Browsing by Author "Zamorano, Juan"
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Item Accuracy and reliability of the AO Spine subaxial cervical spine classifcation system grading subaxial cervical facet injury morphology(2021) Cabrera, Juan; Yurac, Ratko; Guiroy, Alfredo; Joaquim, Andrei; Carazzo, Charles; Zamorano, Juan; White, Kevin; Valacco, Marcelo; The AO Spine Latin America Trauma Study GroupPurpose: A classification system was recently developed by the international association AO Spine for assessing subaxial cervical spine fractures. Significant variability exists between users of the facet component, which consists of four morphological types (F1-F4). The primary aims of this study were to assess the diagnostic accuracy and reliability of this new system's facet injury morphological classifications. Methods: A survey consisting of 16 computed tomography (CT) scans of patients with cervical facet fractures was distributed to spine surgeon members of AO Spine Latin America. To provide a gold standard diagnosis for comparison, all 16 injuries had been classified previously by six co-authors and only were included after total consensus was achieved. Demographic and surgical practice characteristics of all respondents were analyzed, and diagnostic accuracy calculated. Inter- and intra-observer agreement rates were calculated across two survey rounds, conducted one month apart. Results: A total of 135 surgeons completed both surveys, among whom the mean age was 41.6 years (range 26-71), 130 (96.3%) were men, and 83 (61.5%) were orthopedic surgeons. The mean time in practice as a spine surgeon was 9.7 years (1-30). The overall diagnostic accuracy of all responses was 65.4%. Inter-observer and intra-observer agreement rates for F1/F2/F3/F4 were 55.4%/47.6%/64.0%/94.7% and 60.0%/49.1%/58.0%/93.0%, respectively. Conclusion: This study evaluates the AO Spine Classification System specifically for facet injuries involving the subaxial cervical spine in a large sample of spine surgeons. There was significant variability in diagnostic accuracy for F1 through F3-type fractures, whereas almost universal agreement was achieved for F4-type injuries.Publication An independent inter- and intra-observer agreement assessment of the AOSpine upper cervical injury classification system(2022) Urrutia, Julio; Delgado, Byron; Camino, Gaston; Guiroy, Alfredo; Astur, Nelson; Valacco, Marcelo; Zamorano, Juan; Vidal, Catalina; Yurac, RatkoBackground context: The complex anatomy of the upper cervical spine resulted in numerous separate classification systems of upper cervical spine trauma. The AOSpine upper cervical classification system (UCCS) was recently described; however, an independent agreement assessment has not been performed. Purpose: To perform an independent evaluation of the AOSpine UCCS. Study design: Agreement study. Patient sample: Eighty four patients with upper cervical spine injuries. Outcome measures: Inter-observer agreement; intra-observer agreement. Methods: Complete imaging studies of 84 patients with upper cervical spine injuries, including all morphological types of injuries defined by the AOSpine UCCS were selected and classified by six evaluators (from three different countries). The 84 cases were presented to the same raters randomly after a 4-week interval for repeat evaluation. The Kappa coefficient (κ) was used to determine inter- and intra-observer agreement. Results: The interobserver agreement was almost perfect when considering the fracture site (I, II or III), with κ=0.82 (0.78-0.83), but the agreement according to the site and type level was moderate, κ=0.57 (0.55-0.65). The intra-observer agreement was almost perfect considering the injury, with κ=0.83 (0.78-0.86), while according to site and type was substantial, κ=0.69 (0.67-0.71). Conclusions: We observed only a moderate inter-observer agreement using this classification. We believe our results can be explained because this classification attempted to organize many different injury types into a single scheme.Item CT Scan in Subaxial Cervical Facet Injury: Is It Enough for Decision-Making?