Marcel F. Dvorak

A New Classification of Thoracolumbar Injuries: The Importance of Injury Morphology, the Integrity of the Posterior Ligamentous Complex, and Neurologic Status

Study Design. A new proposed classification system for thoracolumbar (TL) spine injuries, including injury severity assessment, designed to assist in clinical management. Objective. To devise a practical, yet comprehensive, classification system for TL injuries that assists in clinical decision-making in terms of the need for operative versus nonoperative care and surgical treatment approach in unstable injury patterns. Summary of Background Data. The most appropriate classification of traumatic TL spine injuries remains controversial. Systems currently in use can be cumbersome and difficult to apply. None of the published classification schemata is constructed to aid with decisions in clinical management. Methods. Clinical spine trauma specialists from a variety of institutions around the world were canvassed with respect to information they deemed pivotal in the communication of TL spine trauma and the clinical decision-making process. Traditional injury patterns were reviewed and reconsidered in light of these essential characteristics. An initial validation process to determine the reliability and validity of an earlier version of this system was also undertaken. Results. A new classification system called the Thoracolumbar Injury Classification and Severity Score (TLICS) was devised based on three injury characteristics: 1) morphology of injury determined by radiographic appearance, 2) integrity of the posterior ligamentous complex, and 3) neurologic status of the patient. A composite injury severity score was calculated from these characteristics stratifying patients into surgical and nonsurgical treatment groups. Finally, a methodology was developed to determine the optimum operative approach for surgical injury patterns. Conclusions. Although there will always be limitations to any cataloging system, the TLICS reflects accepted features cited in the literature important in predicting spinal stability, future deformity, and progressive neurologic compromise. This classification system is intended to be easy to apply and to facilitate clinical decision-making as a practical alternative to cumbersome classification systems already in use. The TLICS may improve communication between spine trauma physicians and the education of residents and fellows. Further studies are underway to determine the reliability and validity of this tool.

Early versus Delayed Decompression for Traumatic Cervical Spinal Cord Injury: Results of the Surgical Timing in Acute Spinal Cord Injury Study (STASCIS)

Background There is convincing preclinical evidence that early decompression in the setting of spinal cord injury (SCI) improves neurologic outcomes. However, the effect of early surgical decompression in patients with acute SCI remains uncertain. Our objective was to evaluate the relative effectiveness of early (<24 hours after injury) versus late (≥24 hours after injury) decompressive surgery after traumatic cervical SCI. Methods We performed a multicenter, international, prospective cohort study (Surgical Timing in Acute Spinal Cord Injury Study: STASCIS) in adults aged 16–80 with cervical SCI. Enrolment occurred between 2002 and 2009 at 6 North American centers. The primary outcome was ordinal change in ASIA Impairment Scale (AIS) grade at 6 months follow-up. Secondary outcomes included assessments of complications rates and mortality. Findings A total of 313 patients with acute cervical SCI were enrolled. Of these, 182 underwent early surgery, at a mean of 14.2(±5.4) hours, with the remaining 131 having late surgery, at a mean of 48.3(±29.3) hours. Of the 222 patients with follow-up available at 6 months post injury, 19.8% of patients undergoing early surgery showed a ≥2 grade improvement in AIS compared to 8.8% in the late decompression group (OR = 2.57, 95% CI:1.11,5.97). In the multivariate analysis, adjusted for preoperative neurological status and steroid administration, the odds of at least a 2 grade AIS improvement were 2.8 times higher amongst those who underwent early surgery as compared to those who underwent late surgery (OR = 2.83, 95% CI:1.10,7.28). During the 30 day post injury period, there was 1 mortality in both of the surgical groups. Complications occurred in 24.2% of early surgery patients and 30.5% of late surgery patients (p = 0.21). Conclusion Decompression prior to 24 hours after SCI can be performed safely and is associated with improved neurologic outcome, defined as at least a 2 grade AIS improvement at 6 months follow-up.

The subaxial cervical spine injury classification system: a novel approach to recognize the importance of morphology, neurology, and integrity of the disco-ligamentous complex.

Study Design. The classification system was derived through a literature review and expert opinion of experienced spine surgeons. In addition, a multicenter reliability and validity study of the system was conducted on a collection of trauma cases. Objectives. To define a novel classification system for subaxial cervical spine trauma that conveys information about injury pattern, severity, treatment considerations, and prognosis. To evaluate reliability and validity of this system. Summary of Background Data. Classification of subaxial cervical spine injuries remains largely descriptive, lacking standardization and prognostic information. Methods. Clinical and radiographic variables encountered in subaxial cervical trauma were identified by a working section of the Spine Trauma Study Group. Significant limitations of existing systems were defined and addressed within the new system. This system, as well as the Harris and Ferguson & Allen systems, was applied by 20 spine surgeons to 11 cervical trauma cases. Six weekslater, the cases were randomly reordered and again scored. Interrater reliability, intrarater reliability, and validity were assessed. Results. Each of 3 main categories (injury morphology, disco-ligamentous complex, and neurologic status) identified as integrally important to injury classification was assigned a weighted score; the injury severity score was obtained by summing the scores from each category. Treatment options were assigned based on threshold values of the severity score. Interrater agreement as assessed by intraclass correlation coefficient of the DLC, morphology, and neurologic status scores was 0.49, 0.57, and 0.87, respectively. Intrarater agreement as assessed by intraclass correlation coefficient of the DLC, morphology, and neurologic status scores was 0.66, 0.75, and 0.90, respectively. Raters agreed with treatment recommendations of the algorithm in 93.3% of cases, suggesting high construct validity. The reliability compared favorably to the Harris and Ferguson & Allen systems. Conclusion. The Sub-axial Injury Classification and Severity Scale provides a comprehensive classification system for subaxial cervical trauma. Early validity and reliability data are encouraging.

