Adolescent idiopathic scoliosis without limb weakness: a differential diagnosis of core myopathy?

BACKGROUND: Core myopathies are a clinically and genetically heterogeneous group of congenital myopathies with the common defined histopathological feature of focally reduced oxidative activity on muscle biopsy. It has a low incidence, however, recent articles show broad clinical spectrum, suggesting that the real incidence should be considerably larger than previously described. Due to the important association between scoliosis and paravertebral muscle imbalance, numerous authors study, by biopsy of the spinal rotator muscles, potential changes that may elucidate the etiology of adolescent idiopathic scoliosis. CASE PRESENTATION: Two patients have been followed at Spine Group of Department of Orthopedics at Federal University of São Paulo, with an initial diagnosis of idiopathic scoliosis. Both patients had clinical and radiological findings compatible with it. The patients authorized, through the Term of Consent, intraoperative biopsy of muscle multifidus from the apex of the thoracic curve on concave and convex sides. After muscle biopsy was performed a histopathological analysis. As regard to the histopathological features: in both patients were identified, the presence of core structures in extensive areas with reduced oxidative activity running along the muscle fiber. CONCLUSIONS: All patients with 'idiopathic' scoliosis deserve a careful neurological evaluation, even if they have minimal muscle symptoms in the extremities. The frequent occurrence of scoliosis in patients with CORE Myopathies, supports the thesis that the change in the paravertebral muscle fiber must be the underlying pathogenic factor in scoliosis and may help us understand the onset and progression of curves in patients previously diagnosed with idiopathic scoliosis.

Surgical approaches for cervical spine facet dislocations in adults.

BACKGROUND: The choice of surgical approach for the management of subaxial cervical spine facet dislocations is a controversial subject amongst spine surgeons. Reasons for this include differences in the technical familiarity and experience of surgeons with the different surgical approaches, and variable interpretation of image studies regarding the existence of a traumatic intervertebral disc herniation and of the neurological status of the patient. Moreover, since the approaches are dissimilar, important variations are likely in neurological, radiographical and clinical outcomes. OBJECTIVES: To compare the effects (benefits and harms) of the different surgical approaches used for treating adults with acute cervical spine facet dislocation. SEARCH METHODS: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (9 May 2014), The Cochrane Central Register of Controlled Trials (The Cochrane Library, 2014 Issue 4), MEDLINE (1946 to April Week 5 2014), MEDLINE In-Process & Other Non-Indexed Citations (8 May 2013), EMBASE (1980 to 2014 Week 18), Latin American and Caribbean Health Sciences (9 May 2014), trial registries, conference proceedings and reference lists of articles to May 2014. SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials that compared surgical approaches for the management of adults with acute cervical spine facet dislocations with and without spinal cord injury. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, assessed risk of bias and extracted data. MAIN RESULTS: We included one randomised and one quasi-randomised controlled trial involving a total of 94 participants and reporting results for a maximum of 84 participants. One trial included patients with spinal cord injuries and the other included patients without spinal cord injuries. Both trials compared anterior versus posterior surgical approaches. Both trials were at high risk of bias, including selection bias (one trial), performance bias (both trials) and attrition bias (one trial). Data were pooled for one outcome only: non-union. Reflecting also the imprecision of the results, the evidence was deemed to be of very low quality for all outcomes; which means that our level of uncertainty about the estimates is high.Neither trial found differences between the two approaches in neurological recovery or status, as shown in one study by small clinically insignificant differences in NASS (Northern American Spine Society) neurological scores (0 to 100: optimal score) at one year of follow-up: anterior mean score: 85.23 versus posterior mean score: 83.86; mean difference (MD) 1.37 favouring anterior approach, 95% confidence interval (CI) -9.76 to 12.50; 33 participants; 1 study). The same trial found no relevant between-approach differences at one year in patient-reported quality of life measured using the 36-item Short Form Survey physical (MD -0.08, 95% CI -7.26 to 7.10) and mental component scores (MD 2.88, 95% CI -3.32 to 9.08). Neither trial found evidence of significant differences in long-term pain, or non-union (2/38 versus 2/46; risk ratio (RR) 1.18, 95% CI 0.04 to 34.91). One trial found better sagittal and more 'normal' alignment after the anterior approach (MD -10.31 degrees favouring anterior approach, 95% CI -14.95 degrees to -5.67 degrees), while the other trial reported no significant differences in cervical alignment. There was insufficient evidence to indicate between-group differences in medical adverse events, rates of instrumentation failure and infection. One trial found that the several participants had voice and swallowing disorders after anterior approach surgery (11/20) versus none (0/22) in the posterior approach group: RR 25.19, 95% CI 1.58 to 401.58); all had recovered by three months. AUTHORS' CONCLUSIONS: Very low quality evidence from two trials indicated little difference in long-term neurological status, pain or patient-reported quality of life between anterior and posterior surgical approaches to the management of individuals with subaxial cervical spine facet dislocations. Sagittal alignment may be better achieved with the anterior approach. There was insufficient evidence available to indicate between-group differences in medical adverse events, rates of instrumentation failure and infection. The disorders of the voice and swallowing that occurred exclusively in the anterior approach group all resolved by three months. We are very uncertain about this evidence and thus we cannot say whether one approach is better than the other. There was no evidence available for other approaches. Further higher quality multicentre randomised trials are warranted.

