Orthopaedic Surgery - Compartment Syndrome of the Foot

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Basics

Foot compartment syndrome (FCS) occurs when hemorrhage and interstitial edema increase pressure within the closed muscle compartments of the foot, resulting in impaired capillary perfusion.

If pressure remains elevated, progressive ischemia of muscles and nerves may lead to myoneural necrosis and permanent functional impairment.

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General Prevention

The most important factor in preventing the long-term consequences of foot compartment syndrome is maintaining a high index of clinical suspicion.

The diagnosis can be difficult because severe foot trauma itself commonly causes pain and swelling.

Early recognition and treatment are essential.

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Epidemiology

Foot compartment syndrome is uncommon and represents less than 5% of limb compartment syndromes.

Its incidence varies according to the mechanism and severity of injury.

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Calcaneus Fractures

FCS has been reported in up to approximately 10% of patients with calcaneal fractures.

The risk is greater with high-energy, displaced, and markedly swollen injuries.

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Crush Injuries

When a crush mechanism is combined with a forefoot injury, compartment syndrome may occur in as many as approximately 18% of cases.

Crush injuries produce extensive soft-tissue damage, hemorrhage, and edema, making them particularly high risk.

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Isolated Foot Injuries

Among isolated foot injuries overall, compartment syndrome is considerably less common, occurring in approximately 2% of cases.

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Pathophysiology

As intracompartmental pressure rises, the pressure gradient required for capillary perfusion decreases.

When local tissue pressure becomes sufficiently high relative to arterial pressure, blood flow becomes inadequate and tissue ischemia develops.

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Myoneural Ischemia

Continued ischemia damages both muscle and peripheral nerves.

If untreated, this progresses to myonecrosis, nerve injury, fibrosis, contracture, and permanent deformity.

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Long-Term Consequences

Late consequences can include chronic pain, paresthesias, stiffness, claw-toe deformity, cavus or cavovarus alignment, and other structural foot deformities.

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Etiology

Foot compartment syndrome most often follows high-energy trauma.

Common causes include calcaneus fractures, midfoot and forefoot injuries, severe crush injuries, and Lisfranc fracture-dislocations.

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Open Injuries

An open wound does not exclude compartment syndrome.

Open foot injuries may still have intact deeper fascial compartments in which dangerously elevated pressures develop.

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Association With Tibial Fractures

FCS can occasionally occur after a tibial fracture.

This may be related to communication between the deep posterior compartment of the leg and the calcaneal compartment of the foot, allowing swelling or hemorrhage to extend distally.

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Diagnosis

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General Principles

Because FCS is relatively uncommon and the injured foot is often painful and swollen even without compartment syndrome, diagnosis requires careful correlation of the mechanism of injury, serial examination, and compartment pressure measurements when necessary.

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Signs and Symptoms

Typical findings include severe pain, tense swelling, and pain with passive stretching of the toes.

The clinical pattern should be assessed repeatedly because symptoms may evolve over time.

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Severe Pain

Pain is often intense and may appear excessive for the apparent injury.

Persistent or progressively worsening pain despite appropriate immobilization and analgesia should raise concern.

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Tense Swelling

The foot may become markedly swollen and tense.

Because substantial swelling commonly accompanies calcaneal and crush injuries, this finding alone is not diagnostic.

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Pain With Passive Toe Stretch

Pain produced by passive movement of the toes is a common feature.

However, it is not specific for compartment syndrome because fractures and severe soft-tissue injuries can also produce pain with passive motion.

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Sensory Changes

Paresthesias or diminished sensation may develop as nerve ischemia progresses.

Sensory findings can be inconsistent and are less reliable than the overall clinical picture.

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Pulses

Diminished or absent pulses are unreliable for early diagnosis.

Foot pulses may remain present despite critically elevated compartment pressures because larger arteries can remain patent while microvascular perfusion is compromised.

Pulselessness is therefore a late and concerning finding.

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Imaging

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Plain Radiographs

Plain radiographs of the foot and ankle should be obtained to identify fractures or dislocations responsible for the swelling and trauma.

