Proximal junctional kyphosis in distraction-based growth-friendly treatment: Definition, risk factors, and timeline
Journal of Children's Orthopaedics, cilt.20, sa.5, ss.566-575, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 20 Sayı: 5
- Basım Tarihi: 2026
- Doi Numarası: 10.1177/18632521261475211
- Dergi Adı: Journal of Children's Orthopaedics
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Directory of Open Access Journals, Academic Search Ultimate (EBSCO), Health Research Premium Collection (ProQuest)
- Sayfa Sayıları: ss.566-575
- Anahtar Kelimeler: III
- Hacettepe Üniversitesi Adresli: Evet
Özet
Purpose: To identify risk factors and characterize the timing and nature of proximal junctional kyphosis (PJK) following dual-rod distraction-based growth-friendly treatment (DB-GFT) in early-onset scoliosis (EOS). Methods: Ninety-five EOS patients (37 male, 58 female) treated with dual growing rod systems between 2004 and 2023, with ≥ 2 years of follow-up, were retrospectively reviewed at a single center. Radiographic parameters were assessed preoperatively, postoperatively, and at final follow-up. PJK was defined as a proximal junctional angle(PJA) ≥10° at final follow-up with an increase of ≥10° compared with preoperative measurement. Serial lateral radiographs were evaluated at 3 or 6 month intervals to determine occurrence and timing of PJK. Univariate and multivariate logistic regression analyses were performed to identify risk factors. Results: The mean age at index surgery was 6.8 years, with a mean follow-up of 5.8 years. PJK developed in 17 patients (17.9%): 3 immediately postoperatively(mechanical) and 14 gradually (biological), of whom 12 were diagnosed after the first year. Univariate analysis identified UIV at T3 or below and T5–T12 kyphosis correction ≥ 30° as significant risk factors. Each 1° increase in preoperative T5–T12 kyphosis increased PJK risk by 3%. Multivariate analysis confirmed preoperative T2–T12 kyphosis ≥45° and UIV at T3 or below as independent risk factors. Conclusions: While extensive kyphosis correction was identified as a significant risk factor on univariate analysis, preoperative T2–T12 kyphosis ≥45° and UIV at T3 or below emerged as independent predictors, underscoring the importance of both preoperative sagittal alignment and UIV selection in surgical planning. Segment-adjusted PJA values may better identify clinically significant cases at risk of progression to proximal junctional failure. As most PJK develops after 1 year, long-term follow-up is essential. The significance of study: Distal upper instrumented vertebra (T3 or below) and preoperative T2-12 thoracic kyphosis significantly increase the risk of proximal junctional kyphosis, which most commonly develops after the first postoperative year.