Evaluating Rib Vertebral Angle Difference as a Key Indicator for Curve Correction Following Traditional Growing Rod Treatment

Abstract Background: Treating children with early onset scoliosis (EOS) is still a matter of controversy and a real challenge for spine surgeons. When surgical correction is required, it is crucial to maximize correction while minimizing iatrogenic hazards. The rib vertebral angle difference (RVAD) measurement gained widespread acceptance and usage in evaluating and treating patients with EOS preoperatively. This study was the first in the literature to analyze the prognostic value of initial RVAD regarding curve correction post-traditional growing rod (TGR) instrumentation. Materials and Methods: Retrospective data collection was performed using patients from our institute’s database. Eighty-three patients with idiopathic EOS (IEOS) were included in this study. All of them were treated by TGRs technique with bi-annual lengthening and in-clinic follow-up every 3 months until fusion. The mean follow-up was 3.12 ± 1.06 years. Cobb’s angle, initial RVAD, curve correction percentage, Early Onset Scoliosis Questionnaire 24 (EOSQ-24), and complications were analyzed. Results: A total of 83 patients (35 males and 48 females) with a mean age of 6.8 ± 1.06 years underwent Growing Rods surgery. The mean pre-operative Cobb’s angle was 72.2° ± 14.3, and the mean pre-operative RVAD was 37.2° ± 18.3. EOSQ-24 scores significantly improved postoperatively (from 35.0 ± 7.5 to 67.5 ± 5.2; P < 0.001). RVAD at presentation showed a strong negative correlation with correction percentage ( R = –0.821, P = 0.0317), with linear regression indicating that RVAD accounted for 69.2% of the variance in correction ( R ² = 0.6919). Complications occurred in 17 patients (20%), including broken screws (15%) and superficial wound infections (5%). Conclusion: RVAD threshold can be used to predict IEOS curve correction percentage post-TGRs instrumentation. This study also demonstrated significant improvements in clinical and radiological outcomes following TGR treatment for IEOS, with minimal complications.