Full-Endoscopic Lumbar Discectomy Approach Selection: A Systematic Review and Proposed Algorithm.

STUDY DESIGN: A systematic review of the literature to develop an algorithm formulated by key opinion leaders. OBJECTIVE: This study aimed to analyze currently available data and propose a decision-making algorithm for full-endoscopic lumbar discectomy for treating lumbar disc herniation (LDH) to help surgeons choose the most appropriate approach [transforaminal endoscopic lumbar discectomy (TELD) or interlaminar endoscopic lumbar discectomy (IELD)] for patients. SUMMARY OF BACKGROUND DATA: Full-endoscopic discectomy has gained popularity in recent decades. To our knowledge, an algorithm for choosing the proper surgical approach has never been proposed. MATERIALS AND METHODS: A systematic review of the literature using PubMed and MeSH terms was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Patient samples included patients with LDH treated with full-endoscopic discectomy. The inclusion criteria were interventional research (randomized and nonrandomized trials) and observation research (cohort, case-control, case series). Exclusion criteria were case series and technical reports. The criteria used for selecting patients were grouped and analyzed. Then, an algorithm was generated based on these findings with support and reconfirmation from key expert opinions. Data on overall complications were collected. Outcome measures included zone of herniation, level of herniation, and approach (TELD or IELD). RESULTS: In total, 474 articles met the initial screening criteria. The detailed analysis identified the 80 best-matching articles; after applying the inclusion and exclusion criteria, 53 articles remained for this review. CONCLUSIONS: The proposed algorithm suggests a TELD for LDH located in the foraminal or extraforaminal zones at upper and lower levels and for central and subarticular discs at the upper levels considering the anatomic foraminal features and the craniocaudal pathology location. An IELD is preferred for LDH in the central or subarticular zones at L4/L5 and L5/S1, especially if a high iliac crest or high-grade migration is found.

Minimally invasive swine spine surgery training: technical aspects, benefits, and anatomical limitations.