AOSpine thoracolumbar spine injury classification system: fracture description, neurological status, and key modifiers.

Study Design. Reliability and agreement study, retrospective case series. Objective. To develop a widely accepted, comprehensive yet simple classification system with clinically acceptable intra- and interobserver reliability for use in both clinical practice and research. Summary of Background Data. Although the Magerl classification and thoracolumbar injury classification system (TLICS) are both well-known schemes to describe thoracolumbar (TL) fractures, no TL injury classification system has achieved universal international adoption. This lack of consensus limits communication between clinicians and researchers complicating the study of these injuries and the development of treatment algorithms. Methods. A simple and reproducible classification system of TL injuries was developed using a structured international consensus process. This classification system consists of a morphologic classification of the fracture, a grading system for the neurological status, and description of relevant patient-specific modifiers. Forty cases with a broad range of injuries were classified independently twice by group members 1 month apart and analyzed for classification reliability using the Kappa coefficient (&kgr;). Results. The morphologic classification is based on 3 main injury patterns: type A (compression), type B (tension band disruption), and type C (displacement/translation) injuries. Reliability in the identification of a morphologic injury type was substantial (&kgr;= 0.72). Conclusion. The AOSpine TL injury classification system is clinically relevant according to the consensus agreement of our international team of spine trauma experts. Final evaluation data showed reasonable reliability and accuracy, but further clinical validation of the proposed system requires prospective observational data collection documenting use of the classification system, therapeutic decision making, and clinical follow-up evaluation by a large number of surgeons from different countries. Level of Evidence: 4

Incidence and Prevalence of Spinal Cord Injury in Canada: A National Perspective

Background: Despite decades of research, there are no national estimates of the incidence or prevalence of spinal cord injury (SCI) in Canada. Our objective was to utilize the best available data to estimate the incidence and prevalence of traumatic SCI (TSCI) and non-traumatic SCI (NTSCI) in Canada for 2010. Methods: Initial incidence (number of TSCIs at injury scene) and discharge incidence (number discharged into the community) were calculated using published TSCI rates from Alberta and NTSCI rates from Australia. Prevalence was estimated by applying TSCI and NTSCI discharge incidence rates to historical Canadian population demographics using a cohort survival model and age-specific mortality rates for tetraplegia and paraplegia. Results: The estimated 2010 initial incidence of TSCI is 1,785 cases per year, and the discharge incidence is 1,389 (41 per million). The estimated discharge incidence for NTSCI is 2,286 cases (68 per million). The prevalence of SCI in Canada is estimated to be 85,556 persons (51% TSCI and 49% NTSCI). Conclusions: This study provides the first estimates of the incidence and prevalence of SCI in Canada. More population-based studies are needed, particularly for NTSCI, as an increasing number of Canadians are expected to be affected by SCI.

Spinal Injuries in Skiers and Snowboarders

Spinal injuries are among the most devastating injuries associated with recreational sports. Snowboarding spinal injury patterns have not been described. During two seasons (1994 to 1995 and 1995 to 1996), 34 skiers and 22 snowboarders suffered serious spinal injuries (fracture or neurologic deficit or both) at two ski areas in British Columbia, Canada. Ski patrol records, the Provincial Trauma Database, and hospital records were reviewed. Injury rates were based on computerized lift-ticket data and a population estimate of 15% snowboarders (ski patrol observation). The incidence of spinal injury among skiers was 0.01 per 1000 skier-days, and among snowboarders was 0.04 per 1000 snowboarder-days. Mean age was 34.5 years for skiers and 22.4 years for snowboarders. Seventy percent of the skiers were men, whereas all of the snowboarders were men. Jumping (intentional jump 2 meters) was the cause of injury in 20% of skiers and 77% of snowboarders. Neither age nor sex accounted for any significant portion of this difference. The rate of spinal injuries among snowboarders is fourfold that among skiers. Although jumping is the primary cause of injury, it is an intrinsic element of snowboarding. Until research defines effective injury-prevention strategies, knowledge of the risk of snowboarding should be disseminated and techniques for safe jumping should be taught.

Impact of surgical intervention on quality of life in patients with spinal metastases.

