Osteoarthritis Flashcards
What is osteoarthritis and which joints are commonly involved?
Cartilage damage and joint space narrowing resulting in pain, functional limitation and impaired quality of life
Hip, knee, lumbar or cervical spine and wrist
Describe the pathophysiology underlying OA
Hyaline cartilage undergoes turnover in which worn out collage and other matrix components are degraded and replaced by chondrocyte cells
Genetic and environmental factors can stimulate apoptosis of chondrocytes, disrupting the normal repair mechanisms causing cartilage damage
Cytokines and protease enzymes increase in the cartilage, trigering OA changes through direct cartilage damage
Cartilage destruction exposes underlying bone resulting in subchondral bone growth, osteophyte formation and bone cysts
Give systemic risk factors for OA
Increased age
More common in women
Post menopause
Family history (indicating genetic component)
Increased bone density (e.g. Paget’s disease)
Give mechanical risk factors
Obesity
Injury - ligament damage
Joint damage due to underlying disease - RA, Paget’s, trauma
Joint site - weight bearing joints at higher risk
Occupation - cleaners - hip, knee shoulders, hairdressers- hand
What are the symptoms of OA
Joint pain - worse on movement, load bearing and at the end of the day
Joint stiffness - in the morning or after rest for <30 mins
Reduced joint function
Joint instability
When is joint pain worse in OA
Movement, load bearing and at the end of the day
What are the signs of OA?
Periarticular tenderness, crepitus, reduced range of movement, muscle wasting, joint deformity and instability, squaring of the thumb
Swelling of the hands - Bouchard’s and Heberden’s nodes
Mild synovitis and effusion
What are heberden’s and bouchard’s nodes?
Heberden’s nodes are bony enlargements of the DIP joints
Bouchard’s nodes are bony enlargements of the PIP joints
Due to osteophyte formation
What is nodal OA?
Hand pain, aching or stiffness for most days of the prior month
Heberden’s and Bouchard’s nodes in 2 or more joints
Commonly in post-menopausal women
How is hip OA classified?
hip pain for most days of prior month
Femoral and/or acetabular osteophytes and joint space narrowing
How is knee OA classified
Knee pain for most days of prior month
Crepitus on movement
Morning stiffness for less than 30 minutes and bone enlargement of the knee
Common in obese women 38 and over
What should you ask about when taking OA history for symptoms and causes
Pain worse on use and relieved by rest Stiffness in morning/after rest Slow onset Reduced joint function and stbaility Particular joint's that are overused - dominant hand Trauma? RA/Paget's? FHx of OA? Occupation
Describe OA on examination
Look - pain on movement, muscle wasting, antalgic gait
Feel - Tenderness, swelling of joints, effusion/synovitis
Move - pain on movement, reduced range of movement, joint deformity, crepitus
What investigations for OA?
RF/Anti-CCP to rule out RA
X-ray
MRI
Joint aspiration - sterile viscous fluid, WCC may be slightly raised
What does the OA x-ray show
Loss of joint space
Osteophytes
Subchondral sclerosis
Subchondral cysts
