Chapter 5 Injuries to the Extremities: Compartment Syndrome and Fasciotomy

This chapter will discuss anatomical considerations and techniques for performing fasciotomies of the upper and lower extremities. Additionally, the pathophysiology and diagnosis of compartment syndrome will be presented.

Learning Objectives

By the end of the ASSET course, participants should be able to do the following:

1. Describe the pathophysiology of compartment syndrome.
2. Describe key elements of clinical assessment for compartment syndrome.
3. Describe tissue pressure measurements consistent with compartment syndrome in the lower extremity.
4. Describe the key anatomical features that enable successful fasciotomy.
5. Demonstrate surgical fasciotomy of the lower leg, utilizing medial and lateral incisions.
6. Demonstrate fasciotomy incisions of the thigh and buttock.
7. Demonstrate fasciotomy of the upper extremity, including the hand.
8. Describe the management of fasciotomy wounds.
9. Describe the pitfalls and potential complications of fasciotomies and untreated or inadequately treated compartment syndrome.

Considerations

• Compartment syndrome (CS) is a limb- threatening—and potentially life-threatening— condition.
• Long-bone fractures and vascular injuries are the most frequent antecedents to CS. Burns, crush injuries, bleeding into a compartment, external compression of the limb, thrombotic or embolic events, ischemia reperfusion, envenomation, electrocution, allergic reactions, intravenous (IV) infiltration, muscle overuse,
• nephritic syndrome, and intramuscular injection have also been implicated.
• If untreated, CS leads to tissue necrosis (Figure 1), permanent functional impairment, and, in severe cases, renal failure and death.
• CS has been found wherever a compartment is present: hand, forearm, upper arm, abdomen, buttock, thigh, calf, and foot. The lower extremity below the knee is most commonly involved (>60 percent of cases), followed by forearm, thigh, and upper arm.

Pathophysiology

• Groups of muscles (with associated nerves and vessels) are surrounded by rigid osseofascial structures that define various compartments in the extremities. These osseofascial compartments have a relatively fixed volume.
• If fluid is introduced into a fixed volume, the pressure rises. Introduction of excess fluid or extraneous constriction increases pressure and decreases tissue perfusion until no oxygen is available for cellular metabolism. This complication can happen by one of the following mechanisms:
  • Reduction in volume—from application of a tight cast, constrictive dressings, or pneumatic antishock garments
  • Increase in contents—hemorrhage secondary to fracture, blunt trauma, coagulopathy, IV infiltration, ischemia/reperfusion, etc.
  • Vascular reperfusion after arterial repair with resultant edema, or restoration of hemodynamics after a profound hypotensive episode
• The general consensus is that measured intracompartmental pressures greater than 30 mmHg (in the absence of hypotension) require intervention.
• Patients with low blood pressure suffer irreversible injury at lower absolute tissue pressures compared with patients with normal blood pressure. Therefore, poly-trauma patients are at increased risk of CS due to associated hypotension.

Diagnosis

Clinical Assessment

• Maintain a high level of suspicion in any injury that causes limb pain.
• The five Ps—pain, pallor, paresthesia, paralysis, and pulselessness—are pathognomonic of CS. However, with the exception of pain, these findings are usually late signs, and extensive and irreversible tissue damage may have already taken place by the time these signs are manifested.
  • The presence of pulses and normal capillary refill does not exclude CS.
• The earliest and most important symptom of CS is pain greater than expected due to the injury alone.
• Severe pain at rest or with any movement should raise a red flag.
• Pain with certain movements, particularly passive stretching or extending of the muscles, is the earliest clinical indicator of CS.
• Compression on the deep peroneal (fibular) nerve results in loss of sensation in the web space between the first two toes and is an early finding in CS of the lower leg.
• The affected limb/compartment may begin to feel tense or hard.
• Compare the affected limb to the unaffected limb.
• Open wounds or open fractures do not exclude CS. In fact, open fractures are at higher risk of CS than closed fractures.
• One must have a higher index of suspicion in poly-trauma patients with associated head injury, drug and/or alcohol intoxication, early intubation, spinal injuries, use of paralyzing drugs, extremes of age, unconsciousness, and/or low diastolic blood pressures. In these patients, pressure measurements of suspected compartments may help make the diagnosis.
• Ultrasound is not helpful in the diagnosis of CS.
• Serial assessments and surveillance for CS should be performed in at-risk patients.

