What thickness of cartilage is considered worrisome for malignant degeneration?
Approximately 1.5 cm thickness. The thinner the more reassuring.
Where are osteochondromas typically found?
Although osteochondromas are found arising from almost everywhere in the skeleton, they have a predilection for the proximal humerus and tibia and distal femur.
There is a bilobed, or two adjacent osteochondromas arising from the left posteromedial femur, measuring approximately 8.8 cm vertically. The proximal end of the lesion commences approximately 14.5 cm superior to the knee joint. The posterior component measures approximately 2.5 cm in diameter, in the medial lesion measures approximately 4 cm. A very thin cartilage cap is present, measures less than 5 mm in thickness.
The medial component protrudes into the vastus medialis, adjacent to the septum between the medial and posterior compartments. It lies just anterior the adductor tendon. The posterior component is adjacent to the popliteal artery where there is no aneurysm. It indents the semimembranosus muscle, separated by a small bursa.
Severe tricompartmental degenerative change is noted in the knee, not fully assessed, but there is extensive osteophyte formation and loss of joint space. Small knee joint effusion and intercondylar synovitis are present.