Trevor disease MRI

Clinical details, discharge summary mentions corrective osteotomy done for congenital progressive uni lateral knee deformity. Previous imaging details not available.

This MRI of knee joint shows post-operative status with corrective osteotomy for femur and tibia.

Well defined bone signal intensity outgrowth with cortex and medulla involving medial epiphysis of distal end of femur, epiphysis of tibial tuberosity with distinct cortex, medulla and fatty marrow in continuity with parent bone. Marked enlargement of patella with fragmentation.

Trevor’s disease

Synonym: Dysplasia epiphysealis hemimelica.

An extremely rare, approximately 1:1,000,000, congenital, non-hereditary condition consist of multiple osteochondromas arising from the epiphyses. Age of presentation is young children with slight male predilection.

There are three different types of involvement. The classic form has characteristic hemimelic distribution involving more than one bone or epiphysis within a single lower extremity. The localised form encompasses single bone involvement, either unilateral or bilateral. The generalised form incorporates the whole limb from pelvis to foot.

The abnormalities comprising the lower extremity is more common than upper, distal ends are more frequently encountered than upper ends of bone, medial aspects predilection is twice more common than lateral. The most common site of involvement is distal end of femur.

The condition typically demonstrates an irregular bone density mass on x-ray/CT arising from the epiphysis. The bony growth delineates areas of fatty marrow as well as foci sclerosis secondary to ossification on MRI. The illustration of continuity of cortex and medulla with the parent bone is must to end the search.

The bony growth can result in widening of joint space, deformity, bursa formation with soft tissue oedema, bursitis, tendinitis secondary to chronic irritation. The bony overgrowth can land up with fragmentation, detachment forming intra-articular bony loose body and changes of secondary osteoarthritis in advanced case.