An international consensus based on the Delphi method to define failure of medical treatment in pyogenic spinal infections.

BACKGROUND CONTEXT: Pyogenic spinal infections (PSIs) are severe conditions with high morbidity and mortality. If medical treatment fails, patients may require surgery, but there is no consensus regarding the definition of medical treatment failure. PURPOSE: To determine criteria for defining failure of medical treatment in PSI through an international consensus of experts. STUDY DESIGN: A two-round basic Delphi method study. SAMPLE: One hundred and fifty experts from 22 countries (authors or co-authors of clinical guidelines or indexed publications on the topic) were invited to participate; 33 answered both rounds defining the criteria. OUTCOME MEASURES: A scale of 1 to 9 (1: no relevance; 9: highly relevant) applied to each criterion. METHODS: We created an online survey with 10 criteria reported in the literature to define the failure of medical treatment in PSIs. We sent this survey via email to the experts. Agreement among the participants on relevant criteria (score ≥7) was determined. One month later, the second round of evaluations was sent. An extra criterion suggested by six responders in the first round was incorporated. The final version was reached with the criteria considered relevant and with high agreement. RESULTS: The consensus definition is: (1) There is an uncontrolled sepsis despite broad spectrum antibiotic treatment, and (2) There is an infection relapse, following a six-week period of antibiotics with clinical and laboratory improvement. CONCLUSIONS: Our definition of failure following nonsurgical treatment of PSI can offer a standardized approach to guide clinical decision-making. Furthermore, it has the potential to enhance scientific reporting within this field.

An independent inter- and intra-observer agreement assessment of the AOSpine upper cervical injury classification system.

BACKGROUND 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.

Update on the Diagnosis and Management of Spinal Infections.

Pyogenic spinal infections are uncommon, but their incidence has increased. Diagnosis is based on clinical, laboratory, and imaging findings. Delayed diagnosis occurs frequently and can lead to poor outcomes. Early radiographic findings are nonspecific; MRI is the best imaging study for diagnosis. The goal of treatment is to eradicate infection, prevent recurrence, preserve spinal stability, avoid deformity, relieve pain, and prevent or reverse neurologic deficit. Current guidelines recommend antibiotics be administered for 6 weeks if there is resolution of symptoms and normalization of inflammatory parameters. Surgery is required in patients with neurologic deficit, uncontrolled sepsis, spinal instability, deformity, and failure of medical treatment and to manage epidural abscess. Classic treatment of epidural abscess is surgical, but recent studies have challenged this approach. Surgical techniques used to manage these infections are varied; they include anterior, posterior, and combined approaches, and minimally invasive surgery. Current management has decreased mortality; however, the prognosis is affected by treatment failure, recurrent infection, or potential of persistent disability secondary to deformity, chronic pain, or permanent neurologic impairment.

Reliability Evaluation of the New AO Spine-DGOU Classification for Osteoporotic Thoracolumbar Fractures.

OBJECTIVES: 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.

Inter- and intra-observer agreement using the new AOSpine sacral fracture classification, with a comparison between spine and pelvic trauma surgeons.

BACKGROUND: 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.

An inter- and intra-rater agreement assessment of a novel classification of pyogenic spinal infections.

PURPOSE: Pola et al. described a clinical-radiological classification of pyogenic spinal infections (PSI) based on magnetic resonance imaging (MRI) features including vertebral destruction, soft tissue involvement, and epidural abscess, along with the neurological status. We performed an inter- and intra-observer agreement evaluation of this classification. METHODS: Complete MRI studies of 80 patients with PSI were selected and classified using the scheme described by Pola et al. by seven evaluators. After a four-week interval, all cases were presented to the same assessors in a random sequence for repeat assessment. We used the weighted kappa statistics (wκ) to establish the inter- and intra-observer agreement. RESULTS: The inter-observer agreement was substantial considering the main categories (wκ = 0.77; 0.71-0.82), but moderate considering the subtypes (wκ = 0.51; 0.45-0.58). The intra-observer agreement was substantial considering the main types (wκ = 0.65; 0.59-0.71), and moderate considering the subtypes (wκ = 0.58; 0.54-0.63). CONCLUSION: The agreement at the main type level indicates that this classification allows adequate communication and may be used in clinical practice; at the subtypes level, the agreement is only moderate.

Mid and lower thoracic kyphosis changes during adulthood: the influence of age, sex and thoracic coronal curvature.

