[Type B injuries of the thoracolumbar spine : misinterpretations of the integrity of the posterior ligament complex using radiologic diagnostics].

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.