Recovery of Motor Function in Patients with Subaxial Cervical Spine Injury Relevant to the Fracture Pattern

In this study, we studied the relationship between fracture patterns and motor function recovery in 70 consecutive patients with cervical spinal cord injury. Fractures were categorized into 6 fracture types and subdivided into stages according to the Allen-Ferguson classification system:compressive flexion (CF), distractive flexion (DF), compressive extension (CE), distractive extension (DE), vertical compression (VC) and lateral flexion (LF). Paralysis was evaluated using the American Spinal Injury Association (ASIA) impairment scale at the time of injury and 3 months afterwards. The residual rate of complete motor palsy (ASIA grade A or B) at the final examination was higher in those patients with DE fractures than those with CF, DF or CE. The final outcomes were as follows. Of the 14 patients who were classified with CF fractures, residual palsy was frequently seen in patients who had stage 5 injury. Of the 27 patients with DF fractures, residual palsy occurred in about half of the patients who had stage 4 or 5 injury. Of the 18 patients with CE fractures, residual palsy occurred in half of the patients with stage 3 injury or higher. Finally, of the 7 patients with DE fractures, the rate of residual palsy was high even for the stage 1 and 2 cases;indeed, all DE patients who had complete motor palsy at the first examination had residual palsy at the final examination. Accordingly, we conclude that motor recovery may be related to fracture pattern.