the nursing home. Half of the patients who could walk with or without crutch before fracture were able to return to home, on the other hand, the ratio of patients who could return to home among the patients with no ability of walk before injury was less than 10%. Mortality rate was 2.1 % at the discharge

Biophysic evaluation of bone quality : application of Fourier transform infrared spectroscopy and phosphorus-31 solid-state nuclear magnetic resonance spectroscopy

In this review, we focus on findings obtained with biophysic techniques, Fourier transformed infrared (FTIR) spectroscopy and phosphorus-31 solid-state nuclear magnetic resonance (31P solid-state NMR) spectroscopy, which may allow us to evaluate bone quality and to predict bone strength. FTIR measures the absorption energy that produces an increase in the vibrational or rotational energy of atoms or groups of atoms within the molecule. FTIR spectroscopy allows us to examine the relative amount of minerals and matrix content and the arrangement of apatite and organic matrix. FTIR spectroscopy should become an important tool, because the relative amount of minerals and the arrangement of apatite and organic matrix could be a measure for evaluating bone quality. 31P solid-state NMR spectroscopy is useful for evaluating the quality of bone and predicting bone strength by calculating the spine-lattice relaxation time (T1) of bone. 31Psolid-stateNMRimaging can be used to measure quantitatively the mass of hydroxyapatite. The T1 relaxation time of both bone and deficient hydroxyapatite was much longer than that of pure hydroxyapatite. T1 relaxation time is one of the promising indices of bone quality

Mineral to matrix ratio determines biomaterial and biomechanical properties of rat femur : application of Fourier transform infrared spectroscopy

We studied the changes of biomaterial and biomechanical properties of the rat femur during development. Thirty male Wistar rats were allocated to 6 groups : aged 6 weeks (n=5), 9 weeks (n=5), 12 weeks (n=5), 15 weeks (n=5), 24 weeks (n=5), and 36 weeks (n=5). The mineral to matrix ratio (M/M ratio) of rat femur by Fourier transform infrared spectroscopy was 0.97 0.10 at the age of 6 weeks, and reached the maximum of 1.52 0.17 at the age of 36 weeks. Total bone mineral density (BMD) by peripheral quantitative computed tomography of the femoral shaft aged 6 weeks was 479.1 58.7 mg/cm3, and reached the maximum of 1022.2 42.3 mg/cm3 at the age of 36 weeks. The ultimate load to failure of the femur of the rat aged 6 weeks by the three-point bending test was 29.6 6.1 N. At the age of 36 weeks, the ultimate load to failure of the rat femur increased to the maximum of 283.5 14.7 N. The results showed that the M/M ratio increased with development as total BMD and bone strength increased. The results suggest that the M/M ratio is one of the determinants of the biomaterial and biomechanical properties of bone

Accurate diagnosis of chronic low back pain in a high-level college athlete : a case report

A 21-year-old woman who was high-level college softball player presented with a 6-month history of low back pain that had been treated unsuccessfully by medication at local clinics. There was tenderness in the left paravertebralmuscle at the lower lumbar level. X-ray and computed tomography revealed congenital scoliosis and an L6 hemivertebra. Short tau inversion recovery magnetic resonance imaging showed a fluid collection at the left L6-S1 facet joint.We performed a diagnostic facet injection, consisting of 1% lidocaine and steroids, that was infiltrated into the left facet joint at L6-S1. Her persistent low back pain disappeared immediately after the facet block. We diagnosed left-sided facet arthritis at L6-S1. Due to her multiple congenital anomalies, excessive loading occurred at the facet joint. Therefore, we opted for conservative management, including mobilization of the thoracic spine and stretching of hamstrings and quadriceps. This case report underscores the importance of accurate diagnosis of low back pain and of the diagnostic utility of short tau inversion recovery magnetic resonance imaging and lumbar facet block in young athletes with chronic spinal pain

A new concept of transforaminal ventral facetectomy including simultaneous decompression of foraminal and lateral recess stenosis : Technical considerations in a fresh cadaver model and a literature review

Percutaneous endoscopic surgery for the lumbar spine, which was established in the last decade, requires only an 8-mm skin incision and causes minimal damage to the paravertebral muscles ; thus, it is considered to be a minimally invasive technique for spinal surgery. It has been used to perform percutaneous endoscopic discectomy via two main approaches : the TF approach is a posterolateral one through the intervertebral foramen and can be done under local anesthesia ; the IL approach is a more traditional one through the interlaminar space and is difficult to perform under local anesthesia. Recently, these techniques have been applied for lumbar spinal stenosis (LSS), the TF method for foraminal stenosis under local anesthesia, and the IL method for central and lateral recess stenosis under general anesthesia. In this study, using a fresh human cadaver model, we performed simultaneous decompression of the lateral recess and foraminal stenosis at L4-5 using the TF approach. Computed tomography confirmed enlargement of the lateral recess and intervertebral foramen. This technique, which can be performed under local anesthesia, should benefit elderly patients with LSS and poor general condition due to multiple comorbidities. Finally, we introduce the concept of percutaneous transforaminal ventral facetectomy using a spinal percutaneous endoscope

Prediction of Asymmetric Yield Strengths of Polymeric Materials at Tension and Compression Using Spherical Indentation

Engineering polymers generally exhibit asymmetric yield strength in tension and compression due to different arrangements of molecular structures in response to external loadings. For the polymeric materials whose plastic behavior follows the DruckerPrager yield criterion, the present study proposes a new method to predict both tensile and compressive yield strength utilizing instrumented spherical indentation. Our method is decomposed into two parts based on the depth of indentation, shallow indentation, and deep indentation. The shallow indentation is targeted to study elastic deformation of materials, and is used to estimate Young's modulus and yield strength in compression; the deep indentation is used to achieve full plastic deformation of materials and extract the parameters in Drucker-Prager yield criterion associated with both tensile and compressive yield strength. Extensive numerical computations via finite element method (FEM) are performed to build a dimensionless function that can be employed to describe the quantitative relationship between indentation force-depth curves and material parameters of relevance to yield criterion. A reverse algorithm is developed to determine the material properties and its robustness is verified by performing both numerical and experimental analysis