Compartment syndrome is caused by increased pressure within the myofascial compartments leading to a decrease in blood flow. Nerves followed by muscle are most sensitive to ischemia and undergo irreversible changes within 6 to 8 hours. It is therefore important to decompress the fascial compartment by performing a fasciotomy and to restore tissue perfusion as soon as possible.

Compartment syndrome is a clinical diagnosis based on the features of ischemia of nerve (paresthesia, pain, and paralysis), muscle (pain on passive stretch), and vessel (pallor and pulselessness). All features may not be present in every patient, and a diagnosis is made based on the overall clinical scenario.

A prophylactic fasciotomy should be performed in all major limb replantations/revascularizations irrespective of the clinical appearance of the limb at the end of the procedure (Fig. 2-4). The limb is insensate and becomes progressively swollen as a result of diminished venous return and ischemia reperfusion injury. When a fasciotomy is not performed, the arterial inflow can be compromised, leading to failure of the replantation.

No investigations are required if a diagnosis of compartment syndrome is clinically apparent. Some laboratory studies (complete blood count, prothrombin time, partial thromboplastin time, serum and urine myoglobin, and creatinine phosphokinase) and imaging studies (radiographs, Doppler, and arteriography) can be used to complement the clinical findings.

If a clinical diagnosis is equivocal, compartment pressure measurements should be obtained. We use a commercially available device (Stryker Intra-Compartmental Pressure Monitor) (Fig. 2-5). The normal tissue pressure is 0 to 8 mm Hg. A fasciotomy is recommended if the tissue pressure is higher than 30 mm Hg. Close monitoring, repeated clinical examination, and serial measurement of compartment pressures may be required for pressure measurements between 20 and 30 mm Hg.

The carpal tunnel is decompressed by a single incision between the thenar and hypothenar muscles in line with the third web space (Fig. 2-9).

The thenar compartment is decompressed by an oblique longitudinal incision along the radial margin of the thenar eminence (see Fig. 2-9).

The hypothenar compartment is released via a longitudinal incision along the ulnar aspect of the palm (see Fig. 2-9).

The dorsal compartments are released by two longitudinal incisions parallel to the radial border of the index and ring metacarpals (Fig. 2-10).

Finger decompression is done by a midaxial incision on the noncontact side of the fingers (ulnar side of index and long finger and radial side of thumb, ring, and small fingers) (Fig. 2-11).

The standard incision for release of the forearm is a curvilinear incision extending from the medial epicondyle to the proximal wrist crease. It is important to curve this incision over the distal forearm so that a flap of skin can cover the median nerve and the flexor carpi radialis (FCR) tendon (Fig. 2-12).

A 10- to 15-cm dorsal longitudinal incision beginning 3 to 4 cm distal to the lateral epicondyle toward the Lister tubercle can decompress the dorsal compartment and the mobile wad of muscles (Fig. 2-13). We prefer to use two parallel longitudinal incisions instead of the standard incision.

One incision is made over the volar radial aspect of the forearm overlying the flexor muscles, and the other is made over the dorsal ulnar aspect over the extensor muscles. This double incision allows decompression of the volar and dorsal compartments and does not expose the median nerve or the tendons at the distal forearm (Fig. 2-14).

A medial incision extending from the anterior axillary line to the medial epicondyle can access the anterior and posterior compartments (see Fig. 2-14). The medial incisions can also be used for exposure of the major neurovascular structures in the arm.

A separate incision over the midportion of the deltoid may be required in rare situations.