COSTS ANALYSIS OF SPINAL COLUMN METASTASES SURGICAL TREATMENT.

Introduction: End-of-life cancer treatment is associated with substantial healthcare costs. Objective: This study aimed to analyze the surgical treatment cost of spinal metastasis and epidural compression patients undergoing surgical treatment. Methods: A retrospective cost analysis of 81 patients with spinal metastasis and epidural compression undergoing surgical treatment. Cost evaluation was defined in the following categories: medications, laboratory and imaging tests, nursery, recovery room, intensive care unit, surgical procedure, and consigned material. The cost of pain improvement, functional activity, and survival was also evaluated. Results: The total cost of surgical treatment for 81 patients was $3,604,334.26, and the average value for each patient was $44,497.95. The highest costs were related to implants (41.1%), followed by hospitalization (27.3%) and surgical procedure (19.7%). Conclusion: The cost of surgical treatment for spinal metastases is one of the most expensive bone complications in cancer patients. The cost of treatment related to outcomes showed differences according to the outcome analyzed. Hospital stay, tests, drugs, and intensive care play an important role in some of the costs related to the specific outcome. Level of Evidence II, Retrospective Study .

Introdução: O tratamento do câncer em fim de vida está associado a custos substanciais em saúde. Objetivo: O objetivo do estudo foi analisar o custo do tratamento cirúrgico de pacientes com metástase espinhal e compressão peridural submetidos ao tratamento cirúrgico. Métodos: Uma análise retrospectiva de custos de 81 pacientes com metástase espinhal e compressão peridural submetidos a tratamento cirúrgico. A avaliação de custos foi definida nas seguintes categorias: medicamentos, exames laboratoriais e de imagem, enfermaria, sala de recuperação, unidade de terapia intensiva, procedimento cirúrgico e material consignado. O custo relacionado à melhora da dor, atividade funcional e sobrevida também foi avaliado. Resultados: O custo total do tratamento cirúrgico de 81 pacientes foi de R $ 3.604.334,26 e o valor médio de cada paciente foi de R $ 44.497,95. Os maiores gastos foram relacionados com implantes (41,1%), seguidos de internação (27,3%) e procedimento cirúrgico (19,7%). Conclusão: O custo do tratamento cirúrgico para metástases espinhais é um dos mais caros entre as complicações ósseas em pacientes com câncer. O custo do tratamento relacionado aos desfechos apresentou diferença de acordo com o desfecho analisado e a permanência hospitalar, exames, medicamentos e terapia intensiva tem papel importante em alguns dos custos relacionados ao desfecho específico. Nível de Evidência II, Estudo retrospectivo .

Sagittal Plane Geometry of Cervical, Thoracic, and Lumbar Endplates.

BACKGROUND: Many studies have emphasized the importance of interface contact between implants and the vertebral endplate (VE). The goal of this study was to analyze the shape and other specific parameters of the VE to provide reference data for better implant interface contact in intervertebral disc space procedures. METHODS: Cervical, thoracic, and lumbar spine midsagittal plane magnetic resonance images of 100 adults (58 women) were analyzed. The morphology of the VEs was classified as concave, convex, flat, or irregular. Midsagittal endplate length (ML), endplate concavity depth (ECD), and endplate concavity axis (ECA) location were measured in the midsagittal plane. The parameters were compared between the cervical, thoracic, and lumbar spines and between the sexes. RESULTS: The VE morphology, ML, ECD, and ECA showed variations along the spine, mainly in the cervical and lower lumbar spines. The sagittal geometry of the VE was not flat or uniform along the cervical, thoracic, and lumbar spines. Different morphological types were observed along different spinal segments and according to sex. In the cervical spine, the majority of cranial VEs were flat, while caudal VEs were mostly concave. CONCLUSION: Sagittal VE geometry should be taken into consideration during the use of intervertebral cages or disc arthroplasty.

The Influence of Thread Tap Mismatch on Pedicle Screw Pullout Strength.

Objective We aimed to study the "in vitro" pullout strength of SpineGuard/Zavation Dynamic Surgical Guidance Z-Direct Screw (DSG Screw, SpineGuard Inc, Boulder, Colorado, USA), a screw designed to be inserted using a direct insertion technique. Methods Dynamic Surgical Guidance Screws of 5.5 and 6.5 mm were introduced into polyurethane blocks with a density of 10 PCF (0,16g/cm 3 ). According to the experimental group, screws were inserted without pilot hole, with pilot without tapping, undertapping and line-to-line tapping. Screw pullout tests were performed using a universal test machine after screw insertion into polyurethane blocks. Results Screws inserted directly into the polyurethane blocks without pilot hole and tapping showed a statistically higher pullout strength. Insertion of the screw without tapping or with undertapping increases the pullout screw strength compared with line-to-line tapping. Conclusion Dynamic Surgical Guidance Screw showed the highest pullout strength after its insertion without pilot hole and tapping.