Imaging helps define the underlying skeletal injury but does not diagnose compartment syndrome itself.

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Compartment Pressure Measurement

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Diagnostic Role

Invasive measurement of intracompartmental pressures is useful when the diagnosis is uncertain and has traditionally been considered the objective diagnostic standard for FCS.

Pressure findings should always be interpreted together with the clinical examination.

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Medial Compartment

The medial, or abductor hallucis, compartment may be accessed by placing the pressure needle directly inferior to the first metatarsal.

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Deep Compartment

The deep compartment may be reached by advancing the needle approximately 1 cm deeper from the medial compartment beneath the arch of the foot.

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Interosseous Compartments

Interosseous pressures can be measured from the dorsal foot, commonly by inserting the needle between the third and fourth metatarsals.

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Lateral Compartment

The lateral compartment can be assessed by inserting the needle plantar to the fifth metatarsal.

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Pressure Threshold

Historically, an absolute compartment pressure greater than approximately 30 mm Hg has been considered concerning.

In modern practice, pressure is often interpreted in relation to the patient’s diastolic blood pressure, and the complete clinical picture remains essential.

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Limitations of Pressure Measurement

An elevated isolated pressure value does not necessarily establish compartment syndrome.

Pressure measurements may vary according to technique, location, blood pressure, and injury pattern.

When measured pressures do not correlate with the physical findings, repeated examination and reassessment are important.

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Treatment

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Initial Stabilization

Circumferential or constrictive dressings should be avoided when compartment syndrome is suspected.

Any tight bandage, splint, or dressing should be loosened or removed because external compression may further increase tissue pressure.

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Limb Position

The injured foot should generally be maintained at approximately the level of the heart while the patient is being observed.

Excessive elevation may reduce arterial perfusion, whereas allowing the foot to hang dependently can worsen swelling.

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Serial Examination

Repeated clinical examinations are essential.

Changes in pain intensity, analgesic requirement, swelling, sensory findings, and pain with passive toe motion should be documented.

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Pressure Monitoring

If the diagnosis remains uncertain, invasive pressure measurements should be obtained promptly.

Repeated measurements may be required if symptoms are evolving.

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Swelling Control

Measures to reduce swelling may be used while the diagnosis is being clarified, provided they do not delay definitive treatment.

Pneumatic foot pumps have historically been described for early post-traumatic swelling in selected situations.

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Diuretics

Diuretic therapy has historically been described as a means of reducing generalized edema, but it does not substitute for decompression when true compartment syndrome is present.

Once FCS is diagnosed, treatment is surgical.

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Early Fasciotomy

The most reliable method of preventing irreversible consequences is early surgical fasciotomy.

Once the diagnosis is established, decompression should not be delayed.

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Surgical Planning

The fasciotomy approach should be selected with future fracture fixation and reconstruction in mind.

Incisions that interfere with later definitive fixation should be avoided whenever possible.

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Activity

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Bed Rest

Patients with massive swelling or suspected FCS should generally remain at bed rest during acute evaluation.

The foot should be kept at heart level and protected from weight-bearing.

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Nursing Care

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Frequent Monitoring

Patients with severe foot trauma require close nursing observation.

Increasing, persistent, or inadequately controlled pain should prompt immediate reassessment by the treating clinician.

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Passive Stretch Testing

Pain with passive toe movement should be reassessed frequently.

A worsening response may indicate increasing compartment pressure.

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Change in Clinical Status

Any deterioration in swelling, pain, sensation, or motor function should prompt urgent physician evaluation and consideration of compartment pressure measurement or operative decompression.

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Physical Therapy

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Late Rehabilitation

Physical therapy may be useful for patients who develop residual problems following FCS.

Treatment can include stretching, range-of-motion exercises, strengthening, gait rehabilitation, and desensitization.

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Desensitization

Desensitization techniques may be useful for patients with persistent hypersensitivity or neuropathic symptoms after severe crush injury or compartment syndrome.

