Female Spine Research Articles

Biomechanical Analysis of a Growing Rod with Sliding Pedicle Screw System for Early-Onset Scoliosis.

Early-onset scoliosis (EOS) remains a challenging condition for which current nonfusion surgeries require iterative lengthening surgeries. A growing rod with sliding pedicle screw system (GRSPSS) was developed to treat spinal deformities without repeated operative lengthening. This study was performed to evaluate whether GRSPSS had similar stability as a conventional pedicle screw system to maintain deformity correction. A serial-linkage robotic manipulator with a six-axis load cell positioned on the end-effector was utilized to evaluate the mechanical stability of the GRSPSS versus conventional fixed scoliosis instrumentation. Ten skeletally mature thoracic female Katahdin sheep spines (T4-L1) were subjected to 2.5 Nm of flexion-extension (FE), lateral bending (LB), and axial rotation (AR) in 2° increments for each state. The overall range of motion (ROM), apical segment ROM, and stiffness were calculated and reported. A two-tailed paired t-test was used to detect significant differences (p < 0.05) between the fixed group and GRSPSS fixation. There were no significant differences in overall range of motion (ROM), apical segment ROM, or stiffness for FE or LB between the GRSPSS group and fixed group. In AR, the GRSPSS group showed increased ROM compared to the fixed group for the overall spine (36.0° versus 19.2°, p < 0.01) and for the instrumented T8-T10 segments (7.0° versus 2.9°, p=0.02). Similarly, the fixed rod elastic zone (EZ) stiffness was significantly greater than the GRSPSS EZ stiffness (0.29 N/m versus 0.17 N/m, p < 0.001). The space around the rod allows for the increased AR observed with the GRSPSS fusion technique and is necessary for axial growth. The GRSPSS fusion model shows equivalent flexion and LB stability to current fusion models and represents a stable fusion technique and may allow for longitudinal growth during childhood.

Endocrine disrupting effects in western mosquitofish Gambusia affinis in two rivers impacted by untreated rural domestic wastewaters

Domestic wastewaters are an important source of endocrine disrupting chemicals in the receiving aquatic environment. Most rural domestic wastewaters (RDWs) in China have been directly discharged into the aquatic environment without any treatment. Here we studied the effects of RDWs on the western mosquitofish (Gambusia affinis) from two rural rivers receiving untreated RDWs. Mosquitofish samples were collected at 5 sampling sites along two rivers during dry and wet seasons. Sex ratios, secondary sex characteristics and transcriptional levels of target genes related to the endocrine system in adult females and males were determined. In parallel, various pollutants including steroid hormones, phenolic compounds, pesticides, polycyclic aromatic hydrocarbons (PAHs) and heavy metals were measured in the water samples at all sites. The results showed that the androgenic effects in the fish were evidenced by significant increase in male to female ratio in fish populations at two sampling sites and by the presence of modified hemal spines in females at four sampling sites when compared to the reference site. The males from the two rivers had increased Vtg mRNA expressions with a maximal 6.2-fold increase relative to the reference site and a delayed development of hemal spines. The redundancy analysis (RDA) showed that some physiological parameters were related to steroid hormones, phenolic compounds and PAHs. The findings from this study suggest that RDWs can lead to masculinization in females and feminization in males.

Normal Bone Mineral Density Measurements in Pubertal Males and Females: A Cross-Sectional DXA Study Abstract

Objective: Our main goal was to present normal BMD measurements in pubertal males and females in order to make contribution to the the database of normative BMD values in our country. Methods: In this study 30 pubertal subjects (14 males, 16 females) with Tanner stage II-V having normal BMD values were enrolled. The mean ages of the male and female groups were 13.6±1.4 and 13.7±1.6 years, respectively (P&amp;gt;0.05). The BMD measurements of lumbar spine (L1-4) and femoral neck were done by dual x-ray absorptiometry (DXA). Lumbar and femoral BMD measurements of male and female subjects were compared. Lumbar and femoral neck BMD values were correlated with the age, weight, height and body mass index of the subjects within each gender groups.Results: There was no significant difference between mean ages, mean weight, mean height and mean BMI of male and females (P&amp;gt;0.05). The mean lumbar BMD value was statistically higher in pubertal females compared to males (P&amp;lt;0.05). There was significant correlation between the mean age and the mean lumbar BMD measurements in female group (P&amp;lt;0.05). There was significant correlation between the mean weight and the mean BMD measurements (lomber and femoral BMD) in male group (P&amp;lt;0.05). Conclusion: In conclusion, DXA is a useful, fast and accurate diagnostic tool for performing BMD measurements of lumbar spine (L1-4) and femoral neck in pubertal males and females.