The Influence of Thread Tap Mismatch on Pedicle Screw Pullout Strength / A influência da incompatibilidade do macho de rosca na resistência à extração do parafuso pedicular

Abstract Objective We aimed to study the "in vitro" pullout strength of SpineGuard/Zavation Dynamic Surgical Guidance Z-Direct Screw (DSG Screw, SpineGuard Inc, Boulder, Colorado, USA), a screw designed to be inserted using a direct insertion technique. Methods Dynamic Surgical Guidance Screws of 5.5 and 6.5 mm were introduced into polyurethane blocks with a density of 10 PCF (0,16g/cm3). According to the experimental group, screws were inserted without pilot hole, with pilot without tapping, undertapping and line-to-line tapping. Screw pullout tests were performed using a universal test machine after screw insertion into polyurethane blocks. Results Screws inserted directly into the polyurethane blocks without pilot hole and tapping showed a statistically higher pullout strength. Insertion of the screw without tapping or with undertapping increases the pullout screw strength compared with lineto-line tapping. Conclusion Dynamic Surgical Guidance Screw showed the highest pullout strength after its insertion without pilot hole and tapping.

Resumo Objetivo Nosso objetivo foi estudar a resistência à extração "in vitro" do parafuso SpineGuard/Zavation Dynamic Surgical Guidance Z-Direct (Parafuso DSG Guia Cirúrgico Dinâmico, SpineGuard Inc, Boulder, Colorado, USA), um parafuso projetado para ser inserido utilizando a técnica de inserção direta. Métodos Os parafusos DSG de 5,5 e 6,5 mm foram introduzidos em blocos de poliuretano com densidade de 10 PCF (0,16g/cm3). De acordo com o grupo experimental, os parafusos foram inseridos sem um orifício piloto, com um orifício piloto sem o macheamento, com macheamento e com macheamento linha a linha. Os testes de extração do parafuso foram realizados em uma máquina de teste universal, após a inserção do parafuso em blocos de poliuretano. Resultados Os parafusos inseridos diretamente nos blocos de poliuretano sem o orifício piloto e o macheamento mostraram uma resistência à extração estatisticamente maior. A inserção do parafuso sem o macheamento ou com o macho de menor diâmetro aumenta a resistência à extração do parafuso em comparação com o macheamento linha a linha. Conclusão O parafuso DSG apresentou a maior resistência à extração após a inserção sem o orifício piloto e o macheamento.

Costs analysis of spinal column metastases surgical treatment / Análise dos custos do tratamento cirúrgico das metástases da coluna vertebral

ABSTRACT Introduction End-of-life cancer treatment is associated with substantial healthcare costs. Objective This study aimed to analyze the surgical treatment cost of spinal metastasis and epidural compression patients undergoing surgical treatment. Methods A retrospective cost analysis of 81 patients with spinal metastasis and epidural compression undergoing surgical treatment. Cost evaluation was defined in the following categories: medications, laboratory and imaging tests, nursery, recovery room, intensive care unit, surgical procedure, and consigned material. The cost of pain improvement, functional activity, and survival was also evaluated. Results The total cost of surgical treatment for 81 patients was $3,604,334.26, and the average value for each patient was $44,497.95. The highest costs were related to implants (41.1%), followed by hospitalization (27.3%) and surgical procedure (19.7%). Conclusion The cost of surgical treatment for spinal metastases is one of the most expensive bone complications in cancer patients. The cost of treatment related to outcomes showed differences according to the outcome analyzed. Hospital stay, tests, drugs, and intensive care play an important role in some of the costs related to the specific outcome. Level of Evidence II, Retrospective Study.

RESUMO Introdução O tratamento do câncer em fim de vida está associado a custos substanciais em saúde. Objetivo O objetivo do estudo foi analisar o custo do tratamento cirúrgico de pacientes com metástase espinhal e compressão peridural submetidos ao tratamento cirúrgico. Métodos Uma análise retrospectiva de custos de 81 pacientes com metástase espinhal e compressão peridural submetidos a tratamento cirúrgico. A avaliação de custos foi definida nas seguintes categorias: medicamentos, exames laboratoriais e de imagem, enfermaria, sala de recuperação, unidade de terapia intensiva, procedimento cirúrgico e material consignado. O custo relacionado à melhora da dor, atividade funcional e sobrevida também foi avaliado. Resultados O custo total do tratamento cirúrgico de 81 pacientes foi de R $ 3.604.334,26 e o valor médio de cada paciente foi de R $ 44.497,95. Os maiores gastos foram relacionados com implantes (41,1%), seguidos de internação (27,3%) e procedimento cirúrgico (19,7%). Conclusão O custo do tratamento cirúrgico para metástases espinhais é um dos mais caros entre as complicações ósseas em pacientes com câncer. O custo do tratamento relacionado aos desfechos apresentou diferença de acordo com o desfecho analisado e a permanência hospitalar, exames, medicamentos e terapia intensiva tem papel importante em alguns dos custos relacionados ao desfecho específico. Nível de Evidência II, Estudo retrospectivo.

