Compartment syndrome
- The deep fascia envelops the limbs
- Other fascial planes divide the limbs into compartments
- The forearm has two compartments
- The thigh has three compartments
- The lower leg therefore has four compartments
Pathophysiology
- The normal lower limb venous pressure is a few mmHg
- Normal intracompartmental pressures are in the range 0 - 10 mmHg
- Compartmental pressure does not interfere with blood flow
- Swelling within a facial compartment results in increased intracompartmental pressure
- Initial venous compromise may progress to reduced capillary flow
- This exacerbates the ischaemic insult and further increases pressure
- A vicious cycle of increasing pressures can be initiated
- Arterial inflow rarely reduced unless pressure exceed systolic blood pressure
Aetiology
- Orthopaedic
- Tibial fractures (especially comminuted fractures)
- Forearm fractures
- Vascular
- Ischaemia-reperfusion injury
- Haemorrhage
- Phlegmasia caerulea dolens
- Iatrogenic
- Vascular puncture in anticoagulated patients
- Intravenous or intra-arterial drug injection
- Soft-tissue injury
- Prolonged limb compression
- Crush injury
- Burns
Clinical features
- Compartment syndromes are normally seen with 48 hours of injury
- Typical clinical features include:
- Increasing pain despite immobilisation of fracture
- Altered sensation in the distribution of nerves passing through the compartment
- Muscle tenderness
- Excessive pain on passive movement
- Peripheral pulses may still be present
Pressure monitoring
- Intracompartmental pressure (ICP) can be measured by several means including:
- Wick catheter
- Simple needle manometry
- Infusion techniques
- Pressure transducers
- Side-ported needles
- Critical pressure for diagnosing compartment syndrome unclear
- Different authors consider surgical intervention if:
- Absolute ICP greater than 30 mmHg
- Difference between diastolic pressure and ICP greater than 30 mmHg
- Difference between mean arterial pressure and ICP greater than 40 mmHg
Treatment
- Remove constricting casts, splints etc
- If no improvement prompt fasciotomies required
- Need to divide skin and deep fascia for the whole length of the compartment
- Wounds should be left open
- May require delayed closure or skin grafting
Picture provided by Wolfgang Fiel, Donauspital, Vienna, Austria
Picture provided by Russell George, Texas Women's Hospital, USA
Outcome
- Timely surgery produces a good functional outcome
- Delay results in muscle ischaemia and necrosis
- Muscle
fibrosis produces the typical Volkmann's ischaemic contracture
Fat embolism
- Due to fat entering torn venous channels at fracture site
- Chylomicrons may also aggregate due to lipase release
- Presents with pyrexia, tachycardia, tachypnoea, reduced consciousness
- May develop petechial rash
- Clotting may be deranged with features of DIC
- Arterial gases show hypoxia and hypercapnia
- Patients may require ventilation
- Mortality can be as high as 15%
Bibliography
McQueen M M, Christie J, Court-Brown
C M. Acute compartment syndrome in tibial diaphyseal fractures.
J Bone Joint Surg [Br] 1996; 78:
95-98
McQueen M M, Court-Brown C M.
Compartment monitoring in tibial fractures. The pressure
threshold for decompression. J Bone Joint Surg [Br] 1996;
78: 99-104.
Parisi D M, Koval K, Egol K. Fat embolism syndrome. Am J Orthop 2002;
31: 507-512.
Pearse M, Nanchahal J. Acute Compartment syndrome of the leg. Br Med J; 2002;
325: 557-558.
Tiwari A, Haq A I, Myint F, Hamilton G. Acute compartment syndromes. Br J
Surg 2002; 89: 397-412.
van Essen G J, McQueen M M.
Compartment syndrome in the lower limb. Hosp Med
1998; 59: 294-297. |