Janan Abbas

Ligamentum Flavum Thickness in Normal and Stenotic Lumbar Spines

Study Design. A descriptive computed tomography (CT) study of the ligamentum flavum (LF) thickness in individuals with normal and stenotic lumbar spines. Objective. To establish standards for normal and pathologic range of LF thickness and its asymmetry as indicated in CT images and to examine its association with vertebral body size, age, and gender. Summary of Background Data. LF lines a considerable part of the posterior and lateral walls of the spinal canal and is a major role contributor to spinal canal stenosis. Due to methodologic deficiencies (e.g., small sample size, lack of control for vertebral body size, gender, and age), the normal range of LF thickness is still controversial. Furthermore, data on important aspect of LF thickness such as left-right differences are missing. Methods. Two groups of individuals were studied. The first group included 65 individuals with lumbar spinal stenosis (LSS) (mean age: 66 ± 9.7 years) and the second, 150 individuals (mean age: 52 ± 19 years) without LSS-related symptoms. LF thickness was measured on CT images (Philips Brilliance 64), obtained from axial plane scan at the intervertebral disc level. Measurements were performed at the levels of L3–L4, L4–L5, and L5–S1. Analysis of variance and t test were carried out to evaluate the association between LF thickness and demographic factors. Results. Absolute and relative LF thickness were significantly greater in the LSS group at the levels of L3–L4 and L4–L5 on both sides, compared to control group (P < 0.05). LF thickness was independent of gender (absolute and relative thickness). Even though LF thickness at all levels significantly increases with age, significant changes after the age of 60 occurred only at L3–L4. Significant asymmetry in LF thickness was found at L3–L4 (2.9 ± 0.90 mm on the right vs. 2.76 ± 0.90 mm on the left) and L5–S1 (3.42 ± 1.1 mm on the right vs. 3.22 ± 1.22 mm on the left) (P < 0.05). Conclusion. LF thickness is an age-dependent and gender-independent phenomenon. LF is significantly thicker on the right side. The borderline between normal and pathologic LF thickness should not be set at 4 mm.

Facet joints arthrosis in normal and stenotic lumbar spines.