Association between spinal alignment and biochemical composition of lumbar intervertebral discs assessed by quantitative magnetic resonance imaging.

BACKGROUND: To evaluate potential associations between spinopelvic parameters and the biochemical composition of lumbar intervertebral discs using quantitative magnetic resonance imaging in asymptomatic young adults. METHODS: Our study group comprised 93 asymptomatic volunteers aged 20-40 years (49 women and 44 men). Lumbar spine T2-weighted images and T2 relaxometry were acquired on a 1.5T MRI scanner. Spinopelvic parameters including sacral slope, pelvic tilt, pelvic incidence, lumbar lordosis, thoracic kyphosis, thoracolumbar alignment, sagittal vertical axis, spinosacral angle, C2 pelvic angle, and T1S1 and L1S1 length were measured on panoramic spine radiographs. RESULTS: Lumbar lordosis decrease correlates with discrete dehydration of nucleus pulposus at all lumbar levels. Also low values of sacral slope, pelvic tilt, pelvic incidence, thoracic kyphosis and spinosacral angle were associated with decrease of T2 relaxation times on annulus fibrosus. CONCLUSIONS: In conclusion, spinopelvic parameters presented a discrete association with lumbar disc composition and water content.

Does the use of dynamic surgical guidance assist accurate pedicle screw placement in patients with osteoporosis or osteopenia? / O uso do guia cirúrgico dinâmico auxilia a acurácia do posicionamento dos parafusos pediculares em pacientes com osteoporose ou osteopenia? / ¿el uso de guía quirúrgica dinámica ayuda a colocar con precisión los tornillos pediculares en pacientes con osteoporosis u osteopenia?

ABSTRACT Objective To compare the use of a dynamic surgical guide (PediGuard®) and pilot hole preparation, with the use of a probe and the aid of fluoroscopy in osteoporotic or osteopenic patients undergoing pedicular fixation of the thoracic or lumbar spine. Methods One hundred and eight patients were randomized. A pilot hole was prepared with the dynamic surgical guide (PediGuard®), or with a probe with the aid of fluoroscopy. A total of 657 vertebral pedicles (120 thoracic and 180 lumbar) were included in the study. The parameters used for the comparison were: accuracy of the pedicular screw, number of fluoroscopic shots, and change in intraoperative trajectory of the perforation after detecting pedicle wall rupture. Results In the group with use of the dynamic surgical guide, malpositioning of the pedicle screws was observed in 8 (2.6%) patients and intraoperative change of perforation trajectory in 12 (4%) patients, and there were 52 fluoroscopic shots. In the group without use of the dynamic surgical guide (PediGuard®), misplacement of the pedicle screws was observed in 33 (11%) patients and intraoperative change of perforation trajectory in 47 (13.2%) patients, and there were 136 fluoroscopic shots. Conclusion The use of the dynamic surgical guide (PediGuard®) in patients with osteoporosis or osteopenia enabled more accurate placement of pedicular screws, with less change in the intraoperative course of the perforation and less intraoperative radiation. Level of Evidence II; Randomized clinical trial of lesser quality.

RESUMO Objetivo Comparar o uso de um guia cirúrgico dinâmico (PediGuard®) e o preparo de orifício piloto com uma sonda e o auxílio de fluoroscopia em pacientes com osteopenia ou osteoporose submetidos à fixação pedicular da coluna torácica ou lombar. Métodos Cento e oito pacientes foram randomizados. Um orifício piloto foi preparado com o guia cirúrgico dinâmico (PediGuard®) ou com uma sonda com auxílio de fluoroscopia. Foram incluídos no estudo 657 pedículos vertebrais (120 torácicos e 180 lombares). Os parâmetros usados para a comparação foram: acurácia da colocação do parafuso pedicular, número de disparos fluoroscópicos e mudança da trajetória intraoperatória da perfuração depois da detecção de ruptura da parede do pedículo. Resultados No grupo de pacientes em que se usou o guia cirúrgico dinâmico, observou-se mau posicionamento dos parafusos pediculares em oito (2,6%) pacientes e alteração da trajetória intraoperatória da perfuração em 12 (4%) pacientes, com 52 disparos fluoroscópicos. No grupo de pacientes em que o guia cirúrgico dinâmico (PediGuard®) não foi usado o mau posicionamento dos parafusos pediculares foi observado em 33 (11%) pacientes, a mudança intraoperatória da trajetória da perfuração foi vista em 47 (13,2%) pacientes, com 136 disparos fluoroscópicos. Conclusão O uso do guia cirúrgico dinâmico (PediGuard®) em pacientes com osteoporose ou osteopenia permitiu a colocação de parafusos pediculares com maior acurácia, com menor alteração da trajetória intraoperatória da perfuração e menor dose de radiação intraoperatória. Nível de Evidência II; Estudo clínico randomizado de menor qualidade.

