Novel dual: rod plate system for EOS improves vertebral wedging and permits spinal growth

BACKGROUND: To determine whether single-stage, growth-friendly instrumentation with a plate-rod spinal system (PRSS) can substantially correct the deformity of EOS at surgery and continue to rectify the deformity throughout the growth period. METHODS: An observational study of 35 children with EOS treated by PRSS between February 2000 and October 2010 during a mean follow-up of 72 months. The mean age at surgery was 7 years. X-rays were taken preoperatively and postoperatively and at each follow-up. The Cobb angle, the apical vertebral wedge angle (AVWA), remaining rod lengths, maximal thoracic kyphosis and total T1-S1 heights were measured and compared. RESULTS: Thirty-one patients, 9 boys and 22 girls, with a mean age of 7 years were completed follow-up. The Cobb angle changed from 64° to 36° after initial surgery and 26° at the last follow-up. The mean AVWA was 15° postoperatively and 5° at the last follow-up. The mean rod tail reserve length decreased from 53 mm immediately after surgery to 12 mm at the last follow-up. The mean preoperative maximum thoracic kyphosis was 41° and changed to 35° and 30° postoperatively and at latest follow-up, respectively. The mean preoperative T1–S1 height for all 32 patients was 52 mm acute lengthening and 122 mm of lengthening by the end of follow-up, respectively. CONCLUSION: The PRSS provided immediate correction of most of the deformity at surgery and continued to rectify remaining scoliosis during the growth period. AVWA may be a useful method for monitoring the function of the PRSS in EOS.