Browsing by Author "Guiroy, Alfredo"
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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.Publication CT Scan in Subaxial Cervical Facet Injury: Is It Enough for Decision-Making?(2023) Cabrera, Juan P.; Yurac, Ratko; Joaquim, Andrei F.; Guiroy, Alfredo; Carazzo, Charles A.; Zamorano, Juan Jose; Valacco, Marcelo; AO Spine Latin America Trauma Study GroupStudy Design: Cross-sectional survey. Objectives: 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.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.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 Low Implant Failure Rate of Percutaneous Fixation for Spinal Metastases: A Multicenter Retrospective Study(2021) Silva, Álvaro; Yurac, Ratko; Guiroy, Alfredo; Bravo, Oscar; Morales, Alejandro; Landriel, Federico; Hem, SantiagoOBJECTIVE: To evaluate incidence and types of implant failure observed in a series of patients with spinal metastases (SM) treated with minimally invasive stabilizationsurgery without fusion. METHODS: In this multicenter, retrospective, observational study, we reviewed the files of patients >18 years old who underwent surgery for SM using percutaneous spinal stabilization without fusion with a minimum 3-month followup. The following variables were included: demographics,clinical findings, prior radiation history, SM location, epidural spinal cord compression scale, Spinal Instability Neoplastic Scale, neurological examination, and surgeryrelated data. Primary outcome measure was implant failure rate, as observed in patients’ last computed tomography scan. Multivariable analysis was performed to identify baseline factors and factors associated with implant failure. RESULTS: Analysis included 72 patients. Mean age of patients was 62 years, 39 patients were men, and 75% of patients had an intermediate Spinal Instability Neoplastic Scale score. Tumor separation surgery was performed in 48.6% of patients. Short instrumentation was indicated in 54.2% of patients. Three patients (4.2%) experienced implant failure (2 screw loosening, 1 screw cut-out); none of them required revision surgery. In 73.6% of cases, survival was >6 months. No significant predictors of failure were identified in the multivariate analysis. CONCLUSIONS: A low implant failure rate was observed over the short and medium term, even when short instrumentations without fusion were performed. These findings suggest that minimally invasive stabilization surgery without fusion may be an effective and safe way to treat complicated SM.Publication Reliability Evaluation of the New AO Spine-DGOU Classification for Osteoporotic Thoracolumbar Fractures(2022) Quinteros, Guisela; Cabrera, Juan; Urrutia, Julio; Carazzo, Charles; Guiroy, Alfredo; Marre, Bartolome; Joaquim, Andrei; Yurac, RatkoObjectives: To perform an interobserver and intraobserver agreement evaluation of the new AO Spine-DGOU classification system for osteoporotic thoracolumbar fractures (OFc). Methods: Complete imaging studies of 97 patients (radiographs, computed tomography scans, and magnetic resonance imaging) with osteoporotic thoracolumbar fractures were selected and classified using the OFc by 6 spine surgeons (3 senior surgeons with more than 15 years of experience and 3 surgeons with less than 15 years). After a 4-week interval, the same cases were presented to the same evaluators in a random sequence for a new classification assessment. The weighted kappa coefficient (wκ) was used to determine the interobserver and intraobserver agreement. Results: The interobserver agreement was moderate, wκ = 0.59 (95% confidence interval 0.54-0.64). The intraobserver agreement was fair, wκ = 0.35 (95% confidence interval 0.29-0.40). Interobserver agreement slightly improved for junior staff between first and second evaluation, suggesting a learning effect. Better agreement was obtained by senior staff at the interobserver and intraobserver agreement. Conclusions: This independent assessment demonstrated that new OFc allows moderate interobserver agreement and fair intraobserver agreement. Further studies are necessary prior to its widespread adoption.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.Item Unplanned Readmission Following Early Postoperative Complications After Fusion Surgery in Adult Spine Deformity: A Multicentric Study(2021) Camino, Gastón; Guiroy, Alfredo; Servidio, Mariano; Astur, Nelson; Nin, Fernando; Álvarado, Fernando; Daher, Murilo; Saciloto, Bruno; Ono, Allan; Letaif, Olavo; Zarate, Baron; Yurac, Ratko; Vialle, Emiliano; Valacco, MarceloStudy design: Multicentric retrospective study, Level of evidence III. Objective: The objective of this multicentric study was to analyze the prevalence and risk factors of early postoperative complications in adult spinal deformity patients treated with fusion. Additionally, we studied the impact of complications on unplanned readmission and hospital length of stay. Methods: Eight spine centers from 6 countries in Latin America were involved in this study. Patients with adult spinal deformity treated with fusion surgery from 2017 to 2019 were included. Baseline and surgical characteristics such as age, sex, comorbidities, smoking, number of levels fused, number of surgical approaches were analyzed. Postoperative complications at 30 days were recorded according to Clavien-Dindo and Glassman classifications. Results: 172 patients (120 females/52 males, mean age 59.4 ± 17.6) were included in our study. 