RESUMEN Objetivo Comparar el uso de una guía quirúrgica dinámica (PediGuard®) y la preparación del orificio piloto con una sonda y la ayuda de fluoroscopia en pacientes con osteopenia u osteoporosis sometidos a fijación pedicular de la columna torácica o lumbar. Métodos Ciento ocho pacientes fueron asignados aleatoriamente. Se preparó un orificio piloto preparado con la guía quirúrgica dinámica (PediGuard®) o con una sonda con ayuda de fluoroscopia. Se incluyeron en el estudio 657 pedículos vertebrales (120 torácicos y 180 lumbares). Los parámetros utilizados para la comparación fueron: precisión de la colocación del tornillo pedicular, número de disparos del dispositivo de fluoroscopia y cambio en la trayectoria intraoperatoria de la perforación después de la detección de ruptura de la pared del pedículo. Resultados En el grupo de pacientes en el que se utilizó la guía quirúrgica dinámica, se observó mal posicionamiento de los tornillos pediculares en 8 (2,6%) pacientes y cambios de la trayectoria intraoperatoria de la perforación en 12 (4%) pacientes, con 52 disparos del aparato de fluoroscopia. En el grupo de pacientes en los que no se utilizó la guía quirúrgica dinámica (PediGuard®), se observó un mal posicionamiento de los tornillos pediculares en 33 (11%) pacientes, el cambio intraoperatorio de la trayectoria de perforación se observó en 47 (13,2%) pacientes, con 136 disparos fluoroscópicos. Conclusión El uso de la guía quirúrgica dinámica (PediGuard®) en pacientes con osteoporosis u osteopenia permitió la colocación de tornillos pediculares con mayor precisión, menos cambios en la trayectoria intraoperatoria de la perforación y dosis más baja de radiación intraoperatoria. Nivel de Evidencia II; Ensayo clínico aleatorizado de menor calidad.

Open versus minimally invasive percutaneous surgery for surgical treatment of thoracolumbar spine fractures- a multicenter randomized controlled trial: study protocol.

BACKGROUND: Thoracolumbar fractures are most frequent along the spine, and surgical treatment is indicated for unstable fractures. Percutaneous minimally invasive surgery was introduced to reduce the pain associated with the open posterior approach and reduce the morbidity of the procedure by avoiding damage and dissection of the paravertebral muscles. The goal of this study is to compare the surgical treatment of fractures of the thoracolumbar spine treated by the conventional open approach and the percutaneous minimally invasive approach using similar types of pedicle spine fixation systems. METHODS/DESIGNS: This study is designed as a multi-center, randomized controlled trial of patients aged 18-65 years who are scheduled to undergo surgical posterior fixation. Treatment by the conventional open approach or percutaneous minimally invasive approach will be randomly assigned. The primary outcome measure is postoperative pain, which will be measured using the visual analogue scale (VAS). The secondary outcome parameters are intraoperative bleeding, postoperative drainage, surgery time, length of hospital stay, SF-36, EQ-5D-5 l, HADS, pain medication, deambulation after surgery, intraoperative fluoroscopy time, vertebral segment kyphosis, fracture vertebral body height, compression of the vertebral canal, accuracy of the pedicle screws, and breakage or release of the implants. Patient will be followed up for 1, 2, 3, 6, 12 and 24 months postoperatively and evaluated according to the outcomes using clinical and radiological examinations, plain radiographs and computed tomografy (CT). DISCUSSION: Surgical treatment of thoracolumbar fractures by the open or percutaneous minimally invasive approach will be compared in a multicenter randomized study using similar types of fixation systems, and the results will be evaluated according to clinical and radiological parameters at 1, 2, 3, 6, 12 and 24 months of follow-up. TRIAL REGISTRATION: ClinicalTrial.gov approval number: 1.933.631, code: NCT03316703 in may 2017.

RELIABILITY OF A BRAZILIAN PORTUGUESE TRANSLATED AND CROSS-CULTURALLY ADAPTED VERSION OF THE MJOA SCALE.

OBJECTIVE: To assess the intra- and inter-observer reliability of a Brazilian Portuguese translated and cross-culturally adapted version of the mJOA questionnaire. METHODS: The reliability of the Brazilian Portuguese version of the mJOA scale was assessed through the evaluation of a sample of patients with cervical myelopathy by two independent experienced spine surgeon examiners. Inter-observer reliability was defined by the Intraclass Correlation Coefficient (ICC) between the evaluations of the two examiners, and intra-observer reliability was assessed by the ICC between the two evaluations of one examiner. RESULTS: Fifty-five patients were included in the study (mean age 58.7 years). The ICC for inter-observer reliability of the Brazilian Portuguese version of the mJOA was 0.967, and the ICC for intra-observer reliability was 0.869, both classified as "almost perfect" (> 0.81). CONCLUSION: The Brazilian Portuguese translated and cross-culturally adapted version of the mJOA questionnaire appears to be valid and reliable. Level of evidence I, Diagnostic Studies, Investigating a Diagnostic Test.

