Introduction: The optimal classification for complex lumbosacral injuries, in particular high-energy sacral fractures and lumbosacral dissociation injuries, remains controversial. Currently used classification systems for complex lumbosacral injuries are largely descriptive; lacking validity, reproducibility, treatment considerations and prognostic information. We set out to develop a comprehensive, yet practical, classification system for complex lumbosacral injuries that assists in clinical decision-making.
Methods: We developed a new classification system and injury severity scoring system for complex lumbosacral injuries derived through extensive literature review, expert opinion and our clinical experience treating combat casualties over the past 10 years. We have seen an increased incidence of complex sacral fractures and lumbosacral dissociation injuries after combat related high-energy blast trauma, motor vehicle collisions and aircraft crashes. A pilot validation study was performed with 4 spine surgeons familiar with lumbosacral injuries and 10 case scenarios. Inter- and intra-observer reliability was analyzed using Intraclass Correlation Coefficient (ICC).
Results: A new classification system was devised based on three injury characteristics: 1) Fracture morphology (Flexion compression, Axial compression, Translation/Rotation, Blast/Shear), 2) Posterior ligamentous complex (PLC) integrity (Intact, Indeterminate, Disrupted) and 3) Neurologic status (Intact, Paresthesias only, Lower extremity motor deficit, Progressive neurologic deficit). A composite injury severity score (CISS) was calculated by summing a weighted score from each category with increasing score associated with increased injury severity. Treatment recommendation is then based on CISS less than 4 (non-operative), greater than 4 (operative), equal to 4 (either). We found good to excellent ICC for inter-observer reliability (Injury Morphology=0.757; PLC integrity=0.720; Neurologic Status=0.990; CISS=0.934), and good to excellent ICC for intra-observer reliability (range 0.712 to 1 for all CISS components).
Conclusions: We propose the Lumbo-Sacral Injury Classification System (LSICS), which provides a comprehensive and practical approach for evaluating injury severity and guiding clinical decision-making. A multi-center study with application of LSICS to a large number of cases is necessary to determine the reliability and validity of this new classification system.
Patient Care: Surgeons are provided with a classification and composite scoring system to assist with clinical decision making.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe lumbpelvic dissociation injury, 2) Describe the lumbosacral injury classification system