Neurological outcomes of transvertebral transposition of the spinal cord and posterior correction in patients suffering from neurologic deficit secondary to angular kyphoscoliosis

English Keywords:Spinal kyphoscoliosis  Transvertebral transposition of the spinal cord  Intraoperative neurophysiologic monitoring

English Abstract:

  【Abstract】 Objectives: To assess the neurological outcomes of transvertebral transposition of the spinal cord and posterior correction in patients suffering from neurologic deficit secondary to kyphoscoliosis. Methods: From January 2005 to January 2014, fourteen patients with at least 1-year follow-up, including 6 females and 8 males, suffering from neurologic deficit secondary to angular kyphoscoliosis and undergoing transvertebral transposition of the spinal cord and posterior correction in our spinal center were reviewed retrospectively. The initial age averaged 22.0±14.5 years(range, 6-53 years). The etiologies of deformity were congenital kyphoscoliosis in 10 patients and idiopathic kyphoscoliosis in 4 patients. Preoperative spinal cord function graded by Frankel criteria was grade C in 5 cases and grade D in 9 cases. The initial major curve was 76.9°±33.2°(range, 65°-100°) with a global kyphosis of 71.5°±31.8°(range, 41°-125°). Neurological examinations were performed before surgery and 1 week after discharge. The change of distance between spinal cord and canal on the convex side at the apex was measured on MR images to evaluate the efficacy of transposition. Results: There were no significant changes in terms of the latency and amplitude of posterior tibial nerve P40 intraoperatively (amplitude: 1.67±0.38μV vs. 1.69±0.36μV, P>0.05; latency: 38.96±2.51ms vs. 38.15±2.14ms, P>0.05), while significant improvements were observed postoperatively(amplitude: 1.67±0.38μV vs. 2.10±0.35μV, P<0.05; latency: 38.96±2.51ms vs. 35.54±2.12ms, P<0.05). The distance between spinal cord and canal on the convex side at the apex changed from 11.9mm(range, 3-21.8mm) to 9.8mm(range, 1.8-17.1mm) (t=4.170，P=0.004), decreased by 2.3±1.6mm on average(range, 0.6-4.4mm). After surgery, the major curve improved to 39.3°±19.0°(range, 15°-55°) with a (50.3±20.6)%(range, 14.5%-85%) correction rate, and the mean loss of correction was 6.2%(range, 1.8%-20%). The mean kyphosis was 41.3°±15.4°(range, 22°-69°), demonstrating a (39.0±17.7)%(range, 20.8%-57.9%) correction rate immediately after operation, and showing a 3.2%(range, 5.2%-10%) correction loss at the final follow-up. Conclusions: Transvertebral transposition of the spinal cord is a useful procedure for the treatment of neurologic deficit secondary to angular kyphoscoliosis, with good neurological recovery.