Tissue Pressure Measurements

• Measurement of tissue pressure (compartment pressure) should be dictated by history, clinical signs, and index of suspicion.
• A rule of thumb is that if one starts to think about tissue pressure measurements, one should probably be doing them.
• Pressures can be measured using the Stryker STIC® Monitor (Figure 2) or using a needle attached to an arterial line setup.

• The pressure threshold for fasciotomy is controversial.
  • Most authors recommend 30 mmHg (40 cm H2O) as the threshold for performing a fasciotomy.
  • In patients with hypotension, consider using the delta-p method, in which the compartment pressure is subtracted from the patient’s diastolic pressure. If the delta-p is below 30 mmHg, fasciotomy should be considered.
  • Some urge prophylactic fasciotomy in high- risk patients at normal pressures to prevent CS, especially when transfer of the patient is needed.
• Other factors to consider are length of time of transport to definitive care and ability to do serial exams.
• “Normal” compartment pressures should not preclude fasciotomy in patients with obvious clinical findings of CS.
• All compartments in the affected extremity must be measured, as one compartment can be high while the others are not.
• Knowledge of compartment anatomy is necessary to measure pressure in all potentially involved compartments.

Surgical Fasciotomy

Lower- Leg Fasciotomy

• The lower leg is the most common site for CS requiring fasciotomy.
• The lower leg has four major tissue compartments bound by investing fascia (Figure 3).
• The most reliable technique for treating or preventing CS in the lower extremity is a two- incision, four-compartment fasciotomy, which utilizes a lateral incision to open the anterior and lateral compartments and a medial incision to open the superficial and deep posterior compartments (Figure 4).
• There is no indication for a single-incision fasciotomy of the lower extremity in traumatically injured patients.
• Proper fasciotomy requires a thorough understanding of the underlying anatomy. The landmarks for each incision should be marked prior to incision, as distortion of the anatomy is likely to occur once the incisions are made.

The Lateral Incision

• The lateral incision of the two-incision, four- compartment fasciotomy is made in a line one fingerbreadth (1–2 cm) anterior to the edge of the fibula. In a swollen extremity, the fibula may not be easily palpable; therefore, a line is drawn from the fibular head to the lateral malleolus to mark the course of the fibula (Figure 5).
• The lateral incision extends from two to three fingerbreadths below the tibial plateau to two to three fingerbreadths above the lateral malleolus, with extension of the skin incisions as needed to ensure that the skin does not serve as a constricting band.

• The lateral incision is carried down through the skin and subcutaneous tissues until fascia is exposed. Care is taken to avoid the lesser saphenous vein and the peroneal nerve (also referred to as the fibular nerve in newer anatomy texts).
• The intermuscular septum is identified and serves as a landmark dividing the anterior and lateral compartments (Figure 6).
• The intermuscular septum can be very difficult to appreciate in a swollen, damaged, or deformed extremity. In this setting, it is useful to follow perforating vessels to the fascia, as they enter into (and can help identify) the intermuscular septum (Figure 6).
• The fascia of the anterior and lateral compartments are opened with scissors in an “H”-shaped fashion, with the cross piece of the “H” made across the intermuscular septum and the legs of the “H” extending the full length of the fascial compartments (Figure 7).
• The scissor tips should be turned away from the septum (Figure 7), taking care to avoid the superficial peroneal (fibular) nerve; this nerve originates around the head of the fibula and runs in the lateral compartment about 2/3 to 3/4 of the way down the leg, where it becomes more superficial and crosses over into the anterior compartment (Figure 8).

Pitfalls of the Lateral Incision

• Improper or incomplete performance of fasciotomy is unfortunately common, with loss of limb and life as a consequence.
• The anterior compartment is the most commonly missed compartment when performing a fasciotomy of the lower extremity.
• The most common reason the anterior compartment is missed is that the incision is made too far posterior, either over or behind the fibula.
• If the incision is made too far posterior, the intermuscular septum between the lateral and superficial posterior compartments is mistaken for the septum between the anterior and lateral compartments, and thus the anterior compartment is not opened (Figures 9 and 10).
• The superficial peroneal (fibular) nerve can be easily transected if one is not careful to keep the tips of the scissors an adequate distance and turned away from the intermuscular septum.
• Inadequate length of the fascial or skin incisions can result in failure to reduce compartment pressures to acceptable levels.

