OBJECTIVETo study the clinical characteristics and treatment of flexion-distraction stage I injuries in subaxial cervical spine.

METHODSTwelve cases of flexion-distraction stage I injuries with delayed symptoms, admitted in our hospital between January 1995 and December 2004, were studied retrospectively. In acute phase, all of 12 cases had neck pain and limited neck movements, neurological deficits were found in 6 of 12 cases. Eight cases had a correct diagnosis, and 2 cases had a error diagnosis, 2 cases missed. All cases were satisfactory by the primary conservative treatment. After 274 days average asymptomatic intervals, all of 12 cases had recurrence of neck pain, delayed neurological deficits were found in 10. MRI showed that all of 12 cases were unstable injuries.

RESULTSAll of the 12 patients were treated operatively. Decompression, fusion and fixation were performed by anterior approach in 9 cases, and by combined anterior and posterior approach in 3 cases. The average follow-up period was 33.1 months. Neck pain had great recovery in all cases, 10 cases with neurological deficits, 7 returned normal. Radiographic evidences of intervertebral bony fusion and good cervical alignment were observed in all of 12 cases.

CONCLUSIONSFlexion-distraction stage I injuries is often caused by ligament and disc injuries, and often missed with subtle symptoms and radiographic changes. Inadequate primary treatment options are often due to failure to recognize the instability, and maybe result in delayed injuries. MRI is helpful for the early accurate evaluation of spinal stability. Unstable injury require early surgical treatment. The anterior approach operation is recommended to most of these patients with acute and old injuries. Combined anterior and posterior approach operation should be considered in these patients who have old injuries with stiff kyphosis.