A Comparative Study on the Consistency of Ultrasound and X-Ray in Assessing Risser Sign

Objectives

Adolescent idiopathic scoliosis (AIS) is a 3-dimensional spinal deformity involving lateral curvature, sagittal plane imbalance, and vertebral rotation. In China, AIS affects over 3 million individuals, with 300,000 new cases annually. AIS impacts physical and psychological well-being, necessitating tailored treatment plans based on growth risk factors. This study evaluates the consistency of ultrasound and X-ray assessments of the Risser sign in AIS patients and explores correlations between iliac crest distance and pelvic rotation degree.

Methods

This prospective study enrolled 80 patients diagnosed with AIS from June to September 2023 at Changzhou Sports Hospital. Eligible participants were aged 10–18 with a Cobb angle >10°. Ultrasonographic examinations were conducted by 3 experienced physicians using the VINNO V10 portable ultrasound system. The primary outcome was the Risser stage determined by X-ray and ultrasound, with secondary outcomes including thoracic and thoracic-lumbar segment rotation angles. Statistical analyses included kappa statistics, correlation analyses, and multiple regression.

Results

Among the 77 valid cases, 154 iliac wings were evaluated, with a high concordance rate of 77% between ultrasound and X-ray assessments. kappa values for left and right iliac crests were 0.723 and 0.808, respectively. Grouping Risser grades (0–1, 2–3, and 4–5) into 3 categories yielded kappa values of 0.93, 0.96, and 0.93, indicating high consistency. Significant correlations were found between iliac crest distances and rotation angles (left iliac crest distance and left thoracic rotation angle, r = 0.56, P < .001; right iliac crest distance and right thoracic-lumbar rotation angle, r = 0.69, P < .001; right iliac crest distance and right thoracic rotation angle, r = 0.39, P < .01).

Conclusions

Ultrasound is a reliable, radiation-free alternative to X-ray for assessing the Risser sign in AIS patients. Despite observed inconsistencies in intermediate Risser grades, ultrasound's ability to reduce radiation exposure and provide consistent results makes it a valuable tool in clinical practice. Further research is needed to optimize ultrasound techniques and explore its potential for early detection and intervention in scoliosis management.