INTRODUCTION: There is conflicting data on how thoracic kyphosis changes throughout adulthood. We evaluated mid and lower thoracic kyphosis (MTK) in various age groups and the influence of age, sex and coronal curve (CC) on MTK. MATERIAL AND METHODS: We studied 1323 patients 15-80 years-old (54.4% females) previously evaluated with chest radiographs. We established three groups: patients 15-40 (group 1); 41-60 (group 2) and 61-80 years old (group 3). MTK (T5-T12) and CC were measured using Cobb's method. We established differences in MTK between groups using ANOVA with Bonferroni correction. We performed a correlation analysis of MTK with age and CC, and a linear regression analysis to determine if age, sex and CC independently predicted MTK. RESULTS: MTK increased with older age: mean MTK group 1 = 23.4°; group 2 = 27.9° and group 3 = 34.4°, p < 0.01. The increase in MTK was observed in both genders. Scoliosis was more common in females (15.4%) than in males (6.7%), p < 0.01. MTK was correlated with age (r = 0.4; p < 0.01) and slightly correlated with CC (r = 0.07, p < 0.01). MTK was larger in females than in males (29.1° vs. 27.6°, p < 0.01). Age (ß-coefficient = 0.26) and CC (ß-coefficient = 0.14), but not sex, independently influenced MTK in the regression analysis. CONCLUSION: MTK increases with advancing age during adulthood in both genders; CC, but not sex, was an independent predictor of MTK.

An independent inter- and intra-observer agreement assessment of the Eno classification of sacroiliac joint degeneration.

BACKGROUND: Recently, a scoring system to grade sacroiliac joint (SIJ) degeneration using computed tomography (CT) scans was described. No independent evaluation has determined the inter- and intra-observer agreement using this scheme. PURPOSE: To perform an independent inter- and intra-observer agreement assessment using the Eno classification and determining gas in the SIJ. MATERIAL AND METHODS: We studied 64 patients aged ≥60 years who were evaluated with abdominal and pelvic computed tomography scans. Six physicians (three orthopaedic spine surgeons and three musculoskeletal radiologists) assessed axial images to grade SIJ degeneration into grade 0 (normal), grade 1 (mild degeneration), grade 2 (significant degeneration), and grade 3 (ankylosis). We also evaluated the agreement assessing the presence of gas in the SIJ. After a four-week interval, all cases were presented in a random sequence for repeat assessment. We determined the agreement using the kappa (κ) or weighted kappa coefficient (wκ). RESULTS: The inter-observer agreement was moderate (wκ = 0.50 [0.44-0.56]), without differences among surgeons (wκ = 0.53 [0.45-0.61]) and radiologists (wκ = 0.49 [0.42-0.57]). The agreement evaluating the presence of gas was also moderate (κ = 0.45 [0.35-0.54]), but radiologists obtained better agreement (κ = 0.61 [0.48-0.72]) than surgeons (κ = 0.29 [0.18-0.39]). The intra-observer agreement using the classification was substantial (wκ = 0.79 [0.76-0.82]), without differences comparing surgeons (wκ = 0.75 [0.70-0.80]) and radiologists (wκ = 0.83 [0.79-0.87]). The intra-rater agreement evaluating gas was substantial (κ = 0.77 [0.72-0.82]), without differences between surgeons (κ = 0.71 [0.63-0.78]) and radiologists (κ = 0.84 [0.78-0.90]). CONCLUSION: Given the only moderate agreement obtained using the Eno classification, it does not seem adequate to be used in clinical practice or in research.

An independent inter- and intraobserver agreement assessment of the AOSpine sacral fracture classification system.

BACKGROUND 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 (κ) to establish the inter- and intraobserver agreement. RESULTS: The interobserver agreement was substantial when considering the fracture severity types (A, B, or C), with κ=0.68 (0.63-0.72), but moderate when considering the subtypes: κ=0.52 (0.49-0.54). The intraobserver agreement was substantial considering the fracture types, with κ=0.69 (0.63-0.75), and considering subtypes, κ=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.

The new AO classification system for intertrochanteric fractures allows better agreement than the original AO classification. An inter- and intra-observer agreement evaluation.

