Reliability Comparison between “Distal Radius and Ulna” and “Simplified Tanner–Whitehouse III” Assessments for Patients with Adolescent Idiopathic Scoliosis

STUDY DESIGN: This is a retrospective clinical study. PURPOSE: In this study, we aim to evaluate the reliability of the distal radius and ulna assessment (DRU) and simplified Tanner-Whitehouse III classification (sTW3) in Japanese patients with adolescent idiopathic scoliosis (AIS). OVERVIEW OF LITERATURE: The greatest curvature of a scoliotic spine occurs at peak-height velocity (PHV), which is the time during which an individual’s height increases at the maximum rate. Diagnosing and appropriately treating AIS before PHV is the most effective way in order to prevent unnecessary deterioration of the scoliosis curve. Although it is difficult to detect scoliosis before PHV, DRU and sTW3, which involve evaluations using a left-hand radiograph, have been reported to be effective. METHODS: We retrospectively evaluated 54 hands of 40 girls with AIS who visited Nara Medical University Hospital from 2000 to 2015 using previously collected radiographs. The examiners included a spine surgeon and a pediatric orthopedic surgeon, each with over 10 years of experience. The reliability of the DRU and sTW3 was evaluated using the kappa coefficient. RESULTS: The left-hand radiographs of 40 female patients with AIS (mean age, 13.9±1.7 years; N=54 hands) were evaluated by two blinded examiners using the sTW3 and DRU methods. The highest inter-observer and intra-observer reliabilities (kappa, 0.64 and 0.62, respectively) for radius evaluation were determined. Radius evaluation by the DRU showed the highest agreement rate and smallest error between the inter- and intra-observer examinations. CONCLUSIONS: The DRU was the most reliable assessment tool, and it has the potential to be useful for precisely determining the stage of skeletal maturity in outpatient clinics.