Radiological diagnostic accuracy study comparing Lenke, Bridwell, BSF, and CT-HU fusion grading scales for minimally invasive lumbar interbody fusion spine surgery and its correlation to clinical outcome.

Prospective randomized double-blinded diagnostic accuracy study about radiological grading of fusion after minimally invasive lumbar interbody fusion procedures (MI-LIFP).To determinate the intra and the inter-observer correlation between different radiological lumbar interbody fusion grading scales (RLIFGS) in patients undergoing MI-LIFP and their correlation to clinical outcome.Besides technological improvements in medical diagnosis and the many existing RLIFGS, surgical exploration continues to be the gold-standard to assess fusion in patients with radiological pseudarthrosis, with little if any research on the relationship between RLIFGS and clinical outcome.We collected data from patients undergoing MI-LIFP procedures operated by a single surgeon from 2009 to 2017, which had follow-up and CT-scan control greater than 12 months, whose clinical registers specified lumbar and radicular visual analogue scale (L and R-VAS) and Oswestry Disability Index (ODI) score preoperatively and at the end of follow-up. Interbody fusion levels were coded for blinded evaluation by three different minimally invasive spine (MIS) surgeons, using Lenke, Bridwell, BSF (Brantigan, Steffe, Fraser), and CT-HU RLIFGS. We established fusion criteria, as described in their original papers. Another independent spine surgeon blindly evaluated successful clinical outcome (SCO), defined as a significant improvement in 2 of 3 of the following issues: L-VAS, R-VAS, or ODI score at follow-up; otherwise, rated as clinical pseudarthrosis. Radiological and clinical data was coded and statistically analyzed using Student T-Test, Pearson P-Test, and ANOVA with statistical package for the social sciences 21 by another blinded researcher, positive and negative predictive values were also calculated for each RLFGS.We found a significant clinical improvement with a moderate intra-observer correlation between scales and no inter-observer or clinical correlation, with no sub-group statistically significant differences.This paper represents the first study about the diagnostic accuracy of RLFGS, we concluded that their diagnostic accuracy is pretty low to determine fusion or pseudoarthrosis based on its low correlation to clinical outcome, we recommend surgeons rely on clinical findings to decide whether a patient has clinical fusion or pseudoarthrosis based on successful clinical outcome.

Segmental T12 Vertebral Artery Injury Treated by Endovascular Coil Placement after Kyphoplasty for Symptomatic Spinal Angioma. Case Report of a Minimal Invasive Solution for a Complication of a Minimally Invasive Spine Procedure.

BACKGROUND: Vertebral angioma is a tumor defined as an abnormality of vascular tissue development. It usually has an asymptomatic behavior, being present in 10%-12% of autopsies and imaging studies. CASE DESCRIPTION: A 70-year-old man consulted because of a long history of low back pain. Imaging studies were compatible with vertebral angioma at T12; we decided to perform a minimally invasive surgical procedure, such as kyphoplasty. During surgery, there was a sharp decrease in pulmonary saturation, and the patient underwent a computed tomography scan evaluation confirming a left hemothorax due to segmental branch vascular injury at T12. Given the patient's poor medical condition and the complexity of an emergent open procedure in the thoracic spine, we decided to undertake a minimally invasive endovascular coil placement to repair the vascular injury. Due to a favorable outcome, we discharged the patient after 72 hours of surveillance. CONCLUSIONS: Even in the case of a complication to occur, we should always consider a minimally invasive solution to solve the problem because patients undergoing these procedures correspond to elderly patients with poor medical conditions or comorbidities.

Dysphagia rates after minimally invasive tubular approach to the anterior cervical spine.

INTRODUCTION: Cervical spine surgery (anterior cervical spine surgery [ACSS]) is a commonly indicated to provide neurological decompression, correct deformity, and preserve stability. Current series report good to excellent results, but a number of patients suffer from dysphagia with reported rates as high as 80%. MATERIALS AND METHODS: Retrospective cohort of patients undergoing ACSS (anterior cervical discectomy and fusion [ACDF]; and arthroplasty, total disc replacement [TDR]) from 2013 to 2017 by a single surgeon. We collected demographic data, surgical outcomes, clinical outcomes, and dysphagia incidence and magnitude (visual analog scale [VAS]), we analyzed results with SPSS 22. RESULTS: A total of 81 patients operated from 2013 to 2018, ACDF was performed in 70, and TDR was performed in 11, mean surgical time was 156.8, mean neck pain and radicular pain VAS reduced significantly in both groups (p < 0.01). Dysphagia was encountered in 18 ACDF patients, and one TDR patient. Overall dysphagia rate was 9.1% in day-1 post-operative, with mean 0.27 magnitude (standard deviation [SD] 0.4) in ACDF group and 0.18 (0.6 SD) in TDR group, 1-month follow-up dysphagia rate was 0%. CONCLUSIONS: Minimally invasive techniques may reduce post-operative dysphagia related to soft-tissue trauma, to 9% in day-1 post-operative (as compared to 39%), and to 0% (as compared to 8.5% reported worldwide) by 1-month follow-up.