OBJECTIVE: To describe the technical specificities and feasibility of simulation of minimally invasive spine surgery in live pigs, as well as similarities and differences in comparison to surgery in humans. METHODS: A total of 22 Large White class swine models, weighing between 60 and 80kg, were submitted to surgical simulations, performed during theoretical-practical courses for training surgical techniques (microsurgical and endoscopic lumbar decompression; percutaneous pedicular instrumentation; lateral access to the thoracic spine, and anterior and retroperitoneal to the lumbar spine, and management of complications) by 86 spine surgeons. For each surgical technique, porcine anatomy (similarities and differences in relation to human anatomy), access route, and dimensions of the instruments and implants used were evaluated. Thus, the authors describe the feasibility of each operative simulation, as well as suggestions to optimize training. Study results are descriptive, with figures and drawings. RESULTS: Neural decompression surgeries (microsurgeries and endoscopic) and pedicular instrumentation presented higher similarities to surgery on humans. On the other hand, intradiscal procedures had limitations due to the narrow disc space in swines. We were able to simulate situations of surgical trauma in surgical complication scenarios, such as cerebrospinal fluid fistulas and excessive bleeding, with comparable realism to surgery on humans. CONCLUSION: A porcine model for simulation of minimally invasive spinal surgical techniques had similarities with surgery on humans, and is therefore feasible for surgeon training.

Minimally invasive swine spine surgery training: technical aspects, benefits, and anatomical limitations

ABSTRACT Objective To describe the technical specificities and feasibility of simulation of minimally invasive spine surgery in live pigs, as well as similarities and differences in comparison to surgery in humans. Methods A total of 22 Large White class swine models, weighing between 60 and 80kg, were submitted to surgical simulations, performed during theoretical-practical courses for training surgical techniques (microsurgical and endoscopic lumbar decompression; percutaneous pedicular instrumentation; lateral access to the thoracic spine, and anterior and retroperitoneal to the lumbar spine, and management of complications) by 86 spine surgeons. For each surgical technique, porcine anatomy (similarities and differences in relation to human anatomy), access route, and dimensions of the instruments and implants used were evaluated. Thus, the authors describe the feasibility of each operative simulation, as well as suggestions to optimize training. Study results are descriptive, with figures and drawings. Results Neural decompression surgeries (microsurgeries and endoscopic) and pedicular instrumentation presented higher similarities to surgery on humans. On the other hand, intradiscal procedures had limitations due to the narrow disc space in swines. We were able to simulate situations of surgical trauma in surgical complication scenarios, such as cerebrospinal fluid fistulas and excessive bleeding, with comparable realism to surgery on humans. Conclusion A porcine model for simulation of minimally invasive spinal surgical techniques had similarities with surgery on humans, and is therefore feasible for surgeon training.

Options for surgical treatment of cervical fractures in patients with spondylotic spine: a case series and review of the literature.

INTRODUCTION: The surgical treatment of unstable cervical fractures is challenging for spinal surgeons. Unstable cervical fractures associated with spondyloarthropathy and deformities that alter function, form and stability present a greater challenge. Having multiple options to manage this difficult situation is important to all spine surgeons and the results of each case depends on the singular characteristics of patients. The purpose of this case report is to describe the main forms of presentation of unstable cervical subaxial fractures in the spondylotic spine and their surgical treatments. CASE PRESENTATION: We present three cases of Caucasian men aged 30, 53 and 59 years with spondylosis with unstable cervical fractures and alternatives choices for surgical treatment, and a review of the literature. Each patient underwent a different surgical procedure of the cervical subaxial spine using an isolated anterior, posterior or combined approach demonstrating good outcomes in all cases. CONCLUSIONS: The treatment of subaxial cervical spinal fractures is complex, and when these fractures are associated with the deformities caused by spondyloarthropathies they can be thought provoking for spine surgeons such as orthopedists or neurosurgeons. The isolated anterior, posterior and combined approaches are safe and effective for treating these pathologies.

Histochemical analysis of paraspinal rotator muscles from patients with adolescent idiopathic scoliosis: a cross-sectional study.