ABSTRACT: Study Design. A descriptive CT study of lumbar facet joint (FJ) arthrosis in general and spinal stenosis populations.Objective. To reveal the prevalence of FJ arthrosis in general and stenosis populations and to establish its relationship to age and gender.Summary of Background Data. FJ arthrosis is a common radiographic finding and has been suggested as a cause of low back and lower extremity pain. It is also considered a dominant player in the genesis of lumbar spinal stenosis. Although it is well accepted that FJ arthrosis is an age dependent phenomenon, controversies still exist as to its association with gender and its prevalence at different spine levels. Additionally, data on FJ arthrosis frequency in spinal stenosis population are missing.Methods. Two groups were studied. The first included 65 individuals with LSS (mean age 66 ± 10 years) and the second, 150 individuals (mean age 52 ± 19 years) without LSS related symptoms. Both left and right FJ arthrosis for each vertebral level (L3 to S1) were evaluated on CT images (Brilliance 64, Philips Medical System, Cleveland Ohio). Chi-Square, Linear-by-Linear Association and McNemar test were carried out to reveal the correlation between FJ arthrosis and demographic factors (age, gender) and prevalence at different lumbar levels in both stenosis and non-stenosis groups. Additionally, a 2-way ANOVA was used to determine the association between BMI and FJ arthrosis.Results. The rate of FJ arthrosis at L3-4 and L4-5 were significantly higher (P<0.001) in the stenotic group compared to the control. In the control group the prevalence of FJ arthrosis increases cephalo-caudally (L3-L4 = 16%, L4-L5 = 28%, L5-S1 = 55%), whereas in the stenotic group there is a sharp increase from L3-4 (27%) to L4-5 (58%), but not from L4-5 to L5-S1 (55%). No association between FJ arthrosis and gender was noted. Although, mean BMI was significantly smaller in the control group compared to the stenotic group, no association between BMI and facet arthrosis was found. In the general population the prevalence of FJ arthrosis at all three levels was greater for the right side; however, significant difference (P = 0.004) was obtained only for L3-4. In all joints studied, the prevalence of FJ arthrosis increases considerably from the young age cohort (18-39) to the old age cohort (>60). Nevertheless, 10% of the young individuals (18-39) have already manifested FJ arthrosis at L5-S1. No arthrosis at that age was observed at L3-4.Conclusion. FJ arthrosis is an age-dependent and BMI and gender-independent phenomenon. In the general population, the prevalence of FJ arthrosis increases cephalo-caudally with the highest frequency at L5-S1. In the stenotic group, the highest frequency was observed at the two caudal levels; L4-5 and L5-S1. The prevalence of FJ arthrosis was greater for the right side.Study Design. A descriptive CT study of lumbar facet joint (FJ) arthrosis in general and spinal stenosis populations. Objective. To reveal the prevalence of FJ arthrosis in general and stenosis populations and to establish its relationship to age and sex. Summary of Background Data. FJ arthrosis is a common radiographic finding and has been suggested as a cause of low back and lower extremity pain. It is also considered a dominant player in the genesis of lumbar spinal stenosis. Although it is well accepted that FJ arthrosis is an age dependent phenomenon, controversies still exist as to its association with sex and its prevalence at different spine levels. In addition, data on FJ arthrosis frequency in spinal stenosis population are missing. Methods. Two groups were studied. The first included 65 individuals with LSS (mean age = 66 ± 10 yr) and the second, 150 individuals (mean age = 52 ± 19 yr) without LSS related symptoms. Both left and right FJ arthrosis for each vertebral level (L3–S1) were evaluated on CT images (Brilliance 64, Philips Medical System, Cleveland, OH). Chi-square, Linear-by-Linear Association and McNemar test were carried out to reveal the correlation between FJ arthrosis and demographic factors (age, sex) and prevalence at different lumbar levels in both stenosis and nonstenosis groups. In addition, a two-way analysis of variance (ANOVA) was used to determine the association between body mass index (BMI) and FJ arthrosis. Results. The rate of FJ arthrosis at L3–L4 and L4–L5 were significantly higher (P < 0.001) in the stenotic group compared to the control. In the control group the prevalence of FJ arthrosis increases cephalocaudally (L3-L4 = 16%, L4–L5 = 28%, L5–S1 = 55%), whereas in the stenotic group there is a sharp increase from L3–L4 (27%) to L4–L5 (58%), but not from L4–L5 to L5–S1 (55%). No association between FJ arthrosis and sex was noted. Although, mean BMI was significantly smaller in the control group compared to the stenotic group, no association between BMI and facet arthrosis was found. In the general population the prevalence of FJ arthrosis at all three levels was greater for the right side; however, significant difference (P = 0.004) was obtained only for L3–L4. In all joints studied, the prevalence of FJ arthrosis increases considerably from the young age cohort (18–39) to the old age cohort (>60). Nevertheless, 10% of the young individuals (18–39) have already manifested FJ arthrosis at L5–S1. No arthrosis at that age was observed at L3–L4. Conclusion. FJ arthrosis is an age-dependent and BMI and sex independent phenomenon. In the general population, the prevalence of FJ arthrosis increases cephalocaudally with the highest frequency at L5–S1. In the stenotic group, the highest frequency was observed at the two caudal levels; L4–L5 and L5–S1. The prevalence of FJ arthrosis was greater for the right side.