78 patients suffered complications (45%) at 30 days, 43% of these complications were considered major. Unplanned readmission was observed in 35 patients (20,3%). Risk factors for complications were: Smoking, previous comorbidities, number of levels fused, two or more surgical approaches and excessive bleeding. Hospital length of stay in patients without and with complications was of 7.8 ± 13.7 and 17 ± 31.1 days, respectively (P 0.0001). Conclusion: The prevalence of early postoperative complications in adult spinal deformity patients treated with fusion was of 45% in our study with 20% of unplanned readmissions at 30 days. Presence of complications significantly increased hospital length of stay.Publication Unstable Thoracolumbar Injuries: Factors Affecting the Decision for Short-Segment vs Long-Segment Posterior Fixation(2022) Cabrera, Juan; Guiroy, Alfredo; Carazzo, Charles; Yurac, Ratko; Valacco, Marcelo; Vialle, Emiliano; Joaquim, Andrei; On behalf of the AO Spine Latin America Trauma Study GroupPublication Variations in management of A3 and A4 cervical spine fractures as designated by the AO Spine Subaxial Injury Classification System(2022) Sheen Kweh, Barry Ting; Wee Tee, Jin; Muijs, Sander; Oner, Cumhur; Schnake, Klaus John; Benneker, Lorin Michael; Neves Vialle, Emiliano; Kanziora, Frank; Rajasekaran, Shanmuganathan; Schroeder, Gregory; Vaccaro, Alexander R.; AO Spine Subaxial Injury Classification System Validation Group; Grin, Andrey; Abdelgawaad, Ahmed Shawky; Zubairi, Akbar Jaleel; Castillo, Alejandro; Vernengo Lezica, Alejo; Ramieri, Alessandro; Guiroy, Alfredo; Grundshtein, Alon; Godinho Jr., Amauri; Henine, Amin; Pershin, Andrei A.; Athanasiou, Alkinoos; Zarate-Kalfopulos, Baron; Benzarti, Sofien; Bernucci, Claudio; Rebholz, Brandon J.; Direito-Santos, Bruno; Lourenço Costa, Bruno; Saciloto, Bruno; Majer, Catalin; Tannoury, Chadi; Cheng, Cristina; Yin Cheung, Jason Pui; Konrads, Christian; Jetjumnong, Chumpon; Chung, Chun Kee; Popescu, Eugen Cezar; Kilinçer, Cumhur; Yurac, RatkoOBJECTIVE Optimal management of A3 and A4 cervical spine fractures, as defined by the AO Spine Subaxial Injury Classification System, remains controversial. The objectives of this study were to determine whether significant management variations exist with respect to 1) fracture location across the upper, middle, and lower subaxial cervical spine and 2) geographic region, experience, or specialty. METHODS A survey was internationally distributed to 272 AO Spine members across six geographic regions (North America, South America, Europe, Africa, Asia, and the Middle East). Participants’ management of A3 and A4 subaxial cervical fractures across cervical regions was assessed in four clinical scenarios. Key characteristics considered in the vignettes included degree of neurological deficit, pain severity, cervical spine stability, presence of comorbidities, and fitness for surgery. Respondents were also directly asked about their preferences for operative management and misalignment acceptance across the subaxial cervical spine. RESULTS In total, 155 (57.0%) participants completed the survey. Pooled analysis demonstrated that surgeons were more likely to offer operative intervention for both A3 (p < 0.001) and A4 (p < 0.001) fractures located at the cervicothoracic junction compared with fractures at the upper or middle subaxial cervical regions. There were no significant variations in management for junctional incomplete (p = 0.116) or complete (p = 0.342) burst fractures between geographic regions. Surgeons with more than 10 years of experience were more likely to operatively manage A3 (p < 0.001) and A4 (p < 0.001) fractures than their younger counterparts. Neurosurgeons were more likely to offer surgical stabilization of A3 (p < 0.001) and A4 (p < 0.001) fractures than their orthopedic colleagues. Clinicians from both specialties agreed regarding their preference for fixation of lower junctional A3 (p = 0.866) and A4 (p = 0.368) fractures. Overall, surgical fixation was recommended more often for A4 than A3 fractures in all four scenarios (p < 0.001). CONCLUSIONS The subaxial cervical spine should not be considered a single unified entity. Both A3 and A4 fracture subtypes were more likely to be surgically managed at the cervicothoracic junction than the upper or middle subaxial cervical regions. The authors also determined that treatment strategies for A3 and A4 subaxial cervical spine fractures varied significantly, with the latter demonstrating a greater likelihood of operative management. These findings should be reflected in future subaxial cervical spine trauma algorithms.