The Medial Incision

• The medial incision is made one fingerbreadth posterior to the medial edge of the tibia and should be generous in length (Figure 11).
• The medial skin incision should extend from two to three fingerbreadths below the tibial plateau to two to three fingerbreadths above the medial malleolus.
• The incision is carried down through the skin and subcutaneous tissues, taking care to identify and preserve the saphenous vein.
• Care should be taken to identify and ligate the saphenous vein tributaries, as they can bleed profusely.
• The fascia underlying the incision is opened the length of the compartment, decompressing the superficial posterior compartment (Figure 12).
• Entry into the deep posterior compartment is accomplished by bluntly and sharply taking down the fibers of the soleus muscle off the edge of the tibia (Figure 13).
• Identification of the neurovascular bundle confirms entry into the deep posterior compartment (Figure 14).

Pitfalls of the Medial Incision

• The deep posterior compartment is the second most commonly missed compartment when performing a fasciotomy of the lower extremity.
• The most common situation in which the deep posterior compartment is missed occurs when the dissection plane is made between the gastrocnemius and soleus muscles; this can lead to mistakenly opening the fascia over the soleus muscle rather than properly opening the deep posterior compartment (Figure 15).
• In an injured extremity, a prominent plantaris tendon (also known as the intern’s nerve) may be mistaken for the posterior tibial neurovascular bundle, leading one to erroneously believe that the posterior compartment has been entered and decompressed (Figure 16).
• Inadvertent injury to the saphenous vein can cause significant bleeding and may result in venous insufficiency if the deep venous system has also been injured.
• Inadequate length of the fascial or skin incisions can result in failure to reduce compartment pressures to acceptable levels.
• The muscles in each compartment should be assessed for viability. Viable muscle is pink, contracts when stimulated, and bleeds when cut (Figure 17).
• Skin incisions should be generous, as the skin can act as a constricting element to an otherwise well-performed fasciotomy.
• Fascial incisions should be carried the full extent of the fascial compartment.

Compartment Syndrome of the Thigh

• CS is uncommon in the thigh because of the large volume required to cause an increase in pressure in these compartments.
• The fascial compartments of the thigh blend anatomically with the hip, allowing for extravasation of blood or fluid out of the compartments.
• Predisposing factors include intramedullary nailing of femoral fractures, severe blunt trauma or crush injury to the thigh, vascular injury, iliac or femoral deep vein thrombosis, and external compression of the thigh.
• Approximately 90 percent of thigh CS cases are attributable to blunt trauma, with about half of these cases associated with femur fractures.
• The thigh contains three compartments: anterior, posterior, and medial (Figure 18).
• The anterior (not the medial) compartment contains the femoral artery and vein and is the most likely to develop CS.
• Two incisions (lateral and medial) are required to decompress all three thigh compartments (Figure 19).
• The lateral incision of the thigh is performed first and is usually adequate to relieve CS of the thigh.
• After the anterior and posterior compartments have been decompressed via the lateral incision, measure the pressure of the medial compartment; if elevated, make a medial incision to release the compartment.
• The lateral incision of the thigh extends from the intertrochanteric line to the lateral epicondyle of the femur to expose the iliotibial band, or fascia lata, which is opened the length of the incision.
• The vastus lateralis muscle is reflected superiorly and medially to expose the lateral intermuscular septum (between the anterior and posterior compartments), which is opened the length of the incision.
• The medial compartment can be opened through a medial incision (Figure 19) placed along the course of the saphenous vein. This is followed by rotation of the sartorius muscle and incision of the medial intermuscular septum between the medial and anterior compartments.

Gluteal Compartment Syndrome

• Gluteal CS is uncommon and can be misdiagnosed as a gluteal contusion. Untreated, it can lead to sciatic nerve palsy, muscle necrosis, rhabdomyolysis, acute renal failure, and death.
• The most commonly cited etiologies are prolonged immobilization and as a complication of intraoperative positioning.
• Other less common causes of gluteal CS include contusion; gluteal artery rupture associated with hip dislocation, acetabular fracture, or displaced pelvic fractures; as a complication of vascular procedures; as a complication of iliac crest bone harvest; infection; intramuscular drug use; leukemia; and, as recently seen in military populations, from blast injury to the buttock (Figure 20).