Morphological, biochemical, and histopathological alterations in the paraspinal skeletal muscle of patients with adolescent idiopathic scoliosis (AIS) have been extensively reported. We evaluated rotator muscle fibers from the apex vertebra of AIS patients through histological and immunohistochemical analysis. A population of 21 female AIS patients who underwent corrective surgery between 2010 and 2013 had biopsies taken from the paraspinal muscle in the convex and concave sides of the thoracic curve apical vertebra. Serial sections were stained following routine protocols for hematoxylin and eosin (HE), Sudan red, Gomori trichrome, NADH, ATPase, and cytochrome oxidase. We assessed muscular atrophy and hypertrophy, fatty proliferation, endomysial and perimysial fibrosis, the presence of hyaline fibers, mitochondrial proliferation, muscular necrosis, nuclear centralization, and inflammation. Two independent professionals evaluated the slices. The thoracic curves had an average Cobb angle of 68 degree. Comparative analysis of the concave and convex sides was performed with McNemar test at a significance level of 5%. Results showed significant differences in both endomysial and perimysial fibrosis and fatty involution between the two sides of the apex vertebra. Paraspinal muscles in the concave side of the scoliosis apex had significantly more fibrosis and fatty involution. However, both sides showed signs of myopathy, muscular atrophy due to necrosis, presence of hyaline fibers, and mitochondrial proliferation.

Impact of surgeons' experience on accuracy of radiographic segmental kyphosis assessment in thoracolumbar fractures: a prospective observational study.

BACKGROUND: The thoracolumbar region is where most fractures of the spine are located. Segmental kyphosis is an important factor for treatment decisions. There are various methods for measuring segmental kyphosis in thoracolumbar fractures. Our objective was to evaluate if the experience of the surgeon has any influence on kyphosis measurement by analyzing three different categories of orthopedic surgeons and evaluate possible clinical impacts. MATERIAL AND METHODS: Six physicians separated into three categories according to the level of experience evaluated 30 lateral view radiographs of the thoracic spine of patients with single-level fracture taken during their outpatient follow-up visits. Images had segmental kyphosis measured by five distinct methods. The x-rays were evaluated twice and in a random order after an eight-week interval. The reproducibility of the measurements was analyzed by the intraclass correlation coefficient (ICC) and its respective 95% confidence interval. RESULTS: The intraclass correlation coefficient (ICC) was calculated to evaluate the inter- and intra-examiner reliability for each method. The methods that disregard the fractured vertebra (1 and 4) achieved the highest intra and inter-observers reliability among the participants. The measurements from methods 3 and 5 were poorly reproducible between examiners. The difference between the averages of the measurements of the five methods studied was greater than 5 degrees in methods 1 and 2, suggesting risk for patient safety. CONCLUSION: Methods that exclude the fractured vertebra were more reproducible for the evaluation of segmental kyphosis in thoracolumbar fractures. The evaluation of the spine fracture must be coupled with other radiographic criteria, more complex image exams and the patient's clinical state to assist the surgeon in deciding between conservative or surgical treatment. The authors suggest that the measurements should be performed by methods that exclude the fractured vertebra and conducted by experienced doctors.

Apophyseal ring fracture associated with two levels extruded disc herniation: case report and review of the literature.

Apophyseal ring fractures are rare injuries that may be associated with lumbar disc herniation in young patients. We report a unique case in the literature of a 15-year-old male patient who played football and was admitted at our service complaining of sciatica radiating into the left leg. An apophysial ring injury of L5 vertebral body was observed. This injury caused two extruded disc herniation in adjacent levels. Surgical procedure was indicated after failure of conservative treatment.

Minimally invasive posterior cervical microforaminotomy in the lower cervical spine and C-T junction assisted by O-arm-based navigation.

Navigated posterior cervical microforaminotomy (PCM) is a promising minimally invasive technique for treating radiculopathy caused by lateral disc herniations and foraminal stenosis. Between December 2009 and October 2010, 14 patients with unilateral foraminal disc herniations or foraminal stenosis at the C6-7 or C7-T1 level underwent PCM assisted by O-arm navigation using the METRx tubular retractor. The main symptoms were radicular arm pain with no significant neck pain. Successful relief of radicular pain was achieved in all 14 patients. Two of the patients were lost during follow-up, and three had to undergo further decompression due to remnant foraminal stenosis being discovered on intraoperative O-arm images. There were no cases of instability or recurrence, and the only complication observed was a dural tear in one patient, which was adequately treated with fibrin glue and bed rest. The duration of symptoms was 4.5 months on average. The mean operation time was 136 minutes, with the additional time required for the image guided surgery assisted by O-arm-based navigation being approximately 28 minutes on average. There were no other complications during the surgical procedure or in the immediate postoperative period. Posterior cervical microforaminotomy assisted by O-arm-based navigation is a safe, effective and minimally invasive procedure for the treatment of lateral disc herniations and foraminal stenosis of the lower cervical spine and C-T junction, offering the possibility of an accurate decompression with a reduced risk of segmental instability.

