Intervertebral disc (IVD) degeneration is a major cause of low back pain (LBP) worldwide which is expected to affect 80% of the world’s population. IVD degeneration (IDD) is a key player in the degenerative cascade associated with LBP. Pro-inflammatory cytokines and mediators, such as nitric oxide, have been shown to be triggers and mediators of IDD. Due to the avascular nature of the adult IVD, the disc is unable to heal or regenerate when damaged. The multi-components of the IVD, namely glycosaminoglycan (GAG)-rich nucleus pulposus (NP), a concentric collagen dense annulus fibrosis (AF), and cartilage endplates (CEPs), further complicate possible regenerative solutions. Cell therapies show promise. This is supported by studies that demonstrate the use of mesenchymal stem cells (MSCs) in animal models showing potential in mitigating inflammatory signaling as well as recovering proteoglycan content. Despite these promising findings, several gaps in knowledge remain. While the biochemical and mechanical properties of an injured disc (via physical or chemical stimulation) have been characterized, the resulting inflammatory signaling cascades remain undefined. A growing body of evidence suggests that TLR4 is involved in the pathogenesis of the IVD. However, it is unknown how TLR4 mediates injury responses of the IVD. Second, it is unknown how mechanical loading of IVDs can influence the transcriptome or secretome of the IVD. The IVD is normally exposed to multimodal loading (e.g., compression, tension, shear, hydrostatic pressure, and osmotic pressure). Both frequency and magnitude regulate whether loading is beneficial or detrimental to disc integrity, which will be explored. Furthermore, the secretome of the IVD, especially during loading, may be essential to creating therapies targeted for regeneration of the IVD. There may be key, distinct paracrine factors that are released in IVD conditioned loading media which can influence the regenerative and anti-inflammatory capabilities of cell-based therapies. To address these gaps, this thesis describes a series of experiments employing novel ex vivo organ culture model to study the response of the IVD to various injury modalities (inflammatory stimulation, puncture injury, compressive loading), and resulting changes in inflammatory, biomechanical, and biochemical responses. Through methods such as RNA sequencing and proteomics, we now have expanded the characterization to beyond candidate genes or proteins, and are more informed on (1) the IVD response to injury, (2) the role of TLR4 signaling in this ex vivo organ culture model, in addition to (3) the downstream effects of loading and how paracrine factors can be used to improve and develop potential cell and molecular therapies. Sex-based differences, in male and female rat caudal IVDs, were also identified and are analyzed in the context of response to injury.

Acupuntura tem sido integrada no tratamento da discopatia intervertebral tóraco-lombar em cães com intuito de analgesia e reabilitação motora e sensorial. Faltam estudos clínicos controlados comparando acupuntura associada ao tratamento médico não cirúrgico. Foram avaliados 61 cães portadores de afecção degenerativa do disco intervertebral tóraco-lombar durante o período de março de 2005 a fevereiro de 2006. Destes 61 animais, 50 foram incluídos no estudo, 26 cães no grupo com acupuntura e 24 cães no grupo sem acupuntura. As avaliações da melhora do estado neurológico foram realizadas através de uma escala funcional numérica em 4 momentos: primeira avaliação, 7º dia de avaliação, 14º dia de avaliação e último retorno. Para análise estatística, nível de significância de 5%, utilizou-se o Teste de Mann Whitney para amostras independentes e o Teste de Friedman para amostras dependentes, seguido do Teste de Wilcoxon para comparações das amostras dentro do mesmo grupo. Os valores das medianas do escore total na 1ª avaliação permitiu comparação entre graus de lesão (1 a 5) subdivididos