Validation of an In Vivo Medical Image-Based Young Human Lumbar Spine Finite Element Model.

Mathematical models of the human spine can be used to investigate spinal biomechanics without the difficulties, limitations, and ethical concerns associated with physical experimentation. Validation of such models is necessary to ensure that the modeled system behavior accurately represents the physics of the actual system. The goal of this work was to validate a medical image-based nonlinear lumbosacral spine finite element model of a healthy 20-yr-old female subject under physiological moments. Range of motion (ROM), facet joint forces (FJF), and intradiscal pressure (IDP) were compared with experimental values and validated finite element models from the literature. The finite element model presented in this work was in good agreement with published experimental studies and finite element models under pure moments. For applied moments of 7.5 N·m, the ROM in flexion-extension, axial rotation, and lateral bending were 39 deg, 16 deg, and 28 deg, respectively. Excellent agreement was observed between the finite element model and experimental data for IDP under pure compressive loading. The predicted FJFs were lower than those of the experimental results and validated finite element models for extension and torsion, likely due to the nondegenerate properties chosen for the intervertebral disks and morphology of the young female spine. This work is the first to validate a computational lumbar spine model of a young female subject. This model will serve as a valuable tool for predicting orthopedic spinal injuries, studying the effect of intervertebral disk replacements using advanced biomaterials, and investigating soft tissue degeneration.

Variation in the number of lateral telson spines of Stygobromus flagellatus (Benedict, 1896) (Amphipoda: Crangonyctidae), a subterranean species from Texas, USA

Stygobromus flagellatus (Benedict, 1896) (Amphipoda, Crangonyctidae) is known from spring systems in Hays, Comal and Travis counties, Texas, USA. Routine censuses of community holding tanks revealed deviations in the number of lateral telson spines of females and males as given in the most recent description of the species. Other discrepancies included “double spines” and varying configurations of lateral telson spines in both females and males, including one female and one male that did not have any trace of lateral telson spines. Explanations for these deviations are discussed.

Vitamin D status in relation to age, bone mineral density of the spine and femur in obese Saudi females – A hospital-based study

The aim of the present study was to evaluate the association between Bone mineral density in lumber spine and femoral neck with serum total levels of vitamin D, sun exposure and Consumption of vitamin D Supplement in obese Saudi females aged between 30 and 54 years old. Recent attention to the high prevalence of osteoporosis and its association with low vitamin D levels in adults has raised the importance of vitamin D evaluation. A low level of vitamin D is considered to be one of the most important risk factors for osteoporosis. In this study; 120 obese Saudi females with no diagnosed chronic diseases attending the Outpatient clinic at king Khalid University hospital in Riyadh. Saudi Arabia, recruited randomly in period of 12 months. In this study, Serum levels of total Vitamin D were considered to be severe deficient if it was lower than 25 ng/mL, mild to moderate deficient if it was between 25 and 60 ng/mL and optimum level if it was 61–200 ng/mL. The results showed that; sun exposure was significantly affect and Correlate with serum level of Vitamin D in the subjects. In addition, daily consumption of Vitamin D supplement was significantly affect and Correlate with serum level of Vitamin D in the subjects of this study. Moreover, the results showed that; 50% of the age group (40–49 years old) having severe deficiency of Vitamin D. While, 50% of the age group (50–59 years old) having optimal level of Vitamin D. And these results mean that age is not Correlated with vitamin D deficiency in subjects of this study.

