Management of mild degenerative cervical myelopathy and asymptomatic spinal cord compression: an international survey.

STUDY DESIGN: Cross-sectional survey. OBJECTIVE: Currently there is limited evidence and guidance on the management of mild degenerative cervical myelopathy (DCM) and asymptomatic spinal cord compression (ASCC). Anecdotal evidence suggest variance in clinical practice. The objectives of this study were to assess current practice and to quantify the variability in clinical practice. METHODS: Spinal surgeons and some additional health professionals completed a web-based survey distributed by email to members of AO Spine and the Cervical Spine Research Society (CSRS) North American Society. Questions captured experience with DCM, frequency of DCM patient encounters, and standard of practice in the assessment of DCM. Further questions assessed the definition and management of mild DCM, and the management of ASCC. RESULTS: A total of 699 respondents, mostly surgeons, completed the survey. Every world region was represented in the responses. Half (50.1%, n = 359) had greater than 10 years of professional experience with DCM. For mild DCM, standardised follow-up for non-operative patients was reported by 488 respondents (69.5%). Follow-up included a heterogeneous mix of investigations, most often at 6-month intervals (32.9%, n = 158). There was some inconsistency regarding which clinical features would cause a surgeon to counsel a patient towards surgery. Practice for ASCC aligned closely with mild DCM. Finally, there were some contradictory definitions of mild DCM provided in the form of free text. CONCLUSIONS: Professionals typically offer outpatient follow up for patients with mild DCM and/or asymptomatic ASCC. However, what this constitutes varies widely. Further research is needed to define best practice and support patient care.

Accuracy and reliability of the AO Spine subaxial cervical spine classification system grading subaxial cervical facet injury morphology.

PURPOSE: 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.

Risk factors for the need of surgical treatment of a first recurrent lumbar disc herniation.

PURPOSE: 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.

CT Scan in Subaxial Cervical Facet Injury: Is It Enough for Decision-Making?

STUDY 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.

Thoracic spine fractures: injury profile and outcomes of a surgically treated cohort.

There are only few reports in literature about the treatment of traumatic lesions of the thoracic spine. They have been grouped together with thoracolumbar fractures, ignoring the particular biomechanics of the thoracic segment. The objective of this retrospective cohort is to describe the clinical presentation and outcomes of surgically treated patients with these injuries. Data were obtained from the institutional database of medical registries, identifying all the patients who had been treated for thoracic spine fractures, from January 1, 1995 through December 31, 2005 in our institution. The study group included the 51 surgically treated patients. General and surgery-related complications were considered as clinical outcomes and injury-related disability was also assessed. Statistical analysis evaluating possible associations with timing and type of surgery, neurological impairment and associated injuries was carried out. Motor vehicle accident was the most frequent mechanism of injury. Six patients had an incomplete neurological deficit, whereas 22 had a complete lesion. Thirty-two patients presented at least one complication. Five of the neurologically intact patients, while 20 of those with neurological impairment presented general complications (p = 0.0001). None of the patients' neurological status deteriorated after surgery. All patients with complete spinal cord injury and those with incomplete cord injury with partial functional recovery received disability compensation. Short pedicle instrumentations should be used whenever possible, but also long instrumentations and mixed constructs may be necessary for the management of such unique fractures.

Speed hump spine fractures: injury mechanism and case series.