(2021) Cabrera, Juan; Yurac, Ratko; Joaquim, Andrei; Guiroy, Alfredo; Carazzo, Charles; Zamorano, Juan; Valacco, Marcelo; And the AO Spine Latin America Trauma Study GroupObjectives: Assessment of subaxial cervical facet injuries using the AO Spine Subaxial Cervical Spine Injury Classification System is based on CT scan findings. However, additional radiological evaluations are not directly considered. The aim of this study is to determine situations in which spine surgeons request additional radiological exams after a facet fracture. Methods: A survey was sent to AO Spine members from Latin America. The evaluation considered demographic variables, routine use of the Classification, as well as the timepoint at which surgeons requested a cervical MRI, a vascular study, and/ or dynamic radiographs before treatment of facet fractures. Results: There was 229 participants, mean age 42.9 ± 10.2 years; 93.4% were men. Orthopedic surgeons 57.6% with 10.7 ± 8.7 years of experience in spine surgery. A total of 86% used the Classification in daily practice. An additional study (MRI/vascular study/and dynamic radiographs) was requested in 53.3%/9.6%/43.7% in F1 facet injuries; 76.0%/20.1%/50.2% in F2; 89.1%/65.1%/28.4% in F3; and 94.8%/66.4%/16.6% in F4. An additional study was frequently required: F1 72.5%, F2 86.9%, F3 94.7%, and F4 96.1%. Conclusions: Spine surgeons generally requested additional radiological evaluations in facet injuries, and MRI was the most common. Dynamic radiographs had a higher prevalence for F1/F2 fractures; vascular studies were more common for F3/F4 especially among surgeons with fewer years of experience. Private hospitals had a lower spine trauma cases/year and requested more MRI and more dynamic radiographs in F1/F2. Neurosurgeons had more vascular studies and dynamic radiographs than orthopedic surgeons in all facet fractures.Publication Espondilodiscitis por Haemophilus parainfluenzae: Un reporte de caso(2022) Yurac, Ratko; Santorcuato, Macarena; Quinteros, Guisela; Zamorano, Juan; Marré, BartoloméIntroduction Haemophilus parainfluenzae (HP) is a gram-negative coccobacillus andan opportunistic pathogen. It is rarely associated with spinal- and musculoskeletal-site infections, and very little reported in the literature. Case Presentation An otherwise healthy, 45-year-old woman who presented with a two-week history of progressive low back pain, fever, coryza and nasal congestion, was found to have intervertebral discitis caused by HP, confirmed by two positive blood cultures and progressive lumbar spine magnetic resonance imaging (MRI) findings. The MRI findings were atypical, consisting of a psoas abscess and small anterior epidural and intraspinal fluid collections associated with spondylodiscitis. The initial diagnosis was delayed because the initial MRI failed to reveal findings suggestive of an infectious process. The treatment consisted of a long course of intravenous followed by oral antibiotics, ultimately yielding a good clinical response. Discussion and Conclusion Haemophilus parainfluenzae is a very rare pathogen inspondylodiscitis. Nonetheless, it should be considered, especially in patients presenting with low back pain and fever and/or gram negative bacteremia. Theinitial work-up should include contrast-enhanced MRI of the spine. Although rare, spondylodiscitis and a psoas abscess can present concomitantly. Prolonged antibiotics are the mainstay of treatment.Publication Granuloma eosinofílico cervical en el adolescente: Reporte de un caso y revisión de la literatura(2022) Yurac, Ratko; Zamorano, Juan; Calvo, Rafael; Castoldi, María; De la Barra, Camila; Quinteros, Guisela; Novoa, FelipeIntroducción El granuloma eosinofílico (GE) es una patología infrecuente, sobre todo en adultos, que puede afectar la columna cervical. A pesar de la vasta literatura, esta enfermedad afecta principalmente a la población infantil, y no hay un consenso sobre el manejo en adultos. Con el objetivo de aportar conocimiento respecto a esta patología poco frecuente, se presenta un caso clínico de GE cervical en un paciente de 16 años, a quien se trató de manera conservadora, con buenos resultados y retorno completo a sus actividades. Caso Clínico Un hombre de 16 años, seleccionado de rugby, consultó por dolor cervical axial persistente y nocturno de 6 semanas de evolución, sin trauma evidente. Al examen, destacó dolor a la compresión axial sin compromiso neurológico asociado. Los exámenes de tomografía computarizada (TC) y resonancia magnética (RM) revelaron lesión lítica en el cuerpo de C3 de características agresivas, de presentación monostótica en tomografía por emisión de positrones-tomografía computada (TEPTC) compatible con tumor primario vertebral. Se decidió realizar biopsia percutánea bajo TC, para definir el diagnóstico y manejo adecuado, la cual fue compatible con células de Langerhans. Al no presentar clínica ni imagenología de inestabilidad ósea evidente