The Surgical Algorithm for the AO Spine Sacral Injury Classification System

Study Design: Global cross-sectional survey. Objective: To establish a surgical algorithm for sacral fractures based on the AO Spine Sacral Injury Classification System. Summary of Background Data: Although the AO Spine Sacral Injury Classification has been validated across an international audience of surgeons, a consensus on a surgical algorithm has yet to be developed for sacral fractures by using the Sacral AO Spine Injury Score (Sacral AOSIS). Methods: A survey was sent to general orthopedic surgeons, orthopedic spine surgeons, and neurosurgeons across the five AO Spine regions of the world. Descriptions of controversial sacral injuries based on different fracture subtypes were given and surgeons were asked whether the patient should undergo operative or non-operative management. The results of the survey were used to create a surgical algorithm based on each subtypes’ Sacral AOSIS. Results: International agreement of 70% was decided on by the AO Spine Knowledge Forum Trauma experts to indicate a recommendation of initial operative intervention. Using this, sacral fracture subtypes of AOSIS 5 or greater were considered operative while those with AOSIS 4 or less were generally non-operative. For subtypes with an AOSIS of 3 or 4, if the sacral fracture was associated with an anterior pelvic ring injury (M3 case-specific modifier), intervention should be left to the surgeons’ discretion. Conclusion: The AO Spine Sacral Injury Classification System offers a validated hierarchical system to approach sacral injuries. Through multi-specialty and global surgeon input, a surgical algorithm was developed to determine appropriate operative indications for sacral trauma. Further validation is required, but this algorithm provides surgeons across the world with the basis for discussion and the development of standard of care treatment. Level of Evidence: Level IV.