OBJETIVO: Avaliar a confiabilidade intra e interobservador da versão do questionário mJOA traduzida e adaptada culturalmente para o português brasileiro. MÉTODOS: A confiabilidade da versão em português da escala mJOA foi avaliada em uma amostra de pacientes com mielopatia cervical por dois examinadores com experiência em cirurgia da coluna vertebral. A confiabilidade interobservador foi definida pelo Coeficiente de Correlação Intraclasse (CCI) entre as avaliações dos dois examinadores e a confiabilidade intraobservador pelo CCI entre duas avaliações de um examinador. RESULTADOS: Cinquenta e cinco pacientes foram incluídos no estudo (média de idade: 58,7 anos). O CCI para confiabilidade interobservador da versão brasileira do mJOA foi 0,967 e o CCI para a confiabilidade intraobservador foi 0,869, ambas classificadas como "quase perfeita" (> 0,81). CONCLUSÃO: A versão do questionário mJOA traduzida e adaptada culturalmente para o português brasileiro demonstrou-se válida e confiável. Nível de Evidência I, Estudos diagnósticos, Investigação de um Exame para Diagnóstico.

Reliability of a brazilian portuguese translated and cross-culturally adapted version of the mjoa scale / Reprodutibilidade da versão traduzida e adaptada culturalmente para o português brasileiro da escala mjoa

ABSTRACT Objective: To assess the intra- and inter-observer reliability of a Brazilian Portuguese translated and cross-culturally adapted version of the mJOA questionnaire. Methods: The reliability of the Brazilian Portuguese version of the mJOA scale was assessed through the evaluation of a sample of patients with cervical myelopathy by two independent experienced spine surgeon examiners. Inter-observer reliability was defined by the Intraclass Correlation Coefficient (ICC) between the evaluations of the two examiners, and intra-observer reliability was assessed by the ICC between the two evaluations of one examiner. Results: Fifty-five patients were included in the study (mean age 58.7 years). The ICC for inter-observer reliability of the Brazilian Portuguese version of the mJOA was 0.967, and the ICC for intra-observer reliability was 0.869, both classified as "almost perfect" (> 0.81). Conclusion: The Brazilian Portuguese translated and cross-culturally adapted version of the mJOA questionnaire appears to be valid and reliable. Level of evidence I, Diagnostic Studies, Investigating a Diagnostic Test.

RESUMO Objetivo: Avaliar a confiabilidade intra e interobservador da versão do questionário mJOA traduzida e adaptada culturalmente para o português brasileiro. Métodos: A confiabilidade da versão em português da escala mJOA foi avaliada em uma amostra de pacientes com mielopatia cervical por dois examinadores com experiência em cirurgia da coluna vertebral. A confiabilidade interobservador foi definida pelo Coeficiente de Correlação Intraclasse (CCI) entre as avaliações dos dois examinadores e a confiabilidade intraobservador pelo CCI entre duas avaliações de um examinador. Resultados: Cinquenta e cinco pacientes foram incluídos no estudo (média de idade: 58,7 anos). O CCI para confiabilidade interobservador da versão brasileira do mJOA foi 0,967 e o CCI para a confiabilidade intraobservador foi 0,869, ambas classificadas como "quase perfeita" (> 0,81). Conclusão: A versão do questionário mJOA traduzida e adaptada culturalmente para o português brasileiro demonstrou-se válida e confiável. Nível de Evidência I, Estudos diagnósticos, Investigação de um Exame para Diagnóstico.

The Role of Mixed Reality Simulation for Surgical Training in Spine: Phase 1 Validation.

STUDY DESIGN: This study shows the first phase of validation of a new model for realistic training on spine surgery, conducted from January 2014 to November 2015. OBJECTIVE: To propose and validate a new tool for neurosurgical education, associating virtual and realistic simulation (mixed reality), for spine surgery. SUMMARY OF BACKGROUND DATA: Surgical simulation is a relatively new filed that has a lot to offer to neurosurgical education. Training a new surgeon may take years of hands-on procedures, increasing the risk to patient's safety. The development of surgical simulation platforms is therefore essential to reducing the risk of potentially serious risks and improving outcome. METHODS: Sixteen experienced spinal surgeons evaluated these simulators and answered the questionnaire regarding the simulation as a beneficial education tool. They evaluated the simulators in regard to dissection by planes, identification of pathology (lumbar canal stenosis), instrumentation and simulation of cerebrospinal fluid (CSF) leak, and the relevant aspects of the computerized tomography (CT) imaging. RESULTS: The virtual and physical simulators for spine surgery were approved by an expert surgery team, and considered adequate for educational purposes. The proportion of the answers was estimated by the confidence intervals. CONCLUSION: The surgery team considered that this virtual simulation provides a highly effective training environment, and it significantly enhances teaching of surgical anatomy and operative strategies in the neurosurgical field. A mixture of physical and virtual simulation provided the desired results of enhancing the requisite psychomotor and cognitive skills, previously acquired only during a surgical apprenticeship. The combination of these tools may potentially improve and abbreviate the learning curve for trainees, in a safe environment. LEVEL OF EVIDENCE: 3.