ANTECEDENTES: La cirugía cervical anterior (CCA) esta comúnmente indicada para proporcionar descompresión neurológica, corregir deformidades y preservar la estabilidad. Las series actuales reportan tasas de disfagia de hasta el 80%. MÉTODO: cohorte retrospectiva de pacientes sometidos a CCA (discectomía y fusión cervical anterior [DFCA], y artroplastia total de disco [ATD]) de 2013 a 2017. Se recopilaron datos demográficos, quirúrgicos, clínicos y de incidencia y magnitud de la disfagia (escala visual analógica [EVA]). Se analizaron los resultados con SPSS 22. RESULTADOS: 81 pacientes operados de 2013 a 2018, ACDF en 70 y ATD en 11, tiempo quirúrgico promedio de 156.8 minutos. La puntuación en la EVA cervical y radicular se redujo significativamente en ambos grupos (p < 0.01). Hubo disfagia en 18 pacientes con DFCA y en uno con ATD. La tasa de disfagia fue del 9.1% en el primer día de posoperatorio, con EVA de 0.27 (desviación estándar [DE]: 0.4) en el grupo DFCA y de 0.18 (DE: 0.6) en el grupo ATD. La tasa de disfagia de seguimiento a 1 mes fue del 0%. CONCLUSIONES: Las técnicas mínimamente invasivas reducen la disfagia posoperatoria en CCA al 9% en el primer día (en comparación con el 39%) y al 0% (en comparación con el 8.5% reportado mundialmente) al mes de seguimiento.

Surgeon training and clinical implementation of spinal endoscopy in routine practice: results of a global survey.

BACKGROUND: Training of spine surgeons may impact the availability of contemporary minimally invasive spinal surgery (MIS) to patients and drive spine surgeons' clinical decision-making when applying minimally invasive spinal surgery techniques (MISST) to the treatment of common degenerative conditions of the lumbar spine. Training requirements and implementation of privileges vary in different parts of the world. The purpose of this study was to analyze the training in relation to practice patterns of surgeons who perform lumbar endoscopic spinal surgery the world over. METHODS: The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Surgeons were asked the following questions: (I) please indicate your training? (II) What type of MISST spinal surgery do you perform? (III) How would you rate your experience in MIS lumbar spinal surgery and what percentage of your practice is MISST? And (IV) which avenue did you use to train for the MISST you currently employ in your clinical practice today? Descriptive statistics were applied to count responses and cross-tabulated them to the surgeon's training. Pearson Chi-square measures, kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances using statistical package SPSS version 25.0. RESULTS: A total of 430 surgeons accessed the survey. The completion rate was 67.4%. Analyzing the responses of 292 surveys submitted by 97 neurosurgeons (33.2%), 161 orthopaedic surgeons (55.1%), and 34 surgeons of other postgraduate training (11.6%) showed that only 14% (41/292) of surgeons had completed a fellowship. Surgeons rated their skill level 33.5% of the time as master and experienced surgeon, and 35.6% of the time as novice or surgeon with some experience. There were more master (64.6% versus 29.2%) and experienced (52% versus 40%) surgeons amongst orthopaedic surgeons than amongst neurosurgeons at a statistically significant level (P=0.11). There were near twice as many orthopaedic surgeons (54.3%) using endoscopic procedures in the lumbar spine as their favorite MISST than neurosurgeons (35.4%; P=0.096). Endoscopic spine surgeons' main sources of knowledge acquisition were (I) learning in small meetings (57.3%), (II) attending workshops (63.1%), and (III) national and international conferences (59.8%). CONCLUSIONS: The majority of spine surgeons reported more than half of their cases employing MISST at a high skill level. Very few MISST surgeons are fellowship trained but attend workshops and various meetings suggesting that many of them are self-thought. Orthopaedic surgeons were more likely to implement endoscopic spinal surgery into the routine clinical practice. As endoscopic spine surgery gains more traction and patient demand, minimal adequate training will be part of the ongoing debate.

Surgeon motivation, and obstacles to the implementation of minimally invasive spinal surgery techniques.

