INTRODUCTION: We report the imaging findings and treatment course in two patients with Sinding-Larsen-Johansson disease.
CASE: The first case was a 10-year-old boy who was a member of a soccer club. He gave a history of feeling slight pain in the left knee after soccer practice. Subsequently, his knee pain became severe when he landed from a high jump in a physical education class. The pain worsened markedly, making it difficult to walk, and he presented to our department. On the basis of the plain x-ray, computed-tomographic (CT) and magnetic resonance imaging (MRI) findings, we made the diagnosis of avulsion fracture-type Sinding-Larsen-Johansson disease. The patient was treated conservatively, and 8 months later, the radiographs showed union of the calcified lesion and patella. The second case was a 12 year-old boy who belonged to a kendo club. He developed left knee pain upon landing from a height during practice for a hurdle race in a physical education class at school. The pain resolved with rest. However, the knee pain recurred when the boy jumped for a running broad jump, and he presented to our department. On the basis of the clinical, plain x-ray and MRI findings, we made the diagnosis of avulsion fracture-type Sinding-Larsen–Johansson disease. The patient was treated conservatively, and by one month later, the pain had resolved and the treatment was completed.
DISCUSSION: We have few opportunities to encounter Sinding-Larsen–Johansson disease, however, the findings on physical examination, such as tender points, CT and MRI, were useful for the diagnosis of the disease in our patients.
CONCLUSION: We encountered two cases of avulsion fracture-type Sinding-Larsen-Johansson disease and were able to observe the time-course of changes in the radiographs until healing in one of the cases. In both cases, conservative treatment alleviated the symptoms and yielded good outcomes.