STUDY DESIGN: Retrospective case series. OBJECTIVES: To describe an injury mechanism and a series of patients with spine fractures after passing over speed humps in a motor vehicle. SUMMARY OF BACKGROUND DATA: The use of speed humps as an effective measure to reduce the rate of traffic accidents is still a matter of discussion. Furthermore, their use in mass transport routes may cause spine injuries among passengers in motor vehicles. METHODS: Review of the database in our medical records, identifying all the patients with spine fractures that occurred after passing over speed humps while in a motor vehicle, from January 1, 1997 to April 30, 2008 in the Hospital del Trabajador de Santiago, Chile. RESULTS: Of a sample of 46 patients with 52 fractures-none of them with neurologic impairment-37 female patients (80.4%) and 9 male patients (19.6%) with an average age of 48.5 years (16 to 70 y), 67.4% (31 of 46) presented comorbidities. Six patients presented 2 spine fractures, all of them at adjacent levels. Forty-four individuals (95.7%) were injured in a bus: 42 of 44 patients (95.5%) were seated on the last row, whereas the remaining 2 patients were bus drivers. All patients had type A Association for Osteosynthesis/Association for the Study of Internal Fixation fractures, 30/52 (57.7%) subtype A1 and 20/52 (38.5%) subtype A3. L1 was the most frequently fractured vertebra (23/52, 44.2%), followed by T12 (11/52, 21.2%). Ten patients (21.7%) required surgical treatment. The average time out of work was 104.3 days; 3 patients (6.5%) received workers' compensation for chronic lumbar pain. The mean follow-up time was 78.6 months (24 to 159). CONCLUSIONS: Seating in a motor vehicle, particularly on the last row in a bus, as it passes over a speed hump may cause severe traumatic spine injuries. These fractures occur more frequently at the thoracolumbar junction and treatment may require surgery.

Minimally Invasive Versus Open Surgery for the Treatment of Types B and C Thoracolumbar Injuries: A PRISMA Systematic Review.

BACKGROUND: Thoracic and lumbar spine injuries may require surgical management, particularly AO Spine types B and C injuries. Open reduction and fixation using pedicle screws, with or without fusion and/or decompression, is the gold standard surgical treatment for unstable injuries. Recent advances in instrumentation design have resulted in less-invasive surgeries. However, the literature is sparse about the effectiveness of these procedures for types B and C injuries. The objective is to compare the outcomes of conventional open surgery versus minimally invasive spine surgery (MISS) for the treatment of AO Spine types B and C thoracolumbar injuries. METHODS: A systematic review of published literature in PubMed, Web of Science, and Scopus was performed to identify studies comparing outcomes achieved with open versus minimally invasive surgery in AO Spine types B and C thoracolumbar injury patients. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used. RESULTS: Five retrospective case-control studies and 3 prospective studies met selection criteria. In general, most of the studies demonstrated that minimally invasive spine surgery is feasible for types B and C injuries, and associated with potential advantages like reduced blood loss, postoperative pain, and muscle injury, and shorter hospital stays. However, no differences were detected in major outcomes, like neurological status or disability. CONCLUSIONS: Published literature currently suggests that minimally invasive spine surgery is a valid alternative for treating types B and C thoracolumbar injuries. However, further comparative prospective randomized clinical trials are necessary to establish the superiority of one approach over the other. LEVEL OF EVIDENCE: 3.

Time to Surgery for Unstable Thoracolumbar Fractures in Latin America-A Multicentric Study.

OBJECTIVE: 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.

The Relationship Between Preoperative Clinical Presentation and Quantitative Magnetic Resonance Imaging Features in Patients With Degenerative Cervical Myelopathy.

BACKGROUND: Degenerative cervical myelopathy encompasses a group of conditions resulting in progressive spinal cord injury through static and dynamic compression. Although a constellation of changes can present on magnetic resonance imaging (MRI), the clinical significance of these findings remains a subject of controversy and discussion. OBJECTIVE: To investigate the relationship between clinical presentation and quantitative MRI features in patients with degenerative cervical myelopathy. METHODS: A secondary analysis of MRI and clinical data from 114 patients enrolled in a prospective, multicenter study was conducted. MRIs were assessed for maximum spinal cord compression (MSCC), maximum canal compromise (MCC), signal changes, and a signal change ratio (SCR). MRI features were compared between patients with and those without myelopathy symptoms with the use of t tests. Correlations between MRI features and duration of symptoms were assessed with the Spearman ρ. RESULTS: Numb hands and Hoffmann sign were associated with greater MSCC ( P < .05); broad-based, unstable gait, impairment of gait, and Hoffmann sign were associated with greater MCC ( P < .05); and numb hands, Hoffmann sign, Babinski sign, lower limb spasticity, hyperreflexia, and T1 hypointensity were associated with greater SCR ( P < .05). Patients with a T2 signal hyperintensity had greater MSCC and MCC ( P < .001). CONCLUSION: MSCC was associated with upper limb manifestations, and SCR was associated with upper limb, lower limb, and general neurological deficits. Hoffmann sign occurred more commonly in patients with a greater MSCC, MCC and SCR. The Lhermitte phenomenon presented more commonly in patients with a lower SCR and may be an early indicator of mild spinal cord involvement. Research to validate these findings is required.

