Osteoarthritis

Question 1

What are the causes of Osteoarthritis?

Answer 1

I - Septic Arthritis
T- Joint injury, Long term stresses, Joint laxity, Malalignment
M - Obesity
C - Congenital

Question 2

What will you find on a history of Osteoarthritis?

Answer 2

Symptoms:
Stiffness of joint - Especially after period of rest e.g. in the Morning (<30 minutes)
Reduced Range of movement
Joint pain - Worse with activities and weight-bearing but relieved by rest. Pain can be referred to the joint above/below. Pain at the extremities of movement more likely
Sometimes Joint effusion - Warmth/swelling
Periarticular Tenderness
Crepitus

Risk Factors:
>50 years
Women
Family history

Specific Questions to ask:
Is it acute - Need to rule out septic arthritis!
History of physical labour
ANy night pain? As this make OA unlikely unless in very severe disease
How long does the stiffness affect you in the morning? >30 mins? is unlikely to be OA
OA does not classically affect the MCP joints so ask about these

Differentials:
Gout - more acute and over a period of a few hours and commonly involves the metatarsophalangeal (MTP) joint
Pseudogout - more acute and over a period of a few hours and often involves the wrist and knee
Rheumatoid arthritis - RA usually causes a symmetrical small joint polyarthritis in the hands, particularly affecting the MCP joints and sparing the DIP joints. Associated with more prolonged morning stiffness
Avascular necrosis - risk factor such as corticosteroid use, can be excluded by Xray/MRI
Septic Arthritis - Acute presentation, differentiated by joint aspiration

Question 3

What will you find on examination of Osteoarthritis?

Answer 3

End of the bed:
Look for obesity - cause of OA in hip/knee
An abnormal gait can be observed.

Affected Joint:
Swelling
Bony Deformity
Malalignment
Palpate crepitus during the range of motion of the joint.  
Limited range of motion

Hands:
Enlargement of the PIP joints (Bouchard nodes)
Enlargement of the DIP joints (Heberden nodes)
Squaring at the base of the thumb (the first carpometacarpal joint)

Question 4

What investigations will you order in Osteoarthritis?

Answer 4

Bloods:
ESR/CRP - To rule out any inflamatory conditions, this shoudl be normal
Rheumatoid Factor - To rule out rheumatoid arthritis
LFT/U&E - TO check function before giving drugs
FBC - To look for an infection

Imaging:
Xray of the affected joint - new bone formation (osteophytes), joint space narrowing, and subchondral sclerosis and cyst

Special Tests:
Joint aspiration - If considering septic arthritis

Question 5

What is the treatment of Osteoarthritis?

Answer 5

Lifestyle:
Exercise – to reduce pain and improve ROM
Wear any appropriate footwear, e.g. Walking boots
Use of Joint supports
Walking Aids - Stick/Frame
Weight loss
Heat packs can reduce pain

Medical:
1st Line - local analgesia e.g. topical NSAIDs
2nd Line - local analgesia + paracetamol
3rd Line - NSAIDs e.g. Naproxen + paracetamol + local analgesia
4th Line - Opioids + NSAIDs + paracetamol + local analgesia
Prescribe a PPI if prescribing an NSAID
Consider Use of intraarticualr steroids at all levels for acute exacerbation of symptoms. Especially in the knee

Surgical:
Joint Replacement - Commonly in the Hip and Knee
Indicated in recurrent untreatable pain with reduced QOL
Failure rate of 1% per year (15-year average). So, hold off if possible
Osteotomy is suitable for unicompartmental knee OA