Objective: To evaluate the safety and effectiveness of correction of scoliosis associated with tethered cord without releasing it.
Methods: Twenty-two cases diagnosed as scoliosis with tethered cord between December 2005 and January 2011 were investigated retrospectively in the study. There were 8 males and 14 females. The age was from 6 to 51 years, averaged 17.7 years. There were 7 patients with clinical symptoms before surgery. All the patients underwent posterior deformity correction and instrumentation by pedicle screws directly without releasing the tethered cord. Spinal cord monitoring was conducted in all the cases. The preoperative and postoperative Cobb angle of the coronal main curve and thoracic kyphosis were measured. Also, the preoperative and postoperative values of the apical vertebra translation, apical vertebra rotation and trunk shift were measured by the same person. The incidence of perioperative complications were recorded.
Results: A total of 20 patients were followed up. The follow-up time was from 6 to 52 months, mean 23.5 months. The average Cobb angle of the coronal main curve were 68° ± 20° before surgery and 38° ± 21° after surgery with a mean correction of 48.1%. The difference was significant (t = 13.9, P < 0.05). The mean kyphosis was 65° ± 18° preoperatively and 28° ± 11° postoperatively, with a correction of 56.7%. The difference was also significant (t = 8.81, P < 0.05). The preoperative values of the apical vertebra translation, apical vertebra rotation and trunk shift were (5.4 ± 2.5) cm, 2.3° ± 0.6° and (2.0 ± 1.8) cm, respectively, which were corrected to (3.2 ± 1.8) cm, 1.2° ± 0.5° and (1.5 ± 1.1) cm after the surgery. Compared to the preoperative values, the difference were significant in the apical vertebra translation (t = 5.69, P < 0.05) and apical vertebra rotation (t = 10.07, P < 0.05). However, there was no difference in trunk shift. Postoperative complications occurred in 3 patients, including transient numbness of the lower extremity in 1 patient and hydrothorax in 2 patients. No neurological and instrumentation complications occurred during the follow-ups. Patients with clinical symptoms before surgery got no serious during the surgery and follow-ups.
Conclusions: If there are no symptoms of tethering in scoliosis patients with tethered cord, the corrective surgeries may be safe and effective when spinal cord monitoring conducted without spinal cord untethering. But more cases are needed to confirm it.