Espondilodiscitis por haemophilus parainfluenzae: un reporte de caso / Spondylodiscitis due to haemophilus parainfluenzae: a case report

INTRODUCCIÓN Haemophilus parainfluenzae (HP) es un cocobacilo gram negativo y un patógeno oportunista. Rara vez se asocia a infecciones vertebrales o musculoesqueléticas, y está muy poco reportado en la literatura. PRESENTACIÓN DELO CASO Una mujer de 45 años, sana, que presentaba un historial de dos semanas de lumbalgia progresiva, fiebre, coriza y congestión nasal, y que tenía discitis intervertebral causada por HP, confirmada por dos hemocultivos positivos y hallazgos progresivos de resonancia magnética (RM) de columna lumbar. Los hallazgos de la RM fueron atípicos, y consistían en un absceso del psoas y pequeñas colecciones de líquido epidural e intraespinal anterior asociadas con espondilodiscitis. El diagnóstico inicial se retrasó debido a que la RM inicial no reveló hallazgos que sugirieran un proceso infeccioso. El tratamiento consistió en un ciclo prolongado de administración intravenosa seguida de antibióticos orales, lo que finalmente produjo una buena respuesta clínica. DISCUSIÓN Y CONCLUSIÓN El HP es un patógeno muy raro en la espondilodiscitis. No obstante, debe tenerse en cuenta, especialmente en pacientes que presentan lumbalgia y fiebre y/o bacteriemia por microorganismos gram negativos. El estudio inicial debe incluir una RM de la columna con contraste. Aunque es poco común, la espondilodiscitis y un absceso del psoas pueden presentarse concomitantemente. Los antibióticos prolongados son el pilar del tratamiento.

INTRODUCTION Haemophilus parainfluenzae (HP) is a gram-negative coccobacillus and an 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 in spondylodiscitis. Nonetheless, it should be considered, especially in patients presenting with low back pain and fever and/or gram negative bacteremia. The initial 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.

Risk Factors for Recurrence of Surgically Treated Conventional Spinal Schwannomas: Analysis of 169 Patients From a Multicenter International Database.

STUDY DESIGN: A retrospective analysis of 169 adult patients operated for a conventional spinal schwannoma from the AOSpine Multicenter Primary Spinal Tumors Database. OBJECTIVE: The aim of this study is to identify risk factors for local recurrence of conventional spinal schwannoma in patients who had surgery. SUMMARY OF BACKGROUND DATA: Schwannomas account for up to 30% of all adult spinal tumors. Total resection is the gold standard for patients with sensory or motor deficits. Local recurrence is reported to be approximately 5% and usually occurs several years after surgery. METHODS: Rates and time of local recurrence of spinal schwannoma were quantified. Predictive value of various clinical factors was assessed, including age, gender, tumor size, affected spinal segment, and type of surgery. Descriptive statistics and univariate regression analyses were performed. RESULTS: Nine (5.32%) out the 169 patients in this study experienced local recurrence approximately 1.7 years postoperatively. Univariate analyses revealed that recurrence tended to occur more often in younger patients (39.33 ±â€Š14.58 versus 47.01 ±â€Š15.29 years) and in the lumbar segment (55.56%), although this did not reach significance [hazard ratio (HR) 0.96, P = 0.127; and P = 0.195, respectively]. Recurrence also arose in the cervical and sacral spine (22.22%, respectively) but not in the thoracic area. Tumors were significantly larger in patients with recurrence (6.97 ±â€Š4.66  cm versus 3.81 ±â€Š3.34  cm), with extent in the cranial caudal direction posing the greatest hazard (HR = 1.321, P = 0.002). The location of the tumor, whether epidural, intradural, or both (P = 0.246), was not significantly related to recurrence. Regarding surgical technique, over 4 times as many patients who underwent intralesional resection experienced a recurrence proportionally to patients who underwent en bloc resection (HR = 4.178, P = 0.033). CONCLUSION: The pre-operative size of the conventional spinal schwannoma and intralesional resection are the main risk factors for local postoperative recurrence. LEVEL OF EVIDENCE: 3.