em graus 1-2 (Md 21 e 20); graus 3-4 (Md 11 e 9) e grau 5 (Md 2). O tempo de retorno a locomoção de animais sem capacidade de locomoção e presença de dor profunda (graus 3-4) foi comparado entre os grupos com (n=10) e sem acupuntura (n=6) através do Teste T-Student, sendo os cães que receberam acupuntura anteciparam em 50% o retorno a locomoção (10,10±6,49 dias) em comparação com cães que não receberam acupuntura (20,83±11,99 dias) com diferença significativa (p<0,034). Apresentaram médias superiores e com diferença significativa no escore total da escala funcional numérica na 7ª e 14ª avaliações (p<0,039 e p<0,020) em relação ao grupo que não recebeu acupuntura, representando um estado neurológico superior. A taxa de sucesso em cães com graus 3-4 no retorno a locomoção foi de 100% e 66%, respectivamente grupo com acupuntura e sem acupuntura, sendo a diferença significativa (p<0,047). Os cães de graus 1-2 não apresentaram diferença significativa, sendo a taxa de sucesso em ambos os grupos de 100%. Os cães de grau 5 tiveram taxa de sucesso no retorno a locomoção de 50% e 12,5%, respectivamente grupo com acupuntura e sem acupuntura, não apresentando diferença significativa (p>0,124). Conclui-se que acupuntura pode ser aplicada associada ao tratamento médico em cães com discopatia tóraco-lombar, antecipando o retorno à locomoção e a melhora na evolução neurológica em cães apresentando percepção à dor profunda intacta e sem capacidade de locomoção. / Acupuncture has been combined in the treatment of thoracolumbar disk disease in dogs with the purpose of analgesia, motor and sensorial rehabilitation. There is a lack of clinical controlled studies comparing acupuncture integrated with medical and non surgical treatment. 61 dogs with thoracolumbar disk disease were evaluated from March 2005 to February 2006. Among these 61 animals, 50 were included in the study: 26 dogs in the group with acupuncture and 24 dogs in the group without acupuncture. The evaluations of the neurological improvement were done through a numerical functional scale in 4 moments: first, seventh, fourteenth evaluations and the last visit. For the statistical analysis, significant level of 5%, Mann Whitney test for independent variables, Friedman test for dependent variables comparisons, followed by Wilcoxon test for dependent variables in the same group, were utilized. The median values of the total scores in the first visit permitted comparisons within lesion levels (1 to 5) divided in levels 1-2 (Md 21 and 20); levels 3-4 (Md 11 and 9) and level 5 (Md 2). The time of return of ambulation in dogs without ambulation and intact deep pain perception (levels 3-4) were compared with acupuncture group (n=10) and without acupuncture group (n=6) through Student T test, where dogs that received acupuncture anticipated in 50% the locomotion return (10,10±6,49 days) in comparison of dogs that didn?t received acupuncture (20,83±11,99days) with significant difference (p<0,034). These dogs showed superior means and significant difference in the total score from the numerical functional scale in the seventh and fourteeth visits (p<0,039 and p<0,020) in relation to the group that didn?t received acupuncture, showing superior neurological state. The success rate of dogs with levels 3-4 in the return of ambulation were 100% and 66%, respectively acupuncture group and without acupuncture, with significant difference (p<0,047). The dogs with levels 1-2 didn?t show difference, so that the success rate in both groups were 100%. The dogs with level 5 had success rate in the return of ambulation of 50% and 12,5%, respectively acupuncture group (n=6) and without acupuncture (n=8), but without significant difference (p>0,124). It was concluded that acupuncture can be applied to the medical treatment in dogs with thoracolumbar disk disease, with anticipation of the return of ambulation and the improvement of neurological state in animals showing intact deep pain perception and without ambulation.

