Background: Type B injuries of the thoracolumbar spine (AO classification) indicate the need for surgical treatment. Type B1 injuries include disruption of the posterior ligament complex (PLC), which can be underdiagnosed when using x-ray and CT. The aims of this study were to determine the frequency of misclassification to compile similarities of type B1 injuries.
Materials and methods: Retrospective study evaluating 361 fractures.
Results: Initially, 39 (41.9%) of 93 type B injuries were misdiagnosed as type A. 59% of 93 injuries belonged in the type B1 category. 29% of these showed no radiological signs of a PLC injury. Among the remaining cases, the following signs were the most frequently seen: vertebral segmental angle >15 degrees (44%), pronounced compression of vertebral cancellous bone despite minimal (<50%) reduced anterior vertebral height (41%), and a considerably reduced anterior vertebral height to <50% (31%).
Conclusion: Type B injuries are frequently misinterpreted. To achieve a correct diagnosis, all clinical and radiological signs must be considered. 29% of all type B1 injuries cannot be detected on x-ray or CT scan.