Musculoskeletal ImagingJoint mice
osteocartilaginous bodies that may arise from transchondral
fractures, disintegration of the
articular surface,
synovial metaplasia and
osteoarthritis. On images these bodies can change in size, disappear, or migrate to and become lodged in bone depressions. They may also pass from the cavity into a neighbouring communicating
synovial cyst.
Routine radiographs can reveal calcified and ossified bodies within joints, but arthrography and MR imaging provide more information. Small bodies may be easily overlooked, however, as their signal intensity may be the same as that of joint fluid. Fluoroscopy is valuable in defining the presence and precise position of fragments within the joint.
DR