Workforce Analysis of Spine Surgeons Involved with Neurological and Orthopedic Surgery Residency Training

Spinal surgery is taught and practiced within 2 different surgical disciplines: neurological surgery and orthopedic surgery. We have provided a unified analysis of spine-focused faculty at U.S. residency programs. A total of 278 Accreditation Council for Graduate Medical Education training programs were assessed to identify 923 full-time faculty members with a spinal surgery designation, defined by spine fellowship training or surgeon case volume >75% spine surgeries. Faculty were assessed with respect to parent discipline, years of fellowship training, academic rank, gender, and academic productivity (h-index). The spine-teaching workforce contains 55% orthopedic surgeons and 45% neurosurgeons with wide gender asymmetry overall and at all faculty ranks. Of the female spine surgeons, those with neurosurgical training (64.44%) nearly doubled the number with orthopedic training (35.56%). Academic productivity increased with academic rank similarly for both genders and subspecialties. Orthopedic spine surgeons had a greater mean fellowship number compared with the neurological spine surgeons. Fellowship time of completion (intraresidency/infolded vs. postresidency) did not significantly affect the h-indexes. Addition of fellowship conferred academic productivity benefit for orthopedic surgeons only. Neurological and orthopedic spine surgery showed similar patterns for the spread of faculty across academic ranks and trends in academic productivity. Marked gender disparity was seen in both neurosurgical and orthopedic surgery, with fewer female spine surgeons seen at every academic rank. Orthopedic spine surgeons had a greater mean fellowship number than did their neurosurgical counterparts, and a lack of fellowship correlated with lower academic productivity in orthopedic, but not neurological, spine surgery.

The Role of Male Variation in Fertilization Success in Determining the Costs and Benefits of Polyandry in the Broadcast Spawning Urchin Lytechinus variegatus.

Although the benefits to males mating with multiple females have been well documented, the benefits to females mating with multiple males (polyandry) are less studied, particularly the mechanism that might drive these potential benefits. Benefits of polyandry might stem from increasing the chance of mating with a high-quality or compatible male or stem from the ability of multiple males to fertilize more eggs than any single male. We examine the fertilization consequences of polyandry in the sea urchin Lytechinus variegatus. This species has variation in spine color, and we conducted matings between individual and pooled sperm from two males that matched or mismatched in color. The results indicate that (1) males with white spines achieved higher fertilization and were more likely to cause polyspermy than males with purple spines, and there was no effect of female spine color on fertilization; (2) when comparing the average success of individual matings with pooled-sperm matings, there was a net benefit to polyandry when purple-spine males were pooled, a net cost when white-spine males were pooled, and no difference when mismatched spine color males were pooled; and (3) the success under pooled-sperm trials, with any of the spine color combinations, never exceeded the success of the more successful male in the individual-male trials. Together these results suggest that the consequences of polyandry depend on the relation between sperm availability and the sensitivity of eggs to sperm limitation and polyspermy with respect to the specific set of available males. The potential fertilization consequences of a female spawning with multiple males might be associated primarily with increasing the amount of sperm available to fertilize her eggs and secondarily with increasing the chances of mating with a higher-quality or more compatible male, as opposed to a diversity of males.

Preliminary female cervical spine injury risk curves from PMHS tests.

The human cervical spine sustains compressive loading in automotive events and military operational activities, and the contact and noncontact loading are the two primary impact modes. Biomechanical and anatomical studies have shown differences between male and female cervical spines. Studies have been conducted to determine the human tolerance in terms of forces from postmortem human subject (PMHS) specimens from male and female spines; however, parametric risk curves specific to female spines are not available from contact loading to the head-neck complex under the axial mode. This study was conducted to develop female-spine based risk curves from PMHS tests. Data from experiments conducted by the authors using PMHS upright head-spines were combined with data from published studies using inverted head-spines. The ensemble consisted of 20 samples with ages ranging from 29 to 95 years. Except one, all specimens sustained neck injuries, consisting of fractures to cervical vertebrae, and disruptions to the intervertebral disc and facet joints, and ligaments. Parametric survival analysis was used to derive injury probability curves using the compressive force, uncensored for injury and right censored for noninjury data points. The specimen age was used as the covariate. Injury probability curves were derived using the best fit distribution, and the± 95% confidence interval limits were obtained. Results indicated that age is a significant covariate for injury for the entire ensemble. Peak forces were extracted for 35, 45, and 63 (mean) years of age, the former two representing the young (military) and the latter, the automobile occupant populations. The forces of 1.2 kN and 2.9 kN were associated with 5% and 50% probability of injury at 35 years. These values at 45 years were 1.0 kN and 2.4 kN, and at 63 years, they were 0.7 kN and 1.7 kN. The normalized widths of the confidence intervals at these probability levels for the mean age were 0.74 and 0.48. The preliminary injury risk curves presented should be used with appropriate caution. This is the first study to develop risk curves for females of different ages using parametric survival analysis, and can be used to advance human safety, and design and develop manikins for military and other environments.

