Complications of Dual Growing Rod Technique in Early Onset Scoliosis: Can We Identify Risk Factors?

Purpose: To identify factors influencing complications in patients with early onset scoliosis (EOS) who underwent the dual growing rod technique.

Methods: Between September 1987 and August 2003, 48 patients with EOS underwent initial surgery using dual growing rods and had a minimum of 2 years follow-up, with 29 patients developing complications. Complications were divided into 4 groups: implant, wound, alignment, and general. Relations analyzed included age at surgery, diagnosis, curve magnitude, initial correction, follow-up length, and lengthening frequency. Our study received IRB approval.

Results: Fifty-five complications occurred in 29 patients. Twenty-seven implant, 14 wound, 5 general and 9 alignment-related complications occurred. Eighteen complications resulted in 23 unplanned procedures. Thirty-seven complications were addressed during planned procedures. Average age of the uncomplicated group was 81.9mos and 61.5mos in the complicated group. Average follow-up of the uncomplicated group was 46.6mos compared to 67.1mos in the complicated group. Average interval between lengthenings was 8.1mos (uncomplicated group) versus 11.8 (complicated group). Both groups had an average Cobb angle >70 prior to initial surgery. Diagnosis was insignificant except for Infantile Idiopathic Scoliosis (IIS), where 8 of 9 total patients had implant-related complications. The implant complication group had 5 of 27 complications requiring unplanned surgeries. Six deep infections occurred. Additionally, 2 of 3 wound problems evolved into deep infections and 2 of 4 superficial infections became deep.

Conclusion: At initial surgery, younger patients had higher complication rates. More complications occurred with longer treatment periods. Most implant problems were addressed during planned surgeries. High correlation existed between diagnosis (IIS) and implant-related problems. Patients whose lengthening intervals were less than or equal to 7mos had fewer implant complications but more wound complications. Patients whose intervals were greater than or equal to 7mos had more implant complications but fewer wound complications. Wound problems should be addressed aggressively to prevent deep wound infections. This technique has a high but manageable complication rate.