CT and MRI features are highly suggestive of an intracapsular osteoid osteoma. Soft tissue and bone marrow edema, as well as joint effusion and synovial enhancement (synovitis), are well-visualized on MRI than CT.

Intraarticular osteoid osteoma, within or near a joint, is considered as a  separate clinical entity. The hip is considered the most commonly involved joint. With intraarticular osteoid osteoma, the reactive cortical sclerosis is minimal or absent (as in our case) due to a lack of cambium from the joint capsule (usually responsible for bone formation).