Influence of morphological variations on cervical spine segmental responses from inertial loading

ABSTRACTObjectives: The objective of this study was to investigate the influence of morphological variations in osteoligamentous lower cervical spinal segment responses under postero-anterior inertial loading.Methods: A parametric finite element model of the C5–C6 spinal segment was used to generate models. Variations in the vertebral body and facet depth (anteroposterior), posterior process length, intervertebral disc height, facet articular process height and slope, segment orientation ranging from lordotic to straight, and segment size were parameterized. These variations included male–female differences. A Latin hypercube sampling method was used to select parameter values for model generation. Forces and moments associated with the inertial loading were applied to the generated model segments. The 7 parameters were grouped as local or global depending on the number of spinal components involved in the shape variation. Four output responses representing overall segmental and soft tissue responses were analyzed for each model variation: response angle of the segment, anterior longitudinal ligament stretch, anterior capsular ligament stretch, and facet joint compression in the posterior region. Pearson's correlation coefficient was used to compute the correlations of these output responses with morphological variations.Results: Fifty models were generated from the parameterized model using a Latin hypercube sampling technique. Variation in response angle among the models was 4° and was most influenced by change in the combined dimension of vertebral body and facet depth, followed by size of the segment. The maximum anterior longitudinal ligament stretch varied between 0.1 and 0.3 and was strongly influenced by the change in the segment orientation. The anterior facet joint region sustained tension, whereas the posterior region sustained compression. For the anterior capsular ligament stretch, the most influential global variation was segment orientation, whereas the most influential local variations were the facet height and facet angle parameters. In the case of posterior facet joint compression, segment orientation was again most influential, whereas among the local variations, the facet angle had the most influence.Conclusion: Shape variations in the intervertebral disc influenced segmental rotation and ligament responses; however, the influence of shape variations in the facet joint was confined to capsular ligament responses. Response angle was most influenced by the vertebral body depth variations, explaining greater segmental rotations in female spines. Straighter spine segments sustained greater posterior facet joint compression, which may offer an explanation for the higher incidence of whiplash-associated disorders among females, who exhibit a straighter cervical spine. The anterior longitudinal ligament stretch was also greater in straighter segments. These findings indicate that the morphological features specific to the anatomy of the female cervical spine may predispose it to injury under inertial loading.

Nursing review of spinal meningiomas.

Background:Spinal meningiomas are found in patients typically between the ages of 75 and 84: some report the average age to be 50. They occur with an incidence of approximately 1000 patients per year in the US, are mostly single (90%) rather than multiple (10%), and arise from the spinal meninges (arachnoid/dura). Tumors are typically posterior/posterolateral (70%) in location, leaving the remaining 30% in the anterior/anterolateral spinal canal. They produce symptoms and signs of radiculopathy (nerve root) and/or myelopathy (cord compression) depending on their site of origin.Methods:Meningiomas may be single/sporadic (90%) or multifocal. They may arise primarily/spontaneously, can be radiation-induced, or associated with neurofibromatosis. They are found most frequently in females vs. males in up to a 3.4:1 ratio, occur predominantly in the thoracic spine. They are found in decreasing order in the cervical and lumbar spinal canals. The diagnosis of a meningioma is based on magnetic resonance (MR) studies, where tumors are isointense on T1 weighted MR, and hyperintense onf T2-weighted MR images; they also typically uniformly enhance with Gd-DTPA. On computed tomography (CT) examinations, they are usually characterized as calcified/hyperdense.Results:The neurological deficits resulting from meningiomas and the rapidity of symptom/sign progression dictate whether they are treated surgically or nonsurgically. Management choices include; stereotactic radiation therapy only, and/or in combination with varied surgical resection techniques.Conclusions:The majority of benign spinal cord tumors are meningiomas (40%) that are predominantly found in the thoracic spine in middle-aged females. Tumor levels (e.g. in descending order cervical, thoracic, lumbar), and their location (e.g. anterior/anterolateral 30%; dorsal/dorsolateral 70%) best determine whether nonoperative, operative, and/or operative intervention combined with routine vs. stereotactic radiosurgery are warranted.