BACKGROUND: A new AO classification for intertrochanteric fractures was recently published; no studies have evaluated its inter- and intra-observer agreement. METHODS: Six evaluators (three hip subspecialists and three residents) assessed radiographs of 68 intertrochanteric fractures; fractures were classified using the original and the new AO classifications. The cases were displayed in a random sequence after a six-week interval for repeat evaluation. We used the Kappa coefficient (k) to determine inter- and intra-observer agreement. RESULTS: Inter-observer agreement was slight (k = 0.128 [0.092-0.170]) using the original and fair (k = 0.250 [0.186-0.327]), with the new AO classification. Orthopedic residents exhibited better agreement than hip surgeons using the original classification (k = 0.302 [0.210-0.416] and k= -0.018 [-0.058-0.029], respectively) and the new classification (k = 0.388 [0.294-0.514] and k = 0.109 [0.031-0.192], respectively). Using both classifications as dichotomous variables (stable or unstable patterns), the agreement was slight (k = 0.158 [0.074-0.246]) using the original classification and moderate (k = 0.425 [0.308-0.550]) with the new AO classification. INTRA-OBSERVER: The agreement was fair using the original (k = 0.350 [0.278-0.424]) and the new (k = 0.295 [0.239 to 0.353]) AO classifications, respectively. Residents had better agreement than hip specialists using the original (k = 0.405 [0.303-0.512]) versus (k = 0.292 [0.193-0.293]) and the new classification (k = 0.449 [0.370 to 0.528] versus k = 0.129 [0.064 to 0.208]). CONCLUSION: The inter-observer agreement using the new AO classification was significantly better than using its original version. Also, the new AO classification system allowed better agreement when distinguishing stable from unstable patterns.

Infecciones piógenas de la columna vertebral / Pyogenic spinal infections

Las infecciones espinales son cuadros clínicos poco frecuentes, que exigen un alto índice de sospecha. La prevalencia de infecciones piógenas de la columna ha ido en aumento, en parte debido al envejecimiento de la población y a un mayor número de pacientes inmunocomprometidos. El estudio imagenológico se puede iniciar con radiografías simples, pero la resonancia magnética es el examen imagenológico de elección, ya que puede dar resultados positivos de forma precoz, entregando información más detallada del compromiso vertebral y tejidos blandos adyacentes. Aunque la clínica y los hallazgos imagenológicos nos pueden orientar, es importante intentar un diagnóstico microbiológico tomando cultivos y muestras para identificar al agente causal antes de iniciar los antibióticos; aunque es óptimo un tratamiento agente-específico, hasta un 25% de los casos queda sin diagnóstico del agente. El tratamiento es inicialmente médico, con antibióticos e inmovilización, pero se debe considerar la cirugía en casos de compromiso neurológico, deformidad progresiva, inestabilidad, sepsis no controlada o dolor intratable. El manejo quirúrgico actual consiste en el aseo y estabilización precoz de los segmentos vertebrales comprometidos. Descartar una endocarditis concomitante y el examen neurológico seriado son parte del manejo de estos pacientes.

Spinal infections are unusual conditions requiring a high index of suspicion for clinical diagnosis. There has been a global increase in the number of pyogenic spinal infections due to an aging population and a higher proportion of immunocompromised patients. The imaging study should start with plain radiographs, but magnetic resonance imaging (mri) is the gold standard for diagnosis. Mri can detect bone and disc changes earlier than other methods, and it provides detailed information on bone and adjacent soft tissues. Blood cultures and local samples for culture and pathology should be obtained, trying to identify the pathogen. According to the result, the most appropriate drug must be selected depending on susceptibility and penetration into spinal tissues. Treatment should start with antibiotics and immobilization; surgery should be considered in cases with neurological impairment, progressive deformity, spine instability, sepsis, or non-controlled pain. Current surgical treatment includes debridement and early stabilization. Practitioners should rule out endocarditis and perform a serial neurological examination managing these patients.

Management of patients with low back pain in the emergency department: Is it feasible to follow evidence-based recommendations?