BACKGROUND: This study aimed to analyze the motivators and obstacles to the implementation of minimally invasive spinal surgery techniques (MISST) by spinal surgeons. Motivators and detractors may impact the availability of MISST to patients and drive spine surgeons' clinical decision-making in the treatment of common degenerative conditions of the lumbar spine. METHODS: The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Descriptive statistics were employed to count the responses and compared to the surgeon's training. Kappa statistics and linear regression analysis of agreement were performed. RESULTS: A total of 430 surgeons accessed the survey. The completion rate was 67.4%. A total of 292 surveys were submitted by 99 neurosurgeons (33.9%), 170 orthopaedic surgeons (58.2%), and 23 surgeons of other postgraduate training (7.9%). Personal interest (82.5%) and patient demand (48.6%) were the primary motivators for MISST implementation. High equipment (48.3%) and disposables (29.1%) cost were relevant obstacles to MISST implementation. Local workshops (47.6%) and meetings in small groups (31.8%) were listed as the primary knowledge sources. Only 12% of surgeons were fellowship trained, but 46.3% of surgeons employed MISST in over 25% of their cases. CONCLUSIONS: The rate of implementation of MISST reported by spine surgeons was found to be high but impeded by the high cost of equipment and disposables. The primary motivators for spine surgeons' desire to implement were personal interest and patient demand.

Regional variations in acceptance, and utilization of minimally invasive spinal surgery techniques among spine surgeons: results of a global survey.

BACKGROUND: Regional differences in acceptance and utilization of MISST by spine surgeons may have an impact on clinical decision-making and the surgical treatment of common degenerative conditions of the lumbar spine. The purpose of this study was to analyze the acceptance and utilization of various minimally invasive spinal surgery techniques (MISST) by spinal surgeons the world over. METHODS: The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Surgeons were asked the following questions: (I) Do you think minimally invasive spinal surgery is considered mainstream in your area and practice setting? (II) Do you perform minimally invasive spinal surgery? (III) What type of MIS spinal surgery do you perform? (IV) If you are performing endoscopic spinal decompression surgeries, which approach do you prefer? The responses were cross-tabulated by surgeons' demographic data, and their practice area using the following five global regions: Africa & Middle East, Asia, Europe, North America, and South America. Pearson Chi-Square measures, Kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances using statistical package SPSS Version 25.0. RESULTS: A total of 586 surgeons accessed the survey. Analyzing the responses of 292 submitted surveys regional differences in opinion amongst spine surgeons showed that the highest percentage of surgeons in Asia (72.8%) and South America (70.2%) thought that MISST was accepted into mainstream spinal surgery in their practice area (P=0.04) versus North America (62.8%), Europe (52.8%), and Africa & Middle East region (50%). The percentage of spine surgeons employing MISST was much higher per region than the rate of surgeons who thought it was mainstream: Asia (96.7%), Europe (88.9%), South America (88.9%), and Africa & Middle East (87.5%). Surgeons in North America reported the lowest rate of MISST implementation globally (P<0.000). Spinal endoscopy (59.9%) is currently the most commonly employed MISST globally followed by mini-open approaches (55.1%), and tubular retractor systems (41.8%). The most preferred endoscopic approach to the spine is the transforaminal technique (56.2%) followed by interlaminar (41.8%), full endoscopic (35.3%), and over the top MISST (13.7%). CONCLUSIONS: The rate of implementation of MISST into day-to-day clinical practice reported by spine surgeons was universally higher than the perceived acceptance rates of MISST into the mainstream by their peers in their practice area. The survey suggests that endoscopic spinal surgery is now the most commonly performed MISST.

Scientific Contributions of the Mexican Association of Spine Surgeons (Asociación Mexicana de Cirujanos de Columna-AMCICO) to the Global Medical Literature: A 21-Year Systematic Review.

BACKGROUND: Contributions from Latin America to the global literature are scarce; until 2011, spine surgeons had published 320 articles in indexed journals. METHODS: This systematic review evaluates the scientific production of the Mexican Association of Spine Surgeons (Asociación Mexicana de Cirujanos de Columna-AMCICO) from its inception in 1998 to 2018 with the PRISMA statement using PubMed and Google Scholar search engines. The inclusion criteria were spine-related articles in indexed journals providing any (or no) level of evidence with ≥1 AMCICO member as an author. Journal metrics, article metrics, and author variables were analyzed using SPSS version 25. RESULTS: Of the 444 surgeons historically belonging to AMCICO, only 126 members contributed a total of 441 articles between 1998 and 2018. An average of 21.00 annual publications with an annual scientific output per capita of 0.05 was found. The most frequent evidence level was III (211 articles, 48%), the highest level was I (12 articles, 3%). The main study objective was clinical research, with 308 articles (70%), and the main study foci was trauma, with 103 articles (23%). An average impact factor of 0.16 and 0.92 was obtained for publications in Spanish and English, respectively. CONCLUSIONS: Scientific publications by AMCICO members are scarce, with a per capita annual index of 0.05 from a total of 441 articles in indexed journals. Second, the impact factor of these journals is low, with a mean value of 0.53. Further strategies should be implemented to increase the number and track the record of Mexican contributions to the scientific literature.

