Compartment Syndrome

Question 1

What is compartment syndrome?

Answer 1

Elevated interstital pressure within a closed facial compartment resulting in microvascular compromise. It is an orthopaedic emergency

Question 2

What are the causes of compartment syndrome?

Answer 2

• Increased internal pressure (bleeding from trauma or swelling from muscle oedema/myositis, intracompartmental fluids/drugs or re-perfusion)
• Increased external compression (casts, bandages, full thickness burns, impaired consciousness, positioning in theatre)
• Or combination of both

Question 3

What are the muscles of the leg

Answer 3

Superficial posterior compartment - Gastrocnemius, plantaris and soleus
Deep posterior compartment - Popliteus, flexor digitorum longus, tibialis posterior and flexor hallucis longus.
Anterior compartment - Extensor digitorum longus, tibialis anterior and extensor hallucis longus

Question 4

Explain the pathophysiology of compartment syndrome

Answer 4

Either have an increase of pressure within the compartment due to increased compartment content (bleeding or oedema) or because of external compression. If untreated this can cause the pressure within the compartment to exceed pressure in capillaries which will reduce blood flow.
The muscles become ischaemic and oedematous due to increased endothelial permeability which further increases pressure.

Question 5

Explain the consequences of if limb is ischaemic for 1 hour, 4 hours or 8 hours

Answer 5

1 hour - Nerve conduction will be normal and muscle viable.
4 hours - Neuropraxia (conduction block) in nerves which is reversible and reversible muscle ischaemia.
8 hours - Nerve axonotmesis (axons divided) and irreversible change. Irreversible muscle ischaemia and necrosis

Question 6

What are the end stage limb changes seen in limb ischaemia?

Answer 6

• Stiff fibrotic muscle compartments,
• Impaired nerve function,
• Clawing of limbs,
• Loss of function

Question 7

What are the clinical features of compartment syndrome/limb ischaemia

Answer 7

Pain - out of proportion to clinical findings, or on passive stretching,
Pallor (pale)
Paraesthesia (deep peroneal nerve affected first so 1st dorsal web space affected)
Paralysis
Pulselessness
There may be swelling, shiny skin, tachycardia, sweating

Question 8

Explain the diagnosis of compartment syndrome?

Answer 8

• Majority are clinical
• However can also measure compartment pressure. If greater than 30mmHg then fasciotomy is indicated

Question 9

Explain the treatment of compartment syndrome

Answer 9

1. Open any dressings/bandages and reassess, if not improvement then surgicial release with delayed wound closure.
2. If internal increase in pressure then also surgical release.

Question 10

Explain the process of surgical release for compartment syndrome

Answer 10

In surgical release there is full length decompression of all compartments, dead muscle is excised, wounds left open and repeat debridement every 48 hours untill pressure down and all dead muscle excised. Then wound closure/skin graft once swelling is down and all necrotic tissue removed.

Question 11

What is the peri-operative management of compartment syndrome?

Answer 11

• Adequate hydration as they loos water through open wounds, monitor and regulate electrolytes, correct acidosis and monitor for myoglobinuria and renal function

Question 12

What is the management of a late presentation of compartment syndrome?

Answer 12

The irreversible damage is already present and a fasciotomy will just pre-dispose to infection so splint the limb in position of function and non operative management (monitor for renal failure)