o compromiso neurológico, se manejó con tratamiento conservador, inmovilización cervical, analgesia oral, y seguimiento estrecho. A los cuatro meses de evolución, se presentó con una TC con cambios reparativos del cuerpo vertebral y sin dolor, y logró retomar sus actividades habituales. Conclusiones El diagnóstico de GE es infrecuente a esta edad, y se debe plantear entre diagnósticos diferenciales de lesiones líticas agresivas primarias vertebrales. Es necesario el uso de imágenes, y la biopsia vertebral es fundamental para confirmar el diagnóstico. Su manejo va a depender de la sintomatología, del compromiso de estructuras vecinas, y de la estabilidad de la vértebra afectada. El manejo conservador con seguimiento clínico e imagenológico es una opción viable.Item Independent Reliability Analysis of a New Classification for Pyogenic Spondylodiscitis(2021) Camino Willhuber, Gaston; Guiroy, Alfredo; Zamorano, Juan; Astur, Nelson; Valacco, MarceloStudy design: Diagnostic study, level of evidence III. Objective: Pyogenic spondylodiscitis can cause deformity, neurological compromise, disability, and death. Recently, a new classification of spondylodiscitis based on magnetic resonance imaging was published. The objective of this study is to perform an independent reliability analysis of this new classification. Methods: We selected 35 cases from our database of different spine centers in Latin America and from the literature; 8 observers evaluated the classification and graded the scenarios according to the methodological grading of the classification developed by Pola et al. Cases were sent to the observers in a random sequence after 3 weeks to assess intraobserver reliability. The interobserver and intraobserver reliabilities were performed with Fleiss and Cohen statistics, respectively. Results: The overall Fleiss κ value for interobserver agreement was substantial, with 0.67 (95% CI = 0.43-0.91) in the first reading and 0.67 (95% CI = 0.45-0.89) in second reading for the main types of classification. The Cohen κ value for intraobserver agreement was also substantial, with 0.68 (95% CI = 0.45-0.92). The interobserver agreement analysis for the subtypes of this classification was overall substantial, with 0.60 (95% CI = 0.37-0.83) in the first reading and 0.61 (95% CI = 0.41-0.81) in the second reading. The overall intraobserver agreement for subtypes of the classification was also substantial, with 0.63 (95% CI = 0.34-0.93). Conclusion: The new classification developed by Pola et al showed substantial interobserver and intraobserver agreements. More studies are required to validate the usefulness of this classification especially in clinical practice.Item Letter to the Editor: Is COVID-19 the Cause of Delayed Surgical Treatment of Spine Trauma in Latin America?(2020) Cabrera, Juan P.; Yurac, Ratko; Guiroy, Alfredo; Carazzo, Charles A.; Joaquim, Andrei F.; Zamorano, Juan; Valacco, Marcelo; AO Spine Latin America Trauma Study GroupLetter to the EditorItem Management of lumbar disc herniation with radiculopathy: Results of an Iberian-Latin American survey(2021) Quinteros, Guisela; Yurac, Ratko; Zamorano, Juan; Díez, Máximo; Pudles, Edson; Marré, BartoloméBackground: Lumbar disc herniation (LDH)/radiculopathy is the most frequent cause of lost workdays in people under 50 years of age. Although there is consensus about how to assess these patients, the optimal management strategy is still debated. Methods: An online survey was sent to spine surgeons who are members of the Iberian-Latin American Spine Society to assess how they treat LDH with radiculopathy. Results: There were 718 surgeons who answered the survey; 66% reported that 76-100% of their monthly clinic work was due to spine issues. The most frequently used conservative treatment modalities included non-opioid analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) (90.5%), followed by physical therapy (55.2%) and pregabalin (41.4%). Notably, 40% of surgeons in the public sector believed that conservative treatment failed if symptoms persisted beyond 6-12 weeks, while 39% of private surgeons deemed conservative management insufficient if it had failed to provide symptomatic relief with 3-6 weeks. Of interest, 78% utilized epidural steroid injections (ESI); 51.7% preferred the transforaminal, 27.2% the interlaminar, and 7.5% the caudal approaches. The most frequent indications for surgery included: cauda equina syndrome, progressive neurological deficits, and intractable pain. Traditional microdiscectomy was the most