Chronic exertional compartment syndrome

Chronic exertional compartment syndrome (CECS), previously known as anterior tibial syndrome, is a type of compartment syndrome that is brought on by exercise.

The exact prevalence is not known since sufferers may modify the way they exercise and therefore never present. CECS can present at any age and any level of physical activity 1. There is no sex predilection. CECS occurs bilaterally in 70-80% 2.

CECS occurs most often in the lower legs. While pain due to shin splints is experienced during exercise and quickly resolves with rest, in CECS the pain persists despite rests and can become severe within hours.

Exercise-related leg pain can be a diagnostic dilemma. Apart from CECS, the differential diagnosis includes vascular insufficiency, popliteal artery entrapment syndrome, repetitive stress injuries and neuropathies. CECS can coexist with shin splints, complicating the diagnosis.

The pathophysiological mechanism is not entirely understood. During physical activity, muscle fibers are recruited and blood flow increases, causing expansion. If fascia restricts this expansion, the pressure within a compartment increases and reduced blood flow with resultant ischemia and pain. There is also increased interstitial fluid. This process is independent of vascular patency 3. The increased interstitial fluid will give rise to localized increased T1 and T2 relaxation times 4. A mechanism independent of ischemia has also been supported by findings in early MR studies 5.

A definite diagnosis is made by measuring intracompartmental presssures (ICP), as in acute compartment syndrome. However there is little evidence and no agreed standard to diagnose CECS on the basis of compartment pressures 6.

According to criteria proposed by Pedowitz et al. 7, CECS of the lower limb is present if one or more of the following intramuscular pressure criteria are met:

  • pre-exercise pressure ≥15 mmHg
  • 1-minute post-exercise pressure of ≥30 mmHg
  • 5-minute post-exercise pressure ≥20 mmHg

MRI in diagnosing chronic exertional compartment syndrome has been found comparable to that of ICP measurement 5,10-12.

Additional studies are needed to delineate the exact role of MRI in the workup of CECS, but MRI can certainly be used as a problem-solving tool in patients refusing or having contraindiations to compartment pressure measurement, or when there is diagnostic confusion (e.g. coexisting pathologies).

  • protocol: it is necessary to perform MRI immediately after exercise-inducing pain. There are out-of-scanner and in-scanner exercise protocols 12
  • imaging features
    • muscular hyperintensity on T2-weighted or fast STIR images with or without muscular swelling
    • inhomogeneous hyperintensity within affected compartments
    • involvement of more than one compartment
    • possible concurrence of medial tibial stress syndrome
    • 31P-NMR spectroscopy (change in relative muscle phosphocreatine concentrations) 13

MIBI perfusion (apparently useful for screening but no correlation with ICP studies) 8.

Thallium-201 single photon emission tomography (no change in blood flow; no difference between CECS and controls) 9.

Training modifications including reducing training volume, wearing orthotics, running on softer surface, physiotherapy, and/or ice application.

Elective compartment decompression by fasciectomy or fasciotomy.

Article information

rID: 22182
Synonyms or Alternate Spellings:
  • Anterior tibial syndrome
  • Chronic exertional compartment syndrome (CECS)
  • Compartment syndrome after exercise

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