The Presence of the Neuronal Nitric Oxide Synthase Isoform in the Intervertebral Disk.

Intervertebral disk degeneration is a progressive and debilitating disease with multifactorial causes. Nitric oxide (NO) might contribute to the cell death pathway. We evaluated the presence of the constitutive form of the neuronal NOS (nNOS) in both health and degenerated intervertebral disk through qPCR and immunohistochemistry. We also analyzed the potential role of nNOS modulation in the tail needle puncture model of intervertebral disk degeneration. Male Wistar rats were submitted to percutaneous disk puncture with a 21-gauge needle of coccygeal vertebras. The selective nNOS pharmacological inhibitor N (ω)-propyl-L-arginine (NPLA) or a nNOS-target siRNA (siRNAnNOShum_4400) was injected immediately after the intervertebral disk puncture with a 30-gauge needle. Signs of disk degeneration were analyzed by in vivo magnetic resonance imaging and histological score. We found that intact intervertebral disks express low levels of nNOS mRNA. Disk injury caused a 4 fold increase in nNOS mRNA content at 5 h post disk lesion. However, NPLA or nNOS-target siRNA slight mitigate the intervertebral disk degenerative progress. Our data show evidence of the nNOS presence in the intervertebral disk and its upregulation during degeneration. Further studies would disclose the nNOS role and its potential therapeutical value in the intervertebral disk degeneration.

Protective effects of cannabidiol on lesion-induced intervertebral disc degeneration.

Disc degeneration is a multifactorial process that involves hypoxia, inflammation, neoinnervation, accelerated catabolism, and reduction in water and glycosaminoglycan content. Cannabidiol is the main non-psychotropic component of the Cannabis sativa with protective and anti-inflammatory properties. However, possible therapeutic effects of cannabidiol on intervertebral disc degeneration have not been investigated yet. The present study investigated the effects of cannabidiol intradiscal injection in the coccygeal intervertebral disc degeneration induced by the needle puncture model using magnetic resonance imaging (MRI) and histological analyses. Disc injury was induced in the tail of male Wistar rats via a single needle puncture. The discs selected for injury were punctured percutaneously using a 21-gauge needle. MRI and histological evaluation were employed to assess the results. The effects of intradiscal injection of cannabidiol (30, 60 or 120 nmol) injected immediately after lesion were analyzed acutely (2 days) by MRI. The experimental group that received cannabidiol 120 nmol was resubmitted to MRI examination and then to histological analyses 15 days after lesion/cannabidiol injection. The needle puncture produced a significant disc injury detected both by MRI and histological analyses. Cannabidiol significantly attenuated the effects of disc injury induced by the needle puncture. Considering that cannabidiol presents an extremely safe profile and is currently being used clinically, these results suggest that this compound could be useful in the treatment of intervertebral disc degeneration.

Effect of pilot hole on biomechanical and in vivo pedicle screw-bone interface.

PURPOSE: To experimentally study the influence of pilot hole diameter (smaller than or equal to the internal (core) diameter of the screw) on biomechanical (insertion torque and pullout strength) and histomorphometric parameters of screw-bone interface in the acute phase and 8 weeks after pedicle screw insertion. METHODS: Fifteen sheep were operated upon and pedicle screws inserted in the L1-L3 pedicles bilaterally. The pilot hole was smaller (2.0 mm) than the internal diameter (core) of the screw on the left side pedicle and equal (2.8 mm) to the internal diameter (core) of the screw on the right side pedicle. Ten animals were sacrificed immediately (five animals were assigned to pullout strength tests and five animals were used for histomorphometric bone-screw interface evaluation). Five animals were sacrificed 8 weeks after pedicle screw insertion for histomorphometric bone-screw interface evaluation. RESULTS: The insertion torque and pullout strength were significantly greater in pedicle screws inserted into pilot holes smaller than internal (core) diameter of the screw. Histomorphometric evaluation of bone-screw interface showed that the percentage of bone-implant contact, the area of bone inside the screw thread and the area of bone outside the screw thread were significantly higher for pilot holes smaller than the internal (core) diameter of the screw immediately after insertion and after 8 weeks. CONCLUSION: A pilot diameter smaller than the internal (core) diameter of the screw improved the insertion torque and pullout strength immediately after screw insertion as well the pedicle screw-bone interface contact immediately and 8 weeks after screw placement in sheep with good bone mineral density.