Study Design. Prospective clinical study. Objective. To assess Health-Related Quality of Life outcomes in patients undergoing surgery for spinal metastases. Summary of Background Data. Increasing life expectancy of patients with spinal metastases has resulted in greater interest in overall quality of life, including pain and neurologic impairment. To assess the overall risks and benefits of surgical intervention, the overall impact of each on the overall health status must be assessed. Methods. All patients who presented to a single institution with bony spinal metastases requiring surgical intervention were eligible. Exclusion criteria: previous surgery for spinal metastases, primary tumors of the spine, and inability to fill out the questionnaires. Patients completed an EORTC QLQ-C30, the HUI-3, the EQ-5D, visual analog pain, and an ECOG functional assessment. at five points: before surgery and at 6 weeks, 3 months, 6 months, and 1 year post surgery. Results. Of 96 patients who presented to the hospital, 85 were enrolled in the study. Average age was 58.6 years (range, 20.3–80.7 years) with 47 male patients; 50% survival as 39.1 weeks. Maximal and average VAS pain levels showed a statistically significant (P < 0.00001) improvement from preoperative to all postoperative time points. Only the QLQ-C30 global health status showed a statistically significant improvement from preoperative to the 6-week (P = 0.017), 3-month (P = 0.039), and 6-month (P = 0.013) time points. There was a statistically significant correlation between baseline global health status and survival time (P = 0.041). Overall distribution of HUI-3 utility calculated Quality of Life Adjusted Years (QALY) during the 1-year postoperative period showed a bimodal distribution with peaks at 0.1 and 0.7 years. Conclusions. Surgery for patients with spinal metastases offers decreased pain and improved quality of life with low rates of surgical complications.

Radiographic measurement parameters in thoracolumbar fractures: a systematic review and consensus statement of the spine trauma study group.

Study Design. Systematic review. Objectives. To review the various radiographic parameters currently used to assess traumatic thoracolumbar injuries, emphasizing the validity and technique behind each one, to formulate evidence-based guidelines for a standardized radiographic method of assessment of these fractures. Summary of Background Data. The treatment of thoracolumbar fractures is guided by various radiographic measurement parameters. Unfortunately, for each group of parameters, there has usually been more than 1 proposed measurement technique, thus creating confusion when gathering data and reporting outcomes. Ultimately, this effect results in clinical decisions being based on nonstandardized, nonvalidated outcome measures. Methods. Computerized bibliographic databases were searched up to January 2004 using key words and Medical Subject Headings on thoracolumbar spine trauma, radiographic parameters, and methodologic terms. Using strict inclusion criteria, 2 independent reviewers conducted study selection, data abstraction, and methodologic quality assessment. Results. There were 18 original articles that ultimately constituted the basis for the review. Of radiographic measurement parameters, 3 major groups were identified, depicting the properties of the injured spinal column: sagittal alignment, vertebral body compression, and spinal canal dimensions, with 14 radiographic parameters reported to assess these properties. Conclusions. Based on a systematic review of theliterature and expert opinion from an experienced group of spine trauma surgeons, it is recommended that the following radiographic parameters should be used routinely to assess thoracolumbar fractures: the Cobb angle, to assess sagittal alignment; vertebral body translation percentage, to express traumatic anterolisthesis; anterior vertebral body compression percentage, to assess vertebral body compression, the sagittal-to-transverse canal diameter ratio, and canal total cross-sectional area (measured or calculated); and the percent canal occlusion, to assess canal dimensions.

The surgical approach to subaxial cervical spine injuries: an evidence-based algorithm based on the SLIC classification system.

Study Design. Systematic review of literature and expert clinical opinions of the members of the Spine Trauma Study Group were combined to develop and refine this algorithm. Obejctive. To develop an evidence-based algorithm for surgical approaches to manage subaxial cervical injuries using a systematic review of the literature, expert opinion, and anticipated patient preferences. Summary of Background Data. There is lack of consensus in the management of subaxial cervical spine trauma, in part, because of the lack of a clinically relevant system for classifying these injuries. The newly developed Subaxial Injury Classification scoring system categorizes injury morphology into 3 broad groups, includes an assessment of the integrity of the discoligamentous soft tissue structures and the patients neurologic status, and thus guides surgical or nonsurgical treatment. The choice of a specific surgical technique and approach is currently not evidence based, and this gap in knowledge is one which the current article seeks to address. Methods. A literature review followed by a consensus of experts approach was used to develop the algorithm and to ensure face and content validity. Results. An algorithm is presented to guide the choice of surgical approach in cervical subaxial burst fractures, distraction injuries, and translation or rotation injuries. The burst or compression injuries and distraction injuries are more likely to be treated with a single anterior approach, whereas the more severe translation or rotation injuries may more commonly be approached posteriorly or with combined anterior and posterior surgery. Conclusion. This algorithm; derived from the Subaxial Injury Classification scoring system, will assist surgeons in answering the 2 most common questions they face when managing subaxial cervical spine trauma: “Should I operate?” and “Which surgical approach should I select?”

Arthroscopic anatomy of the hip

The arthroscopic anatomy of the hip has been studied using a number of portals. Both distraction and positioning are necessary to allow insertion of instruments, and to allow exposure of the important anatomical structures. The internal anatomy of the hip joint is described in detail based on the arthroscopic view from the different portals. This study helps orient those interested in arthroscopy of the hip.