Background: Disc herniations are common and have been demonstrated as one potential source of low back pain. To date epidemiological studies have found associations between lifting, lifting and twisting and twisting with increased risk in the development of disc herniations (Greenough and Fraser, 1994, Kelsey et al., 1984, Mundt et al., 1993). Subsequent, in vitro investigations were able to produce disc herniations through repeatitive flexion extension motions on cervical porcine functional spinal units (Callaghan and McGill, 2001). However, in vitro investigations on axial torque have drawn mixed conclusions and controversy remains on the role it plays with respect to disc herniations (Farfan et al., 1970, Adams et al., 1981). Therefore, the work in this thesis was to investigate the role of dynamic axial torque on the disc herniation mechanism. Methods: Porcine cervical spines were used as they are a good approximation to the human lumbar spine (Yingling et al., 1999). The study design involved repetitive flexion extension motions of the spinal units either preceded or followed by dynamic axial torque. During axial torque the spinal units were loaded to 17.5 Nm (standard deviation = 0.5 Nm) of dynamic axial torque for either 2000 or 4000 testing cycles. These spinal units were compared to spinal units that were loaded in repetitive flexion extension motions only and axial torque only. The spinal units were tested in a servohydraulic dynamic testing machine, combined with a custom jigs which allowed loading in flexion/extension, axial torque and compression. Plane film radiographs with contrast in the nucleus were obtained at regular intervals during and following the mechanical testing. Final dissection determined the disc injury patterns. Results and Discussion: Examination of the sectioned intervertebral discs indicated axial torque in combination with repetitive flexion extension motions, regardless of order, encouraged radial delamination. While, repetitive flexion extension motion alone encouraged posterior or posterolateral herniation patterns. Axial torque alone was unable to initiate a disc herniation. There was an increase in both rotation and stiffness of the intervertebral disc in response to repeated axial torque. There were no differences in rotation and stiffness between the groups. Both x-ray images and computed tomography scans were equally as good at identifying posterior or posterolateral herniations but were not good at detecting radial delamination.

Background: Disc herniations are common and have been demonstrated as one potential source of low back pain. To date epidemiological studies have found associations between lifting, lifting and twisting and twisting with increased risk in the development of disc herniations (Greenough and Fraser, 1994, Kelsey et al., 1984, Mundt et al., 1993). Subsequent, in vitro investigations were able to produce disc herniations through repeatitive flexion extension motions on cervical porcine functional spinal units (Callaghan and McGill, 2001). However, in vitro investigations on axial torque have drawn mixed conclusions and controversy remains on the role it plays with respect to disc herniations (Farfan et al., 1970, Adams et al., 1981). Therefore, the work in this thesis was to investigate the role of dynamic axial torque on the disc herniation mechanism. Methods: Porcine cervical spines were used as they are a good approximation to the human lumbar spine (Yingling et al., 1999). The study design involved repetitive flexion extension motions of the spinal units either preceded or followed by dynamic axial torque. During axial torque the spinal units were loaded to 17.5 Nm (standard deviation = 0.5 Nm) of dynamic axial torque for either 2000 or 4000 testing cycles. These spinal units were compared to spinal units that were loaded in repetitive flexion extension motions only and axial torque only. The spinal units were tested in a servohydraulic dynamic testing machine, combined with a custom jigs which allowed loading in flexion/extension, axial torque and compression. Plane film radiographs with contrast in the nucleus were obtained at regular intervals during and following the mechanical testing. Final dissection determined the disc injury patterns. Results and Discussion: Examination of the sectioned intervertebral discs indicated axial torque in combination with repetitive flexion extension motions, regardless of order, encouraged radial delamination. While, repetitive flexion extension motion alone encouraged posterior or posterolateral herniation patterns. Axial torque alone was unable to initiate a disc herniation. There was an increase in both rotation and stiffness of the intervertebral disc in response to repeated axial torque. There were no differences in rotation and stiffness between the groups. Both x-ray images and computed tomography scans were equally as good at identifying posterior or posterolateral herniations but were not good at detecting radial delamination.