OBJECTIVE: Low back pain is frequently seen in patients visiting the ED, but many patients receive medical care with no demonstrable benefits. We studied the clinical characteristics of patients visiting two EDs in Santiago, Chile, and their management to evaluate how it adheres to evidence-based recommendations. METHODS: We studied 519 patients and retrieved their demographic and clinical data, imaging testing and treatments. We determined the effect of sex, age, time from initial symptoms, pain measured with the visual analogue scale, presence of nerve radiation and the presence of red flags and neurological impairment on image testing and the management received. RESULTS: Mean age was 43.8 years; 57.8% were females. Females presented more often red flags (7.3 vs 3%, P = 0.04) and worse pain (visual analogue scale = 7 vs 6, P = 0.04) than males. Imagings were performed in 18.9% of patients; they were more frequently performed in patients with neurological impairment (P = 0.03) and red flags (P = 0.01). Intravenous non-opioids were administered in 25.6%; opioids were administered in 40.1%. Median time in the ED was 91 min (range 18-591); 16 (3.08%) patients were admitted. Age (odds ratio [OR] 1.04 [1.03-1.05], P < 0.01) and red flags (OR 4.9 [1.60-20.08], P < 0.01) influenced imaging testing; pain intensity influenced opioid use (OR 1.6 [1.29-1.95], P < 0.01), hospital admissions (1.95 [1.14-3.33], P < 0.01) and time in the ED (ß = 0.5, P < 0.01). CONCLUSION: Older age, the presence of red flags and pain intensity influenced the management of patients with low back pain in the ED. Future strategies should emphasise avoiding costly and ineffective management in these patients.

An Independent Validation of the Brighton Spondylodiscitis Score and a Proposal to Modify the Score.

INTRODUCTION: The Brighton Spondylodiscitis Score (BSS) aims to identify patients with pyogenic spinal infections (PSIs) requiring surgery; an independent assessment of the BSS is required. METHODS: We evaluated 60 patients with PSIs. Using the BSS, we determined whether patients with low, moderate, and high risk (LMHR) had different rates of surgery. We proposed a modified score (MS) using a logistic regression (LOGR). Applying the MS, we determined whether patients with LMHR exhibited different rates of surgery. Another LOGR determined the association of the BSS and the MS with surgery. A C-statistic using the BSS and the MS was generated. RESULTS: We studied 60 patients (mean age = 63 years); 37 (62%) were men; 30 (50%) required surgery. Using the BSS, patients with LMHR had similar rates of surgery (P = 0.53). LOGR showed that cervical PSIs had a larger chance of surgery (odds ratio [OR] = 7.3 [1.1 to 51.3]) than other locations. Using the MS, patients with moderate- and high-risk were operated more frequently than low-risk patients (P = 0.04). The BSS did not predict surgery (OR = 1.07; P = 0.31), but the MS did (OR = 1.16; P = 0.02). The C-statistic using the BSS (0.59) improved using the MS (0.69), P = 0.03. DISCUSSION: The discriminatory capacity to predict surgery of the BSS augmented using the MS. LEVEL OF EVIDENCE: II (Diagnostic study: Transverse study).

A novel intraoperative technique seeding morselized bone tissue into pediatric blood culture bottles improves microbiological diagnosis in patients with foot and ankle osteomyelitis.

BACKGROUND: Osteomyelitis, particularly cases involving the foot and ankle, is a challenging situation that frequently leads to amputations and major sequelae. Targeted antibiotics treating an identified pathogen are key to a successful outcome; however, traditional culture methods for bone tissue have poor sensitivity. This study prospectively compared a novel method for obtaining and processing infected bone tissue with the standard technique. METHODS: 107 patients presenting with a diagnosis of osteomyelitis of the foot and ankle between 2008 and 2017 were prospectively included. Diagnosis was done according to clinical, laboratory and imaging findings. We obtained paired samples of bone tissue from all patients; they were processed through a usual culture method (UCM), but they were also morselized and seeded into pediatric blood culture bottles (PBCBs). We compared the culture yield and the number of agents detected using both the McNemar and the Mann-Whitney tests, respectively. RESULTS: We studied 107 patients (63 with diabetic foot infection and 44 with nondiabetic osteomyelitis). The causative agent was identified in 60.7% of cases using the UCM and in 97.2% of cases using PBCBs (p < 0.001). We detected a mean of 1.05 ± 1.03 bacteria using the UCM and 1.67 ± 0.92 bacteria using PBCBs (p < 0.01). CONCLUSION: Cultures using morselized bone seeded in PBCBs identified the causative agent in a significantly larger percentage than the UCM. Additionally, this method identified a larger number of pathogen agents. A better agent identification method has advantages such as identifying more specific antibiotic treatment in these cases.

Do Patients Older Than 60 Years With Inflammatory Bowel Disease Have More Vertebral Fractures Than Age-matched Controls? A Study Using Abdominal and Pelvic CT Scans With Sagittal Reformatting as Screening Tool.

