Osteochondritis dissecans of the elbow and synovial osteochondromatosis


The most striking finding in this study is the ossicle in the olecranon fossa, which is easy to call an os supratrochleare dorsale as a knee jerk reaction. However, synovial osteochondromas also like to find a home in the olecrenon fossa and are much more common, so must be considered if other supportive findings are present such as degenerative joint disease, or in this case osteochondritis dissecans. The other ossific fragments adjacent to the larger ossicle strongly tilt the diagnosis in favor of synovial osteochondroma over a normal variant ossicle in this case. It is not impossible that they had the ossicle as a normal variant first and then subsequently developed OCD, but that would be quite unlikely.