Ultrasonographic evaluation of the Risser sign. Is it a reliable and reproducible method?

Study Design: A prospective study of ultrasonographic evaluation (UE) results of the Risser sign (RS) in adolescents.

Objective: This study aims to assess the efficiency of UE of RS, compare it with radiographic evaluation, and investigate the intraexaminer and interexaminer reliability of UE.

Summary Of Background Data: The use of ultrasound in orthopedic practice has a growing popularity. As a noninvasive radiological method, the evaluation of RS seems to be a promising alternative in patients suffering from scoliosis who require a long-term follow-up.

Methods: This study consists of 142 patients (70 female and 72 male cases) aged between 10 and 17 years, with a mean age of 13.8 ± 1.7 years. Menarche experience, body mass index, and skinfold thickness of the patients were recorded. Forty-five patients were found to have scoliosis. All ultrasonographic and radiographic evaluations were made by 2 blinded orthopedists. X-ray was considered as the gold standard.

Results: Percentage accuracy of UE was found to be 77.7% (κ = 0.698) for the first examiner and 64.30% (κ = 0.542) for the second examiner. Intraexaminer and interexaminer agreement were 0.971 and 0.924 for the UE, respectively. Moreover, interexaminer agreement for radiographic evaluation was 0.689. No significant difference was observed between the values of scoliosis and nonscoliosis patients. When the patients with a skinfold thickness of 16 mm or less and more than 16 mm were examined, the percentage accuracy of the UE was 80.43% (κ = 0.727) for the first group, whereas it was 72.91% (κ = 0.637) in the other group.

Conclusion: We found the intraexaminer and interexaminer agreement for the UE of RS to be reliable. In radiographic evaluation of RS, the intraexaminer and interexaminer agreement were lower. These findings were also consistent with data from the literature. In conclusion, UE of RS is a reliable method; however, the results may vary when x-ray is considered as the gold standard.