It is hypothesized that physiotherapy including a change in running landing pattern and surgical fasciotomy are equally good as treatment options for chronic exertional compartment syndrome (CECS) of the anterior compartment of the lower leg.

The endpoints/outcomes are:

Change from week 0 (start of study) to week 12 (completion of intervention) in: patient reported outcome measure (PROM) (Exercise induced leg pain Questionnaire (EILP)).

Secondary outcomes are: Visual Analogue Scale (VAS) score after an "exercise provocation test": Change in intracompartmental pressure (ICP)Change in muscle compartment compliance. Change in Global Rating of Change Score/Scale (GRC). Change in Single Assessment Numeric Evaluation (SANE)

The study is important because:

1. Results from recent studies suggest that physiotherapy represents a valid alternative to surgery for the treatment of CECS. Surgery is currently standard treatment and a change towards physiotherapy as primary treatment could potentially reduce both complication rates and costs.
2. Intracompartmental pressure (ICP) is gold standard for diagnosing CECS. However, the association between ICP and symptoms of CECS, both before and after physiotherapeutic and surgical treatment, muscle compartment compliance and intracompartmental perfusion, has not been thoroughly investigated.

CECS of the lower leg is a condition of pain induced by exercise. CECS accounts for 14-33% of lower leg pain in athletes, evenly divided among males and females. Symptoms are described as a tight, cramp like ache that occurs at a well-defined and reproducible point in the exercise bout and increases if the training persists. Relief of symptoms typically occurs within 30 minutes of ending the activity.

The anterior compartment is most commonly affected, followed by the deep posterior, the lateral and the superficial posterior compartment. Often more than one compartment in the same leg is involved, and the condition is reported bilateral in up to 95% of affected athletes.

The pathophysiology of CECS is not fully understood. It is, however, generally agreed that exercise induces abnormal elevation in ICP, which interferes with tissue perfusion and cause painful ischemia affecting the nerves and impairing muscle function. A noncompliant muscle compartment, which is unresponsive to the expansion of muscle volume that occurs with exercise, offer a possible pathophysiological explanation for CECS. However, this view is challenged by a study reporting no difference in fascial thickness and stiffness between CECS patients and healthy controls. Furthermore, the thickness of the anterior compartment increased more with exercise in CECS patients relative to controls, questioning decreased compliance as the main pathophysiology in CECS. The definition of a pathologically elevated ICP during exercise is important for the diagnosis of CECS and is currently debated. The criteria suggested by Pedowitz is used as standard by most clinicians for the diagnosis of CECS: 1) a pre-exercise pressure of 15 mmHg or greater, and/or 2) a 1-minute post-exercise pressure of 30 mmHg or greater, and/or 3) a 5-minute post-exercise pressure of 20 mmHg or greater. The precision and diagnostic value of these commonly used criteria is debated, due to a reported overlap in ICP readings between patients and healthy controls at certain time points. Interestingly, in a small cohort of asymptomatic rollerskiers ICP was elevated, according to the Pedowitz criteria, in 100% of participants after 20 minutes of exercise. Despite these uncertainties, it is suggested that ICP measured 1-minute after ceasing exercise has the highest diagnostic value, as it most consistently display higher values in patients with CECS symptoms relative to healthy controls. The different types of catheters (slid catheter, side-port, straight-needle) also clearly influence the absolute values of the measurements and the catheter tip can be wrongfully placed outside the compartment by experienced health professionals in up to 21% of cases when positioned without ultrasound guidance.

Non-invasive modalities such as magnetic resonance imaging (MRI), near infrared spectroscopy (NIRS) and ultrasound measurements have been suggested as future adjuncts or alternatives for diagnosing CECS, but their diagnostic value remains to be established.

In summary, it is generally agreed that ICP measurements are important for diagnosing CECS, but several studies question current practice including the mentioned criteria and particularly the use of non-ultrasound guided catheter positioning.

Both conservative and surgical treatment options are suggested in the literature.

