General Principles

Question 1

Explain the pathogenesis of osteoarthritis.

Answer 1

An active response of Chondrocytes leads to break down of collagen and articular cartilage is damaged. This also results in subchondral sclerosis and bone remodelling leading to osteophyte formation and subchondral bone cysts. There is also progressive joint space narrowing over time.

Question 2

State 3 risk factors for developing osteoarthritis.

Answer 2

Advancing age
Obesity
Female
Manual labour occupation

Question 3

What are Bouchard and Heberden nodes?

Answer 3

Bouchard = swelling of the PIPJs
Heberden = swelling of the DIPJs

Both seen in osteoarthritis

Question 4

How is osteoarthritis diagnosed?

Answer 4

It is usually a clinical diagnosis, but plain x rays can be used to exclude fracture and confirm the diagnosis.

Question 5

What are the classic radiological features of osteoarthritis?

Answer 5

Loss of joint space
Osteophytes
Subchondral sclerosis
Subchondral cysts

Question 6

What is the management for osteoarthritis?

Answer 6

Conservative - advise weight loss, strengthening exercises, supportive wear, physiotherapy.

Medical - simple analgesics, topical NSAIDs, steroid injections.

Surgical - osteotomy, arthrodesis, arthroplasty.

Question 7

What are the three general principles of fracture management?

Answer 7

Reduce, hold, rehabilitate.

Question 8

Why are plaster casts not circumferential for the first 2 weeks?

Answer 8

To allow for swelling, reducing the chances of compartment syndrome.

Question 9

What investigations would you do / how would you manage suspected septic arthritis?

Answer 9

The patient needs an urgent joint aspiration for gram staining, WCC, polarising microscopy and culture.

Management is empirical antibiotics and urgent surgical irrigation and washout.

N.B. If the patient has a prosthetic joint the joint should be aspirated in theatre and they will likely need a revision surgery.

Question 10

What classification system is used for open fractures?

Answer 10

Gustily-Anderson Classification.

Question 11

How should an open fracture be managed?

Answer 11

ATLS protocol - may need resuscitation + stabilisation.
Early plastics input

Urgent realignment and splinting of the limb.
Broad spectrum antibiotics
Tetanus vaccination
Photograph the wound + remove any gross debris
Dress with a saline soaked gauze

Surgical debridement of the wound and fracture site.
Skeletal stabilisation.

Question 12

How should compartment syndrome be managed?

Answer 12

Initial management:

• Keep the limb at a neutral level
• high flow oxygen
• IV fluids (transiently improves perfusion of the limb).
• remove all dressings / splints / casts.
• opioid analgesia

Definitive - urgent fasciotomy.

N.b. We need to monitor renal function due to the potential effects of rhabdomyolysis or repercussion injury.

Question 13

How should septic arthritis be managed?

Answer 13

Empirical antibiotic treatment (after cultures and aspirates).

Native joints need surgical irrigation and debridement in theatre.
Prosthetic joints need washout and may need revision surgery also.

Question 14

What are some risk factors for developing osteomyelitis?

Answer 14

Diabetes
Immunosuppression (steroids / AIDS)
Alcohol excess
IV drug use.

Question 15

What imaging shoul be requested for suspected osteomyelitis?

Answer 15

plain film radiographs of the area.

Definitive diagnosis is through MRI.
GOLD STANDARD diagnosis is from culture from bone biopsy at debridement.

Question 16

How should osteomyelitis be managed?

Answer 16

If the patient is clinically well - long-term IV antibiotics (>4 weeks).

If the patient deteriorates surgery may be required to prevent chronic osteomyelitis from developing. (Curettage of the area).

Question 17

Where do bone mets commonly metastasise from?

Answer 17

Breast
Prostate
Lung
Renal
Thyroid

Question 18

WHat investigations would you do for a suspected bone cancer?

Answer 18

Plain film radiographs
Myeloma screen
Most cases will also need MRI/CT + biopsy
Will need to be discussed at MDT meeting.

Question 19

What staging system is used for orthopaedic tumours?

Answer 19

Enneking staging system:

For benign tumours:

• Latent
• Active
• Aggressive

For malignant tumours:
-TNM staging