Evaluation of Sagittal Spine-Pelvis-Lower Limb Alignment in Elderly Women with Pelvic Retroversion while Standing and Walking Using a Three-Dimensional Musculoskeletal Model.

Study DesignIn vivo biomechanical study using a three-dimensional (3D) musculoskeletal model for elderly individuals with or without pelvic retroversion.PurposeTo evaluate the effect of pelvic retroversion on the sagittal alignment of the spine, pelvis, and lower limb in elderly females while standing and walking.Overview of LiteraturePatients with hip–spine syndrome have concurrent hip-joint and spine diseases. However, the dynamic sagittal alignment between the hip joint and spine has rarely been investigated. We used a 3D musculoskeletal model to evaluate global spinopelvic parameters, including spinal inclination and pelvic tilt (PT).MethodsA total of 32 ambulant females (mean age=78 years) without assistance were enrolled in the study. On the basis of the radiographic measurement for PT, participants were divided into the pelvic retroversion group (R-group; PT≥20°) and the normal group (N-group; PT<20°). A 3D musculoskeletal motion analysis system was used to analyze the calculated value for the alignment of spine, pelvis, and lower limb, including calculated (C)-PT, sagittal vertical axis (C-SVA), pelvic incidence, lumbar lordosis, T1 pelvic angle (C-TPA), as well as knee and hip flexion angles while standing and walking.ResultsWhile standing, C-PT and C-TPA in the R-group were significantly larger than those in the N-group. Hip angle was significantly smaller in the R-group than in the N-group, unlike knee angle, which did not show difference. While walking, C-SVA and C-TPA were significantly increased, whereas C-PT decreased compared with those while standing. The maximum hip-flexion angle was significantly smaller in the R-group than in the N-group. There was a significant correlation between the radiographic and calculated parameters.ConclusionsThe 3D musculoskeletal model was useful in evaluating the sagittal alignment of the spine, pelvis, and leg. Spinopelvic sagittal alignment showed deterioration while walking. C-PT was significantly decreased while walking in the R-group, indicating possible compensatory mechanisms attempting to increase coverage of the femoral head. The reduction in the hip flexion angle in the R-group was also considered as a compensatory mechanism.

Male and Female Cervical Spine Biomechanics and Anatomy: Implication for Scaling Injury Criteria.

There is an increased need to develop female-specific injury criteria and anthropomorphic test devices (dummies) for military and automotive environments, especially as women take occupational roles traditionally reserved for men. Although some exhaustive reviews on the biomechanics and injuries of the human spine have appeared in clinical and bioengineering literatures, focus has been largely ignored on the difference between male and female cervical spine responses and characteristics. Current neck injury criteria for automotive dummies for assessing crashworthiness and occupant safety are obtained from animal and human cadaver experiments, computational modeling, and human volunteer studies. They are also used in the military. Since the average human female spines are smaller than average male spines, metrics specific to the female population may be derived using simple geometric scaling, based on the assumption that male and female spines are geometrically scalable. However, as described in this technical brief, studies have shown that the biomechanical responses between males and females do not obey strict geometric similitude. Anatomical differences in terms of the structural component geometry are also different between the two cervical spines. Postural, physiological, and motion responses under automotive scenarios are also different. This technical brief, focused on such nonuniform differences, underscores the need to conduct female spine-specific evaluations/experiments to derive injury criteria for this important group of the population.

Bone mineral density among Korean females aged 20-50years: influence of age at menarche (The Korea National Health and Nutrition Examination Survey 2008-2011).

To investigate any correlation between bone mineral density (BMD) and age at menarche in Korean females using data from the fourth and fifth Korea National Health and Nutrition Examination Survey (KNHANES IV-V; 2008-2011). In total, 37,753 individuals participated in health examination surveys between 2008 and 2011. A total of 5032 premenopausal females aged 20-50years were eligible. Age, height, weight, and age at menarche were assessed. Results from the univariate linear regression and analysis of covariance (ANCOVA) indicated that age (per 1year), height (per 1cm), weight (per 1kg), exercise (per 1day/week), familial osteoporosis history (yes), parity (n=0 to ≥4), and menarche age distribution were associated with BMD of the total femur, femur neck, and lumbar spine. After stratifying the bone area and adjusting for age, parity, alcohol intake, smoking, exercise, and familial osteoporosis history, no effect was seen for the total femur or femur neck. Age at menarche 16~17 and ≥18years groups were associated with BMD of the lumbar spine only. Age at menarche had a small but significant association with BMD of the lumbar spine in premenopausal Korean females, aged 20-50years. Females with late menarche may achieve lower peak bone mass at some skeletal sites, which may put them at greater risk for osteoporosis in later life.

