Osteoarthritis

Question 1

What is the definition of osteoarthritis?

Answer 1

Degeneration of joint cartilage and underlying bone

Question 2

How common is osteoarthritis?

Answer 2

Commonest joint condition

Question 3

What is the pathophysiology of osteoarthritis?

Answer 3

• Usually primary but may be secondary to other causes
• Damage to articular cartilage
• Inflammatory response that affects the cartilage, subchondrial bone, ligaments, menisci, synovium and capsule
• Balance between cartilage degradation by wear and cartilage production by chondrocytes
• Cartilage becomes oedematous
• Focal erosion of cartilage
• Chrondrocytes die
• Repair is attempted but disorganised = surface is fibrillated and fissured, abnormal sclerotic subchondral bone and overgrowths (osteophytes)
• Cartilage ulceration exposes underlying bone to ↑ stress = microfractures and cysts

Question 4

What are the risk factors/aetiology of osteoarthritis?

Answer 4

• Woman
• Middle age (around 50 years old and prevalence ↑ with age)
• Genetics
• Asians – knee OA more common
• Obesity
• Hypermobility
• Osteoporosis - ↓ risk
• Trauma
• Congenital joint dysplasia
• Occupations – e.g. miners, farmers etc
• Pre-existing joint damage → secondary OA
• Metabolic disease e.g. acromegaly, haemochromatosis → secondary OA
• System diseases e.g. haemophilia, neuropathies

Question 5

What are the signs/symptoms of osteoarthritis?

Answer 5

• Pain on movement – worse at the end of the day
• Crepitus – worse at the end of the day
• Background pain at rest
• Stiffness of joints after rest for up to 30 mins
• Joint instability
• Heberden’s nodes – DIP joints, thumb carpometacarpal joints, knees
• Joint tenderness
• Joint derangement
• ↓ range of movement of joint
• Mild synovitis
• Valgus/varus leg deformity

Question 6

What investigations are needed to diagnose osteoarthritis?

Answer 6

• X ray shows: Loss of joint space, Osteophytes, Subarticular sclerosis, Subchondral cysts (LOSS)
• ↑ CRP
• Arthroscopy
• Aspiration of synovial fluid

Question 7

What are the surgical treatments for osteoarthritis?

Answer 7

• Intra-articular steroid injections

* Joint replacement

Question 8

What are the pharmacological treatments for osteoarthritis?

Answer 8

• Paracetamol/codeine

* NSAIDs

Question 9

What are the non pharmacological treatments for osteoarthritis?

Answer 9

• Exercises to improve muscle strength/fitness
• Walking stick for contralateral side
• Weight loss
• Glucosamine and chondroitin
• Cold/heat therapy
• TENS
• Acupuncture – for knee