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Surgery

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Fasciotomy

Once foot compartment syndrome has been diagnosed, urgent surgical fasciotomy is required.

The goal is complete decompression of the involved compartments before irreversible myoneural injury occurs.

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Three-Incision Technique

A commonly described approach uses three incisions.

Two dorsal incisions are made over the second and fourth metatarsals, while a separate medial incision is made along the arch.

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Dorsal Incisions

The dorsal incisions provide access to the interosseous compartments and can assist with decompression of adjacent spaces.

One incision is positioned over the second metatarsal region and the other over the fourth.

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Medial Arch Incision

The medial incision allows decompression of the abductor hallucis and deeper central muscle compartments.

This approach provides access to important plantar structures not adequately reached from the dorsum.

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Alternative Single Medial Approach

An alternative technique uses a single medial incision.

The abductor hallucis and deep compartments are released, after which the muscles can be reflected plantarly to gain access to additional compartments.

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Interosseous Release Through Medial Approach

Using the single medial technique, the interosseous compartments may be approached internally after mobilization of the plantar musculature.

This avoids multiple dorsal incisions but is technically demanding.

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Plantar-Based Single-Incision Technique

Another described approach uses a plantar-medial incision beginning approximately 5 cm distal to the posterior heel on the non-weight-bearing instep and extending distally.

The intent is to decompress the intermediate and lateral compartments through a single incision.

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Pie-Crusting Technique

A minimally invasive “pie-crusting” technique has also been described.

Multiple small stab incisions are made over the intermetatarsal spaces, followed by blunt fascial release with a hemostat.

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Purpose of Pie-Crusting

The theoretical advantage of this approach is reduction in the size of open wounds and therefore a lower need for skin grafting.

However, complete compartment release remains the overriding surgical priority.

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Wound Management

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Delayed Closure

Fasciotomy wounds are usually left open initially because severe swelling makes immediate closure unsafe.

Closure is commonly attempted approximately 5–7 days later, after edema has substantially decreased.

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Skin Grafting

If the wound edges cannot be approximated without excessive tension, a split-thickness skin graft may be required.

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Follow-Up

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Referral

Severe foot trauma, substantial swelling, or suspected compartment syndrome requires urgent orthopaedic consultation.

Delay in specialist assessment can result in permanent disability.

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Prognosis

The prognosis of a missed or untreated foot compartment syndrome is poor.

Patients frequently develop chronic pain, stiffness, deformity, and impaired walking ability.

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Chronic Pain

Persistent pain may result from muscle necrosis, nerve injury, scar formation, joint stiffness, or abnormal loading of the foot.

It can be significantly disabling.

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Cavus and Cavovarus Deformity

Necrosis and subsequent fibrosis of the intrinsic foot muscles can alter muscle balance.

This may lead to cavus or cavovarus foot deformity.

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Claw Toes

Intrinsic muscle fibrosis and imbalance can produce claw-toe deformities.

Severe fixed claw toes may eventually require operative release or reconstruction.

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Complex Regional Pain Syndrome

Complex regional pain syndrome may develop after severe crush injury or compartment syndrome.

It can cause persistent pain, hypersensitivity, autonomic changes, stiffness, and substantial functional impairment.

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Complications

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Pain

Chronic pain is one of the most frequent consequences of delayed or severe FCS.

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Paresthesias

Nerve ischemia can produce persistent paresthesias, numbness, or sensory disturbance.

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Stiffness

Fibrosis, prolonged immobilization, and joint injury may lead to significant foot and toe stiffness.

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Claw-Toe Deformity

Loss of normal intrinsic muscle function may result in progressive clawing of the toes.

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Foot Deformity

Permanent structural abnormalities may include cavus, cavovarus, toe contractures, abnormal gait, and altered weight-bearing.

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Patient Monitoring

Patients at risk for FCS require repeated assessment of pain, swelling, sensation, motor function, passive stretch discomfort, and compartment pressures when indicated.

Following fasciotomy, monitoring should include wound condition, neurovascular function, edema, fracture healing, toe alignment, range of motion, and the development of chronic deformity or pain.