Two new species of Heth Cobb, 1898 (Nematoda: Ransomnematoidea) from Northern Mindanao, the Philippines

Heth konoplevi n. sp. and Heth initiensis n. sp. are described from an unidentified spirobolid (Rhinocricidae) millipede collected at Mindanao Island, the Philippines. Females of H. konoplevi n. sp. are characterised by the absence of lateral cuticular lappets and the arrangement of lateral spines with an unpaired one in mid-lateral position that brings it closer to H. zeuglocantha from Papua New Guinea. The presence of a cervical collar, lateral cuticular lappets, two pairs of lateral cuticular spines in females and a bursa-like extension around the cloacal region in males of H. initiensis n. sp. makes it closer to some representatives of the genus from the Asia-Pacific and Australasian regions. The description of H. initiensis n. sp. is supplemented by details of the fourth-stage juvenile morphology. Molecular phylogenetic analysis of SSU and LSU rDNA is provided.

A new species of Hedruris Nitzsch, 1821 (Nematoda: Hedruridae) parasitic in the freshwater fish Oligosarcus jenynsii (Günther, 1864) (Characidae) from Argentina.

Nematodes belonging to genus Hedruris Nitzsch, 1821 (Nematoda: Hedruridae) were found in the stomach of the freshwater fish Oligosarcus jenynsii (Günther, 1864) (Characidae) from a shallow eutrophic lake in Argentina. Morphological comparisons with congeneric relatives showed that these nematodes belong to a new species, for which H. bifida n. sp. is proposed. Hedruris bifida n. sp. can be distinguished from its congeners by the following combination of characters: bifid deirids, absence of precloacal papillae and nine pairs of postcloacal papillae and non-mammillated eggs. The new species closely resembles Hedruris suttonae Brugni & Viozzi, 2010¸ the only known species from Argentina; however, the bifid deirids in the new species and the distribution pattern of perianal spines in females clearly distinguish both species. Hedruris bifida n. sp. represents the second nominal species of the genus in Argentina and the eighth species described in the Neotropical region.

First Description of Asexual Generation and Taxonomic Revision of the Gall Wasp GenusLatuspina(Hymenoptera: Cynipidae: Cynipini)

The asexual generation of Latuspina Monzen is described for the first time. Although this genus was established based only on sexual generation upon which females possess a trifurcate hypopygial spine, the asexual generation females of Latuspina , including the type species L. stirps , possess a needle-shaped hypopygial spine, similar to that of many Cynipini, oak gall wasps. Based on the trifurcate hypopygial spine in sexual generation females, Neuroterus atamiensis Ashmead, N. hellwegi Dettmer, and N. nawai Ashmead are transferred to Latuspina in this paper: L. atamiensis comb. nov. , L. hellwegi comb. nov. , and L. nawai comb. nov. In addition, L. kofuensis Ide et Abe sp. nov. and L. abemakiphila Ide et Abe sp. nov. are described as new species from Japan. Latuspina includes nine species in total, but the asexual generation galls and adults of the following four species are unknown: L. abemakiphila , the Taiwanese species L. manmiaoyangae Melika et Tang, and two mainland Chinese species L. acutissimae Wang, Pujade-Villar et Guo and L. shaanxinensis Wang, Pujade-Villar et Guo. Although the host plant of L. shaanxinensis was reported as genus “ Quercus ” without specific name, the other species of Latuspina induce galls on oaks of the section Cerris of the genus Quercus , implying that they are specialized to oaks of this section.

Morphological and postural sexual dimorphism of the lumbar spine facilitates greater lordosis in females.

