Bahaa Medlej

Schmorl’s nodes distribution in the human spine and its possible etiology

Although Schmorl’s nodes (SNs) are a common phenomenon in the normal adult population, their prevalence is controversial and etiology still debatable. The objective was to establish the spatial distribution of SNs along the spine in order to reveal its pathophysiology. In this study, we examined 240 human skeleton spines (T4-L5) (from the Hamann–Todd Osteological Collection) for the presence and location of SNs. To determine the exact position of SNs, each vertebral body surface was divided into 13 zones and 3 areas (anterior, middle, posterior). Our results show that SNs appeared more frequently in the T7-L1 region. The total number of SNs found in our sample was 511: 193 (37.7%) were located on the superior surface and 318 (62.3%) on the inferior surface of the vertebral body. SNs were more commonly found in the middle part of the vertebral body (63.7%). No association was found between the SNs location along the spine and gender, ethnicity and age. This study suggests that the frequency distribution of SNs varies with vertebra location and surface. The results do not lend support to the traumatic or disease explanation of the phenomenon. SNs occurrences are probably associated with the vertebra development process during early life, the nucleus pulposus pressing the weakest part of the end plate in addition to the various strains on the vertebrae and the intervertebral disc along the spine during spinal movements (especially torsional movements).

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.

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 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 Epiphyseal Ring : A Long Forgotten Anatomical Structure with Significant Physiological Function

Study Design. A descriptive study of the epiphyseal rings structural design along the thoracolumbar spine. Objective. To characterize and analyze the shape and size of the epiphyseal ring, to better understand its function. Summary of Background Data. The literature is lacking in metrical data pertaining to the epiphyseal ring that is usually described as a narrow bony labrum on which the external fibers of the anulus fibrosus are anchored. Most researchers express doubts as to whether the term epiphysis is justified in this case. Methods. The sample studied included 240 human skeletons (vertebrae T4–L5) from a normal adult population (divided by sex, ethnicity, and age). Measurements of the vertebral body and epiphyseal ring were taken using a digital caliper at four different locations: anterior, posterior, right, left. In addition, each vertebral surface was photographed and the epiphyseal ring area measured (using image analyzer software Image J). Results. We found that relative to vertebral body size throughout the thoracolumbar spine, the anterior section of the ring was the widest and the posterior section the narrowest. The lateral parts presented intermediate values. Relative to the discal area, the epiphyseal ring area gradually decreased from T7 to T12 and increased from T12 to L4. The area of the inferior ring was always larger than the superior ring (significant only for lumbar vertebrae), regardless of sex, ethnicity, and age. Conclusion. The epiphyseal ring varies largely in size and shape along the thoracolumbar spine. Much of its metrical properties are dictated by the applied mechanical stress regime during various movements, and/or the general anatomic structure of the spine.

Hyperostotic bone disease in a wombat (Vombatus ursinus)

Little is known about wombat diseases in general, and about their congenital diseases in particular. In the current study, the skeleton of a common wombat (Vombatus ursinus) that exhibited generalized hyperostosis is analyzed, and possible diagnoses are reviewed. Macromorphological analyses revealed that the diaphyses of the long bones manifested an increased diameter with extensive diaphyseal new-bone formation (periosteal and endosteal). Cross-sections of the diaphyses showed that the cortical-medullary demarcation was indistinct. The calvarial bones were thickened. Radiographs showed uniform sclerosis of the long bones with loss of trabecular pattern. Microradiography showed extensive bone remodeling, a hyper-vascularized lamellated layer of bone and numerous linear formation defects. Possible causes for the lesions, including sclerosing bone dysplasia disorders, acquired syndromes causing hyperostosis, and metabolic diseases typical of animals in captivity, are discussed.