Abstract Background: The process that involves the migration of the nucleus pulposus from the innermost annular layers and culminates with the final extrusion of the nucleus has been limited to a few studies. This investigation was directed towards a better understanding of the herniation process. The architecture of the annulus fibrosus and the mechanism of progressive disc herniation were analyzed, using a controlled porcine model. Microscopic and histochemical techniques were employed. <br /><br /> Methodology: Two studies were performed. In the first stage, the macroscopic and microscopic structures of twelve cervical intervertebral discs were compared with young human disc data from studies reported in the literature. Important structural features were studied such as annulus fibrosus thickness, number of lamellae, lamellae thickness, orientation of the lamellae fibers and blood supply. In the second study, sixteen fresh-frozen functional spine units were submitted to repetitive flexion?extension motions combined with a low compressive load in a servo-hydraulic dynamic testing system. Discograms, dissections and histochemical techniques were applied to characterize the cumulative damage. The experiment produced eight complete herniations, four partial herniations and four specimens without any microscopic detectable annular damage. <br /><br /> Results and Discussion: The structure of the cervical porcine disc resembles the lumbar human disc. Some differences are evident. The size of the annulus is smaller, the thickness of the lamellae is narrower and the number of layers is fewer in the pig. It is hypothesized that the flexion-extension motion combined with a low-level load produced an increased hydraulic pressure in the inner wall of the posterior annulus. This pressure and repetitive motion first produced a small cleft, spreading the collagen bundles inside the first layer. The nuclear material was "pumped" through the small cleft to the first layer filling the layer creating a fluid-filled pocket between the collagen fibers. Once the "pocket" acquired enough pressure a new cleft was produced in the weakest part of the layer allowing the nuclear material to create a new "pocket" in the second layer. This was the first stage of damage and disc herniation production. This mechanism was repeated until the nucleus traveled along the annulus reaching the posterior longitudinal ligament. At this point a complete extrusion herniation was produced. <br /><br /> Conclusion: The porcine model appears to be suitable as a model to understand the mechanism of disc herniation when the spine is subjected to flexion-extension motions combined with a low-level load. The first cumulative injury appears to be a cleft between the lamellae bundles produced by the nuclear hydraulic pressure. A cumulative load/cumulative injury model approach was used to create the damage that was quantified in the study.

Title Effectiveness of conservative and microdiscetomy treatment for patients with lumbar disc herniation Background Lumbar disc herniation is a common cause of the radiating leg pain and related disabilities that affects people mostly in the middle age. Patients that suffer from lumbar disc herniation respond well to conservative treatment, but for some amount of them surgery could be considered if conservative care is failed after 6 weeks. Although variety of conservative methods that common available in the treatment of lumbar disc herniation, there is conflicting evidence that one type of treatment is clearly superior to others and disagreement over superiority of either surgical intervention or longer conservative treatment for patients with persistent symptoms lasting more than 6 weeks without serious neurological deficit. Aim The main purpose of this thesis is to assess the efficacy of main types of conservative and surgery treatments of the lumbar disc herniation and factors that influence clinical outcomes in patients undergoing this treatment. Method This thesis is a literature review, reviewing articles from relevant journals and books. The relevant sources were searched and collected from database of PubMed, Cochrane library and ScienceDirect from beginning of 2012 to the middle of...

<p>It has been claimed that there are considerable differences between pri-vate and non-private patients with regard to the outcome of back surgery.This can be found in the yearly report from the register concerning backsurgery in Sweden. However, the results seem doubtful and the referencescould not be found. Therefore, we analyze the data about nearly 1200patients from the clinic of back surgery in Str¨angn¨as (CSS). It includesthree time periods with somewhat different questionnaires from 1986 to2007 with both private and non-private patients. In the third period,the patients have been evaluated using the SF-36 questionnaire. The re-sults show that most of the differences between private and non-privatepatients are minor and not statistically significant.</p>

It has been claimed that there are considerable differences between pri-vate and non-private patients with regard to the outcome of back surgery.This can be found in the yearly report from the register concerning backsurgery in Sweden. However, the results seem doubtful and the referencescould not be found. Therefore, we analyze the data about nearly 1200patients from the clinic of back surgery in Str¨angn¨as (CSS). It includesthree time periods with somewhat different questionnaires from 1986 to2007 with both private and non-private patients. In the third period,the patients have been evaluated using the SF-36 questionnaire. The re-sults show that most of the differences between private and non-privatepatients are minor and not statistically significant.