Previous work suggests females are evolutionarily adapted to have greater lumbar lordosis than males to aid in pregnancy load-bearing, but no consensus exists. To explore further sex-differences in the lumbar spine, and to understand contradictions in the literature, we conducted a cross-sectional retrospective study of sex-differences in lumbar spine morphology and sacral orientation. In addition, our sample includes data for separate standing and supine samples of males and females to examine potential sex-differences in postural loading on lumbosacral morphology. We measured sagittal lumbosacral morphology on 200 radiographs. Measurements include: lumbar angle (L1-S1), lumbar vertebral body and disc wedging angles, sacral slope and pelvic incidence. Lumbar angle, representative of lordotic curvature between L1 and S1, was 7.3° greater in females than males, when standing. There were no significant sex-differences in lumbar angle when supine. This difference in standing lumbar angle can be explained by greater lordotic wedging of the lumbar vertebrae (L1-L5) in females. Additionally, sacral slope was greater in females than males, when standing. There were no significant sex-differences in pelvic incidence. Our results support that females have greater lumbar lordosis than males when standing, but not when supine - suggesting a potentially greater range of motion in the female spine. Furthermore, sex-differences in the lumbar spine appear to be supported by postural differences in sacral-orientation and morphological differences in the vertebral body wedging. A better understanding of sex-differences in lumbosacral morphology may explain sex-differences in spinal conditions, as well as promote necessary sex-specific treatments.

Demographic Trends of Patients with Compressive Myelopathy in a Developing Asian Country

Study DesignProspective case series.PurposeTo analyze the demographic picture of the patients suffering from compression myelopathy due to various spinal problems. Overview of Literature: There is a lack of literature depicting demographic picture of such patients with spinal injuries as most of the articles have shown the epidemiology of spinal cord injuries either managed conservatively or operatively. None have focused on the patients with compressive myelopathy requiring surgeries.MethodsPatients with spinal pathologies with a neurological deficit due to compressive myelopathy requiring surgical decompression of dorsal and thoracolumbar region were studied. The different kinds of etiologies, the demographic profiles involved, the involvement of various regions of spine in each of the etiologies, sex distribution of different etiologies, association of age and sex with the occurrence of paraplegia, and association of thoracolumbar junction (TLJ) involvement by age and sex were studied. This study addressed the dorsal and TLJ till L2 vertebrae surgically treated by anterior transthoracic transpleural approach.ResultsWith regard to gender, 75% of the females and 67.3% of the males were paraplegic but there was no relationship between gender and the occurrence of paraplegia (p >0.05). There was also no association between TLJ involvement and the age and sex of the patients (p >0.05). Seventy percent of the patients were paraplegic with a mean age of 38.90 years and 30% were paraparetic with a mean age of 43.43 years. Male to female ratio stood at 4.43:1.ConclusionsTraumatic spine in females is increasing. The occurrence of paraplegia and involvement of TLJ is not affected by the age and the sex of the patients. Deep epidemiological understanding of spinal pathologies can lead to a better appreciation of the potential impact of health care management strategies and health policies to prevent and minimize their consequences considering limited worldwide reports on the same.

The Lumbar Lordosis in Males and Females, Revisited.

BackgroundWhether differences exist in male and female lumbar lordosis has been debated by researchers who are divided as to the nature of variations in the spinal curve, their origin, reasoning, and implications from a morphological, functional and evolutionary perspective. Evaluation of the spinal curvature is constructive in understanding the evolution of the spine, as well as its pathology, planning of surgical procedures, monitoring its progression and treatment of spinal deformities. The aim of the current study was to revisit the nature of lumbar curve in males and females.MethodsOur new automated method uses CT imaging of the spine to measure lumbar curvature in males and females. The curves extracted from 158 individuals were based on the spinal canal, thus avoiding traditional pitfalls of using bone features for curve estimation. The model analysis was carried out on the entire curve, whereby both local and global descriptors were examined in a single framework. Six parameters were calculated: segment length, curve length, curvedness, lordosis peak location, lordosis cranial peak height, and lordosis caudal peak height.Principal FindingsCompared to males, the female spine manifested a statistically significant greater curvature, a caudally located lordotic peak, and greater cranial peak height. As caudal peak height is similar for males and females, the illusion of deeper lordosis among females is due partially to the fact that the upper part of the female lumbar curve is positioned more dorsally (more backwardly inclined).ConclusionsMales and females manifest different lumbar curve shape, yet similar amount of inward curving (lordosis). The morphological characteristics of the female spine were probably developed to reduce stress on the vertebral elements during pregnancy and nursing.