Intended for healthcare professionals

Practice Easily Missed?

Chronic exertional compartment syndrome

BMJ 2013; 346 doi: https://doi.org/10.1136/bmj.f33 (Published 15 January 2013) Cite this as: BMJ 2013;346:f33

This article has a correction. Please see:

  1. Ronald S Paik, orthopedic resident,
  2. Douglas Pepples, primary care sports fellow,
  3. Mark R Hutchinson, professor of orthopedics and sports medicine
  1. 1Sports Medicine Service, University of Illinois at Chicago, Chicago, IL 60612, USA
  1. Correspondence to: M R Hutchinson mhutch{at}uic.edu

A 31 year old woman with no medical history of note presented with bilateral lower leg pain on running. The pain was absent when she started running; gradually built after the first kilometer, forcing her to stop; then resolved shortly after stopping. She tried not running for several weeks, but the pain returned when she started again. Physical examination at rest was normal, with no swelling or focal tenderness. The differential diagnosis included muscle strain, medial tibial stress syndrome, stress fracture, chronic exertional compartment syndrome (CECS), and popliteal artery entrapment syndrome. Dynamic intracompartmental pressure measurements confirmed the diagnosis of CECS.

  • How common is CECS?

  • Prevalence depends on the population studied

  • Runners and endurance athletes have a higher risk than sedentary populations or those who engage in upper extremity dominant sports.1 In a prospective study of exercise active people (not formally defined as athletes) who had exercise induced leg pain, 49% were diagnosed as having the syndrome.2 In a case series of athletes with exercise induced leg pain, the incidence of pressure confirmed CECS was 27%3

  • People with diabetes may be at increased risk, even with minimal exertional activity2

  • Prevalence is similar in men and women, and median age of onset is about 20 years4

What is CECS?

CECS is an ischaemic condition that occurs when a fascial compartment is unable to accommodate the increase in volume associated with muscle contraction and swelling. The increased volume increases intracompartmental pressure and reduces perfusion of the tissues within the fascial compartment. The condition is most common in the lower leg but has also been described in the thigh, forearm (gymnasts and climbers), and foot (runners and during aerobic training). Symptoms depend on the fascial compartment affected and the nerve or structures contained within (figure).

Figure1

Cross sectional anatomy of the leg midway between the knee and ankle, including muscles and neurovascular structures in each of the four leg compartments

Why is CECS missed?

The diagnosis is often missed because patients are asymptomatic at rest with minimal findings on physical examination. It may be confused with other conditions. For example, in a case series of 42 patients with diabetes who were thought to have claudication, but who had normal pedal pulses and ankle brachial indexes, 38 were found to have CECS.5 Clinicians need to be aware of the potential diagnosis and be willing to challenge patients with exertional tests to reproduce the symptoms. In addition, CECS may co-occur with other diseases, including stress fractures or medial tibial stress syndrome (tenderness over the posterior medial border of the tibia related to traction from muscular attachments or diffuse overuse of periosteum and medial border of tibia), which can make diagnosis more difficult.6 The diagnosis may also be missed owing to overuse of the non-specific label of “shin splints.” Clinicians need to make a specific and anatomic diagnosis that leads to targeted treatment.

Why does this matter?

When the diagnosis is missed, patients may undergo myriad failed treatments that target symptoms but not the cause of the problem. Athletes may give up their sport completely. Rarely, CECS converts to an acute compartment syndrome as athletes continue competing despite pain. In such cases, pressures build and do not resolve with rest. Acute compartment syndrome is a surgical emergency that can cause permanent impairment, muscle loss, paralysis, or limb loss if left untreated.

How is CECS diagnosed?

Clinical features

Despite a lack of data on the predictive value of specific symptoms, expert consensus is that history plays an important role in diagnosis. Patients are typically symptom free at rest. Exertion causes a dull achy pain and tightness. The pain begins in a typical manner after a set duration. It gradually increases in severity, forcing the patient to stop the activity. Pain and tightness subside within a few minutes of cessation. When symptomatic, the compartment may be palpably tense, like a drum. Some patients also have neurologic symptoms including numbness, tingling, or weakness corresponding to the nerve in the affected compartment. If the lower leg is affected, anterolateral pain is most common, with a palpable tight fascial over the anterior or lateral compartments. If present, paresthesias occur over the dorsal aspect of the foot. If the anterior compartment is affected, ankle dorsiflexion may be weak. If the lateral compartment is affected, ankle eversion may be weak. If the deep compartment is affected, toe flexion may be weak, with numbness on the planar aspect of the foot. In contrast, patients with stress fractures or medial tibial stress syndrome have localized pain over the bone and not the soft tissues. In addition, athletes with stress fractures and medial tibial stress syndrome have pain at rest and pain with first impact but no delay in onset.