Conservative treatment, including physiotherapy, has been attempted with varying success and is generally believed by many to be insufficient for the long-term treatment of CECS. However, inducing muscle hypotrophy via injection of botulinum toxin, was efficient in reducing exercise induced pain in CECS patients, but also resulted in decreased muscle strength, although without measurable functional consequences. Interestingly, changing the gait pattern in order to achieve a forefoot/midfoot strike during running, which potentially decrease pressure in the anterior compartment and eccentric load of the anterior compartment muscles has proven successful for treatment of anterior CECS. These studies suggest a role for non-operative treatment of CECS, but to our knowledge, no randomized controlled studies exist regarding the effect of physiotherapy or other non-surgical interventions.

Surgical fasciotomy, with release of the compartment(s) with elevated intra-compartmental pressure, has been shown by many investigators to be effective using both open, mini-open and endoscopically assisted techniques. There are, however, considerable variations in the reported outcomes of surgery. In a large cohort, 45% had symptom recurrence after surgery and 16% experienced surgical complications including infection, neurological damage, and hematoma. Moreover, the need for revision surgery can be as high as 11%. Other groups report more successful outcome of surgery with patient satisfaction of 60 to 90%, including a retrospective follow-up study, in which operation was successful in 81% of patients and non-operative treatment successful in only 41% of patients.

CECS is a common condition in athletes and although disagreements exist, the diagnosis is typically made based on a history of pain in the calf muscles during exercise that resolves within 30 minutes of ending the activity as well as a positive ICP reading. Typically the patients are offered fasciotomy if the symptoms persist.

No studies have compared the effect of fasciotomy to any non-surgical treatment strategies in a randomized controlled setting. Moreover, correlation between symptom severity, ICP measurements, muscle compartment compliance and perfusion, and effect of treatment is not fully elucidated. Finally, the possible effect of changing the landing pattern in combination with physical therapy has not been attempted in a randomized setting.

It is hypothesized that physiotherapy including a change in running landing pattern and surgical fasciotomy are equally good as treatment options for chronic exertional compartment syndrome (CECS) of the anterior compartment of the lower leg.

The endpoints/outcomes are:

Change from week 0 (start of study) to week 12 (completion of intervention) in: patient reported outcome measure (PROM) (Exercise induced leg pain Questionnaire (EILP)).

Secondary outcomes are: Visual Analogue Scale (VAS) score after an "exercise provocation test": Change in intracompartmental pressure (ICP)Change in muscle compartment compliance. Change in Global Rating of Change Score/Scale (GRC). Change in Single Assessment Numeric Evaluation (SANE)

The study is important because:

1. Results from recent studies suggest that physiotherapy represents a valid alternative to surgery for the treatment of CECS. Surgery is currently standard treatment and a change towards physiotherapy as primary treatment could potentially reduce both complication rates and costs.
2. Intracompartmental pressure (ICP) is gold standard for diagnosing CECS. However, the association between ICP and symptoms of CECS, both before and after physiotherapeutic and surgical treatment, muscle compartment compliance and intracompartmental perfusion, has not been thoroughly investigated.

Inclusion criteria:

• Age between 18 and 50 years
• Symptoms for more than 3 months
• Symptoms from both legs. Pain (cramp like, tight, burning or pressure) in the anterior part of the lower leg starting after approximately 10 minutes of exercise
• Pain worsened with prolonged lower extremity exertion
• Majority of pain relieved within 30 minutes of rest.

Exclusion criteria:

• Previous fasciotomy in the lower leg
• History of serious trauma involving the lower leg (fracture, muscle/tendon rupture)
• ASA (America Association of Anaesthesiologists Classification of Physical Health) > 2
• Clinical symptoms consistent with unilateral anterior CECS or lateral and posterior CECS
• Clinical symptoms consistent with lumbar spine radiculopathy, periostit/shin-splint, stress fracture, popliteal artery entrapment syndrome, isolated peroneal nerve entrapment, with isolated muscle fascia herniation.