Microsurgical Resection of Intraspinal Benign Tumors Using Non-Expansile Tubular Access.

BACKGROUND: Intraspinal tumors are 10 to 15 times less common than brain tumors. The midline approach with extensive laminectomies represents the current gold-standard for resection, causing instability, muscle damage, and kyphosis among other well-known complications. Minimally invasive series reported their results using retractor-based systems. We analyzed a patient series treated with a non-expansile tubular approach, describing the technique, grade of resection, and clinical outcomes. METHODS: A series of consecutive cases operated between 2016 and October 2018 were analyzed retrospectively. The database included age, sex, clinical presentation, intraspinal location (intra/extradural), number of laminotomies, grade of resection, surgical time, bleeding, and follow-up. The initial and follow-up clinical condition was analyzed using the Frankel scale. RESULTS: A total of 13 patients underwent surgery: 3 intraspinal/extradural (23%), 8 intradural/extramedullary (61.5%), and 2 intramedullary tumors (15.3%); these were classified as 5 meningiomas (38.4%), 4 neurofibromas (30.7%), 2 schwannomas (15.3%), 1 hemangioblastoma (7.6%), and 1 astrocytoma (7.6%). Eleven (84.61%) patients had complete motor improvement, 1 patient had partial improvement, and 1 patient had no improvement (7.6% each). An 18-mm working channel tube was used for extramedullary lesions and 20-mm tubes for intramedullary injuries. Total tumor resection was achieved in 11 patients (84.6%) and subtotal in 2 patients (15.38%) corresponding to intramedullary tumors. CONCLUSIONS: Although this study consisted of a small series, we have shown the possibility of resecting intraspinal tumors (some intradural-intramedullary) with non-expansile tubes in a safe and effective way with no complications. Most of the patients had complete neurological improvement at the end of follow-up.

Ten-Step Minimally Invasive Cervical Decompression via Unilateral Tubular Laminotomy: Technical Note and Early Clinical Experience.

BACKGROUND: Minimally invasive techniques utilizing tubular retractors have become an increasingly popular approach to the spinal column. The concept of a unilateral laminotomy for bilateral decompression (ULBD), first applied in the lumbar spine, has recently been applied to the cervical spine for the treatment of cervical spondylotic myelopathy (CSM). A better understanding of the indications and surgical techniques is required to effectively educate surgeons on how to appropriately and safely perform tubular cervical laminotomy via ULBD. OBJECTIVE: To describe a 10-step technique for minimally invasive cervical laminotomy and report our early clinical experience. METHODS: A retrospective review identified 15 patients with CSM who were treated with this procedure. Visual analogue scale (VAS), neck disability index (NDI), and modified Japanese Orthopaedic Association (mJOA) scores were obtained pre- and postoperatively. RESULTS: The mean age of the 15 patients was 73.1 ± 6.8 yr. The median number of levels treated was 1 (range 1-3). Mean operative time was 125.3 ± 30.8 or 81.7 ± 19.2 min per level. Mean estimated blood loss was 57.3 ± 24.6 cc. Median postoperative hospital length of stay was 36 h. No complications were encountered. Median follow-up was 18 mo. Mean pre- and postoperative VAS were 6.4 ± 2.4 and 1.0 ± 0.8, respectively (P < .001). Mean pre- and postoperative NDI were 46.4 ± 19.2 and 7.0 ± 6.9, respectively (P < .001). Mean pre- and postoperative Mjoa were 11.3 ± 2.5 and 14.5 ± 0.5, respectively (P < .001). CONCLUSION: In our early clinical experience, minimally invasive cervical ULBD is safe and effective. Adherence to the presented 10-step technique will allow surgeons to safely address bilateral cervical pathology while avoiding complications.

Assessment of Paraspinal Muscle Atrophy Percentage after Minimally Invasive Transforaminal Lumbar Interbody Fusion and Unilateral Instrumentation Using a Novel Contralateral Intact Muscle-Controlled Model.