• The gluteal region contains three distinct compartments (Figure 21):
  • Tensor compartment: Comprised of the tensor fasciae latae muscle enclosed by the superficial and deep portions of the fascia lata; innervated by the superior gluteal nerve and vessels
  • Medius/minimus compartment: Composed of the gluteus medius and minimus muscles bounded by the iliac wing and combined layers of fascia lata; supplied by the superior gluteal nerve and vessels
  • Maximus compartment: Contains the gluteus maximus muscle enclosed by iliac bone and fascia; supplied by the inferior gluteal nerve and vessels
• Each of the distinct compartments is at risk for developing CS.
• Physical examination findings of gluteal CS include buttock numbness, pain with passive stretch of the gluteal muscles, tense swelling of the buttock region, and sciatic nerve symptoms.
• Clinical suspicion should prompt measurement of intracompartmental pressures, with pressures >30 mmHg (or a delta-p of <30 mmHg) confirming the diagnosis.
• If the mechanism of injury is thought to be related to gluteal artery rupture, efforts to control the bleeding through the use of interventional radiology should be considered prior to fasciotomy (Figure 22).

Gluteal Fasciotomy

• The most commonly cited technique is a posterior (Kocher-Langenbeck) approach to the hip.
• In this approach, the patient is placed in the lateral decubitus position, and the hip is flexed to 90° (Figure 23).
• A line is drawn in a curvilinear fashion from the posterior superior iliac spine to the greater trochanter and down the femur, with the incision extending from about 8 cm above the greater trochanter to about 6 cm down the shaft of the femur (Figure 23).
• The gluteal fascia is incised in the same plane as the underlying muscle (superior medial to inferior lateral) to decompress the gluteus maximus, which requires multiple epimysiotomies (opening the fascia overlying the muscle). This is accomplished by using blunt dissection to split the gluteus maximus in line with the fibers, taking care not to disrupt neurovascular structures (Figure 23).
• Superior retraction of the maximus will reveal the fascia overlying the gluteus minimus. The medius/minimus compartment is released by incising this fascia.
• At this point, compartment pressures should be measured to confirm adequate decompression and to measure the tensor compartment, which can be decompressed through the same incision if needed.
• An alternative approach described in the literature is a question-mark-style incision that begins at the posterior superior iliac spine and follows along the curve of the buttock down onto the greater trochanter below the gluteal cleft (Figures 24 and 25)

Compartment Syndrome of the Foot

• CS of the foot requiring fasciotomy is uncommon but can cause significant morbidity if missed.
• Both calcaneal fractures and crush injuries of the foot (e.g., Lisfranc fractures) may have between 10 percent and 40 percent risk of associated CS.
• Unlike the leg or forearm, there are no classic signs of CS in the foot. Pain on passive stretch and diminished pulses are not consistent physical findings.
• Tense tissue bulging of the dorsum or plantar space may be the most reliable finding.
• Maintain a high index of suspicion.
• Pressure measurement of all major compartments is required. Absolute pressures greater than 30 mmHg (or delta-p of less than 30 mmHg) are indications for decompression
• Early involvement of subspecialty consults (orthopaedics or podiatry) is highly recommended.
• There are four compartments of the foot: interosseous, lateral, central, and medial (Figure 26).
• Three incisions are used to decompress the foot compartments when CS is diagnosed (Figure 27).
• Two incisions are made on the dorsum of the foot, with the first just medial to the second metatarsal and the second just lateral to the fourth metatarsal (Figure 27).
• The extensor tendons are identified on top of the foot through the incisions; a blunt clamp (or scissor tips) is used to push beyond and then spread on either side of the tendons and between the metatarsal bones to decompress the interosseous compartment.
• The remaining three compartments are decompressed through an incision placed on the medial aspect of the foot in the arch, with the clamp or scissors pushed under the arch of the bony structures of the foot from medial to lateral to open the medial, central, and lateral compartments in turn (Figure 27).