The influence of vision and support base on balance during quiet standing in patients with adolescent idiopathic scoliosis before and after posterior spinal fusion.

BACKGROUND CONTEXT: Scoliosis is the most common postural alteration in adolescence and is characterized by deviations of the spine in three planes. Surgical treatment based on arthrodesis has been developed, but the effects of such restructuring on the systems involved in postural control need to be better understood. PURPOSE: To assess the influence of vision and the support base on balance in the quiet standing position in adolescents awaiting surgical treatment for idiopathic scoliosis. STUDY DESIGN/SETTING: Longitudinal study/Ribeirão Preto Clinics Hospital (HC-FMRP-USP) and Laboratory of Assessment and Rehabilitation of Equilibrium at the FMRP-USP. PATIENT SAMPLE: Adolescent idiopathic scoliosis patients and controls. OUTCOME MEASURES: Center of pressure (CoP) sway area of the 95% confidence ellipse. METHODS: Thirty female adolescents were divided into two groups according to their spinal alignment: control (n=15) and scoliosis groups (SGs) (n=15). The subjects with scoliosis were evaluated before and 7, 30, 60, and 90 days after surgery; the controls were evaluated once. The area of CoP oscillation was measured with the eyes open and closed and with two different support bases (feet apart or together). The force platform was purchased with funding support (US $8,375.00) provided by the Research Foundation of São Paulo (FAPESP). The study sponsors had no involvement in the study. Data were collected from the force platform and then statistically assessed through a linear model analysis of mixed effects. RESULTS: Data reveal that subjects in the SG oscillated more than controls, and postsurgery subjects had more oscillation than presurgery subjects. The results also indicated that both groups (control and scoliosis) showed more oscillation among those subjects with feet apart and eyes closed, but subjects with scoliosis were more affected by vision deprivation than by a reduced support base. CONCLUSIONS: Our results indicate that adolescents with idiopathic scoliosis are more dependent on visual information and that surgical correction does not change this relationship.

Biological evaluation of the bone healing process after application of two potentially osteogenic proteins: an animal experimental model.

OBJECTIVE: The aim of this work was to analyse qualitatively and quantitatively the newly formed bone after insertion of rhBMP-2 and protein extracted from Hevea brasiliensis (P-1), associated or not with a carrier in critical bone defects created in Wistar rat calvarial bone, using histological and histomorphometrical analyses. MATERIALS AND METHODS: Eighty-four male Wistar rats were used, divided into two groups, according to the period of time until the sacrifice (2 and 6 weeks). Each one of these groups was subdivided into six groups with seven animals each, according to the treatments: (1) 5 µg of pure rhBMP-2, (2) 5 µg of rhBMP-2/monoolein gel, (3) pure monoolein gel, (4) 5 µg of pure P-1, (5) 5 µg of P-1/monoolein gel and (6) critical bone defect controls. The animals were euthanised and the calvarial bone tissue removed for histological and histomorphometrical analyses. RESULT AND CONCLUSION: The results showed an improvement in the bone healing process using the rhBMP-2 protein, associated or not with a material carrier in relation to the other groups, and this process demonstrated to be time dependent.

Mechanical performance of cylindrical and dual-core pedicle screws after repeated insertion.

STUDY DESIGN: Ex vivo study of the mechanical performance of cylindrical and dual-core pedicle screws after insertion, removal, and reinsertion in the same hole. OBJECTIVE: To evaluate the effect of repeated use of same screw hole on the insertion torque and the retentive strength of the cylindrical and dual-core screws. SUMMARY OF BACKGROUND DATA: Insertion and removal of pedicle screws is sometimes necessary during surgical procedure to assess the integrity of the pilot-hole wall. However, this maneuver may compromise the implant-holding capacity. METHODS: Sixty thoracolombar vertebrae (T13­L5), harvested from 10 healthy calves, were used to insert 2 different designs of pedicle screws: cylindrical (5.0-mm outer diameter) and dual-core screws (5.2-mm outer diameter). Three experimental groups were created on the basis of the number of insertions of the screws and 2 subgroups were established according to the core pedicle screw design (dual-core and cylindrical). The insertion torque was measured during initial insertion, second insertion, and third insertion. Pullout screw tests were performed using a universal testing machine to evaluate the pullout strength after initial insertion, second insertion, and third insertion. RESULTS: Significant reductions of 38% in mean insertion torque and 30% in mean pullout strength of dual-core screw were observed between the initial insertion and the third insertion. The cylindrical screw observed significant reductions of 52.5% in mean insertion torque and 42.3% in mean pullout strength between the initial insertion and the third insertion. A reduction of mean insertion torque and pullout strength between the first insertion and the second insertion but without significance was also observed for both types of screws. CONCLUSION: Insertions and reinsertion of either cylindrical or dual-core pedicle screws have compromised insertion torque and pullout strength of the implants as measured by mechanical tests.

