Simplified S1 vertebral bone quality (vbq) score to assess proximal junctional kyphosis after Lenke 5 adolescent idiopathic scoliosis surgery.

Abstract

Proximal junctional kyphosis (PJK) is a common complication following corrective surgery for adolescent idiopathic scoliosis (AIS) with a Lenke 5 curve. Previous studies have suggested that PJK may be associated with osteopenia, which is prevalent in AIS patients. MRI-based vertebral bone quality (VBQ) scores have been proposed as a valuable tool to assess preoperative bone quality. However, accurately measuring VBQ scores in Lenke 5 AIS patients with a structural lumbar curve can be challenging. Recently, a simplified S1 VBQ score has been proposed as an alternative method when the traditional VBQ score is not applicable. This study aims to evaluate the predictive value of the simplified S1 VBQ score in predicting the occurrence of PJK after corrective surgery for Lenke 5 AIS. We conducted a retrospective analysis of patient data to assess the predictive utility of the S1 VBQ score for PJK in Lenke 5 AIS patients. Demographic, radiographic, and surgical data were collected, and S1 VBQ scores were calculated based on preoperative T1-weighted MRI images. Univariate analysis, linear regression, and multivariate logistic regression were performed to identify potential risk factors for PJK and to assess the correlation between other variables and the S1 VBQ score. Receiver operating characteristic analysis and area under the curve values were used to evaluate the predictive efficiency of the S1 VBQ score for PJK. A total of 105 patients (aged 15.50 ± 2.36years) were included in the analysis, of whom 24 (22.9%) developed PJK. S1 VBQ scores were significantly higher in the PJK group compared to the non-PJK group (2.83 ± 0.44 vs. 2.48 ± 0.30, P < 0.001), and there was a significant positive correlation between the S1 VBQ score and proximal junctional angle (PJA) (r = 0.46, P < 0.0001). Multivariate analysis revealed that the S1 VBQ scores and preoperative thoracic kyphosis (TK) were significant predictors of PJK. This study provided evidence that higher S1 VBQ scores were independently associated with PJK occurrence following corrective surgery for Lenke 5 AIS. Preoperative measurement of the S1 VBQ score on MRI may serve as a valuable tool in planning surgical correction for Lenke 5 AIS.