Browsing by Author "Valacco, Marcelo"
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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 An independent inter- and intraobserver agreement assessment of the AOSpine sacral fracture classification system(2021) Urrutia, Julio; Meissner-Haecker, Arturo; Astur, Nestor; Valencia, Manuel; Yurac, Ratko; Camino-Willhuber, Gaston; Valacco, MarceloBACKGROUND CONTEXT: The AOSpine sacral classification scheme was recently described. It demonstrated substantial interobserver and excellent intraobserver agreement in the study describing it; however, an independent assessment has not been performed. PURPOSE: To perform an independent inter- and intraobserver agreement evaluation of the AOSpine sacral fracture classification system. STUDY DESIGN: Agreement study. METHODS: Complete computerized tomography (CT) scans, including axial images, with coronal and sagittal reconstructions of 80 patients with sacral fractures were selected and classified using the morphologic grading of the AOSpine sacral classification system by six evaluators (from three different countries). Neurological modifiers and case-specific modifiers were not assessed. After a four-week interval, the 80 cases were presented to the same raters in a random sequence for repeat assessment. We used the Kappa coefficient (k) to establish the inter- and intraobserver agreement. RESULTS: The interobserver agreement was substantial when considering the fracture severity types (A, B, or C), with k=0.68 (0.63−0.72), but moderate when considering the subtypes: k=0.52 (0.49−0.54). The intraobserver agreement was substantial considering the fracture types, with k=0.69 (0.63−0.75), and considering subtypes, k=0.61(0.56−0.67). CONCLUSION: The sacral classification system allows adequate interobserver agreement at the type level, but only moderate at the subtypes level. Future prospective studies should evaluate whether this classification system allows surgeons to decide the best treatment and to establish prognosis in patients with sacral fractures.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.Publication Inter- and intra-observer agreement using the new AOSpine sacral fracture classification, with a comparison between spine and pelvic trauma surgeons(2021) Meissner, Arturo; Diaz, Claudio; Klaber, Ianiv; Zamora, Tomas; Valencia, Manuel; Camino, Gaston; Astu, Nelson; Yurac, Ratko; Valacco, Marcelo; Urrutia, JulioBackground: Sacral fractures treatment frequently involves both spine and pelvic trauma surgeons; therefore, a consistent communication among surgical specialists is required. We independently assessed the new AOSpine sacral fracture classification's agreement from the perspective of spine and pelvic trauma surgeons. Methods: Complete computerized tomography (CT) scans of 80 patients with sacral fractures were selected and classified using the new AOSpine sacral classification system by six spine surgeons and three pelvic trauma surgeons. After four weeks, the 80 cases were presented and reassessed by the same raters in a new random sequence. The Kappa coefficient (κ) was used to measure the inter-and intra-observer agreement. Results: The inter-observer agreement considering the fracture severity types (A, B, or C) was substantial for spine surgeons (κ= 0.68 [0.63 - 0.72]) and pelvic trauma surgeons (κ= 0.74 (0.64 - 0.84). Regarding the subtypes, both groups achieved moderate agreement with κ= 0.52 (0.49 - 0.54) for spine surgeons and κ= 0.51 (0.45 - 0.57) for pelvic trauma surgeons. The intra-observer agreement considering the fracture types was substantial for spine surgeons (κ= 0.74 [0.63 - 0.75]) and almost perfect for pelvic trauma surgeons (κ= 0.84 [0.74 - 0.93]). Concerning the subtypes, both groups achieved substantial agreement with, κ= 0.61 (0.56 - 0.67) for spine surgeons and κ= 0.68 (0.62 - 0.74) for pelvic trauma surgeons. Conclusion: This classification allows an adequate communication for spine surgeons and pelvic trauma surgeons at the fracture severity type, but the agreement is only moderate at the subtype level. Future prospective studies are required to evaluate whether this classification allows for treatment recommendations and establishing prognosis in patients with sacral fractures.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 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 Group