Comparison of Farfan modified and Frobin methods to evaluate the intervertebral disc height / Comparação dos métodos de Farfan modificado e de Frobin, para aferição da altura do disco intervertebral / Comparación de los métodos de Farfan modificado e de Frobin para la medición de la altura del disco intervertebral

OBJECTIVE: To evaluate the reliability and reproducibility of Farfan modified and Frobin methods to measure the intervertebral disc height in radiographs with inter- and intraobserver comparison. METHOD: Six radiographs of different patients treated for low back pain have been collected and digitized, and five lumbar disc of each patient were evaluated by six examiners with different levels of experience. The measures were done in Image Pro Plus 6.0 software. RESULTS: When compared, both methods showed more than 95% concordance. In intraexaminer analysis, both also shown to be reliable and reproducible, with a high level of concordance. By comparing the correlation between classes of examiners, the higher the level of experience, the greater the agreement for both methods. CONCLUSION: Farfan modified and Frobin are reliable methods to measure the disc height in the lateral radiographs. The higher level of experience of the examiner, the higher was the correlation between measurements. .

OBJETIVO: Avaliar a confiabilidade e reprodutibilidade dos métodos de Farfan modificado e de Frobin, para aferição da altura radiográfica dos discos intervertebrais lombares, em comparação inter e intraobservadores. MÉTODO: Foram coletadas e digitalizadas imagens radiográficas de seis pacientes em acompanhamento ambulatorial por lombalgia, sendo avaliados cinco discos lombares de cada paciente. As mensurações foram realizadas no software Image Pro Plus versão 6.0, por seis examinadores com diferentes níveis de experiência. RESULTADOS: Ao serem comparados entre si, os métodos demonstraram concordância superior a 95%. Na análise intraexaminadores, ambos também demonstraram ser reprodutíveis e confiáveis com alta concordância. Ao comparar a concordância entre as classes dos examinadores, quanto maior o nível de experiência maior foi a concordância em ambos os métodos. CONCLUSÃO: Tanto o método de Farfan modificado quanto o de Frobin, podem ser utilizados de forma confiável para avaliar a altura discal nas radiografias em perfil. Quanto maior o nível de experiência do examinador, mais alta foi a concordância entre as aferições. .

OBJETIVO: Evaluar la confiabilidad y reproducibilidad de los métodos de Farfan modificado y Frobin para medición de la altura radiográfica de los discos intervertebrales lumbares por comparación inter e intraobservadores. MÉTODO: Imágenes radiográficas fueron recogidas y digitalizadas de 6 pacientes con queja de dolor lumbar; fueron evaluados cinco discos lumbares de cada paciente. Las mediciones fueron realizadas en el software Image Pro Plus versión 6.0, por seis examinadores con diferentes niveles de experiencia. RESULTADOS: Al ser comparados entre sí, los métodos demostraron concordancia superior a 95%. En el análisis intraexaminador, ambos métodos también se demostraron reproductibles y confiables con alta concordancia. Al comparar la concordancia entre las clases de los examinadores, cuanto mayor el nivel de experiencia mayor fue la concordancia entre ambos métodos. CONCLUSIÓN: Tanto el método de Farfan modificado como el de Frobin, pueden ser utilizados de forma confiable para evaluar la altura discal en las radiografías en perfil. Cuanto mayor el nivel de experiencia del examinador, mayor la concordancia entre ambas mediciones. .