Compartment Syndrome of the Forearm and Hand

• CS of the forearm and hand is much less common than in the lower extremity.
• Forearm CS most commonly follows a supracondylar fracture of the humerus but has also been associated with more distal fractures, crush injury, burns, or vascular injury.
• The forearm has three main compartments: The anterior (or volar) compartment (which many orthopaedic surgeons subdivide into superficial and deep volar compartments); the mobile wad compartment; and the dorsal compartment.
• The compartments of the forearm are much less well defined and more closely interconnected than those of the lower leg. As such, some practitioners have advocated that complete forearm decompression can be accomplished with a single volar incision.
• Given the above, the volar incision should be made first and the dorsal compartment reassessed prior to making the dorsal incision; however, one should have an extremely low threshold for making the dorsal incision.
• Multiple approaches to the volar incision have been described in the literature; the most commonly recommended/described incision is depicted in Figure 28. This incision crosses the antecubital fossa in a curvilinear fashion to the radial aspect of the upper forearm and then is carried toward the ulnar aspect down to the wrist, then across the wrist in a transverse fashion and onto the palm to release the carpal tunnel.
• This volar incision allows for decompression of the anterior (volar) and mobile wad compartments, as well as the carpal tunnel. This incision is preferred because of potentially better cosmetic results, maintenance of adequate skin blood supply between this and the dorsal incision, and maintenance of a vascularized skin flap to cover the median nerve and flexor tendons at the wrist.

• The dorsal incision extends from the level of the lateral epicondyle to the radial aspect of the wrist (Figure 29).

• To ensure that the compartments of the forearm are completely decompressed, it is important to do a complete epimysiotomy of each of the muscles to expose the muscle bellies in the entire length of the forearm (Figure 30).
• The transverse carpal ligament is generally wider than one might expect (> 2 cm), and there is a haptic and audible crunch that accompanies its division. If one “cuts until the crunch is gone,” the carpal tunnel is fully opened.
• In most cases of suspected CS of the forearm, the carpal tunnel should be opened completely at the wrist. This is accomplished by identifying the median nerve at the wrist crease and using scissors with the opened blades on either side of the transverse carpal ligament above the median nerve, guiding subsequent division (Figure 31).
• If CS of the hand is present or suspected, two additional incisions are made on the dorsum of the hand over the second and fourth metacarpals, as seen in Figures 29 and 32.
• CS of the hand can occur from trauma but most often occurs from iatrogenic injuries (arterial line complication or infiltration of IV medications).
• The hand contains 10 osseofascial compartments: the thenar, hypothenar, adductor, and seven interosseous compartments (Figure 32).
• The interosseous and adductor compartments are decompressed through the two dorsal incisions. Decompression of the thenar and hypothenar compartments may require additional incisions, as depicted in Figure 32.
• Symptoms of CS in the hand do not include abnormalities of sensory nerves, as there are no nerves within the compartment. The most consistent clinical finding is a tense, swollen hand in the intrinsic minus position (metacarpophalangeal joints extended and interphalangeal joints flexed).
• The pressure threshold for CS in the hand is much less than in the legs; 15–20 mmHg is an indication for surgical release.
• A high index of suspicion must be maintained, and if available, early involvement of a hand specialist is recommended.

After Care

• Necrotic muscle should be debrided at the time of original fasciotomy.
• Open wounds should be covered with nonadherent dressing or moist gauze.
• The wound(s) should be frequently reevaluated, with further debridement as indicated.
• Negative pressure wound therapy is useful once the wound has been adequately debrided and may reduce time to wound closure.
• Delayed primary closure or split-thickness skin grafting may be performed after the acute process subsides.
• Monitor for rhabdomyolysis. High serial creatine phosphokinase (CPK) levels, worsened acute renal failure, or unexplained acidosis should prompt reinspection of the fasciotomy and may be an indicator of incomplete fasciotomy or new necrotic tissue.

Complications

• Surgical site infection
• Incomplete fasciotomy
• Missed compartment
• Loss of limb
• Permanent nerve damage
• Vascular injury, bleeding
• Cosmetic deformity from fasciotomy
• Multisystem organ failure and rhabdomyolysis from missed or incompletely treated CS