- Etiology: repetitive compressive or shear forces at radiocapitellar joint, shear injury leads to vascular insufficiency, occurs when ossification is near complete
- Radiograph: insensitive, lucency in capitellum, comparison with asymptomatic side elbow radiograph for assessment of fragmentation vs. normal variant
- MRI: lesion usually anterolateral in capitellum and is at periphery of ossifying epiphysis and deep to articular surface, low signal intensity on T1WI and variable signal intensity on T2WI
- DDX: Panner disease in patients younger than 11 years old
— Panner disease: younger 7-12 years, affects all or part of capitellum, normal overlying cartilage, no loose body formation
— Osteochondritis dissecans of the elbow: older age group 12-15 years,affects anterolateral capitellum, may have overlying cartilage defects / loose bodies - Complications:
- Treatment:
- Clinical: 11-17 years old in patients playing baseball, gymnastics, weightlifting, javelin