A morphological adaptation of the thoracic and lumbar vertebrae to lumbar hyperlordosis in young and adult females

The lumbar shape in females is thought to be unique, compensating for lumbar hyperlordosis. Yet, the morphological adaptation of various vertebral parameters in the thoracic and lumbar spine to this unique posture in young and adult females has only been partially addressed in the literature. Our aim was to investigate the gender association to vertebral shape in the thoracic and lumbar spine as a possible adaptation to lumbar hyperlordosis in young and adult females. A three-dimensional digitizer was used to measure the vertebral body sagittal wedging, relative spinous process thickness, and relative interfacet width at the T1–L5 level. Two hundred and forty complete, non-pathological skeletons of adults and 32 skeletons of young individuals were assessed. Three major results were found to be independent of age and ethnicity: (a) VB sagittal wedging in females was significantly less kyphotic than males from T9 to L2 (T11 excluded) with a cumulative mean difference of 8.8°; (b) females had a significantly relatively thinner lumbar spinous processes and (c) females had a relatively wider superior interfacet distance (T9–T10 and L1–L4) than males. We conclude that the combination of less kyphotic VB wedging in the lower thoracic and upper lumbar vertebrae, relatively greater interspinous space and larger interfacet width in the lumbar spine in females are key architectural elements in the lumbar hyperlordosis in females and may compensate for the bipedal obstetric load during pregnancy.

Hyperostosis frontalis interna: criteria for sexing and aging a skeleton

Estimation of sex and age in skeletons is essential in anthropological and forensic medicine investigations. The aim of the current study was to examine the potential of hyperostosis frontalis interna (HFI) as a criterion for determining sex and age in forensic cases. Macroscopic examination of the inner aspect of the frontal bone of 768 skulls (326 males and 442 females) aged 1 to 103, which had undergone a head computerized tomography scan, was carried out using the volume rendering technique. HFI was divided into two categories: minor and major. HFI is a sex- and age-dependent phenomena, with females manifesting significantly higher prevalence than males (p < 0.01). In both females and males, prevalence of HFI increases as age increases (p < 0.01). We present herein the probabilities of designating an unknown skull to a specific sex and age cohort according to the presence of HFI (standardized to age distribution in an Israeli population). Moreover, we present the probability of an individual belonging to a specific sex or age cohort according to age or sex (respectively) and severity of HFI. We suggest a valid, reliable, and easy method for sex and age identification of unknown skulls.

Hyperostosis frontalis interna: what does it tell us about our health?

Objectives: To examine whether the prevalence and severity of hyperostosis frontalis interna (HFI) has significantly changed during the past 100 years.

Hyperostosis Frontalis Interna and Androgen Suppression

Although hyperostosis frontalis interna (HFI) has been documented in the medical literature for over 300 years, its etiology remains undetermined. It is generally assumed to be associated with hormonal disturbances of the gonads. The aim of this study was to examine the association between androgen deprivation and development of HFI in males. Two groups of males over 60‐years old were compared: a control group that included 180 healthy males, 45 suffering from benign prostatic hypertrophy (BPH) and a study group of 127 males with prostate cancer: 67 who received complete androgen block treatment, and 60 who received different treatments or none at all. CT head scans were used to identify and classify HFI (Brilliance 64, Philips Medical Systems, slice thickness 3 mm × 1.5 mm). It was found that males who received a complete androgen block manifested significantly higher prevalence of HFI compared to healthy males. However, no significant difference in HFI prevalence was found between males suffering from BPH and healthy males or males with prostate cancer who had not received a complete androgen block. A positive association between length of hormonal treatment and manifestation of HFI was shown. It can be concluded that BPH does not promote development of HFI; males who are hormonally treated for prostate cancer are at a higher risk of developing HFI compared to healthy males; the longer the duration of hormonal treatment, the higher the risk of developing HFI. Anat Rec 293:1333–1336, 2010.

The Lumbar Lordosis in Males and Females, Revisited

Background Whether 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. Methods Our 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 Findings Compared 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). Conclusions Males 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.

Sacral orientation and spondylolysis.