Novel surgical strategies for spinal disc repair are currently being developed that require materials that (1) possess the appropriate mechanical properties to mimic the tissue the material is replacing or repairing and (2) maintain their mechanical function for long durations without negatively affecting the tissue response of adjacent tissue (i.e. bone). Polymers formed through photopolymerization have emerged as candidate biomaterials for many biomedical applications, but these materials possess limited toughness in vivo due to the presence of water inherent in most tissues. Therefore, the overall objective of this research was to develop photopolymerizable (meth)acrylate networks that are both mechanically and biologically compatible under physiological conditions to be implemented in spinal repair procedures. The fundamental approach was to determine structure-property relationships between toughness and network structure in the presence of phosphate buffered saline (PBS) using several model copolymer networks in order to facilitate the design of photopolymerizable networks that are tough in physiological solution. It was demonstrated that networks toughness could be optimized in PBS by tailoring the Tg of the copolymer network close to body temperature and incorporating the appropriate "tough" chemical structures. The ability to maintain toughness up to 9 months in PBS was dependent upon the viscoelastic state and overall hydrophobicity of the network. In tandem, the effect of network chemistry and stiffness on the response of MG63 pre-osteoblast cells was assessed in vitro. The ability of MG63 cells to differentiate on (meth)acrylate network surfaces was found to be primarily dependent on surface chemistry with PEG-based materials promoting a more mature osteoblast phenotype than 2HEMA surfaces. Amongst each copolymer group, copolymer stiffness was found to regulate osteoblast differentiation in a manner dependent upon the surface chemistry. In general, photopolymerizable (meth)acrylate networks that were deemed "tough" were able to promote osteoblast differentiation in a manner comparable if not exceeding that on tissue culture polystyrene (TCPS). This research will impact the field of biomaterials by elucidating the interrelationships between materials science, mechanics, and biology.

Thesis (M.S.P.H.)--University of South Florida, 2008. / Title from PDF of title page. Document formatted into pages; contains 45 pages. Includes bibliographical references.

Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Neck pain is a common phenomenon that occurs in a large percentage of the population every day. While many occurrences are not deemed critical such as those from muscle strain which can be treated with rest and pain medication, others due to sports injuries, whiplash from car accidents, bad posture or degeneration of the intervertebral disc can be quite severe. In extreme cases failure of the vertebra(e) or the intervertebral disc requires surgery and possibly the use of cervical implants. Where intervertebral discs fail due to herniation or Degenerative Disc Disease (DDD), Anterior Cervical Discectomy and Fusion (ACDF) is a common surgical method used to remove the a ected disc and replace it with a cervical cage implant. These implants are designed to restore the height between the vertebrae, allowing bone from both vertebrae to grow through them and mineralise. Additive Manufacturing (AM) technologies can produce parts with complex geometries not possible using conventional manufacturing methods. This design freedom, coupled with CT scans of a patient, allow for tailoring an implant to the speci c anatomy of the a ected vertebrae using CAD software. Such an approach must be regulated and shown to be technically and commercially feasible before it can be implemented in industry. This study sought to develop a framework for manufacturing customized cervical cage implants using additive manufacturing. The e cacy of customization to reduce the risk of subsidence was investigated by means of non-destructive and destructive mechanical testing on six cadaver specimens, using readily available PEEK cage implants as a benchmark. The results showed that the customized implant was comparable to the PEEK, with no statistically signi cant di erence between the two. In extreme cases, where PEEK implants cannot be used, customized implants could be a suitable alternative to reduce the risk of subsidence. A manufacturing cost analysis