OSTEOARTHRITIS: (OA) OSTEOCHONDROSIS. OSTEOARTHRITIS: (OA) - It's a degenerative process involving the whole joint, but beginning in the articular cartilage. Other features. Causes of osteoarthritis Excessive load
Causes of osteoarthritis
2)Diseased Cartilage. The Cartilage may be weakened by inflammatory or metabolic disorders.
3) Unsupported Cartilage. If subchondral bone is deprived of its blood supply it becomes necrotic (a vascular necrosis). Obvious examples are caisson disease, hip fracture and dislocation.
Radiographs are normal early in the disease, but narrowing of the joint space develops as the disease progresses. Ninety percent of individuals over the age of 40 years have radiographic changes characteristic of osteoarthritis, however, only 30% have symptoms. Other x-ray features include subchondral sclerosis, marginal osteophytes, and subchondral cysts.37 In osteoarthritis, subchondral cysts are surrounded by a dense rim of bone that differentiates them from the marginal erosions that occur in rheumatoid arthritis. Laboratory features in arthritis are nonspecific and are generally not helpful in making the diagnosis.
A: Radiograph showing degenerative changes between C4 and C7. B and C: Radiographs taken after anterior vertebrectomy of C5 and C6, iliac crest strut graft, and anterior plate fixation.
Ankylosing spondylitis is a chronic seronegative inflammatory disease that affects the axial skeleton, especially the sacroiliac joints, hip joints, and spine. Extraskeletal involvement is found in the aorta, lung, and uvea. The incidence of ankylosing spondylitis is 0.5–1 per 1000 people. Although males are affected more frequently than females, mild courses of ankylosing spondylitis are more common in the latter.
The onset is insidious, with early symptoms including pain in the buttocks, heels, and lower back. Patients complain typically of morning stiffness, the improvement of symptoms with activity during the day, and the return of symptoms in the evening. The earliest changes involve the sacroiliac joints and then extend upward into the spine. Spinal disease results in loss of motion and subsequent loss of lordosis in the cervical and lumbar spine. Synovitis in the early stages leads to progressive fibrosis and ankylosis of the joints during the reparative phase. Enthesitis occurs at the insertion of the annulus fibrosus on the vertebral body with eventual calcification that results in the characteristic "bamboo spine." The pain from the inflammatory process subsides after full ankylosis of the affected joints occurs. Approximately 30% of patients develop uveitis, and 30% have chest tightness. Limited chest expansion indicates thoracic involvement. Fewer than 5% of patients have involvement of the aorta, characterized by dilation and possible conduction defects. In addition, patients may suffer from renal amyloidosis and pulmonary fibrosis.
The earliest radiographic changes are visible in the sacroiliac joints. Symmetric bilateral widening of the joint space is followed by subchondral erosions and ankylosis. Bony changes in the spine affect the vertebral body. Changes include loss of the anterior concavity of the vertebral body, squaring of the vertebra, and marginal syndesmophyte formation, which give the spine the appearance of bamboo. Ankylosis of the apophyseal joints also develops. The disease generally starts in the lumbar spine and migrates cephalad to the cervical spine. Atlantoaxial instability is seen occasionally.