Sex differences in bone mass and size are thought to contribute to the greater incidence of vertebral fractures in women. While these sex differences are widely recognized, the relative contributions of bone mass, bone density, and bone size to the differences in vertebral strength and fracture risk between men and women have not been fully delineated. Furthermore, it is unknown whether the roles of each of these factors in determining vertebral strength change differently with age in men and women. We studied the bone content, density and geometry as well as vertebral loading and the factor of risk of the L3 vertebra in a sample of prepubertal males and females. Our first aim was to assess differences in vertebral bone dimensions, bone density, vertebral loading patterns and fracture risk, as measured by the factor of risk, in prepubertal children. Our second aim was to determine whether pre-pubertal growth affects the geometry and density of L3 differently in boys and girls. We measured vertebral dimensions, cross-sectional area and volumetric BMD of the third lumbar vertebral body in 93 prepubertal children (54 boys and 39 girls), using dual-energy X-ray absorptiometry scans obtained in the posterior-anterior and lateral projections. We also employed basic biomechanics to estimate vertebral loading during upright standing and forward bending. Bone strength and loading data were used to assess sex differences in the factor of risk in prepubertal children. Twenty children (11 boys and 9 girls) were assessed at baseline and seven months later to examine the effects of growth on bone size and vBMD. At baseline, boys and girls were similar for age, height, weight and calcium intake. L3 width and depth were 6.7% and 5.8% greater in boys than girls, respectively (P<0.001 and P=0.01, respectively). In contrast, vertebral height was 3.5% greater in girls than boys (P= 0.04). While vertebral loading was similar between sexes, stresses on the spine were 12.2% lower in boys during upright standing and 12.0% lower in boys during forward bending at both 50° and 90°, as compared to girls (P<0.001, P<0.01 and P<0.01, respectively). The factor of risk was similar between boys and girls under each loading condition. During growth, changes in vertebral size and density were not different between boys and girls. Our results indicate that even prior to puberty, sex differences in vertebral size contribute to differences in vertebral stress during standing and forward bending. Furthermore, before the onset of puberty, growth does not result in disparate changes between sexes. / Graduation date: 2004

Thesis (M.Tech.: Chiropractic)-Durban University of Technology, 2008 / To evaluate the lumbar lordosis, lumbosacral angle, lumbosacral disc angle, lumbosacral lordosis angle, intervertebral disc angles and heights, interpedicular distances, sagittal canal diameters and the lumbar gravity line (selected radiographic parameters) in young to middle aged Indian females in Durban. To determine any association between the selected radiographic parameters and the age of the subjects, weight, height and body mass index of the subjects, occupation, smoking, previous pregnancy and leg length inequality (selected anthropometric and demographic factors). Methods: Sixty healthy, asymptomatic, young to middle aged, Indian females were recruited for this study. All subjects underwent a case history, a physical examination and radiographic evaluation (AP and lateral views) of the lumbar spine. SPSS version 15.0 (SPSS Inc., Chicago, Ill, USA) was used to analyze the data. Results: The mean (± SD) of the lumbar lordosis, lumbosacral angle, lumbosacral disc angle and lumbosacral lordosis angle was 49º (± 6º), 39º (± 8º), 12º (± 5º) and 143.2º (± 5º) respectively. For the lumbar intervertebral disc angles at L1-L2, L2-L3, L3-L4, L4-L5 and L5- S1 levels, the mean (± SD) was 6º (± 2º), 8º (± 2º), 10º (± 3º), 12º (± 4º) and 12º (± 5º) respectively. The anterior and posterior intervertebral disc heights at the respective vertebral levels were: L1-L2: anterior: 8 mm (± 2), posterior 5 mm (± 2); L2-L3: anterior: 10 mm (± 2), posterior 5 mm (± 2); L3-L4: anterior: 12 mm (± 2), posterior 5 mm (± 2); L4-L5: anterior: 14 mm (± 3), posterior 5 mm (± 2) and L5-S1: anterior: 13 mm (± 4), posterior 6 mm (± 2). The mean (± SD) of the interpedicular distance at the L1, L2, L3, L4 and L5 vertebral levels was 23 mm (± 2), 24 mm (± 2), 25 mm (± 2), 27 mm (± 2) and 31 mm (± 3) respectively. For the sagittal canal diameter at the L1, L2, L3, L4 and L5 vertebral levels, the mean (± SD) was 20 mm (± 5), 21 mm (± 3), 21 mm (± 3), 21 mm (± 3) and 19 mm (± 3) respectively. The lumbar gravity line intersected the sacrum in 67.3% of the subjects. In 29.1% of the subjects, the lumbar gravity line passed anterior to the sacrum while in 3.6% of the subjects, it passed posterior to the sacrum. iv A significant association was found between lumbar lordosis and the height of the subjects in this study (p = 0.004). A decrease in the intervertebral disc height at L5-S1 was associated with smoking (p = 0.005). A decrease in the intervertebral disc height at L4-L5 was associated with previous pregnancy (p = 0.016). Body mass index of 26–30 kg.m-2 was significantly associated with an increase in the intervertebral disc angles at L3-L4 (p = 0.028) and L4-L5 (p = 0.031). A decrease in the L5-S1 intervertebral disc angle was also significantly associated with smoking (p = 0.023). There was a significant association between previous pregnancy and an increase in the intervertebral disc angle at L3-L4 (p = 0.016). A significant association was found between the age of the subjects and the L5-S1 intervertebral disc angle (p = 0.007). Specifically it was the 23–27 year group and 33–37 year group who were significantly different from each other (p = 0.033). Conclusion: Similarities and differences were found in the mean values of the radiographic parameters measured in this study and those reported in the literature. A number of the selected anthropometric and demographic factors were associated with some of the lumbar radiographic parameters. Further studies are required to establish the clinical significance of these findings.