Apophyseal ring fracture associated with two levels extruded disc herniation: case report and review of the literature / Fratura do anel apofisário associada à hérnia discal extrusa de dois níveis: relato de caso e revisão da literatura

Apophyseal ring fractures are rare injuries that may be associated with lumbar disc herniation in young patients. We report a unique case in the literature of a 15-year-old male patient who played football and was admitted at our service complaining of sciatica radiating into the left leg. An apophysial ring injury of L5 vertebral body was observed. This injury caused two extruded disc herniation in adjacent levels. Surgical procedure was indicated after failure of conservative treatment.

As fraturas do anel apofisário são lesões raras, que podem estar associadas à hérnia de disco lombar nos pacientes jovens. Apresentamos aqui um caso único na literatura de paciente de 15 anos, gênero masculino, praticante de futebol, com queixa de ciatalgia para o membro inferior esquerdo. Houve lesão do anel apofisário, nos planaltos superior e inferior do corpo vertebral de L5, ocasionando hérnias discais extrusas nos níveis adjacentes. O procedimento cirúrgico foi indicado após a falha do tratamento conservador.

Perfil do cirurgião de coluna brasileiro / Brazilian spine surgeon profile / Perfil del cirujano brasileño de columna

OBJETIVO: Realizar estudo transversal identificando o perfil do cirurgião de coluna no Brasil. MÉTODOS: Foram coletados dados por meio de questionários com múltiplas alternativas, em dois eventos de relevância para a cirurgia de coluna no âmbito nacional em 2011, o Congresso da Sociedade Brasileira de Coluna (SBC) e o Simpósio Internacional de Coluna (SINCOL). Os dados foram submetidos a análise estatística comparando e estratificando as informações obtidas conforme o perfil encontrado. RESULTADOS: Obtivemos 182 questionários respondidos por ortopedistas e neurocirurgiões com particularidades e semelhanças em suas condutas médicas. CONCLUSÕES: Os dados obtidos nessa pesquisa podem ser importantes para o desenvolvimento de políticas de saúde na área de cirurgia de coluna no Brasil.

OBJECTIVE: To conduct cross-sectional study identifying the profile of the Brazilian spinal surgeon. METHODS: Data were collected through a questionnaire with multiple alternatives during two major events for spine surgery at national level in 2011, the Congresso da Sociedade Brasileira de Coluna (Congress of the Brazilian Spine Society) and Simpósio Internacional de Coluna (International Spine Symposium, SINCOL). The data were submitted to statistical analysis comparing and stratifying the information obtained according to the profile. RESULTS: We obtained 182 questionnaires answered by orthopedists and neurosurgeons with peculiarities and similarities on their medical management. CONCLUSIONS: The data obtained in this study may be important for the development of health policies in the spine surgery in Brazil.

OBJETIVO: Llevar a cabo estudio transversal para identificar el perfil del cirujano de columna en Brasil. MÉTODOS: Los datos fueron recolectados por medio de cuestionarios con opciones múltiples, en dos eventos de relevancia para la cirugía de columna vertebral, a nivel nacional en 2011, Congreso Brasileño de la Sociedad Brasileña de Columna (SBC) y el Simposio Internacional de Columna (SINCOL). Los datos fueron sometidos a análisis estadístico, comparándose y estratificándose las informaciones obtenidas, de acuerdo con el perfil encontrado. RESULTADOS: Se obtuvieron cuestionarios respondidos por 182 ortopedistas y neurocirujanos, con particularidades y similitudes en sus actividades médicas. CONCLUSIONES: Los datos obtenidos en este estudio pueden ser importantes para el desarrollo de políticas de salud en el área de la cirugía de columna en Brasil.