STUDY DESIGN: Retrospective comparative clinical study. PURPOSE: This study aimed to assess paraspinal muscle atrophy in patients who underwent minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and unilateral pedicle screw fixation using a novel contralateral intact muscle-controlled model. OVERVIEW OF LITERATURE: The increased incidence of paravertebral lumbar muscle injuries after open techniques has raised the importance of implementing minimally invasive spine surgical techniques using tubular retractors and minimally invasive screw placement. The functional cross-sectional area (FCSA) represents the lean muscle mass; furthermore, FCSA is a useful marker of the contractile ability of a muscle following a spine surgery. However, the benefits of unilateral fixation and MI-TLIF on paraspinal muscles have not been defined. METHODS: We performed a retrospective imagenological review on eleven patients who underwent unilateral MI-TLIF and unilateral transpedicular screw lumbar placement. FCSAs of the multifidus and erector spinae were measured 1 year after surgery at adjacent levels and were compared to the contralateral intact muscles. Measurement differences between the surgical and nonsurgical sites were compared. The interobserver reliability was calculated using an intraclass correlation coefficient. RESULTS: The mean FCSA at the surgical site was 20.97±5.07 cm2 at the superior level and 8.89±2.87 cm2 at the inferior level. The mean FCSA at the contralateral nonsurgical site was 20.15±5.95 cm2 at the superior level and 9.20±2.66 cm2 at the inferior level was. The superior and inferior FCSA measurements showed no significant difference between the surgical and nonsurgical sites (p=0.5, p=0.922, respectively). CONCLUSIONS: Using a mini-open tubular approach through the sulcus between the longissimus and iliocostalis, MI-TLIF and unilateral pedicle screw instrumentation produced minimal paraspinal muscle damage at the superior and inferior adjacent levels.

Learning curve in single-level minimally invasive tlif: experience of a neurosurgeon / Curva de aprendizagem em tlif minimamente invasiva em um nível: experiência de um neurocirurgião / Curva de aprendizaje en tlif por mínima invasión de un nivel: experiencia de un neurocirujano

ABSTRACT Objective: To describe the learning curve that shows the progress of a single neurosurgeon when performing single-level MI-TLIF. Methods: We included 99 consecutive patients who underwent single-level MI-TLIF by the same neurosurgeon (JASS). Patient's demographic characteristics were analyzed. In addition, surgical time, intraoperative blood loss and hospital stay were evaluated. The learning curves were calculated with a piecewise regression model. Results: The mean age was 54.6 years. The learning curves showed an inverse relationship between the surgical experience and the variable analyzed, reaching an inflection point for surgical time in case 43 and for blood loss in case 48. The mean surgical time was 203.3 minutes (interquartile range [IQR] 150-240 minutes), intraoperative bleeding was 97.4ml (IQR 40-100ml) and hospital stay of four days (IQR 3-5 days). Conclusions: MI-TLIF is a very frequent surgical procedure due to its effectiveness and safety, which has shown similar results to open procedure. According to this study, the required learning curve is slightly higher than for open procedures, and is reached after about 45 cases.

RESUMO Objetivo: Descrever a curva de aprendizagem que mostra o progresso de um único neurocirurgião na realização de MI-TLIF em um só nível. Métodos: Foram incluídos 99 pacientes consecutivos submetidos a MI-TLIF de um só nível pelo mesmo neurocirurgião (JASS). Foram analisadas as características demográficas dos pacientes. Além disso, avaliou-se o tempo operatório, a perda de sangue intraoperatória e o tempo de internação hospitalar. As curvas de aprendizagem foram realizadas com um modelo de regressão segmentada. Resultados: A média de idade foi 54,6 anos. As curvas de aprendizagem mostraram uma relação inversa entre a experiência cirúrgica e a variável analisada, atingindo um ponto de inflexão para o tempo de cirurgia no caso 43 e da perda sanguínea no caso 48. O tempo médio de cirurgia foi de 203,3 minutos (amplitude interquartil [IQR] 150 - 240 minutos), de sangramento intraoperatório foi 97,4 ml (IQR 40-100 ml) e de internação hospitalar foi de quatro dias (IQR 3-5 dias). Conclusões: O MI-TLIF é um procedimento realizado com muita frequência devido à sua eficácia e segurança, que tem mostrado resultados comparáveis com o procedimento aberto. De acordo com este estudo, a curva de aprendizagem necessária é ligeiramente maior do que para os procedimentos abertos, sendo que é atingida depois de cerca de 45 casos.

