Thoracic spinal cord injury without radiographic abnormality in a skeletally mature patient: a case report.

Study Design: A case of thoracic spinal cord injury without radiographic abnormality in a skeletally mature patient is reported.

Objectives: To report, for the first time in the literature, a case of thoracic spinal cord injury without radiographic abnormality or any ligamentous injury in a skeletally mature patient, and to propose a unique mechanism of spinal cord traction injury resulting from associated bilateral high-energy lower limb injuries. SUMMERY OF BACKGROUND DATA: Thoracic spinal cord injury without radiographic abnormality is extremely uncommon in skeletally mature patients. Hyperflexion with an associated distraction force usually produces the spinal cord injury, which is associated with posterior ligamentous injury of the spine. In the only reported case of thoracic spinal cord injury without radiographic abnormality in a skeletally mature patient to date (1993), despite the absence of evidence showing bony injury associated with cord damage on plain radiographs and computed tomograms, the magnetic resonance image demonstrated significant injury to the posterior ligamentous structures of the spine. Thoracic spinal cord injury in a skeletally mature patient without associated bony and ligamentous injury has never before been reported.

Methods: A 17-year-old skeletally mature motorcyclist was involved in a road traffic accident and sustained multiple injuries. Clinical examination showed tenderness over L1 and L2 vertebrae with complete loss of sensation and motor power below L2. In addition, the patient also sustained a stable pelvic fracture; fracture of the right acetabulum; open dislocation of the right knee with complete disruption of both cruciate ligaments, the posteromedial capsule, and the medial collateral ligament; open fracture of the left tibia and fibula; displaced fracture of the medial condyle of the left femur; fracture of the right distal radius; and fracture of the right proximal humerus. The plain radiographs of the whole spine and computed tomography scanning of the thoracolumbar spine showed no evidence of bony injury. The contemporary magnetic resonance image scanning of the entire spine showed disruption of the spinal cord from T10 downward, with patchy high signal in the cord and loss of normal architecture. After appropriate management of the associated limb injuries, the patient was transferred to the regional spinal unit for rehabilitation.

Results: Thoracic spinal cord injury in a skeletally mature patient occurred in the absence of associated bony and ligamentous injury, and probably resulted from a longitudinal traction force transmitted through the sciatic nerves to the spinal cord as a result of associated high-energy bilateral lower limb injuries.

Conclusions: A rare case of thoracic spinal cord injury without radiographic abnormality manifested as a result of traction injury to the sciatic nerves caused by bilateral violent lower limb injuries in a skeletally mature patient is presented. To the best of the authors' knowledge, such a case has not been reported previously.