[The efficacy of one-stage posterior correction surgery for scoliotic patients with little symptomatic syringomyelia].

Objective: To investigate the safety and effectiveness of one-stage posterior correction of scoliosis associated with little symptomatic syringomyelia.

Methods: A total of 19 cases diagnosed as scoliosis with little symptomatic syringomyelia between January 2003 and November 2010 were included in this study (study group), the patients underwent one-stage posterior correction and instrumentation without neurosurgery for the syringomyelia. At the same time, 9 cases with severe symptomatic syringomyelia were included as the control group, the patients underwent neurosurgery before scoliosis correction, including suboccipital decompression and syrinx shunting. All patients underwent posterior pedicle screw or screw-hook hybrid instrumentation. The preoperative, postoperative and the last follow-up of the Cobb angle of the coronal main curve and thoracic kyphosis were measured. Also, the preoperative and postoperative of the apical vertebra translation, apical vertebra rotation and trunk shift were measured by the same person. The perioperative and the last follow-up complications of neurological injury were recorded. The surgical outcome and postoperative complications between the 2 groups were compared with the t student and chi-square statistics methods.

Results: There were no significant differences in gender, age, the location, length and diameter of the syringomyelia of the 2 groups (P > 0.05). The follow-up period ranged from 6 to 45 months, with a mean of 28.6 months. The average preoperative Cobb angles of coronal main curves of the 2 groups were 71° ± 23° and 68° ± 19°, the postoperative Cobb angles were 27° ± 20° and 25° ± 16°, and the last follow-up Cobb angles were 29° ± 17° and 32° ± 20°. The coronal correction rate was 66% ± 19% in the study group and 65% ± 21% in the control group (t = 0.136, P = 0.893). There was no significant difference at the last follow-up(t = 0.210, P = 0.837). The average preoperative Cobb angles of thoracic kyphosis of the 2 groups were 35° ± 18° and 32° ± 19°, the postoperative Cobb angles were 25° ± 10° and 23° ± 9°, and the last follow-up Cobb angles were 24° ± 4° and 28° ± 8°. The mean sagittal correction rate of the 2 groups were 50% ± 58% and 57% ± 53% (t = -0.303, P = 0.764). There was also no significant difference at the last follow-up time (t = 0.769, P = 0.490). There were no significant difference, in terms of the postoperative of the apical vertebra translation, apical vertebra rotation and trunk shift between the 2 groups (P > 0.05). One case in the study group complicated with a pedicle screw breaking the anterior cortex of the vertebra and one in the control group complicated with a hook loosening, postoperatively. At the last follow-up time, the neurological symptoms of the 2 groups got no aggravating.

Conclusion: One-stage posterior correction of scoliosis associated with little symptomatic syringomyelia may be effective and safe.