RESUMEN Objetivo: Describir la curva de aprendizaje que muestre el progreso de un sólo neurocirujano para la realización de MI-TLIF de un sólo nivel. Métodos: Se incluyeron 99 pacientes consecutivos sometidos a MI-TLIF en un solo nivel por un mismo neurocirujano (JASS). Se analizaron las características demográficas de los pacientes. Además se evaluó el tiempo quirúrgico, sangrado transoperatorio y tiempo de estancia hospitalaria. Las curvas de aprendizaje se realizaron con un modelo de regresión dividida en segmentos. Resultados: Se obtuvo un promedio de edad de 54,6 años. Las curvas de aprendizaje mostraron una relación inversa entre la experiencia quirúrgica y la variable analizada, alcanzando un punto de inflexión para tiempo quirúrgico en el caso 43 y para el sangrado en el caso 48. El promedio de tiempo quirúrgico fue de 203,3 minutos (amplitud intercuartil [IQR] 150 - 240 minutos), del sangrado transoperatorio fue 97,4 ml (IQR 40 - 100 ml) y de la estancia hospitalaria fue de cutro días (IQR 3 - 5 días). Conclusiones: El MI-TLIF es un procedimiento realizado con gran frecuencia debido a su efectividad y seguridad y que ha demostrado resultados equiparables con el procedimiento abierto. De acuerdo a este estudio la curva de aprendizaje requerida es discretamente mayor que para procedimientos abiertos, alcanzándola aproximadamente tras 45 casos.

Minimally invasive single-door plate laminoplasty with lateral mass screw fixation for the unstable segment. report of two cases with long follow-up / Laminoplastia em porta aberta minimamente invasiva com fixação com parafusos de massa lateral para o segmento instável. relato de dois casos com acompanhamento prolongado / Laminoplastía en puerta abierta mínimamente invasiva y fijación com tornillo de masa lateral para o segmento inestable. reporte de dos casos con seguimiento a largo plazo

ABSTRACT Objective: To report two cases of multilevel cervical spondylotic myelopathy with monosegmental instability, in which we performed a minimally invasive microsurgical transmuscular approach with tubular retractors to create a single-door plate laminoplasty combined with fixation of the unstable segment with lateral mass screws. Methods: The surgical procedures were performed by the senior author. In both patients, the follow-up was performed using the Oswestry Disability Index (ODI), the Visual Analogue Scale for neck and radicular pain (radVAS, neckVAS), the Neck Disability Index (NDI) and the Short Form 36 (SF-36), in the preoperative (preop) and postoperative (postop) periods, and at 1, 3, 6, 12, 18 and 24 months. A radiological evaluation also was performed, which included AP, lateral and flexion-extension films at 6, 12 and 24 months and CT-scan at 12 months. Results: Case 1 - preop ODI: 40%, 24 months postop ODI: 4%; preop radVAS: 7, 24 months radVAS: 0; preop neckVAS: 8, postop 24 months neckVAS: 0; preopNDI: 43%, 24 months PostopNDI: 8%; SF-36 - preop Physical Functioning (PF): 40, preop Vitality (VT): 40, preop Emotional role functioning (RE): 33.3, Bodily pain (BP): 51, General Health (GH): 57, Social Functioning (SF): 75; postop PF: 95, VT: 95, RE: 100, BP: 74, GH: 87, SF: 100. Case 2 - preopODI: 46%, 24 months postopODI: 10%; preop radVAS: 7, 24m radVAS: 0; preop neckVAS: 9, postop 24 months neckVAS: 0; preopNDI: 56%, 24 months PostopNDI: 15%; SF-36 - preop PF: 39, VT: 45, RE: 33.3, BP: 50, GH: 49, SF: 70; postop PF: 90, VT: 100, RE: 100, BP: 82, GH: 87, SF: 100. No complications, cervical instability or signs of failed surgery were found trough and at final follow-up at 24 months. We found significant clinical improvement in both patients. Conclusions: Minimally invasive cervical laminoplasty combined with lateral mass screw fixation for the unstable segment is a useful technique in cases with multilevel cervical spondylotic myelopathy associated with monosegmental instability. Additional comparative studies are needed to establish its efficacy.