was conducted to determine economic feasibility. The estimated cost and selling price of the customized implants under various utilization scenarios and mark-ups was compared to readily available PEEK implants. The estimated selling prices of the customized implants compared favourably to the PEEK verifying the economic viability of using AM. / AFRIKAANSE OPSOMMING: Nek pyn is 'n algemene verskynsel wat daagliks na tevore kom in die bevolking. Baie gevalle word nie as krities geklasi seer nie soos byvoorbeeld spier pyn wat behandel kan word deur genoegsame rus en pyn medikasie. Pyn wat deur sportbeserings, sweepslag beserings 'whiplash' tydens motor ongelukke, verkeerde postuur, of deur slytasie van 'n intervertebrale skyf veroorsaak is, word dikwels as ernstig geklasi seer. In ekstreme gevalle waar die werwel(s) of die inervertebrale skyf(we) faal, sal chirurgie en servikale inplantate moontlik nodig wees. Waneer intervertebrale skywe faal weens herniatie of Degeneratiewe Skyf Siekte (DDD) kan 'n algemene chirurgiese metode, Anterieure Servikale Discectomie en Fusie (ACDF), gebruik word om die gea ekteerde skyf te verwyder en dit te vervang met 'n servikale samesmelting implantaat. Hierdie implantate herstel die hoogte tussen rugwerwels en is ontwerp sodat die been deur dit kan groei en mineraliseer. Komplekse geometrieë kan vervaardig word deur toevoegingsvervaardiging (AM) tegnologieë. Die ontwerp vryheid, gepaard met CT-skanderings en CAD-sagteware stel mens in staat om die geometrie van die implantaat aan te pas tot die spese eke anatomie van die gea ekteerde vertebra. So 'n benadering moet gereguleer word en eers tegnies en kommersieel uitvoerbaar bewys word voordat dit in die bedryf geïmplementeer kan word. Hierdie studie poog verder om 'n raamwerk vir die vervaardiging van persoonlike servikale implantate deur middel van toevoegingsvervaardiging te ontwikkel. Die doeltre endheid van persoonlike implantate om te verhoed dat die chirurg die eind-plaat beskadig, en sodoende die risiko van insakking te verminder, is ondersoek deur middel van meganiese toetse op ses kadawer monsters. Hierdie toetse is gedoen met behulp van geredelik beskikbaar PEEK servikale implantate as 'n maatstaf. Die resultate het getoon dat die persoonlike- en PEEK implantate vergelykbaar is. In moontlike gevalle waar PEEK implantate nie geskik sou wees nie, kan persoonlike implantate 'n alternatiewe opsie wees om die risiko van insakking te verminder.

Acupuntura tem sido integrada no tratamento da discopatia intervertebral tóraco-lombar em cães com intuito de analgesia e reabilitação motora e sensorial. Faltam estudos clínicos controlados comparando acupuntura associada ao tratamento médico não cirúrgico. Foram avaliados 61 cães portadores de afecção degenerativa do disco intervertebral tóraco-lombar durante o período de março de 2005 a fevereiro de 2006. Destes 61 animais, 50 foram incluídos no estudo, 26 cães no grupo com acupuntura e 24 cães no grupo sem acupuntura. As avaliações da melhora do estado neurológico foram realizadas através de uma escala funcional numérica em 4 momentos: primeira avaliação, 7º dia de avaliação, 14º dia de avaliação e último retorno. Para análise estatística, nível de significância de 5%, utilizou-se o Teste de Mann Whitney para amostras independentes e o Teste de Friedman para amostras dependentes, seguido do Teste de Wilcoxon para comparações das amostras dentro do mesmo grupo. Os valores das medianas do escore total na 1ª avaliação permitiu comparação entre graus de lesão (1 a 5) subdivididos em graus 1-2 (Md 21 e 20); graus 3-4 (Md 11 e 9) e grau 5 (Md 2). O tempo de retorno a locomoção de animais sem capacidade de locomoção e presença de dor profunda (graus 3-4) foi comparado entre os grupos com (n=10) e sem acupuntura (n=6) através do Teste T-Student, sendo os cães que receberam acupuntura anteciparam em 50% o retorno a locomoção (10,10±6,49 dias) em comparação com cães que não receberam acupuntura (20,83±11,99 dias) com diferença significativa (p<0,034). Apresentaram médias superiores e com diferença significativa no escore total da escala funcional numérica na 7ª e 14ª avaliações (p<0,039 e p<0,020) em relação ao grupo que não recebeu acupuntura, representando um estado neurológico superior. A taxa de sucesso em cães com graus 3-4 no retorno a locomoção foi de 100% e 66%, respectivamente grupo com acupuntura e sem acupuntura, sendo a diferença significativa (p<0,047). Os cães de graus 1-2 não apresentaram diferença