Intra-epiphyseal stress injury of the proximal tibial epiphysis: Preliminary experience of magnetic resonance imaging findings

• Purely intra-epiphyseal stress injuries of the proximal tibial epiphysis are described for the first time.
• The variation in the MRI findings of these injuries depending on the stage of maturation is demonstrated.
• We postulate a patho-mechanism to explain the variations in site and appearance of stress injuries in this region.

Stress induced injuries affecting the physeal plate or cortical bone in children and adolescents, especially young athletes, have been well described. However, there are no reports in the current English language literature of stress injury affecting the incompletely ossified epiphyseal cartilage. We present four cases of stress related change to the proximal tibial epiphysis (PTE) along with their respective magnetic resonance imaging (MRI) appearances ranging from subtle oedema signal to a pseudo-tumour like appearance within the epiphyseal cartilage. The site and pattern of intra-epiphyseal injury is determined by the type of tissue that is affected, the maturity of the skeleton and the type of forces that are transmitted through the tissue. We demonstrate how an awareness of the morphological spectrum of MRI appearances in intra-epiphyseal stress injury and the ability to identify concomitant signs of stress in other nearby structures can help reduce misdiagnosis, avoid invasive diagnostic procedures like bone biopsy and reassure patients and their families.