The dimensions of the cervical spinal canal (C3 – C7) of the South African black population were measured on skeletal remains of 179 individuals (90 males and 89 females divided into age categories of 30-45; 46-60 and 61-75 years), and compared to measurements taken from CT-scans of 55 individuals divided into the same categories. There was no significant difference between measurements taken on skeletal material and CT-scans. The spinal canal is larger in males (mean = 13.96mm) than in females (mean = 13.84mm) and the Pavlov ratio is larger for females (mean = 0.89) than males (mean = 0.81). The Pavlov ratio seems to overestimate the occurrence of spinal stenosis in this population group, as almost all individuals older than 46 years are classified as stenotic according to this ratio. The shape of the cervical spinal canal was determined morphometrically by processing digital images taken of vertebrae (C3 – C7) of 60 individuals with the tps-Series of software programs and was found to be significantly different between males and females. In males the canal is congenitally triangular, whereas in females the canal assumes a more “safe”, rounded shape. The low Pavlov ratio for this population group, especially in males, can possibly be explained by these shape differences. Even slight degenerative changes affecting the spinal canal, such as osteophytosis or ossification of the posterior longitudinal ligament (OPLL), will alter the triangular-shaped male canal in such a way that the spinal cord may become compromised. Cervical vertebrae of 107 individuals were inspected for occurrence of osteophytes within the spinal canal and the incidence of OPLL. Osteophyte occurrence within the cervical spinal canal is the same for males and females and OPLL occurs frequently within this population group, especially in the cephalic region (incidence: C3 = 64.5%; C4 = 47.7%; C5 = 21%; C6 = 12.2%; C7 = 7.5%). / Dissertation (MSc (Anatomy))--University of Pretoria, 2008. / Anatomy / unrestricted

This study examines the possible correlations between vertebral osteoporosis, spondylolysis, spondylolisthesis, Schmorl’s nodes, vertebral osteoarthritis, osteophytosis, and laminal spurs. Further, this study examines the effects of sex, age, ancestry, and occupation on the vertebral pathologies. A total of 238 individuals (54 African Americans and 184 randomly selected European Americans) from the William M. Bass Donated Skeletal Collection at the University of Tennessee, Knoxville, were analyzed. Vertebral pathologies and anomalies were assessed using visual morphometric scoring methods outlined in previous research. It is hypothesized that positive correlations exist between osteoporosis and other vertebral pathologies and a positive correlation exists between vertebral pathologies and strenuous occupations. It is also hypothesized that there is a difference in the prevalence of vertebral pathologies between European American and African American ancestries due to African Americans generally showing higher bone mineral density than European Americans (Aloia 2008). The results of this research demonstrate numerous relationships: females are correlated with more severe osteoarthritis, osteoporosis, and spondylolisthesis, while males correlate with Schmorl’s nodes; European Americans are correlated with osteoporosis, osteoarthritis, osteophytosis, and Schmorl’s nodes, while African Americans are correlated with laminal spurs; individuals 40 years or older are correlated with osteoporosis, osteoarthritis, Schmorl’s nodes, and laminal spurs; and lastly, labor intensive occupations (i.e., construction worker) are correlated with osteoarthritis, osteophytosis, and Schmorl’s nodes, all with p-values less than 0.05. The majority of the pathological conditions also correlate with each other, for example, osteoporosis and osteoarthritis. This research demonstrates how pathological conditions correlate with sociodemographic risk factors and with other pathological conditions, which can help with the identification process of skeletal remains in archaeological and forensic contexts.

Disc degenerative changes are directly or indirectly associated with spinal pain and disability. Literature revealed a high prevalence of disc degeneration in the thoracic region, however thoracic MRI degeneration trends and information on disc biochemical matrix constituents are limited for thoracic discs compared to lumbar and cervical discs. The objective of this thesis was to use MRI to investigate the prevalence of disc degenerative changes affecting the human thoracic spine, and to determine the factors affecting spinal disc biochemical matrix. A 3-point subjective MRI grading scale was used to grade the films. The feasibility of using archived formalin-fixed cadaver material was investigated to analyse collagen and elastin crosslinks. The prevalence of degenerative changes in human thoracic discs and vertebrae (T1 to T12) was determined retrospectively from an audit of 216 MRI cases, using sagittal T1- and T2-weighted MR images. In a subsequent series of ex-vivo studies, human thoracic discs and LF from 26 formalin-fixed and two fresh spines, involving all thoracic levels, were examined macroscopically to determine the degeneration status. Subsequently, disc and ligament tissues were analysed biochemically for collagen (pyridinoline and deoxypyridinoline) and elastin (desmosine and isodesmosine) crosslinks. These crosslinks were extracted from hydrolysed samples by cellulose partition chromatography, and analysed by reverse-phase HPLC. Collagen content was determined using its hydroxyproline content, and proteoglycan content was assayed using a modified DMB assay for chondroitin sulphate. Finally the MRI and macroscopic assessments of thoracic discs, were compared with the biochemical data from two fresh cadaver thoracic spines. The 3-point MRI grading scale had a high inter- (k = 0.57 to 0.78) and intra-rater (k = 0.71 to 0.87) reliability. There were no significant differences in the collagen and elastin content and extent of collagen crosslinks between formalin fixed and unfixed ligament and disc tissues, after 25 weeks of formalin fixation. From the in-vivo MRI series of investigations (n = 216 MRI films), the prevalence of thoracic disc degenerative and vertebral morphological changes revealed significant age, gender and spinal level trends (p < 0.05).Generally, males had a higher propensity for disc degeneration in contrast to females, especially older females, where the trend showed a higher prevalence of osteophytes and vertebral body changes. In particular, the mid and lower thoracic levels have a higher prevalence of degenerative changes, except for osteophytes and anterior vertebral wedging. With increased age, there was a concomitant increase in anterior wedging and bi-concavity and disc degenerative changes except for end-plates. The biochemical investigations on the ex-vivo series of formalin-fixed thoracic discs (n = 303) also revealed significant changes in the disc matrix due to degeneration status, age, gender and spinal regional factors. With increased age, normal disc matrices have significantly lower collagen content and extent of pyridinoline (p < 0.001). In contrast, the degenerated disc matrix revealed significantly higher collagen content and extent of deoxypyridinoline (p < 0.05). These findings suggest that an altered matrix existed in normal ageing discs, which render the disc prone to injury and degeneration over the life span. The higher collagen and deoxypyridinoline in degenerated disc matrices reflects an increase in chondrocyte synthesis, and is also a novel finding, suggesting that they may be used as markers of ageing and degeneration processes. The biochemical investigations on another series of ex-vivo spinal LF tissues (n = 364), revealed that this had a lower collagen and pyridinoline, but significantly higher elastin and deoxypyridinoline compared to spinal discs (p < 0.05). Elastin crosslinks however were difficult to detect in spinal discs, being present in negligible amounts in a few lumbar discs. The elastin crosslinks in the LF were not significantly affected by age, but were significantly higher in calcified, and female ligamentum tissues, and also in the lumbar region (p < 0.05). These MRI prevalence findings enhanced our knowledge of vertebral body and disc degeneration trends in the thoracic region and contributed to the interpretation of MR images for pathology in the human thoracic spine. Information on the associated collagenous and elastic changes in the disc and ligamentum matrices provide original data and insight on the pathogenesis of degeneration in the disc matrix from a biochemical perspective, highlighting gender, age and spinal level influences on the matrix tensile strength and cellular synthetic activities.