RESUMO Objetivo: Relatar dois casos de mielopatia espondilótica cervical em múltiplos níveis com instabilidade de um só segmento, nos quais realizamos uma microcirurgia minimamente invasiva por via transmuscular com retratores tubulares para criar uma laminoplastia em porta aberta com fixação do segmento instável com parafusos de massa lateral. Métodos: Os procedimentos cirúrgicos foram realizados pelo autor principal. Em ambos os pacientes, o acompanhamento foi realizado usando Índice de Incapacidade de Oswestry (ODI), Escala Visual Analógica para dor cervical e radicular (EVAc e EVArad), Índice de Incapacidade Relacionada ao Pescoço (NDI) e o Short Form 36 (SF-36) nos períodos pré-operatório (pré-op) e pós-operatório (pós-op) e em 1, 3, 6, 9, 12, 18 e 24 meses. Realizou-se também a avaliação radiológica, que incluiu vistas AP, laterais e de flexão-extensão aos 6, 12 e 24 meses e TC aos 12 meses. Resultados: Caso 1 - ODI pré-op: 40%, ODI 24 meses pós-op: 4%; pré-op EVArad: 7, EVArad 4 meses: 0; EVAc pré-op: 8, EVAc pós-op 24 meses: 0; NDI pré-op: 43%, NDI pós-op 24 meses: 8%; SF-36 - capacidade funcional (CF) pré-op: 40, vitalidade (VT) pré-op: 40, aspectos emocionais (AE) pré-op: 33,3, dor (D): 51, estado geral da saúde (ES): 57, aspectos sociais (AS): 75; CF : 95, VT: 95, AE: 100, D: 74, ES: 87, AS: 100 pós-op. Caso 2 - ODI pré-op: 46%, ODI 24 meses pós-op: 10%; EVArad pré-op : 7, EVArad 24 meses: 0; EVAc pré-op: 9, EVAc 24 meses pós-op: 0; NDI pré-op: 56%, NDI 24 meses pós-op: 15%; SF-36 pré-op: CF: 39, VT: 45, AE: 33,3, D: 50, ES: 49, AS: 70; CF: 90, VT: 100, AE: 100, D: 82, ES: 87, AS: 100 pós-op. Não houve complicações, instabilidade cervical ou sinais de falha da cirurgia durante o acompanhamento de 24 meses. Ambos os pacientes apresentaram melhoras significativas. Conclusões: A laminoplastia cervical minimamente invasiva combinada com fixação de parafuso de massa lateral do segmento instável é uma técnica útil nos casos com mielopatia espondilótica cervical em vários níveis associada à instabilidade de um só segmento. É necessário realizar estudos comparativos adicionais para estabelecer a eficácia do procedimento.

RESUMEN Objetivo: Relatar dos casos de mielopatía espondilótica cervical en múltiples niveles con inestabilidad de un solo segmento, en los que realizamos una microcirugía mínimamente invasiva por vía transmuscular con retractores tubulares para crear una laminoplastia en puerta abierta con fijación del segmento inestable con tornillos de masa lateral. Métodos: Los procedimientos quirúrgicos fueron realizados por el autor principal. En ambos pacientes, el seguimiento fue realizado usando Índice de Discapacidad de Oswestry (ODI), Escala Visual Analógica para dolor en el cuello y radicular (EVAc y EVArad), Índice de Discapacidad Cervical (NDI) y el Short Form 36 (SF-36) en los períodos preoperatorio (preop) y postoperatorio (posop) y en 1, 3, 6, 9, 12, 18 y 24 meses. Se realizó también la evaluación radiológica, que incluyó proyecciones AP, laterales y de flexión-extensión a los 6, 12 y 24 meses y TC a los 12 meses. Resultados: Caso 1 - ODI preop: 40%, ODI 24 meses posop: 4%; EVArad preop: 7, EVArad 4 meses: 0; EVAc preop: 8, EVAc posop 24 meses: 0; NDI preop: 43%, NDI posop 24 meses: 8%; SF-36 - función física (FF) preop: 40, vitalidad (VT) preop: 40, rol emocional (RE) preop: 33,3, dolor corporal (DC): 51, salud general (SG): 57, función social (FS): 75; FF: 95, VT: 95, RE: 100, DC: 74, SG: 87, FS: 100 posop. Caso 2 - ODI preop: 46%, ODI 24 meses posop: 10%; EVArad preop: 7, EVArad 24 meses: 0; EVAc preop: 9, EVAc 24 meses posop: 0; NDI preop: 56%, NDI 24 meses posop: 15%; SF-36 preop: FF: 39, VT: 45, RE: 33,3, D: 50, SG: 49, FS: 70 preop; FF: 90, VT 100, RE 100, DC 82, SG: 87, FS: 100 posop. No hubo complicaciones, inestabilidad cervical o signos de falla de la cirugía durante el seguimiento de 24 meses. Ambos pacientes presentaron mejoras significativas. Conclusiones: La laminoplastia cervical mínimamente invasiva combinada con fijación de tornillo de masa lateral del segmento inestable es una técnica útil en los casos con mielopatía espondilótica cervical en múltiples niveles asociada a la inestabilidad de un solo segmento. Es necesario realizar estudios comparativos adicionales para establecer la eficacia del procedimiento.

A prospective clinical study comparing MI-TLIF with unilateral versus bilateral transpedicular fixation in low grade lumbar spondylolisthesis.