Study Design. A descriptive study (based on skeletal material) was designed to measure sacral anatomic orientation (SAO) in individuals with and without spondylolysis. Objective. To test whether a relationship between SAO and spondylolysis exists. Summary of Background Data. Spondylolysis is a stress fracture in the pars interarticularis (mainly of L5). The natural history of the phenomenon has been debated for years with opinions divided, i.e., is it a developmental condition or a stress fracture phenomenon. There is some evidence to suggest that sacral orientation can be a “key player” in revealing the etiology of spondylolysis. Methods. The pelvis was anatomically reconstructed and SAO was measured as the angle created between the intersection of a line running parallel to the superior surface of the sacrum and a line running between the anterior superior iliac spine (ASIS) and the anterior-superior edge of the symphysis pubis (PUBIS). SAO was measured in 99 adult males with spondylolysis and 125 adult males without spondylolysis. The difference between the groups was tested using an unpaired t test. Results. Spondylolysis prevalence is significantly higher in African-Americans compared to European-Americans: 5.4% versus 2.04% in males (P < 0.001) and 2.31% versus 0.4%, P < 0.001 in females. SAO was significantly lower in the spondylolytic group (44.07° ± 11.46°) compared to the control group (51.07° ± 8.46°, P < 0.001). Conclusion. A more horizontally oriented sacrum leads to direct impingement on L5 pars interarticularis by both L4 inferior articular facet superiorly and S1 superior articular facet inferiorly. Repetitive stress due to standing (daily activities) or sitting increases the “pincer effect” on this area, and eventually may lead to incomplete synostosis of the neural arch.

Socioeconomic and physical characteristics of individuals with degenerative lumbar spinal stenosis.

Study Design. A descriptive study of the association between demographic factors, and physical characteristics, and degenerative lumbar spinal stenosis (DLSS). Objective. To shed light on the association between socioeconomic parameters, physical characteristics, and DLSS. Summary of Background Data. Lumbar spinal stenosis is a prevalent and disabling condition in the aging population. DLSS is considered to be the most common type and is essentially associated with disc disease, facet joint arthrosis, ligamentum flavum thickening, and osteophyte formation. Although there is ample information regarding the association between body mass index, cardiovascular disorders, smoking habits, and disc disease, very little is known about their association with DLSS. Data on the association of body physique (e.g., height and weight) and DLSS are limited. Methods. Two sample populations were studied. The first included 165 individuals with DLSS (mean age, 64 ± 9.9 yr) and the second 180 individuals without spinal stenosis related symptoms (mean age, 62.5 ± 12.6 yr). An evaluation of the cross-sectional area of the dural sac and degenerative listhesis for all participants was performed using computed tomographic lumbar spine images, obtained by Philips EBW station (Brilliance 64, Philips Medical System, Cleveland, OH). All participants were interviewed to obtain demographic, physical, and health data. Independent t test, Mann-Whitney and &khgr;2 tests were used to determine the association between parametric and nonparametric variables and DLSS. Logistic regression analysis was carried out to reveal predicting variables for DLSS. Results. Females with stenosis were significantly heavier and shorter than their counterparts in the control group. We also noticed that they delivered babies more often than those in the control group. Prevalence of individuals experiencing diabetes mellitus was significantly higher in the males with stenosis than control group. In the stenosis group, the frequencies of individuals engaged in heavy manual labor (males) and housekeeping (females) were significantly higher than that of their counterparts in the control group. Conclusion. Heavy manual labor and diabetes mellitus in males and housekeeping (females) play major roles in the genesis of DLSS.

Intracranial volume, cranial thickness, and hyperostosis frontalis interna in the elderly.

According to the “brain reserve hypothesis,” a larger premorbid brain protects against the development of dementia. The aim of this study was to reveal a possible pathophysiology of brain degenerative diseases by studying intracranial bone lesions that act to reduce intracranial volume (ICV), such as hyperostosis frontalis interna (HFI).