significativa, sendo a taxa de sucesso em ambos os grupos de 100%. Os cães de grau 5 tiveram taxa de sucesso no retorno a locomoção de 50% e 12,5%, respectivamente grupo com acupuntura e sem acupuntura, não apresentando diferença significativa (p>0,124). Conclui-se que acupuntura pode ser aplicada associada ao tratamento médico em cães com discopatia tóraco-lombar, antecipando o retorno à locomoção e a melhora na evolução neurológica em cães apresentando percepção à dor profunda intacta e sem capacidade de locomoção. / Acupuncture has been combined in the treatment of thoracolumbar disk disease in dogs with the purpose of analgesia, motor and sensorial rehabilitation. There is a lack of clinical controlled studies comparing acupuncture integrated with medical and non surgical treatment. 61 dogs with thoracolumbar disk disease were evaluated from March 2005 to February 2006. Among these 61 animals, 50 were included in the study: 26 dogs in the group with acupuncture and 24 dogs in the group without acupuncture. The evaluations of the neurological improvement were done through a numerical functional scale in 4 moments: first, seventh, fourteenth evaluations and the last visit. For the statistical analysis, significant level of 5%, Mann Whitney test for independent variables, Friedman test for dependent variables comparisons, followed by Wilcoxon test for dependent variables in the same group, were utilized. The median values of the total scores in the first visit permitted comparisons within lesion levels (1 to 5) divided in levels 1-2 (Md 21 and 20); levels 3-4 (Md 11 and 9) and level 5 (Md 2). The time of return of ambulation in dogs without ambulation and intact deep pain perception (levels 3-4) were compared with acupuncture group (n=10) and without acupuncture group (n=6) through Student T test, where dogs that received acupuncture anticipated in 50% the locomotion return (10,10±6,49 days) in comparison of dogs that didn?t received acupuncture (20,83±11,99days) with significant difference (p<0,034). These dogs showed superior means and significant difference in the total score from the numerical functional scale in the seventh and fourteeth visits (p<0,039 and p<0,020) in relation to the group that didn?t received acupuncture, showing superior neurological state. The success rate of dogs with levels 3-4 in the return of ambulation were 100% and 66%, respectively acupuncture group and without acupuncture, with significant difference (p<0,047). The dogs with levels 1-2 didn?t show difference, so that the success rate in both groups were 100%. The dogs with level 5 had success rate in the return of ambulation of 50% and 12,5%, respectively acupuncture group (n=6) and without acupuncture (n=8), but without significant difference (p>0,124). It was concluded that acupuncture can be applied to the medical treatment in dogs with thoracolumbar disk disease, with anticipation of the return of ambulation and the improvement of neurological state in animals showing intact deep pain perception and without ambulation.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2007. / This thesis is concerned with the simulation of the in vivo biomechanical performance of a cervical disc replacement. A representative (averaged) maximum range of motion (ROM), determined by measurement of 10 student participants (5 male, 5 female), was used as head motion input to a simulation model of the cervical spine containing a disc implant at the C5/C6 intervertebral level. Intradiscal pressure, relative applied force on the C5 vertebrae, bending moments and vertebral rotations were recorded. The force and motion components of the results obtained were critically evaluated against the ISO and ASTM experimental protocol standards, probing the representativeness of these standards to the actual in vivo behaviour of the cervical functional spinal unit. Further, the wear resulting from a lifetime (10 million cycles) of the ISO prescribed -and simulation determined input cycles was simulated using a linear wear model with a triangulation technique for volume lost due to wear, and compared to in vitro results in the literature. The inputs used for the wear model were determined from a validated non-linear static contact finite element method (FEM) model. The simulation “chain” shows great potential as a comparative tool for the preexperimental testing of spinal implant designs and may be used with relative success as an alternative to expensive prototype testing.