Dissertation submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic Faculty: Health Sciences, Durban University of Technology, 2009 / Aim To determine the profile of traumatic cervical spine fractures with respect to the epidemiology, clinical presentation, types of fractures, conservative and surgical intervention, short-term post-intervention (i.e. post-conservative and post-surgical) complications and short-term post-surgical rehabilitation of patients presenting at the Spinal Unit of King George V Hospital over a 12-week period. Methods Patients who presented to the King George V Hospital Spinal Unit from surrounding hospitals with traumatic cervical spine fractures were evaluated by the medical staff. Data concerning the epidemiology, clinical presentation, types of fractures, conservative and surgical intervention, short-term post-intervention (i.e. post-conservative and postsurgical) complications and short-term post-surgical rehabilitation data were recorded by the researcher. A p-value of <0.05 was considered as statistically significant. Appropriate statistical tests were applied to the hypothesis-testing objectives. These involved the Pearson’s Chi Square Tests for categorical variables or Fisher’s Exact Tests as appropriate where sample sizes were small. Paired t-tests were done to compare preand- post-surgical Frankel grading and Norton Pressure Sore Assessment scores. Results The number of patients who presented to the Spinal Unit over a 12-week period was 20, of this number 17 were males, three were females and all were black. Eleven patients were treated surgically while nine patients were treated conservatively. The most frequent aetiology of cervical spine fractures was motor vehicle accidents (n = 10) followed by falls (n = 9). The most common co-existing medical conditions were smoking (n = 7), HIV (n = 5), alcohol abuse (n = 3) and obesity (n = 3). The most frequent locations of cervical spine fractures were C2 (n = 6), C1 (n = 4) and the posterior column of C6 (n = 3), while dislocations occurred primarily at the C5-C6 levels (n = 5) of the lower cervical spine. Odontoid fractures (n = 6), Jefferson’s fractures (n = 4) and unilateral facet dislocations (n = 6) were the most common fractures and dislocations v observed. Head injuries (n = 4) and lower limb fractures (n = 3) were the most common extra-spinal fractures. All subjects who sustained head injuries also had associated C1 or C2 fractures. Neurological complications most frequently involved the upper limb where loss of motor function (n = 8) and weakness (n = 4) were observed. The majority of the patients (n = 8) reported a Frankel Grading of E. There were no significant associations between types of fracture and gender with the exception of fracture/dislocation observed in two females. There was a statistically significant difference in the NPSA score (p = 0.004). Conservative care utilized included soft collar (n = 6), cones calipers (n = 6), physiotherapy (n = 4), Minerva jacket (n = 4) and SOMI (sterno-occipital mandibular immobilization) brace (n = 1) while surgical intervention included anterior decompression (n = 8), anterior fusion (n = 8), allograft strut (n = 8), discectomy (n = 8), anterior cervical plating (n = 8), anterior screw fixation (n = 2), a transoral approach (n = 1) and a corpectomy (n = 1). The short-term post-conservative care complications observed in this study were an occipital pressure sore (n = 1), severe discomfort (n = 1) as well as severe neck pain (n = 1), while the short-term post-surgical complications were severe neck pain (n = 2), oral thrush (n = 1), pneumonia (n = 1), odynophagia (n = 1) and hoarseness (n = 1). Of the 11 patients who underwent cervical spine surgery, ten were sent for physiotherapy and one for occupational therapy. No significant associations were seen between the type of cervical spine fracture and the age of the subject. There was a significant association between fracture/dislocation and the female gender (p = 0.016). There was significant negative association between odontoid fracture and: anterior decompression, anterior fusion, allograft strut, discectomy and anterior cervical plating (p = 0.006). Conclusion The results of this study reflect the presentation and management of cervical spine fractures at a referral spinal unit of a public hospital in KwaZulu Natal. The impact of HIV and other co-existing medical conditions were not determined due to the small sample size in this study. Further epidemiological studies are required to be conducted in the Spinal Units of all South African public hospitals in order to confirm or refute the observation of this study.

