Osteoarthritis Flashcards
What is osteoarthritis?
What causes it?
- described as “wear and tear” in the joints
- it occurs in the synovial joints
- it is a result of a combination of genetic factors, overuse and injury
it is NOT an inflammatory condition like rheumatoid arthritis
What is thought to be the underlying cause of osteoarthritis?
an imbalance between the cartilage wearing down and the chondrocytes repairing it
this results in structural issues within the joint
What are the risk factors for osteoarthritis?
- obesity
- increasing age
- occupation
- female gender
- trauma
- family history
What joints are most commonly affected in OA?
- the hips and the knees are most commonly affected
- sacroiliac joints
- cervical spine (cervical spondylosis)
in the hands:
- distal interphalangeal joints (DIPs)
- carpometacarpal joint (CMC) at the base of the thumb
- wrist
What mnemonic is used to remember the 4 key XR changes in osteoarthritis?
LOSS
L - loss of joint space
O - osteophytes (bone spurs)
S - subchondral cysts (fluid-filled holes in the bone)
S - subarticular sclerosis (increased density of bone along the joint line)
How do XR changes in osteoarthritis correlate with disease severity?
- XR changes do not always correlate with symptom severity
- significant XR changes may be seen in someone without symptoms
What is the typical presentation of OA?
- joint pain and stiffness
- this is worse with activity and at the end of the day
- it results in joint deformity, instability and reduced function
in contrast with an inflammatory arthritis which is worse in the morning and improves with activity
What are the general signs of osteoarthritis?
- bulky, bony enlargement of the joint
- reduced range of motion
- crepitus on movement
- effusions (fluid) around the joint
patients may present with referred pain caused by OA
e.g. if they present with lower back / knee pain - consider a problem with the hip
What are the typical signs of OA that can be seen in the hands?
- Heberden’s nodes (in the DIP joints)
- Bouchard’s nodes (in the PIP joints)
- squaring at the base of the thumb (CMC joint)
- weak grip
- reduced range of motion
Why is the carpometacarpal joint commonly involved in OA?
- the CMC joint is a saddle joint
- the metacarpal of the thumb sits on the trapezius like a saddle
- it gets a lot of use from everyday activities, so is prone to wear and tear
What do the NICE guidelines suggest about making a diagnosis of OA?
diagnosis can be made without investigations if:
- patient is > 45
- they present with typical activity-related pain
- there is no morning stiffness (or stiffness lasts < 30 mins)
morning stiffness lasting > 30 mins is associated with inflammatory arthritis
What is the first step in management of OA?
patient education + advice on lifestyle changes, such as:
- weight loss (to reduce load on joint)
- physiotherapy (improves strength + function)
- occupational therapy (e.g. special devices / adaptations to the home)
- orthotics (e.g. knee braces)
What medications can be used in the management of OA?
a stepwise approach to analgesia
first-line:
* oral paracetamol +/- topical NSAID gel
- topical capascin cream is an alternative
second-line:
* addition of oral NSAIDs
- co-prescribe PPI (e.g. omeprazole) for gastric protection
third-line:
* consider opiates (e.g. codeine)
- opiates should be used with caution
- topical NSAIDs are only effective if OA affects the knees / hands
Why must opiates be used with caution in OA?
- they are not effective in chronic pain relief
- they carry significant side effects and patients can become dependent on them
- patients often become dependent with little pain relief benefit
As well as analgesia, what other approaches are used in the management of OA?
intra-articular steroid injections:
- provide temporary reduction in inflammation + improves symptoms
joint replacement:
* for severe cases
- usually involves hip or knee
What cautions need to be taken when giving NSAIDs?
Who is particularly at risk?
- NSAIDs are better when used intermittently
- they should be used for a short period to get pain under control to avoid side effects
- particular caution should be taken in older patients and those on anticoagulants (incl. aspirin + DOACs)
What are the side effects associated with long-term NSAID use?
GI effects:
* gastritis
* peptic ulcers (leading to upper GI bleeding)
renal effects:
* AKI or progressive kidney disease
CV effects:
* HTN, heart failure, stroke, MI
!! EXACERBATION OF ASTHMA !!
What are the features of hip OA?
How is its severity assessed?
- chronic history of groin ache following exercise + relieved by rest
- the Oxford hip score is used to assess severity
OHS - 12-item patient-reported questionnaire where each parameter is marked out of 4
- a score of 40-48 indicates satisfactory joint function, with lower scores indicating more severe hip OA
What red flag features suggest a diagnosis that is NOT OA of the hip?
- pain at rest
- pain at night
- morning stiffness lasting > 2 hours
What are the 3 steps in the management of hip OA?
- oral analgesia
- intra-articular steroid injections for short-term benefit
- total hip replacement is the definitive treatment
What are the complications associated with total hip replacement?
perioperative complications:
* VTE
* intraoperative fracture
* nerve injury
* surgical site infection
leg length discrepancy
posterior dislocation:
* presents acutely with a “clunk”, pain + inability to weight bear
- internal rotation + shortening of affected leg
aseptic loosening:
* resulting in prosthetic joint infection
What are the RFs for development of hand OA?
- previous trauma to the joint
- obesity
- age > 55
- female gender
- hypermobility of a joint
- occupation (e.g. farmer / cotton worker)
- positive family history
osteoporosis reduces the risk of OA
What joints tend to be affected in hand OA?
- the DIPs are affected more often than the PIPs
- the CMC joint is involved
- the joints are affected bilaterally
- usually one joint is affected at a time over a period of several years
What are the typical symptoms of hand OA?
- episodic joint pain that is provoked by movement + relieved by rest
- stiffness that is worse after long periods of inactivity
- Heberden’s / Bouchard’s nodes due to osteophyte formation
- squaring of the base of the thumb (fixed thumb adduction)
stiffness in the morning tends to only last for a few mins (much longer in RA)