Prevalence of Klippel-Feil Syndrome in a Surgical Series of Patients with Cervical Spondylotic Myelopathy: Analysis of the Prospective, Multicenter AOSpine North America Study.

Study Design Prospective study. Objective To evaluate the prevalence of Klippel-Feil syndrome (KFS) in a prospective data set of patients undergoing surgical treatment for cervical spondylotic myelopathy (CSM) and to evaluate if magnetic resonance imaging (MRI) features in patients with KFS are more pronounced than those of non-KFS patients with CSM. Methods A retrospective analysis of baseline MRI data from the AOSpine prospective and multicenter CSM-North American study was conducted. All the patients presented with at least one clinical sign of myelopathy and underwent decompression surgery. The MRIs and radiographs were reviewed by three investigators. The clinical and imaging findings were compared with patients without KFS but with CSM. Results Imaging analysis discovered 5 of 131 patients with CSM (∼3.82%) had single-level congenital fusion of the cervical spine. The site of fusion differed for all the patients. One patient underwent posterior surgery and four patients received anterior surgery. Postoperative follow-up was available for four of the five patients with KFS and indicated stable or improved functional status. All five patients demonstrated pathologic changes of adjacent segments and hyperintensity signal changes in the spinal cord on T2-weighted MRI. Multiple MRI features, most notably maximum canal compromise (p = 0.05) and T2 signal hyperintensity area (p = 0.05), were worse in patients with CSM and KFS. Conclusions The high prevalence of KFS in our surgical series of patients with CSM may serve as an indication that these patients are prone to increased biomechanical use of segments adjacent to fused vertebra. This supposition is supported by a tendency of patients with KFS to present with more extensive MRI evidence of degeneration than non-KFS patients with CSM.

Does Magnetic Resonance Imaging Improve the Predictive Performance of a Validated Clinical Prediction Rule Developed to Evaluate Surgical Outcome in Patients With Degenerative Cervical Myelopathy?

STUDY DESIGN: Ambispective study. OBJECTIVE: To determine whether MRI parameters improve the predictive performance of a validated clinical prediction rule used to assess functional outcomes in surgical patients with DCM. SUMMARY OF BACKGROUND DATA: Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in the elderly worldwide. A clinical prediction rule was developed to discriminate between patients with mild myelopathy postoperatively (mJOA ≥ 16) and those with substantial residual neurological impairment (mJOA < 16). Recently, a separate magnetic resonance imaging (MRI)-based prediction model was created. However, a model exploring the combined predictive value of imaging and clinical variables does not exist. METHODS: One hundred and fourteen patients with MRIs were examined from a cohort of 278 patients enrolled in the AOSpine CSM-North America Study. Ninety-nine patients had complete preoperative imaging and postoperative outcome data. MRIs were evaluated for the presence/absence of signal change on T2- and T1-weighted images. Quantitative analysis of the T2 signal change was conducted and maximum canal compromise and cord compression were calculated. The added predictive performance of each MRI parameter to the clinical model was evaluated using receiver operator characteristic curves. RESULTS: The model developed on our subsample yielded an area under the receiver operator curve (AUC) of 0.811 (95% CI: 0.726-0.896). The addition of imaging variables did not significantly improve the predictive performance. Small improvements in prediction were obtained when sagittal extent of T2 hyperintensity (AUC: 0.826, 95% CI: 0.743-0.908, 1.35% increase) or Wang ratio (AUC: 0.823, 95% CI: 0.739-0.907, 1.21%) was added. Anatomic characteristics, such as maximum canal compromise and maximum cord compression, did not improve the discriminative ability of the clinical prediction model. CONCLUSION: In our sample of surgical patients, with clinical and image-evidence of DCM, MRI parameters do not significantly add to the predictive performance of a previously published clinical prediction rule. It remains plausible that combinations of the strongest clinical and MRI predictors may yield a similar or a superior prediction model. LEVEL OF EVIDENCE: 3.

