Long-Term Radiographic and Pulmonary Function Outcomes After Dual Growing-Rod Treatment for Severe Early-Onset Scoliosis

Abstract

Background:We evaluated long-term outcomes (radiographic parameters and pulmonary function) at a minimum follow-up of 5 years after use of dual growing rods (DGRs) to treat severe early-onset scoliosis (sEOS).Methods:Among a total of 112 patients who were diagnosed with early-onset scoliosis (EOS) and were treated with DGRs between 2006 and 2015, 52 patients had sEOS, with a major Cobb angle of >80°. Of these patients, 39 with a minimum follow-up of 5 years had complete radiographic and pulmonary function test results and were included. The Cobb angle of the major curve, T1-S1 height, T1-T12 height, and maximum kyphosis angle in the sagittal plane were measured on radiographs. Pulmonary function test results were collected in all patients before the initial operation (preoperatively), 12 months after the initial operation (postoperatively), and at the last follow-up. The changes in pulmonary function and complications during treatment were analyzed.Results:The mean age of patients before the initial operation was 7.7 ± 1.2 years, and the mean follow-up period was 75.0 ± 14.1 months. The mean number of lengthenings was 4.5 ± 1.3, and the mean interval between lengthenings was 11.2 ± 2.1 months. The Cobb angle improved from 104.5° ± 18.2° preoperatively to 38.1° ± 10.1° after the initial surgical procedure (postoperatively) and 21.9° ± 8.6° at the final follow-up. The T1-S1 height increased from 25.1 ± 4.0 cm preoperatively to 32.4 ± 3.5 cm postoperatively and to 39.5 ± 4.0 cm at the final follow-up. However, no significant difference was detected between the increased pulmonary function parameters at 1 year and those before the operation (p > 0.05), except for residual volume, whereas pulmonary function parameters had significantly increased at the final follow-up (p < 0.05). During the treatment period, 17 complications occurred in 12 patients.Conclusions:DGRs are effective in treating sEOS in the long term. They allow longitudinal growth of the spine, and the correction of the spinal deformity can provide conditions that make improving pulmonary function possible in patients with sEOS.Level of Evidence:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Dual Growing Rods and the Apical Control Technique for Treating Congenital Early-Onset Scoliosis

“…The pulmonary function test in this case series showed that, as percentages of the predicted volume, the FEV1 was 71.61% and the forced vital capacity (FVC) was 69.88%, which indicated a relatively satisfactory result. In theory, pulmonary function is closely related to scoliosis correction and spinal height, as both affect lung volume 26 . A T1-T12 height of ≥18 cm may represent a threshold value for adequate forced vital capacity (>50% of predicted), and a T1-T12 height of ≥22 cm at skeletal maturity appears to allow nearly normal pulmonary function 10 .…”

What’s New in Pediatric Orthopaedics

“…The researchers compared preoperative and postoperative parameters with those of healthy children and found decreased deviation from normality. Another study of 52 children with severe early-onset scoliosis found improved pulmonary function parameters >1 year following initial dual growing rod surgery 53 . Pulmonary function was not significantly different at 12 months after the surgical procedure, even though the spinal height had significantly improved in the first year, indicating that lung function may take longer to catch up with the change in thoracic volume.…”