Subaxial cervical AO Spine Injury Score
see also AOSpine subaxial cervical spine injury classification system
An A0 injury was assigned an injury score of 0, A1 a score of 1, and A2 a score of 2. Given the significant increase in severity, A3 was given a score of 4. Based on equal severity assessment, A4 and B1 were both assigned a score of 5. B2 and B3 injuries were assigned a score of 6. Unstable C-type injuries were given a score of 7. Stable F1 injuries were assigned a score of 2, with a 2-point increase for F2 injuries. Likewise, F3 injuries received a score of 5, whereas more unstable F4 injuries a score of 7. Neurologic status severity rating scores increased stepwise, with scores of 0 for N0, 1 for N1, and 2 for N2. Consistent with the Thoracolumbar AO Spine Injury Score, N3 (incomplete) and N4 (complete) injuries were given a score of 4. Finally, case-specific modifiers M1 (PLC injury) received a score of 1, while M2 (critical disc herniation) and M3 (spine stiffening disease) received a score of 4 1)
Nineteen patients (age 17-79 years) sustained cervical injury from high-energy breaking waves while in shallow beach water. Six patients dived into a wave; 6 patients were struck by a large wave while standing upright; and 7 tumbled in the waves while engaged in nonspecified recreational activity. All 7 patients with subaxial cervical AO Spine Injury Score (AO-SIS) >10 had cervical spine injury with cord signal change and required operative management. Diving mechanism, AO-SIS >10, and cord signal change all predicted significant disability or death at 12 months (P < 0.01). The present study and 7 additional studies reporting on 534 patients (mean age, 45.4 years) were analyzed. Within the reported literature, most patients (94.2%) sustained a spinal cord injury. On long-term follow-up, an estimated 64.8% of patients had permanent neurologic injury and 12.5% had permanent quadriplegia.
Griepp et al. offer the first description of cervical injuries sustained in water-related recreational activity using the AO-SIS. The morphology of injuries varied significantly and seemed to depend on body position and wave kinetic energy. Patients presenting with cervical injury in this setting and yielding AO-SIS >10 are likely to have poor functional recovery 2).