Identification of predictors for proximal junctional kyphosis and failure following all-posterior surgery for adolescent-onset kyphotic deformities


Kaya S., YILAR S.

Spine Deformity, 2026 (ESCI, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1007/s43390-026-01390-2
  • Dergi Adı: Spine Deformity
  • Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI), Scopus, EMBASE, MEDLINE
  • Anahtar Kelimeler: Proximal junctional kyphosis, Proximal junctional failure, Proximal junctional angle
  • Atatürk Üniversitesi Adresli: Evet

Özet

Objective: To identify independent predictors of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) in patients with adolescent-onset kyphotic deformities. Methods: We retrospectively reviewed consecutive patients with kyphotic deformities presenting during adolescence who underwent all-posterior corrective surgery performed by a single experienced spine surgeon between 2015 and 2023. A total of 132 patients met the inclusion criteria. Demographic, radiographic, and surgical variables were collected. Patients were classified as PJK(+) or PJK(–). To address clinical relevance, a secondary analysis further stratified PJK(+) patients into asymptomatic radiographic PJK and a PJF-surrogate group. Group comparisons were performed using Mann–Whitney U and chi-square or Fisher’s exact tests. Variables associated with PJK and the PJF-surrogate outcome were entered into multivariable logistic regression models. Results: The median age was 18 years (IQR, 16–22), with 68 females (51.5%) and 64 males (48.5%) and a median follow-up of 52 months (minimum 24 months). PJK developed in 36 of 132 patients (27.2%). Age, immediate postoperative proximal junctional angle (PJA), ΔPJA, and ΔSVA values were significantly higher in the PJK(+) group (all p < 0.05). In multivariable analysis, immediate postoperative PJA and sagittal vertical axis difference (ΔSVA) were independent predictors of PJK, with excellent model discrimination (AUC 0.95). In the secondary analysis, patients meeting PJF-surrogate criteria demonstrated significantly higher immediate postoperative PJA and greater ΔPJA from postoperative to final follow-up (all p < 0.05). Immediate postoperative PJA remained an independent predictor of PJF-surrogate status in multivariable analysis (OR 1.58; p = 0.012). Conclusions: Higher immediate postoperative PJA and ΔSVA were independently associated with the development of PJK. Early postoperative junctional alignment may serve as an indicator of patients at risk for clinically relevant junctional deterioration.