Osteoarthritis

Question 1

What is osteoarthritis?

What causes it?

Answer 1

• 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

Question 2

What is thought to be the underlying cause of osteoarthritis?

Answer 2

an imbalance between the cartilage wearing down and the chondrocytes repairing it

this results in structural issues within the joint

Question 3

What are the risk factors for osteoarthritis?

Answer 3

• obesity
• increasing age
• occupation
• female gender
• trauma
• family history

Question 4

What joints are most commonly affected in OA?

Answer 4

• 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

Question 5

What mnemonic is used to remember the 4 key XR changes in osteoarthritis?

Answer 5

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)

Question 6

How do XR changes in osteoarthritis correlate with disease severity?

Answer 6

• XR changes do not always correlate with symptom severity
• significant XR changes may be seen in someone without symptoms

Question 7

What is the typical presentation of OA?

Answer 7

• 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

Question 8

What are the general signs of osteoarthritis?

Answer 8

• 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

Question 9

What are the typical signs of OA that can be seen in the hands?

Answer 9

• 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

Question 10

Why is the carpometacarpal joint commonly involved in OA?

Answer 10

• 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

Question 11

What do the NICE guidelines suggest about making a diagnosis of OA?

Answer 11

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

Question 12

What is the first step in management of OA?

Answer 12

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)

Question 13

What medications can be used in the management of OA?

Answer 13

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

Question 14

Why must opiates be used with caution in OA?

Answer 14

• 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

Question 15

As well as analgesia, what other approaches are used in the management of OA?

Answer 15

intra-articular steroid injections:

• provide temporary reduction in inflammation + improves symptoms

joint replacement:
* for severe cases

• usually involves hip or knee

Question 16

What cautions need to be taken when giving NSAIDs?

Who is particularly at risk?

Answer 16

• 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)

Question 17

What are the side effects associated with long-term NSAID use?

Answer 17

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 !!

Question 18

What are the features of hip OA?

How is its severity assessed?

Answer 18

• 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

Question 19

What red flag features suggest a diagnosis that is NOT OA of the hip?

Answer 19

• pain at rest
• pain at night
• morning stiffness lasting > 2 hours

Question 20

What are the 3 steps in the management of hip OA?

Answer 20

• oral analgesia
• intra-articular steroid injections for short-term benefit
• total hip replacement is the definitive treatment

Question 21

What are the complications associated with total hip replacement?

Answer 21

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

Question 22

What are the RFs for development of hand OA?

Answer 22

• 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

Question 23

What joints tend to be affected in hand OA?

Answer 23

• 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

Question 24

What are the typical symptoms of hand OA?

Answer 24

• 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)