Observe the condyle deformation,
bone sclerosis (yellow arrows); formation of free bodies and occupation of the joint space (red arrow).
However, it is well known that in OA the subchondral
bone sclerosis and osteophyte formation appear parallel to cartilage degeneration [2,16], and it has been even suggested already in the 1986 by Radin and Rose that the initiation of the cartilage degradation can be driven by stiffening of the subchondral bone [17].
According to the grading system of knee osteoarthritis using standing radiographs, (2) which was modified from Ahlbach, the radiographic findings of osteoarthritis of the knee were classified into 6 grades: Grade 0, normal joint; Grade 1,
bone sclerosis or osteophyte formation; Grade 2, narrowing of the joint space of less than 3 mm; Grade 3, obliteration of joint space or subluxation; Grade 4, defect of the tibial plateau of less than 5 mm; and Grade 5, defect of tibial plateau of more than 5 mm.
It is increased in patients with diseases associated with
bone sclerosis [26] a finding which corresponds well with the patient presented as case 14 in the present study.
DISCUSSION: Osteoid Osteoma is benign bone lesion consisting of well demarcated osteoblastic mass called nidus of less than two centimeter size surrounded by a distinct zone of reactive
bone sclerosis [2].
Punctate
bone sclerosis may be seen owing to intra-osseous deposition of the tophi; (2) with para-articular deposition of tophi, there is asymmetric soft-tissue swelling.
When it affects the carpal bones, as in our case, the differential diagnosis would broaden to include other causes of carpal
bone sclerosis including kienbock's disease, rheumatoid arthritis, chronic infections like tuberculosis, etc and often histopathology maybe required to rule out these conditions.