Compartment Syndrome – Lower extremity
Closed fractures of the extremities especially the legs are susceptible to rapid increase in the osteofascial compartment of the muscles leading to compartment syndrome. The rise in intracompartmental pressure leads to impaired venous drainage , further rise rise leads to reduced arterial and capillary perfusion and tissue hypoxia. The cause of the rapid rise in intracompartmental pressures is due to tissue oedema, haematoma associated with fractures and contussed soft tissue. The anatomically restricted fascial compartments of the leg especially is unyielding to swelling tissues and so further rises without intervention will compromises viability vulnerable tissues such as muscle and nerves.
Other causes of compartment syndrome are tight POP casts, tourniquets etc, but these presents less often at KATH. Most clinicians apply half casts to closed fresh fractures prior to referral
Most cases presenting to KATH were involved in road traffic injury with resultant fractures . It is common for such patients to present with other injuries due to high energies mechanisms usually involved . Most patients are unrestrained passengers on buses which accounts for the multiple injuries.
Patient may complain of pain , paraesthesia of the affected limb . This may be out of proportion relative to the primary injury. Unconscious patients presenting with extremity compartment syndrome pose a peculiar challenge. The attending physician should be able able to make a diagnosis based on clinical signs.
They are evaluated according to the ATLS protocol which details the primary survey and resuscitation, secondary survey and then treatment.
On examination of the extremity, one finds a swollen , tense limb which is tender out of proportion. There may be blisters , ecchymosis , the skin may appear cold and pale. Absence of distal pulses is usually a late sign . Its is important to note that patient’s anxiety may not cause him to complain so much about the pain from the affected limb , a complaint which so often is what we doctors lay a lot of emphasis on. It is therefore important to be thorough in the examination in order to pick the other signs and not write them of as being part of the primary injury. Interestingly both cases shown here were missed by the doctors who first saw them. They were correctly diagnosed by the teams on duty. Further delays in picking these vital clues to diagnosing compartment syndrome can lead to increased risk for limb loss. Affected limbs must always be elevated above level of the heart to encourage venous return and reduce swelling .
Both cases were managed by performing fasciotomies as shown in the pictures. bridging external fixator was mounted to stabilize the segmental femur fractures in the the first case (fig 1).
Daily dressing with resulting blood loss leads to anaemia which must be corrected by transfusion of packed RBCs. Daily urine monitoring is necessary as free myoglobin released from damaged muscle could block renal tubules leading to acute renal failure. Mannitol , frusemide, alkalinisation of urine and intravenous crystalloids are used in the managment of such a complication . Limb ischaemia of more than 6 hours is better managed by amputation as post fasciotomy of such ischaemic limbs can lead to ischaemic reperfusion syndrome, ARDS, acute renal failure.
Dr. R Ametih , resident , department of general surgery, KATH