common technique (68.5%) utilized, followed by 7.5% advocating endoscopic disc resection, and just 6.4% favoring the tubular discectomy. Conclusion: There is considerable heterogeneity among Iberian and Latin American spine surgeons in the treatment of LDH/radiculopathy. Although most begin with the utilization of NSAIDs and non-opioid analgesics, followed by ESI (88%), surgery was recommended for persistent symptoms/signs for those failing between 3 and 6 weeks (private sector) versus 6-12 weeks (public sector) of conservative therapy.Publication Mielopatía cervical degenerativa: una patología cada vez más frecuente y que requiere diagnóstico y manejo precoz(2022) Yurac, Ratko; Matamala, José; Zamorano, Juan; Harrop, James; Davies, Benjamin; Nouri, Aria; Fehlings, MichaelDegenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adults. Its prevalence is increasing as a result of population aging. The diagnosis of DCM is often delayed or overlooked, resulting in secondary neurologic morbidity. The natural course of DCM typically presents as a gradual neurological deterioration, with symptoms ranging from muscle weakness to complete paralysis, with variable degrees of sensory deficits and sphincter dysfunction. Magnetic resonance imaging (MRI) and electrophysiological studies allow the assessment of spinal cord function and its structural damage to determine treatment and clinical outcomes. All patients with signs and symptoms consistent with DCM should be referred to a spine surgeon for assessment and tailored treatment. Those patients with mild DCM can be managed non-operatively but require close monitoring and education about potentially alarming signs and symptoms. Surgery is not currently recommended for asymptomatic patients with evidence of spinal cord compression or cervical spinal stenosis on MRI, but they require a structured follow-up. Patients with moderate or severe DCM require surgical decompression to avoid further progression. The objective of this review is to raise awareness of degenerative cervical myelopathy and its increasing prevalence as well as to aid non-surgical healthcare workers for a timely diagnosis and management of this disabling condition.Item Risk factors for the need of surgical treatment of a first recurrent lumbar disc herniation.(Springer International Publishing AG, 2016) Ratko, Yurac; Zamorano, Juan; Lira, Fernando; Valiente, Diego; Ballesteros, Vicente; Urzúa, AlejandroPURPOSE: A recurrent lumbar disc herniation (RLDH) is the most prevalent cause for new radicular pain after surgery for disc herniation-induced sciatica. Reported risk factors include age, gender and smoking, while its surgical treatment is associated to a higher rate of complications and costs. The purpose of this study is to identify factors that increase the risk of requiring surgical treatment for a first RLDH in workers' compensation patients. METHODS: Nested case-control: 109 patients operated for an RLDH (cases) between June 1st 1994 and May 31st 2011 (minimum follow-up 1 year) and 109 randomly selected patients operated for a first disc herniation with no recurrence during the study period (controls). Age, gender, smoking status, type of work and MRI characteristics of the index herniation were statistically evaluated as potential risk factors. RESULTS: Patient's age of less than 35 years (p = 0.001) and a subligamentous herniation (p < 0.05) at the time of the index surgery were identified as risk factors for requiring surgical treatment of a first RLDH. No statistical differences were observed between both groups regarding the other evaluated variables. CONCLUSION: A subligamentous disc herniation and patient's age inferior to 35 years at the time of the first surgery are risk factors for requiring surgical treatment of a first RLDH among workers' compensation patients.Publication Surgical timing prevails as the main factor over morphologic characteristics in the reduction by ligamentotaxis of thoracolumbar burst fractures(2023) Cirillo, Juan; Farias, Ignacio; Cristóbal Del Pino; Gimbernat, Marcos; Urzúa, Alejandro; Tapia, Carlos; Zamorano, JuanBackground: thoracolumbar burst fractures are associated with spinal canal occupation. The indirect decompression of the spinal canal and reduction of the fragment can be achieved with the distraction of the middle column and ligamentotaxis. Nevertheless, the factors that influence the effectiveness of this procedure and its temporality are controversial. Methods: The aim of this observational, cross-sectional