BACKGROUND: Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has become one of the standard techniques for approaching ipsilateral decompression, anterior column fusion, and posterior stabilization. This procedure is usually accompanied by the placement of bilateral transpedicular screws in the corresponding segment. The purpose of this study was to evaluate the clinical efficacy of unilateral screw fixation compared with bilateral fixation in patients diagnosed with low-grade symptomatic lumbar spondylolisthesis who underwent an MI-TLIF technique. METHODS: A prospective and comparative study was performed in 67 patients with grade 1 symptomatic lumbar spondylolisthesis. The sample was allocated on both unilateral fixation group (n=33) and bilateral fixation group (n=34). Clinical outcomes were evaluated using Oswestry Disability Index (ODI), visual analogue scale (VAS) for leg and back pain, and Short Form 36 Health Survey (SF-36), preoperatively, and at 1, 3, 6, and 12 months postoperatively. Changes over time and differences between the groups were analyzed. Statistical analyses included: Friedman test, Student's t-test and Mann-Whitney's U. A two-tailed P value of <0.05 was considered significant. RESULTS: During 1-year of evaluation there were no significant clinical differences between both groups. CONCLUSIONS: Patients with grade 1 symptomatic lumbar spondylolisthesis treated with MI-TLIF with unilateral screw fixation had similar clinical results than those treated with bilateral fixation at 12 months postoperatively.

Microscopy-assisted interspinous tubular approach for lumbar spinal stenosis.

Various minimally invasive techniques have been reported as an alternative to conventional lumbar decompression. The major advantage of these minimally invasive procedures lies in their reduction of unnecessary exposure and tissue trauma. Our objective was to describe a minimally invasive procedure for lumbar spinal stenosis decompression by enlarging the lumbar interspinous space, approaching it with a tubular retractor, and assisting with microscopy. Thoracolumbar fascia and paravertebral muscles are preserved throughout the whole procedure. Iatrogenic instability of the spine can be avoided if during the procedure both joints are just undercut in order to decompress the subarticular space. The approach described in this manuscript could be used as an alternate minimally invasive surgical procedure for the treatment of central and lateral lumbar spinal stenosis.

Microsurgical landmarks in minimally invasive transforaminal lumbar interbody fusion / Referências microcirúrgicas em fusão intersomática lombar transforaminal minimamente invasiva / Referencias microquirúrgicas en la fusión intersomática lumbar transforaminal de mínima invasión

Microsurgical landmarks of the facet joint complex were defined to provide guidance and security within the tubular retractor during transforaminal surgery. A retrospective observational study was performed in segments L4-L5 by the left side approach. Microsurgical relevant photos, anatomical models and drawing were used to expose the suggested landmarks. The MI-TLIF technique has advantages compared with conventional open TLIF technique, however minimally invasive technique implies lack of security for the surgeon due to the lack of defined microanatomical landmarks compared to open spine surgery, and disorientation within the tubular retractor, the reason why to have precise microsurgical references and its recognition within the surgical field provide speed and safety when performing minimally invasive technique.

Foram definidas referências anatômicas microcirúrgicas do complexo facetário para obter orientação e segurança no interior do retrator tubular durante a cirurgia transforaminal. Realizou-se um estudo observacional retrospectivo dos procedimentos MI-TLIF nos segmentos L4-L5 com acesso lateral esquerdo. Foram empregados fotos microcirúrgicas relevantes, modelo anatômico e esquemas para expor as referências sugeridas. A técnica de MI-TLIF tem vantagens quando comparada com a técnica TLIF a céu aberto convencional, no entanto, a técnica minimamente invasiva implica falta de segurança para o cirurgião, devido à ausência de referências microanatômicas definidas em comparação com a cirurgia a céu aberto, além de falta de orientação no interior do retrator tubular. Por isso, ter referências microcirúrgicas precisas e seu reconhecimento dentro do campo cirúrgico proporciona rapidez e segurança ao realizar a técnica minimamente invasiva.

Se definieron las referencias anatómicas microquirúrgicas del complejo facetario para aportar orientación y seguridad dentro del portal tubular durante la cirugía transforaminal. Se realizó un estudio observacional retrospectivo de procedimientos MI-TLIF en segmentos L4-L5 abordados del lado izquierdo. Se utilizaron fotos microquirúrgicas relevantes, modelo anatómico y esquemas para exponer las referencias anatómicas sugeridas. La técnica de MI-TLIF tiene ventajas comparada con la técnica abierta convencional de TLIF, sin embargo la técnica mínimamente invasiva confiere falta de seguridad para el cirujano debido a la carencia de referencias microanatómicas definidas comparado con la cirugía abierta y desorientación dentro del acceso tubular por lo que tener referencias microquirúrgicas precisas y su reconocimiento dentro del campo quirúrgico aportan rapidez y seguridad al realizar la técnica mínimamente invasiva.