Compartment syndrome should be suspected in leg injuries or after exceptional physical strain when the patient experiences atypical pain aggravated by passive tension of muscles in the affected compartment.
The muscles may be rescued by prompt surgical treatment provided that the acute syndrome is suspected early enough.
The diagnosis is in most cases clinical and is based on typical history and on non-specific findings.
Mechanism
An acute compartment syndrome develops when pressure is elevated inside a muscle compartment closed by fasciae, leading to disturbed blood circulation in the muscles and nerves of the affected compartment.
Acute compartment syndrome usually develops as a consequence of trauma.
If left untreated, the condition leads to immediate muscle and nerve damage in the compartment and later to muscle contracture and permanent disturbance in the limb function.
Chronic compartment syndrome ("shin splints") is often associated with sports or repeated long-lasting strain. According to a theory, the pain results from mechanical irritation of the bone and periosteum and, on the other hand, from the increased intracompartmental pressure caused by swollen muscle.
Aetiology
Fractures and interventions to treat them (cast, traction, manipulation, intramedullary nailing)
Most often a fracture of the tibial diaphysis or the distal forearm
High-energy trauma, comminution of the bone, patient's young age and male sex increase the risk.
The syndrome is more easily developed in the anterior compartment of the leg (anterior tibial syndrome) and in the flexor compartment of the forearm.
Direct blow and contusion injuries to the limbs without a fracture
Prolonged compression of the limb or the buttock (unconsciousness, deep intoxication)
Burns
Vascular injuries (especially injuries to the popliteal artery or vein in association with a fracture)
Vascular surgery interventions to the limb
Acute symptoms and findings
Pain
Usually disproportionately severe with respect to the original trauma; poor response to strong analgesics
Pain in passive extension of the muscle
Tender, swollen, hard muscle compartment
Impaired function of the muscles in the affected compartment
Sensory loss
Usually a sign of an advanced condition
The location of the sensory deficit may help in identifying the threatened muscle compartment.
Loss of peripheral pulses is rare and often a late-stage finding.
Measurement of intracompartmental pressure is not necessary to establish the diagnosis but it is used if the patient's condition is difficult to assess due to e.g. unconsciousness and the treatment of the acute syndrome is not delayed by the arrangement of the investigation. If the intracompartmental pressure exceeds 30 mmHg or if the difference between diastolic blood pressure and the pressure in the muscle compartment (delta pressure) is less than 30 mmHg (i.e., the intracompartmental pressure approaches the diastolic blood pressure), acute muscle compartment syndrome is probable.
Treatment
Acute muscle compartment syndrome is treated with emergency fasciotomy.
In order to minimize complications, the operation should be performed within a few hours from the onset, so that no muscle necrosis occurs.
Open surgery through a sufficiently long skin incision; iatrogenic nerve injuries must be avoided
The fasciotomy incision is left open to be closed later, possibly using skin grafts and/or flaps.
Chronic muscle compartment syndrome
Chronic anterior tibial syndrome is characterized by pain in the anterolateral part of the leg.
Tenderness on palpation diffusely at the anterior tibial muscle compartment, extending wider than in stress fracture
Treatment is comprised of rest, stretching, restricted loading and anti-inflammatory analgesics. If troublesome symptoms last for months, a fasciotomy can be considered.
Ding A, Machin M, Onida S ym. A systematic review of fasciotomy in chronic exertional compartment syndrome. J Vasc Surg 2020;72(5):1802-1812. [PubMed]
Campano D, Robaina JA, Kusnezov N ym. Surgical Management for Chronic Exertional Compartment Syndrome of the Leg: A Systematic Review of the Literature. Arthroscopy 2016;32(7):1478-86. [PubMed]