study was to evaluate the effectiveness of indirect reduction by ligamentotaxis in thoracolumbar burst fractures according to the fracture's radiologic characteristics and the procedure's temporality. Patients diagnosed with a thoracolumbar burst fracture between 2010 and 2021 were submitted to indirect reduction by distraction and ligamentotaxis. A retrospective analysis of radiologic characteristics and temporality of the procedure was performed with an independent sample t-test or Pearson's correlation coefficient, as required. Results: A total of 58 patients were included in the analysis. Postoperatively, ligamentotaxis significantly improved all radiologic parameters (canal occupation, endplates distance, and vertebra height). Still, none of the radiological characteristics of the fracture (width, height, position, sagittal angle) were associated with the postoperative change in canal occupation. The endplates distance and the temporality of ligamentotaxis significantly predicted the reduction of the fracture. Conclusion: Fragment reduction effectiveness is more significant when performed as early as possible and adequate distraction is achieved using the internal fixator system. The radiologic characteristics of the fractured fragment do not determine its reduction capacity.Item Time to Surgery for Unstable Thoracolumbar Fractures in Latin America—A Multicentric Study(2021) Guiroy, Alfredo; Carazzo, Charles; Zamorano, Juan; Cabrera, Juan; Joaquim, Andrei; Guasque, Joana; Sfredo, Ericson; White, Kevin; Yurac, Ratko; Falavigna, AsdrubalObjective We sought to identify delays for surgery to stabilize unstable thoracolumbar fractures and the main reasons for them across Latin America. Methods We reviewed the charts of 547 patients with type B or C thoracolumbar fractures from 21 spine centers across 9 Latin American countries. Data were collected on demographics, mechanism of trauma, time between hospital arrival and surgery, type of hospital (public vs. private), fracture classification, spinal level of injury, neurologic status (American Spinal Injury Association impairment scale), number of levels instrumented, and reason for delay between hospital arrival and surgical treatment. Results The sample included 403 men (73.6%) and 144 women (26.3%), with a mean age of 40.6 years. The main mechanism of trauma was falls (44.4%), followed by car accidents (24.5%). The most frequent pattern of injury was B2 injuries (46.6%), and the most affected level was T12-L1 (42.2%). Neurologic status at admission was 60.5% intact and 22.9% American Spinal Injury Association impairment scale A. The time from admission to surgery was >72 hours in over half the patients and over a week in >25% of them. The most commonly reported reasons for surgical delay were clinical instability (22.9%), lack of operating room availability (22.7%), and lack of hardware for spinal instrumentation (e.g., screws/rods) (18.8%). Conclusions Timing for surgery in this sample of unstable fractures was over 72 hours in more than half of the sample and longer than a week in about a quarter. The main reasons for this delay were clinical instability and lack of economic resources. There is an apparent need for increased funding for the treatment of spinal trauma patients in Latin America.Publication Traumatic cervical spine injury due to pole dance accident: A potentially catastrophic unreported injury with a happy ending. Case report and literature review(2022) Yurac, Ratko; Zamorano, Juan; Marre, Andrea; Díaz, CristianBackground: Pole dancing is a sport that has become very popular. However, there is scarce literature on injuries associated with this sport. Here, we present a 23-year-old female who sustained a traumatic C4-C5 vertex cervical spine injury caused by a fall of 1 m while practicing pole dancing in an inverted position, requiring a 360 decompression/fusion. Case description: A 23-year-old female sustained a 1 m fall in an inverted position while pole dancing resulting in a direct axial impact to the head. She developed the rapid onset of quadriparesis that was attributed to the emergent CT/MR-documented cervical flexodisruptive luxofracture (AOSpine C4-C5 fracture: C, F4 unilateral, N3, M2). Four hours post injury, she underwent a C4-C5 anterior cervical discectomy and fusion. Four days later, a posterior fusion was performed to add to the stabilization. Six years later, the patient remains neurologically intact. Conclusion: Pole dance is an emerging sport which carries a risk of cervical spine injury.