Comparação das alterações do potencial evocado somatosensorial no tratamento cirúrgico da escoliose idiopática entre técnicas com e sem amarrilha sublaminar / Comparison of the somatosensory evoked potentials changes in the surgical treatment of idiopathic scoliosis between two techniques with and without sublaminar wiring / Comparación de las alteraciones del potencial evocado somatosensorial en el tratamiento quirúrgico de la escoliosis idiopática entre técnicas con y sin amarilla sublaminar

OBJETIVO: comparar o número de eventos com alteração no potencial evocado somatosensorial (PESS) e sua repercussão entre técnicas de tratamento cirúrgico da escoliose idiopática com e sem amarrilha sublaminar. MÉTODOS: análise retrospectiva de 25 cirurgias de correção de escoliose idiopática, flexíveis, realizadas no período de novembro de 1996 a setembro de 1999, nas quais foram utilizadas técnicas sem amarrilha sublaminar (sistema de Cotrel-Dubousset) (Grupo I) e com amarrilha (sistema de Harrington-Luque e haste de Hartshill) (Grupo II). Todos os procedimentos foram realizados com monitoração neurofisiológica da função medular através do PESS. RESULTADOS: no Grupo II, foi observada uma frequência maior de alterações do PESS tanto na amplitude como na latência da onda, durante e ao final da cirurgia. Na série revista, constatou-se uma elevada porcentagem de resultados falso-positivos. Em nenhum paciente foi observada qualquer alteração neurológica no pós-operatório. CONCLUSÃO: permanece em aberto qual o método mais seguro para o tratamento cirúrgico da escoliose idiopática. Os resultados apresentados neste trabalho sugerem uma menor incidência de alterações na monitoração neurofisiológica da medula em pacientes tratados pelo sistema de Cotrel-Dubousset.

OBJECTIVE: to compare the number of events with alteration in the somatosensory evoked potentials (SSEP) and its repercussion between different techniques of surgical treatment for idiopathic scoliosis, with and without sublaminar wiring. METHODS: twenty-five surgical procedures with flexible curves for treatment of idiopathic scoliosis were reviewed in the period of November 1996 to September 1999. They were divided into two groups: without sublaminar wiring (Cotrel-Dubousset's system) (Group I); and with sublaminar wiring (Harrington-Luque's system and rectangle of Hartshill) (Group II). In all surgeries, the intraoperative neurophysiologic monitoring with Somatosensory Evoked Potentials (SSEPs) was used. RESULTS: according to the findings, a bigger frequency of monitoring changes was observed during and at the end of the surgery in Group II. A high incidence of false-negative changes was also verified. No patient with neurological damages was observed. CONCLUSION: There are still doubts about the safest method for the surgical treatment of idiopathic scoliosis. The results presented in this study suggest a smaller incidence of SSEPs changes in the patients treated with Cotrel-Dubousset's system.

OBJETIVO: comparar el número de eventos con alteración en el potencial evocado somatosensorial (PESS) y su repercusión entre técnicas de tratamiento quirúrgico de la escoliosis idiopática, con y sin amarilla sublaminar. MÉTODOS: análisis retrospectivo de 25 cirugías de corrección de escoliosis idiopática, flexibles, realizadas en el periodo de noviembre de 1996 a septiembre de 1999, en las cuales fueron utilizadas técnicas sin amarilla sublaminar (sistema de Cotrel-Dubousset) (Grupo I) y con amarilla (sistema de Harrington-Luque y asta de Hartshill) (Grupo II). Todas las cirugías fueron realizadas con monitorización neurofisiológica de la función medular por medio de PESS. RESULTADOS: en el Grupo II fue observada una frecuencia mayor de alteraciones del PESS, tanto en la amplitud como en la latencia de onda, durante y al final de la cirugía. En la serie revista, se constató un elevado porcentaje de resultados falsos-positivos. En ningún paciente fue observada cualquier alteración neurológica en el postoperatorio. CONCLUSIÓN: está en discusión cuál es el método más seguro para el tratamiento quirúrgico de la escoliosis idiopática. Los resultados presentados en este trabajo sugieren una menor incidencia de alteraciones en la monitorización neurofisiológica de la médula en los pacientes tratados por el sistema de Cotrel-Dubousset.