Application Value Of SLIC Classification And Dvorak Evidence-based Algorithm For The Evaluation And Treatment Of Subaxial Cervical Spine Injury

Background:Injuries to.lower cervical spine are prevalent and spinal injury classification systems have important guiding significance for the diagnosis, treatment, and prognosis of these injuries. Previous classification systems have poor practical application as they have attempted to describe the injury purely on descriptive terms and lack unified quantitative criteria or standardized surgical options. Vaccaro et al proposed a new classification system in2007called SLIC (Subaxial Cervical Spine Injury and Severity Score) classification system. Objective description of injury morphology combined with the integrity of disco-ligamentous complex (DLC) and neurological status of the patient provides a comprehensive assessment of the extent of the lower cervical spine injury. Dvorak et al presented evidence-based treatment guidelines for subaxial cervical spine injuries based on SLIC classification. Dvorak’s evidence-based guidelines have only been in application for a short time period and as such, the classification and the value of the evidence-based guidelines require further verification.Part1Reliability and repeatability of SLIC classification for subaxial cervical spine injuryObjective:To evaluate the reliability and repeatability of the SLIC classification system.Methods:A total of28patients with lower cervical spine injury were admitted from January2011to July2011. Consensus among4spine surgeons was reached regarding the treatment methods, surgical approach and how to determine the status of DLC injury after reading and discussing in detail the SLIC classification and treatment method. Imaging films (X-Ray, CT, and MRI) were made available to each of the surgeons and the SLIC scores, treatment method and surgical recommendations were noted. This process was repeated3times at different points in time. Using SPSS16.0the data were statistically analyzed using Cohen Kappa coefficient. Results:The Kappa coefficient score for SLIC classification morphology, neurological status, SLIC score (0.84-0.89) show highest degree of reliability, DLC state subclass shows moderate reliability (0.5) and, treatment options (0.74) are consistent with the higher reliability. SLIC subclass of morphology, neurological status, SLIC Total and treatment options show highest repeatability as indicated by Kappa coefficient of0.92,0.90,0.87and,0.80respectively whereas DLC state (0.63) shows high repeatability.Conclusion:SLIC scoring system of the subaxial cervical spine injury has a high reliability and reproducibility and provides a better guidance for the treatment of subaxial cervical spine injury.Part2Application of SLIC classification and Dvorak evidence-based algorithm for the evaluation and treatment of subaxial cervical spine injuryObjective:To evaluate the application of SLIC classification and Dvorak evidence-based algorithm for the evaluation and treatment of subaxial cervical spine injury.Methods:Retrospective analysis investigating the relationship between SLIC surgical algorithm and functional and neurologic recovery based on JOA score, ASIA scale and imaging studies.Results:46cases of cervical spine injury were grouped according to the SLIC classification system and Dvorak evidence-based guidelines. All46surgeries were completed successfully and the patients were followed up for a period of12months, average6months. Neurological improvement at the end of1year based on JOA score was statistically significant P<0.05with average improvement of1-2grades in the ASIA scale. Radiological healing was satisfactory with restoration of physiological cervical curvature and no implant failure. Conclusion:SLIC classification system and Dvorak evidence-based guidelines for subaxial cervical spine injury assessment and treatment options have a good reference value. This system can be readily applied in clinical setting although long term prospective studies on a larger base needs to be carried out to guide a clinical classification evaluation system. The choice of surgical approach for burst or compression fractures and hyperextension injuries is often a single anterior approach. Translation or rotation injuries often require a combined anterior and posterior surgical approach. The need for preoperative traction and postoperative tracheostomy may affect the choice of surgical approach.