Investigations

Pre-exertion and postexertion intracompartmental pressure testing, in which a large bore needle is inserted into the compartment, is the gold standard for confirming the diagnosis. Although it is unclear whether the examiner should assess all four compartments, both legs, or also assess 10 minutes after exertion, assessing the effect of exertion is essential.6 7 8 Pressure can be measured using a needle manometer, a slit catheter, the microtip pressure method, a wick catheter, or microcapillary infusion. Some techniques can measure pressures during exercise, whereas others require repeated needle placement before and after exertion. The Stryker Intra-Compartmental Pressure Monitor (Stryker Corp) is a handheld battery powered system with good reproducibility between examiners.9

Use of the following criteria results in less than a 5% incidence of false positives: resting pressure ≥15 mm Hg plus a one minute post-exercise pressure ≥30 mm Hg or a five minute postexercise pressure ≥20 mm Hg.10 Around 42% of orthopedic surgeons in the United Kingdom use a pressure of greater than 35 mm Hg after exercise (sensitivity of 77% and specificity of 83%).11 Most surgeons insist on a positive pressure test before proceeding with surgery for CECS. Recent systematic reviews have questioned these thresholds and recommended a more rigorous standardized process.8 12

Alternative methods to confirm the diagnosis include near infrared spectroscopy and magnetic resonance imaging. Although not routinely available, near infrared spectroscopy non-invasively measures tissue oxygen saturation in the relevant anatomic compartment; tissue oxygen saturation less than 50% has a sensitivity of 78% and a specificity of 67%.13 Magnetic resonance imaging measures changes in the T2 signal intensity at rest and after exertion. Unfortunately, this non-invasive approach has had poor diagnostic results compared with intracompartmental measurements and near infrared spectroscopy.13

How is CECS managed?

If associated diagnoses, such as stress fractures or medial tibial stress syndrome, are present, conservative treatment should be tried initially, although evidence for its effectiveness has not been validated in evidence based literature or comparative studies. This may include reducing or stopping the inciting activities—together with non-steroidal anti-inflammatory drugs, bracing, stretching, or orthotics as indicated—to target alignment anomalies, inflammation, or stress fracture that may push an asymptomatic exertional compartment syndrome to a symptomatic one. Once symptoms resolve, the athlete can gradually return to activity to assess whether symptoms recur.

In our experience, however, conservative treatment is ineffective in most patients with CECS confirmed by pressure measurements because they eventually require surgical intervention unless they give up sport entirely. Surgery usually entails subcutaneous fasciotomy via one or two small incisions. We find that this offers good to excellent results in 80-90% of patients, although the success rate decreases to 73% in cases of revision.14 More guarded outcomes might be expected in patients with diabetes, inconsistent symptoms, associated diseases, or deep posterior compartments.2 14 15 16 17 18 19 Fasciectomy or excision of a band of fascia is reserved for resistant or recurrent cases.

Key points

  • Patients typically have no pain at rest but develop pain after a set duration and intensity of activity; symptoms subside with a short period of rest

  • Tenderness is usually elicited in the middle of the muscle compartment, not on the bone; pain near the bone should alert the clinician to alternative or associated diagnoses, such as tibial stress fractures or medial tibial stress syndrome

  • If chronic exertional compartment syndrome (CECS) is suspected, obtain intracompartmental pressure measurements at rest and after exertion

  • For patients with confirmed CECS and no associated problems, conservative treatment rarely allows the athlete to return to competition. If this fails or is unsuitable, subcutaneous fasciotomy should be performed.

Notes

Cite this as: BMJ 2013;346:f33

Footnotes

  • This is one of a series of occasional articles highlighting conditions that may be more common than many doctors realize or may be missed at first presentation. The series advisers are Anthony Harnden, university lecturer in general practice, Department of Primary Health Care, University of Oxford, and Richard Lehman, general practitioner, Banbury. To suggest a topic for this series, please email us at easilymissed{at}bmj.com.

  • Each author contributed to this article through conception, research, writing, development, or editing. MRH is the senior author and guarantor.

  • Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organization other than employment by the university for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years, and no other relationships or activities that could appear to have influenced the submitted work.

  • Provenance and peer review: Commissioned; externally peer reviewed.

  • Patient consent not required (patient anonymised, dead, or hypothetical).

References

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