O tratamento da afecção de disco intervertebral tóraco-lombar com eletroacupuntura tem o objetivo de analgesia e reabilitação motora e sensorial. As melhoras funcionais observadas após lesão medular decorrem de fenômenos de plasticidade sináptica, correspondendo a um mecanismo compensatório e não de reparo estrutural. S100&beta; é considerado um fator neurotrófico glial que pode estar relacionado a estas alterações. Durante o período de fevereiro de 2007 a junho de 2008 foi realizado um estudo clínico prospectivo em cães com extrusão de disco intervertebral (n=10) submetidos à eletroacupuntura (grupo EA) sem o uso de corticosteróides. Foram coletadas amostras de líquido cefalorraquidiano (LCR) destes animais em dois momentos: durante o exame de mielografia e/ou tomografia computadorizada (M1) e após 35.5±21.33 dias de tratamento (M2). Níveis de S100&beta foram investigados no LCR de cães do grupo EA através da técnica de Western blot. LCR de cães sem sinais neurológicos (grupo normal, n=7) foram utilizados para comparação. Para a análise estatística, com nível de significância de 5%, foram utilizadas ANOVA para medidas repetidas e medidas independentes e comparação múltipla de Bonferroni, teste t-Student para a comparação entre duas médias e correlação linear de Pearson para as variáveis quantitativas. Todos os animais do grupo EA, graus de lesão 3 a 5, obtiveram melhora neurológica crescente e significativa (P-valor <0.001) através da Escala Funcional Numérica (EFN) nos M1 e M2 e M3 (momento da última avaliação). O grupo EA foi dividido em grupo A - cães com retorno à locomoção em até 30 dias (6.7±7.89; n=7) e grupo B - após 30 dias (76±17.06; n=3) do tratamento. Níveis de S100&beta; (Média±DP) em cães do grupo A foram superiores no M1 (P-valor=0.0107) em relação ao M2 e grupo normal, mas entre M2 e grupo normal não houve diferença significativa (P-valor=0.423). No entanto, níveis de S100&beta; em cães do grupo B foram superiores no M2 (P-valor=0.039) em relação ao M1 e normal, e não houve diferença significativa entre M1 e grupo normal (P-valor=0.756). Níveis de S100&beta; no M1 não diferiram (P-valor=0.069) entre os grupos A e B. Entretanto, níveis de S100&beta; no M2 em cães do grupo B foram superiores (P-valor=0.032) ao M2 em cães do grupo A. Não houve correlação dos níveis de S100&beta; no M1 com idade (r2=0.2042, P-valor=0.189); peso (r2=0.02634, P-valor=0.654), evolução clínica (r2=0.0062; P-valor=0.828), tempo de retorno à locomoção (r2=0.2522; P-valor=0.139) e extensão da extrusão (r2=0.0345; P-valor=0.607). Níveis de S100&beta; no M1 não apresentaram diferenças significativas entre os graus de lesão 3, 4 e 5 (P- valor=0.931); entre o grupo com escores de compressão extradural 1 e 2 comparado com grupo com escore de compressão 3 (P-valor=0.771); entre grupo de cães com EFN10 (P-valor=0.520) e entre grupo de cães com escores de nº de lesões 1, 2, 3 e 4 (P- valor=0.526). Níveis de S100&beta; no M2 não apresentaram diferenças significativas com a evolução clínica (r2=0.0304; Pvalor=0.629), extensão da extrusão (r2=0.0158; Pvalor=0.729), entretanto houve uma tendência a correlação com o tempo de retorno à locomoção (r2=0.3852; P-valor=0.055). A eletroacupuntura promoveu uma modulação dos níveis de S100&beta; detectados no LCR de cães com extrusão de disco intervertebral tóraco-lombar. A eletroacupuntura induziu aumento de S100&beta; no LCR de cães com recuperação motora tardia sugerindo sua contribuição na plasticidade neural após injúria da medula espinhal devido à extrusão de disco intervertebral. / Electroacupuncture treatment in dogs with thoracolumbar disk disease has the purpose of analgesia, motor and sensorial rehabilitation. The functional improvements observed after spinal cord lesion are resulting of synaptic plasticity. This fact is a result of compensatory mechanisms and not structural repair. S100&beta; is considered a glial neurotrophic factor. It can be involved with these improvements. A prospective clinical study during February 2007 to June 2008 evaluated electroacupuncture (EA) treatment (group EA) in dogs with thoracolumbar disk extrusion (n=10) without corticosteroids. Cerebrospinal fluids (CSF) were collected from these animals in two time points: during the mielography and/or computed tomography (M1) and after 35.5±21.33 (Mean±SD) days after EA treatment (M2). S100&beta; levels