Introduction: The challenges of treating children with early onset scoliosis mandate control of the deformity and maintenance of pulmonary function while allowing spinal and truncal growth. Previous publications have demonstrated safety and effectiveness of the growing rod technique in a limited number of patients. The purpose of this study was to report on a large series of patients managed with growing rods from a single center.
Methods: This is a retrospective review of 88 consecutive patients lengthened from 1999 to 2006 with minimum 2‐year follow up. Diagnoses included infantile and juvenile scoliosis (26), congenital (19), neurofibromatosis (4), syndromic (15) and neuromuscular (24). Number and frequency of lengthening, changes in scoliosis Cobb angle and complications were recorded.
Results: 88 pts with average age of 6.7 yrs (range 2.1 ‐ 11) underwent single submuscular growing rod insertion. 27 patients had a simultaneous short apical fusion. The mean follow up was 3.8 yrs (2 ‐ 9.5 yrs); pts underwent an average of 4.4 lengthenings with a mean interval of 8.1 months. 30 pts went on to final fusion at a mean age of 12 yrs. The preop scoliosis improved from 70° (range 50 ‐ 110) to 37° (range 14 ‐ 81) after insertion, 39° (7 ‐ 75) at last lengthening and 32° at final fusion (18 ‐ 70). In the group without apical fusion, 5.5 cm of length was obtained, compared to 3.8 cm with apical fusion (p<0.05). Complications included 3 deep infections; one patient required removal of instrumentation. Six pts had proximal anchor loss and 2 had distal pedicle screw migration. 14 pts (16%) had rod fractures, with the highest incidence after the 5th lengthening and more commonly in the apical fusion group. Two pts were converted to early fusion due to severe junctional kyphosis. FVC in the idiopathic group of pts was 62% predicted preoperatively and 64% at last follow up. FVC in pts with congenital scoliosis was 54% predicted preoperatively and 45% at last follow up.
Conclusion: Single submuscular growing rod constructs were effective in maintaining spinal growth and correcting deformities in early onset scoliosis. Considering the number of procedures performed per patient, the complication rate was acceptable and favorable to dual rod instrumentation series.