Arthritis Flashcards
What four features comprise every natural synovial joint?
the articular cartilage, the synovial membrane, a fibrous capsule and the synovial fluid.
What is the function of the synovial joint ?
the synovial joint is designed to allow transmission of loads across the joint and movement of the bone ends relative to each other with minimal friction and wear.
What is a simple joint?
A simple joint is one which contains two articulating surfaces for example the proximal inter-phalangeal joints of the fingers.
What is a compound joint?
A joint which has more than two articulating surfaces in known as a compound joint, for example, the radio-carpel joint.
What is a complex joint?
The knee joint is more complex still with intra-articular structures, the menisci, subdividing the joint cavity. The knee is known as a complex joint.
What is the function of the articular cartilage ?
The cartilage forms a layer of 3 to 4 mm thick covering each articulating bone end. It is important in keeping friction and wear to a minimum.
What is the function of the synovial membrane ?
The joint is then encapsulated within a thick fibrous capsule which is lined with the synovial membrane. The synovial membrane merges with the ends of the articular cartilage and the intra-articular bone. It lines the intra-articular ligaments and tendons, and functions by secreting and absorbing synovial fluid.
What is the function of the synovial fluid ?
Lubricating the intra-articular space within the joint is a viscous fluid, the synovial fluid, which also functions to provide nutrition to the intra-articular surfaces. whilst keeping friction and wear to a minimum.
How many types of arthritis are there?
30-40
Osteoarthritis epidemiology
OA is the most common type of arthritis worldwide
8 million people living in the UK with OA and 81% in constant pain or limited activities
Most common reason for knee and hip replacements (140,000 each in year in UK)
What is Osteoarthritis?
Inflammation, cartilage loss(causes more inflammation) and some joint swelling(due to increased fluid) Changes to bone-knobbly new outgrowths on side + increased friction and Weaker muscles= painful
Cysts can also form in the bone due to changes.
Osteoarthritis lab findings
No specific blood tests (inflammatory markers and anti-bodies are normal) My see extra growth on X-rays / feel it on examination. OA doesn’t affect other organs .
Inflammatory arthritis features
Morning stiffness more than 30 minutes (better on movement)
Raised inflammatory markers (CRP)
Definite joint swelling
Positive blood tests for certain antibodies
Inflammatory back pain
Not just in old people!
What is Rheumatoid Arthritis?
Inflammatory arthritis- autoimmune
F:M 3:1 affects approx 1% of population
Most common age 40-50s (but occurs at all ages)
Rheumatoid Arthritis Features
Joint swelling, heat, pain and morning stiffness
Small joints of the hands and feet
Other organs can be affected too
80% positive Rheumatoid Factor blood test (doesn’t always=RA)
CCP blood test (specific for RA)
It is very treatable (not treated=increase vasculitis risk) treat with immunosuppression (5% don’t respond)
increased CV/infection/osteoporosis risk
Rheumatoid nodules-collections of inflammatory tissue
(usually left untreated check for rheumatoid lung disease)
