Langenskiöld Classification for Blount Disease: Is It Reliable?

Blount disease (BD) is a developmental disease which medial part of the proximal tibial physis resulting genu varum. Plain radiographs are necessary for diagnosis. For this purpose, Langenskiöld classification is used. There are not enough data about Langenskiöld classification's reliability in the English literature. The purpose of this study is to evaluate the intra- and inter-reliability of Langenskiöld classification in BD.

Thirty seven patients with BD were included in this cross-sectional study. Two separate presentations including clinical findings and standard knee radiographs were evaluated by three different groups (residents, surgeons, and pediatric orthopedic surgeons) and were sent to the observers every other month by hiding patients' personal information. Intraobserver and interobserver reliabilities in these three groups were examined. Intraclass correlation coefficient (ICC) tests were used for this purpose.

Intraobserver reliability (ICC) was similar (excellent) in three groups (0.822, 0.804, and 0.763). Interobserver reliability among three groups was meanly excellent.

Agreement to Langenskiöld classifications found excellent for three groups. Surgical experience did not change intraobserver and interobserver reliability in Langenskiöld classification.