Osteoarthritis (OA) is a progressive degenerative disease of the synovial joints in which the articular cartilage and the adjacent
subchondral bone show the most noticeable changes.
Other symptoms include narrowing of the joint space, synovial membrane thickening, osteophyte formation and increased density of
subchondral bone.
Importantly, there were no indications of chondrolysis, osteonecrosis,
subchondral insufficiency fractures, or clinically significant
subchondral bone changes in any subgroup.
Bone loss develops as the unstable bony surfaces continue to rub roughly and unevenly, leading to joint space narrowing, exposure of the underlying
subchondral bone, and precipitation of a process of bone remodeling in which the
subchondral bone thickens.
The most common cause of non-traumatic bone fractures is avascular bone necrosis (AVN); the terms ischemic necrosis, osteochondritis dissecans,
subchondral avascular necrosis are also used (6).
The presence of synovitis, capsulitis, and enthesitis or structural changes, in the context of erosions,
subchondral sclerosis, periarticular fat deposition and ankylosis are suggestive of and are not sufficient alone to make the diagnosis of axial spondyloarthropathy (9).
Joint safety was a composite measure consisting of adjudicated outcomes of rapidly progressive osteoarthritis (RPOA) type 1 or type 2,
subchondral insufficiency fracture, osteonecrosis or pathological fracture.
Joint safety was a composite measure consisting of adjudicated outcomes of rapidly progressive osteoarthritis type 1 or type 2,
subchondral insufficiency fracture, osteonecrosis or pathological fracture.
Additional findings on MR include decreased or absent enhancement, low T1 signal of the
subchondral bone, and thickening of the cartilage overlying the flattened femoral head.
Spontaneous osteonecrosis of the knee (SONK) was first reported in 1968 by Ahlback.[1] It was defined as a distinct clinical entity with characteristic findings including a
subchondral lesion in the weight-bearing region of a single condyle.
When the disease reaches the
subchondral region, there is separation in the articular cartilage, resulting in cartilage and bone erosion, destruction, and effusion.