INTRODUCTION: It is undetermined whether patients with inflammatory bowel diseases (IBDs) have increased prevalence of vertebral compression fractures (VCFs) since many VCFs are asymptomatic and radiographs may overlook them. We compared the prevalence of VCFs in patients older than 60 years with and without IBDs. METHODS: We studied 55 patients with IBDs and 165 controls who underwent CT scans for nonspinal conditions. We evaluated the presence of VCFs, fracture severity using the Genant score, and we determined whether age, sex, diagnosis of IBD, treatment, and time since diagnosis were associated with VCFs. Using logistic regression analysis, we assessed the independent effect of each variable. RESULTS: Mean age was 72.7 years; 165 patients (75%) were women. Thirty-five patients (16%) had at least one VCF (16.4% IBD; 15.8% controls, P = 0.92); both groups exhibited similar fracture severity. Patients with VCFs were older than patients without VCFs (79.8 versus 70.2, P < 0.01 IBD; 76.4 versus 72.4, P = 0.02 controls). No other clinical variables were different in patients with and without VCFs in either cohort. Only age was independently associated with VCFs in both cohorts. DISCUSSION: VCFs were not more frequent or severe in patients older than 60 years with IBD presented than in age-matched controls.

A New Classification System for Pilon Fractures Based on CT Scan: An Independent Interobserver and Intraobserver Agreement Evaluation.

BACKGROUND DATA: A new pilon fracture classification system based on CT scan data was recently published, showing almost perfect interobserver and intraobserver agreement among the authors who developed it. However, an independent assessment has not been done. OBJECTIVE: To do an independent agreement evaluation of the new pilon fracture classification system with physicians with different levels of expertise in the management of pilon fractures. METHODS: Seventy-one cases of acute pilon fracture were retrospectively collected. Fractures were classified by six evaluators (three foot and ankle surgeons and three orthopaedic surgery residents) using CT scans according to the morphological grading of the new pilon fracture classification system developed by Leonetti et al. Cases were presented to the same evaluators in a random sequence after a 6-week interval to determine intraobserver agreement. The kappa coefficient (κ) was used to determine agreement among evaluators. RESULTS: The interobserver agreement was substantial regarding the main fracture type (I, II, III, or IV), with an overall κ value of 0.69 (0.65 to 0.72). When including the II and III subtypes, the overall agreement was still substantial, with a κ value of 0.61 (95% confidence interval: 0.58 to 0.64). The intraobserver agreement was substantial when considering the main fracture categories (I, II, III, or IV), with a κ value of 0.78 (confidence interval: 0.72 to 0.84), and full agreement at the type level was observed in 76% (324/426) of evaluations. There was no notable difference between the foot and ankle surgeons and orthopaedic surgery residents in the interobserver and intraobserver agreement. CONCLUSION: The new classification system demonstrated substantial interobserver and intraobserver agreement between evaluators with different levels of expertise in the management of pilon fractures. Prospective studies should be done to evaluate its prognostic value and utility in clinical practice.

Prevalence of lumbar high-intensity zone: assessment using a screening tool independent of spinal symptoms.

High-intensity zone is an area of high-intensity signal within the posterior annulus fibrosus observed in magnetic resonance imaging; initially described in painful discs, recent studies have described similar prevalence in symptomatic and asymptomatic subjects. Since its' prevalence in the general population has not been established, we used a screening tool independent of spinal symptoms to determine high-intensity zone prevalence. We studied 217 patients evaluated with abdominal-pelvic magnetic resonance imaging; we looked for high-intensity zone, disc degeneration, spondylolysis, spondylolisthesis, Modic changes and scoliosis. We determined if these variables, age and sex affected the presence of high-intensity zone; through a logistic regression analysis we evaluated their independent effect. Patients' mean age was 56.3±17.4 years; 66.8% were females. Prevalence of high-intensity zone (11.06%) was larger in males (18.06%) than females (7.59%), p = 0.02. Patients with and without high-intensity zone did not differ in age or presence of scoliosis. High-intensity zone was more frequent in degenerated discs, but not in levels with spondylolisis, spondylolisthesis or Modic changes. Male sex (OR = 2.3, 1.04-5.38) and disc degeneration (OR = 6.76, 1.77-25.81) independently influenced the presence of high-intensity zone. The prevalence of high-intensity zone in this sample of the general population, including 217 subjects, was 11.06%. Similarly, a recent meta-analysis mentioned a 9.5% prevalence in asymptomatic subjects; on the other hand it stressed a 10.4% prevalence in symptomatic subjects. All these data do not plead for a strict correlation between high-intensity zone and low back pain complaints.