Role of magnetic resonance imaging in predicting surgical outcome in patients with cervical spondylotic myelopathy.

STUDY DESIGN: Ambispective, retrospective cohort study from prospectively collected data. SUMMARY OF BACKGROUND DATA: Cervical spondylotic myelopathy is the commonest cause of spinal cord impairment in the elderly population worldwide. Although magnetic resonance imaging (MRI) is the primary imaging modality for confirming the diagnosis, its role in predicting surgical outcome remains unclear. METHODS: Two hundred seventy-eight patients with 1 or more clinical signs of myelopathy were enrolled; and they underwent decompression surgery. Complete baseline clinical and MRI data were available for 102 patients. MRI parameters measured included presence/absence of signal change on T1 and T2, T2 signal quantitative factors, and anatomical measurements. A dichotomized postoperative modified Japanese Orthopedic Association (mJOA) score at 6 months was used to characterize patients with mild myelopathy (≥16) and those with substantial residual neurological impairment (<16). Univariate analysis assessed the relationship between baseline parameters and outcome. Multivariate logistic regression was conducted after a conceptual division of variables into 3 groups: T1 signal analysis, T2 signal analysis, and anatomical measurements. RESULTS: Baseline mJOA (P<0.001; odds ratio [OR]=1.644, 95% confidence interval [95% CI]: 1.326-2.037), maximum canal compromise (MCC) (P=0.0322; OR=0.965, 95% CI: 0.934-0.997), T2 hyperintensity region of interest area (P=0.0422; OR=0.67; 95% CI: 0.456-0.986), and sagittal extent (P=0.026; OR=0.673; 95% CI: 0.475-0.954) were significantly associated with outcome univariately. The final model was comprised of T1 hypointensity (P=0.029; OR=0.242; CI: 0.068-0.866), MCC (P=0.005; OR=0.940; CI: 0.90-0.982) and baseline mJOA (P<0.001; OR=1.743; CI: 1.353-2.245), yielding an area under the receiver operating characteristic curve (AUC) of 0.845. CONCLUSION: Baseline mJOA is a strong predictor of postsurgical outcome in cervical spondylotic myelopathy at 6 months. However, a model inclusive of MCC and T1 hypointensity assessment provides superior predictive capacity. This suggests that MRI analysis has a significant role in predicting surgical outcome. LEVEL OF EVIDENCE: 3.

Isolated transverse sacral fractures.

BACKGROUND CONTEXT: The limited literature available about transverse sacral fractures describes two populations of patients: one with severe associated injuries and neurologic impairment and another with insufficiency fractures after low-energy trauma. Nevertheless, we have observed that isolated sacral fractures can occur in a third group of patients without the previously described features. PURPOSE: To describe the clinical features of a population of patients with isolated transverse sacral fractures and evaluate the results of their conservative treatment according to our experience. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Forty-two patients with isolated transverse sacral fractures with a mean follow-up of 22 months (range, 18-24 months). OUTCOMES MEASURES: Neurologic recovery, pain relief, time out of work, and disability. METHODS: We included all the patients admitted at our institution for an isolated transverse sacral fracture between 1996 and 2005. The information obtained from their medical records was analyzed using an electronic spreadsheet (Microsoft Excel for Mac v.2011; Microsoft, Redmond, WA, USA). RESULTS: Thirty-four patients (80%) sustained a low-energy trauma, whereas only two (4.8%) presented transient neurologic impairment. Every fracture was confirmed with a sacrococcygeal computed tomography (CT) scan. All the patients referred no local pain 6 months after the accident and were able to return to their preinjury activity level. None of the patients required compensation for disability. CONCLUSION: Transverse sacral fractures should be suspected in patients referring local pain after sustaining low-energy trauma, even in the absence of risk factors for an insufficiency fracture. These injuries are difficult to detect in plain X-rays, so a sacrococcygeal CT scan is recommended. Conservative treatment is associated with excellent results in this population of patients.

