Complications of scoliosis surgery in children with myelomeningocele.

The purpose of the present study was to evaluate whether the high incidence of complications in scoliosis surgery in myelomeningocele (MMC) could be attributed to the surgical technique and whether improvements were possible. Between 1984 and 1996, 77 patients with MMC and scoliosis were treated surgically. The clinical and radiological follow-up ranged from 1 to 10 years with a mean follow-up of 3.6 years. The mean age at time of surgery was 12 years 8 months. The average preoperative scoliosis measured 90.20 degrees and was corrected by 47%. The first four patients were stabilized with Harrington rods after anterior correction with a Zielke device (group 1). Twenty-five patients were operated only from posterior, using Cotrel-Dubousset (CD) instrumentation (group 2). In 13 patients an anterior release and discectomy was performed prior to CD posterior instrumentation (group 3). In 26 patients (group 4) this was combined with an anterior instrumentation. The 9 patients of group 5 had congenital vertebral malformations which made a special treatment necessary. Complications could be divided into hardware problems, such as implant failure, dislocation or pseudarthrosis, infections, anesthetic, and neurologic complications. Hardware problems were seen in 29% of all patients. More hardware problems were seen with the Harrington rod (75%) and after solitary posterior instrumentation (30%). The occurrence of pseudarthrosis was dependent on the surgical technique, the extent of posterior spondylodesis, and lumbosacral fusion. Patients with hardware problems had a mean loss of correction of 49% compared to 13% in the other patients. Depending on the different surgical techniques a loss of more than 30% was seen in 12-75% of the cases. Early postoperative shunt failure occurred in four cases; delayed failure - after more than 1 year - in three cases. One patient died within 1 day due to an acute hydrocephalus, another died after 2 1/2 years because of chronic shunt insufficiency with herniation. Wound problems were not dependent on the surgical technique, but on the extent of posterior spondylodesis and the lumbosacral fusion. Based on this analysis we believe our current practice of instrumented anterior and posterior fusion is justified. Further, we are very careful to check shunt function prior to acute correction of spinal deformity.