Cytokine inhibition and time-related influence of inflammatory stimuli on the hyperalgesia induced by the nucleus pulposus.

INTRODUCTION: The symptoms of lumbar disc herniation, such as low back pain and sciatica, have been associated with local release of cytokines following the inflammatory process induced by the contact of the nucleus pulposus (NP) with the spinal nerve. MATERIAL AND METHODS: Using an animal experimental model of intervertebral disc herniation and behavioral tests to evaluate mechanical (electronic von Frey test) and thermal (Hargreaves Plantar test) hyperalgesia in the hind paw of rats submitted to the surgical model, this study aimed to detect in normal intervertebral disc the cytokines known to be involved in the mechanisms of inflammatory hyperalgesia, to observe if previous exposure of the intervertebral disc tissue to specific antibodies could affect the pain behavior (mechanical and thermal hyperalgesia) induced by the NP, and to observe the influence of the time of contact of the NP with the fifth lumbar dorsal root ganglion (L5-DRG) in the mechanical and thermal hyperalgesia. RESULTS: The cytokines present at highest concentrations in the rat NP were TNF-α, IL-1ß and CINC-1. Rats submitted to the disc herniation experimental model, in which a NP from the sacrococcygeal region is deposited over the right L5-DRG, showed increased mechanical and thermal hyperalgesia that lasted at least 7 weeks. When the autologous NP was treated with antibodies against the three cytokines found at highest concentrations in the NP (TNF-α, IL-1ß and CINC-1), there was decrease in both mechanical and thermal hyperalgesia in different time points, suggesting that each cytokine may be important for the hyperalgesia in different steps of the inflammatory process. The surgical remotion of the NP from herniated rats 1 week after the implantation reduced the hyperalgesia to the level similar to the control group. This reduction in the hyperalgesia was also observed in the group that had the NP removed 3 weeks after the implantation, although the intensity of the hyperalgesia did not decreased totally. The removal of the NP after 5 weeks did not changed the hyperalgesia observed in the hind paw, which suggests that the longer the contact of the NP with the DRG, the greater is the possibility of development of chronic pain. CONCLUSION: Together our results indicate that specific cytokines released during the inflammatory process induced by the herniated intervertebral disc play fundamental role in the development of the two modalities of hyperalgesia (mechanical and thermal) and that the maintenance of this inflammation may be the most important point for the chronification of the pain.

Prevalência da escoliose lombar em adultos / Prevalencia de la escoliosis lumbar en adultos / Prevalence of lumbar scoliosis in adults

OBJETIVO: Avaliar a prevalência da escoliose degenerativa do adulto (tipo de novo) em uma amostra da população brasileira. MÉTODOS: foram estudados 1149 exames radiográficos simples de abdome na incidência anteroposterior, realizados no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, no período de julho de 2008 a fevereiro de 2009. RESULTADOS: a prevalência da escoliose do adulto na amostra da população estudada foi de 1,74 por cento, sendo maior na faixa etária entre 60 e 69 anos. Não foi observada diferença estatisticamente significativa (p = 0,41) entre os sexos, e a medida média do ângulo da escoliose foi de 19,1º. CONCLUSÃO: A PREVAlência da escoliose do adulto na amostra da população estudada está dentro dos resultados já apresentados na literatura.

OBJECTIVE: to evaluate the prevalence of adult degenerative scoliosis (de novo) in a sample of the population. METHODS: We studied 1149 plain anteroposterior abdominal radiographs in achieved in the Hospital das Clínicas of the Faculty of Medicine of Ribeirão Preto from July 2008 to February 2009. RESULTS: The prevalence of scoliosis in the adult population sample studied was 1.74 percent, being higher in the group aged between 60 and 69 years. There was no statistic significant difference (p=0.41) between the sexes, and the average length of the angle of scoliosis was 19.1º. CONCLUSION: The prevalence of scoliosis in the sample of the adult population studied is consistent with the presented results in the literature.

OBJETIVO: Evaluar la prevalenciade la escoliosis degenerativa del adulto (tipo de 'novo') en una muestra de la población. MÉTODOS: Se estudiaron 1149 radiografías de abdomen simple en proyección anteroposterior; esto se realizó en el Hospital de la Facultad de Medicina de Ribeirão Preto de julio de 2008 a febrero de 2009. RESULTADOS: La preponderanciade la escoliosis en la población de la muestra de adultos estudiados fue de 1,74 por ciento, siendo mayor en el grupo entre 60 y 69 años. No hubo diferencias significativas (p = 0,41) entre los sexos, y la medida promediodel ángulo de la escoliosis fue de 19,1º. CONCLUSIÓN: La prevalencia de la escoliosis en la muestra de adultos de la población estudiada está de acuerdo con los resultados presentados en la literatura.