La actividad de metaloproteinasa-9 se asocia a estrés oxidativo en el síndrome coronario agudo / Metalloproteinase-9 activity is associated with oxidative stress in acute coronary syndrome

Antecedentes: La metaloproteinasas (MMPs) son enzimas proteolíticas que participan en la inestabilidad de la placa aterosclerótica. En cultivos celulares, la actividad de metaloproteinasas-2 y 9 (MMP-2 y MMP-9) aumenta en presencia de radicales libres del oxígeno. En una experiencia preliminar en pacientes con síndrome coronario agudo (SCA) hemos encontrado una posible asociación entre ambos fenómenos. Objetivo: Evaluar la relación entre actividad de enzimas de degradación de la matriz extracelular y estrés oxidativo (EO) en el SCA. Métodos: Estudiamos en forma prospectiva a 40 pacientes con SCA sin supradesnivel del segmento ST, puntaje TIMI ≥ 3 y alteraciones al electrocardiograma o elevación de Troponina I, que no presentaran un proceso inflamatorio. Se midió actividad de MMP-2 y MMP-9 (por zimografía en geles), malondialdehido (MDA) (mediante sustancias reactivas al ácido tiobarbitúrico) y PCR ultrasensible (PCRus) (ELISA), al ingreso y al quinto día. Se utilizó test t de Student para muestras pareadas y correlación lineal de Pearson. Resultados: De los 40 pacientes, 31 fueron hombres, la edad promedio fue 61+/-12 (38-85) años, todos con elevación de Troponina I. El puntaje TIMI fue de 4 (3-7). El 85 por ciento de los pacientes presentaron elevación de PCRus al ingreso (15,0+/-28,7 mg/L) y ésta aumentó al día 5 (35,3+/-38 mg/L, p=0,01); los niveles plasmáticos de MDA se encontraron elevados al ingreso (1,54+/-0,75 µM/L) y descendieron al quinto día (1,04+/-0,32 µM/L, p<0,0001). Al quinto día, la actividad de MMP-9 cayó a un 74+/-27 por ciento del valor basal (p<0,0001). No se observó cambio en la actividad de MMP-2. Se demostró una correlación positiva entre las fracciones de cambio de MDA y MMP-9 (r=0,43, p<0,0001). Conclusiones: En pacientes con SCA se observa un aumento precoz en el grado de inflamación, actividad de MMP-9 y de EO...

Background: Metalloproteinases are proteolytic enzymes that participate in atherosclerotic plaque instability. In cellular cultures there is increased activity of metalloproteinases-2 and 9 (MMP-2 and MMP-9) in the presence of free oxygen radicals. In a preliminary experience in patients with acute coronary syndrome (ACS) we have found a possible association between both phenomena. Objective: To evaluate the relation between activity of matrix degradation proteins and oxidative stress (OS) in acute coronary syndrome. Methods: Fourty patients with non-ST segment elevation acute coronary syndrome were prospectively studied. All had a TIMI risk score ≥ 3, ischemic changes on electrocardiogram or Troponin I elevation, without a concomitant inflammatory condition. We determined MMP-2 and MMP-9 activities (gel zymography), malondialdehyde (MDA) (thiobarbituric acid reactive species) and high sensitive C reactive protein (hsCRP) plasma levels at admission and 5 days later. Paired samples Student’ t test and Pearson’s lineal correlation were used for statistical analysis. Results: Of the 40 patients, 31 were male, mean age 61+/-12 years old (range 38-85), all of them with Troponin I elevation. The TIMI risk score was 4 (3-7). 85 percent presented hsCRP elevation (15.0+/-28,7 mg/L at admission and 35.3+/-38 mg/L at day 5). MDA plasma levels were increased at admission (1,54+/-0,75 µM/L) and diminished at day 5 (1,04+/-0,32 µM/L, p<0,0001). Compared to basal values, MMP-9 activity decreased to 74+/- 27 percent at day 5, (p<0,001). No significant change was observed in MMP-2 activity between both measurements. A significant positive correlation was found between change fractions of MDA levels and MMP-9 activity (r=0,43, p<0,0001). Conclusions: In patients with ACS we observed an early increase in inflammation markers, MMP-9 activity and OS. The correlation demonstrated between MMP-9 activity and OS suggests a common role of both phenomena in the pathophysiology...