Abstract Background: The process that involves the migration of the nucleus pulposus from the innermost annular layers and culminates with the final extrusion of the nucleus has been limited to a few studies. This investigation was directed towards a better understanding of the herniation process. The architecture of the annulus fibrosus and the mechanism of progressive disc herniation were analyzed, using a controlled porcine model. Microscopic and histochemical techniques were employed. <br /><br /> Methodology: Two studies were performed. In the first stage, the macroscopic and microscopic structures of twelve cervical intervertebral discs were compared with young human disc data from studies reported in the literature. Important structural features were studied such as annulus fibrosus thickness, number of lamellae, lamellae thickness, orientation of the lamellae fibers and blood supply. In the second study, sixteen fresh-frozen functional spine units were submitted to repetitive flexion?extension motions combined with a low compressive load in a servo-hydraulic dynamic testing system. Discograms, dissections and histochemical techniques were applied to characterize the cumulative damage. The experiment produced eight complete herniations, four partial herniations and four specimens without any microscopic detectable annular damage. <br /><br /> Results and Discussion: The structure of the cervical porcine disc resembles the lumbar human disc. Some differences are evident. The size of the annulus is smaller, the thickness of the lamellae is narrower and the number of layers is fewer in the pig. It is hypothesized that the flexion-extension motion combined with a low-level load produced an increased hydraulic pressure in the inner wall of the posterior annulus. This pressure and repetitive motion first produced a small cleft, spreading the collagen bundles inside the first layer. The nuclear material was "pumped" through the small cleft to the first layer filling the layer creating a fluid-filled pocket between the collagen fibers. Once the "pocket" acquired enough pressure a new cleft was produced in the weakest part of the layer allowing the nuclear material to create a new "pocket" in the second layer. This was the first stage of damage and disc herniation production. This mechanism was repeated until the nucleus traveled along the annulus reaching the posterior longitudinal ligament. At this point a complete extrusion herniation was produced. <br /><br /> Conclusion: The porcine model appears to be suitable as a model to understand the mechanism of disc herniation when the spine is subjected to flexion-extension motions combined with a low-level load. The first cumulative injury appears to be a cleft between the lamellae bundles produced by the nuclear hydraulic pressure. A cumulative load/cumulative injury model approach was used to create the damage that was quantified in the study.

Background: Quantitative imaging surrogates of myelin and axonal integrity using magnetization transfer and diffusion tensor imaging may provide beneficial prognostic details on long-term post-surgical recovery in dogs with spinal cord injury (SCI) secondary to intervertebral disc herniation (IVDH). Hypothesis: Magnetization transfer ratio (MTR), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), and fractional anisotropy (FA) will be significantly different in patients with a successful outcome compared to patients with an unsuccessful outcome. Animals: 61 dogs with SCI secondary to IVDH were included in the final analysis. All dogs had to undergo surgical correction for SCI secondary to IVDH and be followed out for 12 weeks. Methods: Prospective cohort study. MTR, MD, AD, RD, and FA were calculated in dogs with SCI secondary to IVDH. A Wilcoxon signed-rank test was used to compare MTR, MD, AD, RD, and FA values between patients with a successful outcome and patients with an unsuccessful outcome. Statistical significance was set at p<0.05. For quantitative imaging surrogates with a significant relationship with outcome, a receiver operator characteristic (ROC) curve analysis was performed and the sensitivity and specificity for predicting successful outcome. Results: MTR (p=0.0013) was significantly lower in patients with a successful outcome compared to patients with an unsuccessful outcome. FA (p=0.435) was not significantly between groups. MD (p=0.0006), AD (p=0.0008) and RD (p=0.0002) were significantly higher in patients with a successful outcome compared to patients with an unsuccessful outcome. ROC curves were performed for MTR, AD and RD. If MTR was ≤ 53, AD ≥ 1.7 × 10-3mm2/s or RD ≥ 0.37 × 10-3 mm2/s, this resulted in a sensitivity of 96.3% and specificity of 100 in predicting a successful outcome. Conclusion and clinical relevance: MTR, MD, AD, and RD were helpful in predicting successful outcome in canine patients with surgically treated SCI secondary to IVDH. A larger cohort is needed for further evaluation. / Master of Science / Background: Certain magnetic resonance imaging (MRI) techniques can provide information about the severity of spinal cord injury. The information obtained from these MRI techniques can be helpful in predicting prognosis in dogs with intervertebral disc disease (IVDD). Hypothesis: We hypothesized that the measurements obtained from these MRI techniques would be able to predict the patients who would be able to walk following surgery (good long-term outcome), versus the patients who did not regain the ability to walk following surgery (poor long-term outcome). Animals: 62 MRIs were performed on dogs with IVDD in our study and were followed out for 12 weeks following surgery to assess long-term outcome. Results: Of the 5 MRI techniques investigated, 4 of the techniques were found to be helpful in predicted long-term outcome. When these techniques were combined, the ability to predict long-term outcome improved. Using the combined technique, all 53 patients predicted to have a good long-term had a good long-term outcome. For patients with a poor long-term outcome, 9 were predicted to have a poor long-term outcome, but only 7 patients had a poor long-term outcome. Conclusion and clinical relevance: MRI can be helpful in predicting long-term outcome in dogs with IVDD following surgery. A larger population of dogs is needed for further evaluation.