in CSF were investigated in dogs of group EA by Western blot. CSF of dogs without neurological signs (group normal; n=7) were used for comparisons. For the statistical analysis, significant level of 5%, ANOVA for repeated and not repeated variables (post-test Bonferroni´s), Student-t test for two variables comparisons and Pearsons linear correlation for quantitative variables, were used. All dogs (group EA) with lesion levels of dysfunction 3 to 5, reached neurological improvements with significant higher scores (P-value<0.001) from a functional numerical score (FNS) at each successive time points (M1; M2; M3 last evaluation). Group EA dogs were divided in group A - dogs with return of ambulation before 30 days (6.7±7.89; n=7) and group B - after 30 days (76±17.06; n=3). S100&beta; levels (Mean±SD) in group A dogs were higher in M1 (P-value=0.0107) than M2 and group normal, and there was not significant difference between M2 and group normal (P-value=0.423). Although, S100&beta; levels in group B dogs were higher in M2 (P-value=0.039) than M1 and group normal, and there was not significant difference between groups B M1 and normal (P-value=0.756). S100&beta; levels in M1 were not different (P-value=0.069) between dogs of group A and B. However, S100&beta; levels at M2 in group B dogs were significantly higher (P-value=0.032) than group A. The S100&beta; levels in M1 have no correlation with age (r2=0.2042; P-value=0.189); weight (r2=0.0263; P-value=0.654), duration of clinical signs (r2=0.0062; P-value=0.828), time of ambulation return (r2=0.2522; P-value=0.139) and extrusion length (r2=0.0345; P-value=0.607). There were no associations between S100&beta; levels at M1 and lesion levels of dysfunction 3, 4 e 5 (Pvalue=0.931); between extradural compression scores 1 and 2 compared with score 3 (Pvalue=0.771); between dogs with FNS10 (Pvalue=0.520) and between group of dogs with number of lesions scores 1, 2, 3 and 4 (Pvalue=0.5262). S100&beta; levels at M2 have no correlation with duration of clinical signs (r2=0.0304; Pvalue=0.629), extrusion length (r2=0.0158; P-value=0.729), however there was a tendency of correlation with time of ambulation return (r2=0.3852; Pvalue=0.055). Electroacupuncture can modulate the S100&beta; levels in CSF of dogs with thoracolumbar disk extrusion. Electroacupuncture up-regulated S100&beta; in CSF of dogs with late motor rehabilitation. This fact suggests its contribution in the neural plasticity after spinal cord lesion due to intervertebral disk extrusion.

Hipotrofía nos músculos que estabilizam a coluna tem sido identificada nos pacientes com lombalgia. Entretanto, não se sabe se a perda muscular é causa ou conseqüência desta disfunção, nem se ela é influenciada pelo tipo de alteração discal que o indivíduo apresenta. Este estudo testou a hipótese de que a hipotrofía dos pacientes com lombalgia seja dependente do tipo de alteração discal. Para avaliar a condição muscular em diferentes tipos de alteração discal, optou-se por um estudo retrospectivo e por uma seleção aleatória de 78 exames de ressonância magnética de indivíduos com lombalgia. Em cada exame foram realizadas medidas quantitativas da porcentagem de gordura na área de secção transversa dos mm. multífidus e psoas, nos três últimos níveis da coluna lombar. A alteração discal foi encontrada em 95% dos exames, sendo o abaulamento o achado de imagem mais freqüente, seguido pela protrusão discal. A porcentagem de gordura variou conforme o tipo de alteração discal. Nos níveis com abaulamento há em ambos os músculos estudados 6% a mais de tecido gorduroso do que nos níveis onde há protrusão e esta diferença foi estatisticamente significante. Músculos nos níveis onde há protrusão sem fissura no anel fibroso apresentaram maior substituição gordurosa do que aqueles onde há protrusão com fissura. A porcentagem de gordura foi influenciada por características anatômicas como músculo estudado e nível da coluna, e por características como idade e sexo dos sujeitos. Estes resultados indicam que a hipotrofía muscular em pacientes com lombalgia não é um processo uniforme e generalizado, mas sim correlacionado a diferentes variáveis, entre elas o tipo de alteração discal que o paciente apresenta. / Low back pain patients present atrophy on muscles responsible for spine stabilization. However, it is not clear if