Joints Flashcards
What is a joint?
Connection between two bones
How do joints provide structural strength?
Solid joints are tightly connected (eg cranial sutures)
What are synovial joints?
They have a joint space to allow for motion
What is the articular surface of adjoining bones in a synovial joint made of?
hyaline cartilage (type II collagen) that is surrounded by a joint capsule
What facilitates smooth motion of the synovial joint?
Synovium lining the joint capsule secretes fluid rich in hyaluronic acid to lubricate the joint and facilitate smooth motion.
What is osteoarthritis?
Progressive degeneration of articular cartilage; most common type of arthritis
What is the most common type of arthritis?
osteoarthritis
What is osteoarthritis most often due to?
wear and tear
What is the major risk factor for osteoarthritis?
Age
In whom is osteoarthritis common?
after 60 years
In addition to age, what are some additional risk factors for osteoarthritis?
obesity and trauma.
What joints are affected by osteoarthritis?
a limited number of joints (oligoarticular); hips, lower lumbar spine, knees, and the distal interphalangeal joints (DIP) and proximal interphalangeal joints (PIP) of fingers are common sites
What is the classic presentation for osteoarthritis?
joint stiffness in the morning that worsens during the day
What are the pathologic features for osteoarthritis?
1) Disruption of the cartilage that lines the articular surface; fragments of cartilage floating in the joint space are called joint mice 2) Eburnation of the subchondral bone 3) Osteophyte formation (reactive bony outgrowths); classically arises in the DIP (Heberden nodes) and PIP (Bouchard nodes) joints of the lingers
What are Heherden nodes?
Osteophyte formation in distal interphalangeal joints
What are Bouchard nodes?
Osteophyte formation in proximal interphalangeal joints
What is rheumatoid arthritis?
Chronic, systemic autoimmune disease
In whom does rheumatoid arthritis classically arise?
in women of late childbearing age
What is rheumatoid arthritis associated with?
HLA-DR4
What is rheumatoid arthritis characterized by?
involvement of joints
What is the hallmark for rheumatoid arthritis?
synovitis leading to formation of a pannus (inflamed granulation tissue).
What does rheumatoid arthritis lead to?
destruction of cartilage and ankylosis (fusion) of the joint
What are the clinical features for rheumatoid arthritis?
1) Arthritis with morning stiffness that improves with activity 2) Fever, malaise, weight loss, and myalgias 3) Rheumatoid nodules 4) Vasculitis 5) Baker cyst 6) Pleural effusions, lymphadenopathy, and interstitial lung fibrosis
For rheumatoid arthritis, describe the arthritis that is seen clinically?
Symmetric involvement of PIP (proximal interphalangeal joints) joints of the fingers (swan-neck deformity), wrists (ulnar deviation), elbows, ankles, and knees is characteristic; DIP (distal interphalangeal joints) is usually spared (unlike osteoarthritis)
What is a difference between the arthritis seen in rheumatoid arthritis and osteoarthritis?
In rheumatoid arthritis the DIP is usually spared unlike osteoarthritis
For rheumatoid arthritis, what is seen on x-ray?
Joint-space narrowing, loss of cartilage, and osteopenia
What are rheumatoid nodules?
They are a central zone of necrosis surrounded by epithelioid histiocytes; arise in skin and visceral organs
What is vasculitis?
Multiple organs may be involved.
What is Baker cyst?
swelling of bursa behind the knee