A dor lombar acomete a humanidade desde tempos remotos, tendo seus primeiros relatos descritos no \"Papiro de Edwin Smith\" (1500 a.C.). Acredita-se que durante a vida até 90% da população terá pelo menos um episódio de dor lombar, sendo tal patologia uma das principais causas de afastamento do trabalho, acarretando em vultosos prejuízos financeiros anuais. Cinco a 10% dos pacientes que possuem lombalgia também apresentam dor irradiada para o membro inferior (ciatalgia) e esta última, 85% das vezes é secundária à hérnia de disco lombar (HDL), cuja prevalência anual na população geral é estimada em 2.2%. O objetivo deste estudo foi avaliar a eficácia da aplicação do laser diodo de 980 nm intradiscal no tratamento da ciatalgia em pacientes portadores de hérnias lombares contidas em comparação com o grupo controle. Vinte e cinco pacientes (30 discos intervertebrais) com HDL e dor neuropática de distribuição metamérica foram randomizados, 12 no grupo controle e treze no grupo laser. No grupo controle foi feita injeção de dexametasona, clonidina e lidocaína intradiscais e no grupo laser aplicada média de 900 J de energia intradiscal, além das mesmas medicações. Os grupos foram avaliados nos tempos antes, imediatamente após, um mês, dois, três, seis e 12 meses decorridos do procedimento quanto aos parâmetros: dor, pela Escala Numérico Visual (ENV), uso de medicações para o controle desse sintoma e efeitos colaterais. Os resultados demonstraram queda nas médias das ENVs e necessidade de medicações para controle da dor em ambos os grupos logo após o tratamento (p<0,05), que perdurou no grupo laser onde houve média de redução de 80,73% nas ENVs, e de 75,51% na necessidade de medicação em um ano de seguimento (p<0,05). Já no grupo controle, as ENVs e as necessidades de analgésicos voltaram a ser semelhantes aos valores anteriores ao tratamento a partir do segundo mês de avaliação (p>0,05). Foi verificada predominância da doença no sexo masculino (68%), com faixa etária média de 44 anos, e baixa incidência de efeitos colaterais semelhantemente a dados anteriormente relatados. O laser diodo de 980 nm é eficaz na redução da ciatalgia secundária à herniação discal contida e superior à injeção intradiscal de clonidina, dexametasona e lidocaína, no que se refere à duração da redução das ENVs e da necessidade de medicações analgésicas. / Lumbar pain affects mankind from earliest times having its first descriptions in the \"Edwin Smith Papyrus\" (1500 BC). It is believed that during life up to 90% of the population will have at least one episode of low back pain, being such pathology one of the main causes of work withdrawal with huge annual financial losses. Five to 10% of patients with low back pain also have lower-limb pain (sciatica), and the latter, 85% of the time, is secondary to lumbar disc herniation (LDH), whose annual prevalence in the general population is estimated at 2.2%. The objective of this study was to evaluate the efficacy of intradiscal diode laser 980 nm wavelength in comparison with a control group on sciatica treatment in patients with contained lumbar disc herniations. A total of 25 patients (30 intervertebral discs) with LDH and neuropathic pain of metameric distribution were randomized, 12 patients in the control group and 13 patients in the laser group. In the control group, intradiscal injection of dexamethasone, clonidine and lidocaine was performed and in the laser group an average of 900 J of intradiscal energy was delivered, in addition to the same medications. The groups were evaluated at the time before, immediately after, 1, 2, 3, 6, and 12 months after the procedure for the parameters: pain measured by Visual Numerical Scale (VNS), medication use to control this symptom and side effects. The results showed a decrease in VNS and the need for pain control medications in both groups after treatment (p<0.05) that lasted in the laser group which demonstrated an average in VNSs reduction of 80,73% and in pain analgesic needs of 75,51% after 1 year (p<0,05). In the control group, VNSs and analgesic needs were again similar to pre-treatment values from the second month of evaluation (p>0.05). The predominance of the disease was found in males (68%), with a mean age of 44 years and a low incidence of side effects similar to the data reported before. The 980 nm diode laser is effective in reducing sciatica due to contained LDH and superior to intradiscal injection of clonidine, dexamethasone and lidocaine for the duration of the reduction of VNS and need for analgesic medications.