Bibliography: leaves 102-116. / 116, [43] leaves, [51] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Analyses the characteristics and relative incidence of annular defects in the human lumbar spine and investigates their role in the pathogenesis of invertebral disc degeneration. / Thesis (Ph.D.)--University of Adelaide, Dept. of Pathology, 1992

Thesis (Ph.D.)--University of Alberta, 2010. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Rehabilitation Science, Faculty of Rehabilitation Medicine. Title from pdf file main screen (viewed on April 30, 2010). Includes bibliographical references.

O sistema de fixação vertebral utilizando o parafuso pedicular é um dos métodos mais eficientes no tratamento de patologias da coluna vertebral. Quando o parafuso estiver submetido à força de arrancamento, ele gera tensões ao redor, principalmente próximo do canal medular, situação que pode ser analisada pela técnica da fotoelasticidade. O objetivo foi analisar as tensões internas geradas em modelos fotoelásticos de vértebras, utilizando diferentes medidas de parafusos do sistema de fixação vertebral, submetidos à força de arrancamento. Foi utilizado um modelo de vértebra lombar em material fotoelástico utilizando três medidas de diâmetros externos de parafusos pediculares (5, 6 e 7mm) do tipo USS1. As tensões internas ao redor do parafuso foram avaliadas em 18 pontos pré-determinados utilizando um polariscópio de transmissão plana. As regiões de maiores concentrações de tensões foram observadas entre o canal medular e as curvas do processo transverso. Nas comparações das médias das tensões cisalhantes entre os parafusos 5 e 7mm, e 6 e 7mm foram observadas diferenças estatísticas significativas, o que não ocorreu com os parafusos de 5 e 6mm onde não foram observadas diferenças estatisticamente significativas. Foi observado que as tensões internas são mais elevadas em áreas irregulares próximas do canal medular, o que sugere ser uma região crítica, em termos de esforços mecânicos. / The system of vertebrae fixation using the pedicular screw is one of the most efficient methods to treat vertebral spine pathologies. When the screw is submitted to pullout strength, it causes internal stress near the medullary canal and this situation can be analyzed using the photoelasticity technique. The objective of this study was to examine the internal stress of a photoelastic vertebrae model using different sizes of screws for the vertebral fixation submitted to pulling out. A lumbar vertebral model made of photoelastic material with three different pedicular screw sizes (5, 6 and 7mm), type USS1 was used. The internal stress around the screw were tested in 18 pre established points by a plain transmission polariscope. The areas of greater concentration of stress were placed between the medullary canal and the transverse process. Comparing the maximum average pulling out stress, statistical differences were observed between screws 5 and 7, and 6 and 7. On the other hand, when screws 5 and 6mm where compared no significant differences were found. This study identified that the internal stress are greater in irregular areas, near the medullary canal, suggesting that this may be a critical region.

Submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic, Durban University of Technology, 2017. / Radiographs are the most commonly used modalities for the purpose of diagnosing skeletal disorders. Radiographs are important for chiropractors to exclude any contra-indications prior to spinal manipulative therapy. If contra-indications are found treatment is modified to what best suits each patient. There is a gap in the literature regarding chiropractors reading the same set of radiographs and agreeing on findings. Objectives The study investigated inter- and intra-examiner reliability of lumbar spine radiograph analysis by chiropractors and its impact on clinical management. Methods Inter- and intra-examiner examination of radiographs occurred in two rounds separated by two weeks. Six chiropractors read the same 30 radiographs and clinical history was only available in the second round. Results Inter-observer agreement for categorisation for Round One was 96.78% and Round Two 89.49%. Inter-observer agreement in management was 96.45% in round one and 96.00% in Round two. Agreement between chiropractors had no statistically significant difference. Identification average improved from 0.09 to 0.89 kappa. Overall specificity was relatively high and sensitivity was relatively low. Conclusion Reliability/Agreement between chiropractors was strong in both rounds. Categorising of the diagnosis improved from poor to substantial from Round One to Round Two. Case history improved the accuracy of interpreting the radiographs although this change was not statistically significant. / M

Thesis (M.Tech.: Chiropractic) -Dept. of Chiropractic, Technikon Natal, 2002 1 v. (various pagings) / The purpose of this study was to evaluate the effect of wearing a scuba diving cylinder on static lumbar spine posture, in terms of clinical objective findings, namely radiographic changes in the lumbar lordosis, lumbosacral angle, lumbosacral disc angle, and the lumbar gravity line, during upright standing on land.

Thesis (M.Tech.: Chiropractic)- Dept. of Chiropractic, Durban University of Technology, 2008. x, 52 leaves, Appendices A-E, [25] leaves. / To determine whether a relationship exists between core stability and bowling speed in Action Cricket bowlers. Methods: Thirty asymptomatic indoor Action Cricket fast and fast-medium bowlers were divided into two groups of 15 each, with Group A having well-developed core stability and group B having poorly-developed core stability. The concept of matched pairs was used for age and cricket experience in order to maintain homogeneity between the groups. The core stability and bowling speed of each participant was measured using a pressure biofeedback unit (PBU) and speed sports radar respectively. SPSS version 15.0 was used to analyse the data.

published_or_final_version / abstract / Orthopaedics and Traumatology / Doctoral / Doctor of Philosophy