Spinal osteotomy for longitudinal split spinal cord malformation associated with tethered cord syndrome of congenital scoliosis

English Keywords:Scoliosis  Split spinal cord malformation  Tethered cord syndrome  Osteotomy

English Abstract:

  【Abstract】 Objectives: To study the safety of spinal osteotomy for congenital scoliosis associated with longitudinal split spinal cord malformation(SSCM) and tethered cord syndrome(TCS). Methods: From June 2007 to June 2013, a total of 23 patients underwent spinal osteotomies for longitudinal SSCM associated with TCS in our hospital. 6 of them were male, and 17 cases were female with an average age of 16.9 years(range, 10 to 23 years). 8 patients presented with lumbosacral pain, including 5 patients with only lumbosacral pain. 18 patients had neurological deficit. There were 9 patients with type Ⅰ SSCM and 14 patients with type Ⅱ SSCM. During surgery, bony spurs were resected in patients with type Ⅰ SSCM, while nothing was done for type Ⅱ SSCM; pedicle subtraction osteotomy(PSO) was performed in 10 patients and vertebral column resection(VCR) in 13; posterior fusion surgery was performed following the correction. The local of conus medullaris of all patients were below L3. Preoperative average coronal Cobb angle was 94.5°±25.4°(65°-156°). All coronal Cobb angle and SBNS grade were measured before operation, after operation and at final follow-up. Results: All patients were followed up for a minimum of 24 months after initial surgical treatment with an average follow-up of 38.9±18.3 months(range, 24-79 months). The average operation time was 571.1±136．5min(range, 310-835min), and the average intraoperative blood loss was 4888.3±2482.3ml(range, 500-9600ml). Postoperative coronal Cobb angle ranged from 3° to 73°(average, 33.7°±15.9°). Compared with preoperative Cobb angle, postoperative Cobb angle showed significant decrease(P<0.05). The immediate postoperative correction rate was (62.3±14.1)%. At the final follow-up, the coronal Cobb angle ranged from 5° to 82°(average, 37.4°±17.2°), with a correction loss 4.2°±2.3°. The final correction rate was （58.1±14.7）％, Compared with preoperation, these indexes showed significant differences(P<0.05). The neurological function was improved in 18 cases. 13 patients improved from preoperative SBNS grade Ⅱ to grade Ⅰ. 2 patients from preoperative SBNS grade Ⅲ to grade Ⅱ. Although neurological function scores of the other 3 cases improved, SBNS grading remained unchanged. The coronal deformity and the local back pain relieved very well. The overall perioperative complications were noted in 5 cases. Postoperative unilateral lower limb neurological deterioration was noted in 2 cases, which recovered at 2 weeks and 3 months respectively. Cerebrospinal fluid leakage was noted in 1 case, pleural rupture in 1 case and urinary infection in 1 case. No infection surgical site, nonunion, pseudarthrosis, implant failure and permanent neurological deterioration were noted in all cases. Conclusions: The spinal osteotomy for SSCM associated with TCS is safe , effective and of well recovery of neurological function.