O processamento é uma das principais características da radiografia digital. Diante da frequência da discopatia em cães, a importância do exame radiográfico na investigação inicial desta doença e na orientação de outros exames de imagem (tomografia computadorizada, mielotomografia e imagem por ressonância magnética), buscou-se avaliar a efetiva contribuição das ferramentas de processamento da imagem no diagnóstico das hérnias de disco. Para tanto, foram avaliados 80 forames intervertebrais através da radiologia computadorizada pelos filtros padrão, invertido e realce de borda e a combinação entre esses (padrão e invertido, padrão e realce de borda e realce de borda e invertido) para pesquisa da opacificação do forame intervertebral associada às hérnias de disco em cães. A análise radiográfica foi realizada por dois avaliadores às cegas com tempo de experiência superior a 10 anos em radiodiagnóstico. Foram calculadas as medidas de sensibilidade, especificidade, valores preditivos positivos e negativos, acurácia e razão de verossimilhanças para os respectivos filtros e a combinação destes pelos dois avaliadores. A tomografia computadorizada foi tomada como padrão ouro da detecção de opacificação do forame intervertebral. O coeficiente de kappa e seu respectivo intervalo de 95% de confiança foram utilizados para analisar a concordância dos resultados. Os valores de sensibilidade obtidos pelos avaliadores foram de 58,7% na detecção das opacificações pelo filtro padrão, 52,2% pelo filtro invertido e 50% de sensibilidade no estudo realizado pelo filtro realce de borda. Na combinação entre os filtros padrão e invertido e realce de borda e invertido os valores foram os mesmos com 43,5%, sendo que a sensibilidade do filtro padrão associado com o filtro realce de borda foi de 50%. A acurácia alcançada na detecção das opacificações do forame intervertebral pelos filtros individualmente foi de 78,8% para o filtro padrão, 75% para o filtro invertido e 75,6% para o filtro realce de borda, não apresentando diferenças significativas quando a combinação entre os filtros foi realizada, obtendo-se 76,9% nas associações entre os filtros padrão e invertido e padrão e realce de borda e 75,6% através dos filtros realce de borda e invertido. O processamento da imagem digital pode aumentar a acurácia na detecção das opacificações do forame, no entanto os filtros podem somente realçar uma alteração existente e não aumentar a capacidade de detecção da lesão pelo exame radiográfico simples sendo necessária para tal, a associação de exames de imagem mais sensíveis (mielografia/tomografia computadorizada/ imagem por ressonância magnética). A preferência pessoal na utilização dos filtros também foi comprovada. / Processing is a major feature of digital radiography. Given the frequency of disc disease in dogs, the importance of radiographic examination in the initial investigation of this disease and the guidance of other imaging studies (computed tomography, myelography and magnetic resonance imaging), it was evaluate the effective contribution of the processing tools image in the diagnosis of herniated discs. For this, eigthy intervertebral foramina through were evaluated computed radiography by standart filters, reverse and edge enhancement and the combination of these (standard and inverted pattern, standard and edge enhancement and edge enhancement and inverted) in the investigation of opacification of the intervertebral foramen associated with hernia disc in dogs. Radiographic analysis was performed by two raters blind to time of more than 10 years experience in diagnostic radiology. It was calculated measures of sensitivity, specificity, positive and negative predictive values, accuracy and likelihood ratio for the respective filters and the combination of the two evaluators. Therefore, the CT scan was taken as the gold standard of detection opacification of the intervertebral foramen. The kappa coefficient and its corresponding interval of 95% confidence intervals were used to analyze the correlation of the results. The sensitivity values obtained by the evaluators were 58.7% in detecting the opacities of the standard filter, the filter inverted 52.2% and 50% sensitivity in the study by edge enhancement filter. In combination between standard and inverted filters and edge enhancement and inverted values were the same with 43.5%, and the sensitivity of the filter pattern associated with the filter edge enhancement was 50%. The accuracy achieved in the detection of opacities of the intervertebral foramen by the filters individually was 78.8% for the standard filter, 75% to inverted filter and 75.6% for edge enhancement filter, showing no significant differences when the combination between the filters was performed. yielding 76.9% associations between the filters standard and inverted pattern, and pattern and edge enhancement and 75.6% through the filter edge enhancement and inverted. The digital image processing can increase the accuracy in the detection of opacities foramen, however filters can only highlight a change and not increase the existing capacity of lesion detection by simple radiographic examination is necessary association of more sensitive imaging ( myelography / CT / MRI). Personal preference through the use of filters was also confirmed.