Osteoarthritis Flashcards
What are the main features of OA seen on XR?
- loss of joint space .
- osteophyte
- subchondral sclerosis
- subchondral cysts
LOSS
Which bone reading is used for the FRAX calculator?
Neck of femur
because readings at the lumbar spine and total hip can be falsely elevated in the presence of degenerative change and so are less reliable as a predictor of fracture
Define OA.
degenerative joint disorder in which there is progressive loss of hyaline cartilage + new bone formation at the joint surface and its margin.
What is the pathophysiology of OA?
Microtrauma –> inflammation –> osteophytes –> subchondral cysts
What is the aetiology of OA?
Multifactorial - genetic, biological, biochemical components
What are the risk factors for osteoarthritis?
- Age
- Obesity
- Female sex
- Joint abnormality or trauma
What is the relationship between symptom severity and radiological changes in OA?
Worse radiographic OA changes do not correlate with severity of pain and symptoms
What joints are most commonly affected by OA?
knee, hip, hands, and lumbar and cervical spine
What % of people over 60 are affected by OA?
10%
Framingham OA study found that 27% of people under 60 and 44% of people over 70 have radiographic OA.
How can OA be classified?
Primary - most common
Secondary - to joint disease or other diseases like obesity, haemochromatosis and occupation
What are the clinical features of OA?
- Joint pain
- Stiffness
- <30min morning stiffness
- Swelling
- Crepitus on movement
- Due to new bone formation
- Background ache at rest
- BUT pain should not be present at rest or at night except in advanced disease
- Instability
- Perceived lack of power due to pain
- Heberden’s nodes (DIP)
- Bouchard’s nodes (PIP)
- Squaring at the base of the thumb
- Reduced range of movement
- Mild synovitis
What investigations are used to diagnose OA?
X rays of affected joint
CRP and ESR - normal but may be elevated slightly; exclude inflammatory arthritis
Other:
- RF
- anti-CCP
- MRI - to exclude other conditions; may show cartilage loss, bone marrow lesions, and meniscal tears. Offer in spinal OA with neurological deficits.
- USS
What type of OA is shown if it is found to also affect the knees?
Nodal OA = usually in postmenopausal women and affects DIP, PIP, CMC and knees
Bouchard’s and Heberden’s seen. XR shown below.
Which joints are not typically affected by OA and would suggest an alternative diagnosis?
- MCP
- Wrist
- Ankle
More likely RhA
What are the DIP joint deformities in OA called?
Heberden’s nodes
