Osteoarthritis

Question 1

Describe the onset of osteoarthritis

Answer 1

Insidious onset (4-5 years) where the pain gets worse and makes exercise difficult.

Question 2

What are the common sites of osteoarthritis?

Answer 2

• CMCJ (base of thumb)
• PIPJ
• DIPJ
• Hips
• Lumbar + cervical spine
• Knees
• Feet

Question 3

What are the differentials for exacerbation of knee pain and swelling?

Answer 3

• Crystal (pseudogout/gout) - diuretics increase risk of gout
• Septic arthritis
• Mechanical disruption (meniscal, ligaments, bursa)
• Rapidly progressive OA
• Osteonecrosis

Question 4

What are the examination findings of OA?

Answer 4

• Small cool effusion (fluid around joint)
• Painful flexion of joint e.g. knee
• Crepitus
• Antalgic gait
• Weakness +/- muscle wasting
• Joint line tenderness
• Deformity
• Bony swelling
• Instability
• Nodal OA - Heberdens (DIPJs) and Bouchards (PIPJs) nodes

Question 5

What investigations can be done for osteoarthritis?

Answer 5

• Consider bloods - mainly to rule out alternate cause i.e. IA (CRP, ESR, CCP, RF), or gout (urate)
• X-ray

Question 6

What are the x-ray findings of OA?

Answer 6

• Loss of joint space
• Osteophytes on joint margins
• Subchondral bone sclerosis
• Subchondral cysts - small pseudocystic areas with sclerotic walls situated in the subchondral bone

Question 7

What is the 1st line treatment of OA?

Answer 7

• All patients should be offered help with weight loss, given advice about local muscle strengthening exercise and general aerobic fitness
• Paracetamol and topical NSAIDs are 1st line analgesics - topical NSAIDs are only for OA of the knee or hand

Question 8

What is the 2nd line treatment of OA?

Answer 8

Oral NSAIDs/COX-2 inhibitors, opioids, capsaicin cream and intra-articular corticosteroids.
- A PPI should be co-prescribed with NSAIDs and COX2 inhibitors

Question 9

What are the non-pharmacological treatment options for OA?

Answer 9

• Supports and braces e.g. splints
• TENS
• Shock-absorbing insoles or shoes

Question 10

What further treatments can be given for OA if medicines/lifestyle changes are not helping?

Answer 10

• If conservative methods fail, refer for consideration of joint replacement
• Can be offered steroid injection depending on severity of symptoms

Question 11

What is the pathology of OA?

Answer 11

OA relates to dysregulation of tissue turnover, focal articular cartilage damage leads to hypertrophy of subchondral bone, marginal osteophytes, modest patch synovitis and thickening of joint capsule and ligaments.

Question 12

What are the risk factors of OA?

Answer 12

• Age
• Gender - F>M
• BMI
• Previous joint injury
• Intense sport activities
• Occupation (hand, hip)
• Quadriceps strength (knee)
• Alignment (knee)
• ‘Pistol grip deformity’ (hip)
• Genetic
• Secondary OA

Question 13

When should you consider secondary OA?

Answer 13

• If it presents at a young age (<40)
• Atypical distribution of joints e.g. MCPs, elbows/shoulders, ankles
• Needs high index of suspicion and detailed PMH and FH is required

Question 14

What are the causes of secondary OA?

Answer 14

• Metabolic: crystal-associated, Wilson’s, haemochromatosis, acromegaly
• Traumatic: joint injury, surgery, fracture through a joint or osteonecrosis
• Anatomical/congenital: slipped femoral epiphysis, epiphyseal dysplasia, Perthe’s, congenital dislocation of hip
• Neuropathic: diabetes, syphillis
• Inflammatory: any inflammatory arthropathy, septic arthritis

Question 15

What are the symptoms of osteoarthritis?

Answer 15

• Episodic joint pain, usually an intermittent ache that is worse on movement and relieved by rest
• Stiffness after prolonged periods of inactivity e.g. <30mins in the morning
• Painless nodes
• Squaring of the thumbs - deformity of the carpometacarpal joint so fixed adduction of the thumb