muscle waste is related to the cause or if it is a consequence of this disfunction. Nor it is clear if muscle athophy is affected by the type of disc pathology. This study tested the hypothesis that muscle waste in low back pain patients influenced by the type of disc derangement. Magnetic resonance scans of 78 low back pain patients were randomly analysed. Cross sectional area percentage of fat tissue in multifidi and psoas major muscles was measured on the lower levels of the lumbar spine. Disc pathology was found in 95% of the exams and disc bulge was the most frequent abnormality, followed by disc protrusion. Fat percentage varied according to disc pathology and this difference was statistically significant. Muscles on levels with disc bulge presented 6% more fat deposits than muscles on levels with disc protrusion. Muscles on levels with discs without anular tear present more fat infiltration than muscles on levels with anular tear. Fat percentage was also influenced by anatomic aspects such as evaluated muscle and spine level, and sample characteristics as age and sex. The results indicated that muscle atrophy in low back pain patients is not a uniform and generalized feature. It is correlated to different variables, such as type of disc pathology

Hipotrofía nos músculos que estabilizam a coluna tem sido identificada nos pacientes com lombalgia. Entretanto, não se sabe se a perda muscular é causa ou conseqüência desta disfunção, nem se ela é influenciada pelo tipo de alteração discal que o indivíduo apresenta. Este estudo testou a hipótese de que a hipotrofía dos pacientes com lombalgia seja dependente do tipo de alteração discal. Para avaliar a condição muscular em diferentes tipos de alteração discal, optou-se por um estudo retrospectivo e por uma seleção aleatória de 78 exames de ressonância magnética de indivíduos com lombalgia. Em cada exame foram realizadas medidas quantitativas da porcentagem de gordura na área de secção transversa dos mm. multífidus e psoas, nos três últimos níveis da coluna lombar. A alteração discal foi encontrada em 95% dos exames, sendo o abaulamento o achado de imagem mais freqüente, seguido pela protrusão discal. A porcentagem de gordura variou conforme o tipo de alteração discal. Nos níveis com abaulamento há em ambos os músculos estudados 6% a mais de tecido gorduroso do que nos níveis onde há protrusão e esta diferença foi estatisticamente significante. Músculos nos níveis onde há protrusão sem fissura no anel fibroso apresentaram maior substituição gordurosa do que aqueles onde há protrusão com fissura. A porcentagem de gordura foi influenciada por características anatômicas como músculo estudado e nível da coluna, e por características como idade e sexo dos sujeitos. Estes resultados indicam que a hipotrofía muscular em pacientes com lombalgia não é um processo uniforme e generalizado, mas sim correlacionado a diferentes variáveis, entre elas o tipo de alteração discal que o paciente apresenta. / Low back pain patients present atrophy on muscles responsible for spine stabilization. However, it is not clear if muscle waste is related to the cause or if it is a consequence of this disfunction. Nor it is clear if muscle athophy is affected by the type of disc pathology. This study tested the hypothesis that muscle waste in low back pain patients influenced by the type of disc derangement. Magnetic resonance scans of 78 low back pain patients were randomly analysed. Cross sectional area percentage of fat tissue in multifidi and psoas major muscles was measured on the lower levels of the lumbar spine. Disc pathology was found in 95% of the exams and disc bulge was the most frequent abnormality, followed by disc protrusion. Fat percentage varied according to disc pathology and this difference was statistically significant. Muscles on levels with disc bulge presented 6% more fat deposits than muscles on levels with disc protrusion. Muscles on levels with discs without anular tear present more fat infiltration than muscles on levels with anular tear. Fat percentage was also influenced by anatomic aspects such as evaluated muscle and spine level, and sample characteristics as age and sex. The results indicated that muscle atrophy in low back pain patients is not a uniform and generalized feature. It is correlated to different variables, such as type of disc pathology