DECOMPRESSION OF COMPARTMENT SYNDROME

There are no satisfactory nonsurgical methods for treating compartment syndromes; however, cooling of the tissue may prolong tolerance to ischemia and proper hydration may help avoid the renal damage after decompression. Surgical decompression, which allows the volume of the compartments to increase, is the primary means of relieving pressure. Each of the surrounding envelopes of the compartment may play a role in limiting compartment volume and must be considered, including volume-restricting plaster casts and circular dressings. Splitting and spreading a plaster cast may result in a 65% decrease in intracompartmental pressure. However, if symptoms of neurologic deficit persist more than 1 hour after cast splitting, the top half of the cast and all circular dressings must be removed and the limb examined. The skin may be a limiting envelope if, for example, there is significant subcutaneous edema or thermal injuries that have merged skin and fascia. In these cases, adequate decompression is achieved with a long dermatomy and fasciotomy.

INCISIONS FOR FOREARM AND HAND

The forearm consists of three compartments; volar, dorsal, and the mobile wad with the volar compartment most commonly involved in compartment syndrome. The primary approaches for decompression of the forearm are straight dorsal and curvilinear volar incisions (see Plate 7-16). Both approaches lower pressures in the volar compartment, and in about one half of patients they also lower pressures in the dorsal compartment and as such should be performed first with dorsal pressures rechecked afterward. The curvilinear volar incision is preferred because it allows exposure of all major nerves, arteries, and the mobile wad. The advantage of the dorsal ulnar incision is a better skin coverage over the neurovascular bundles and tendons after decompression. The curvilinear volar incision begins proximal to the antecubital fossa and extends to the middle of the palm. It is gently curved medially until it reaches the midline at the junction of the middle and distal thirds of the forearm and is continued straight distally to the proximal wrist crease, just ulnar to the palmaris longus tendon. The forearm incision is extended across the volar wrist crease to aid release of the carpal tunnel. It is carried no farther radially than the midaxis of the ring finger to avoid injury to the superficial palmar branch of the median nerve.

Median nerve neuropathy, in addition to carpal tunnel release, requires exploration of the nerves in the proximal forearm. The three main areas of potential nerve compression are the bicipital aponeurosis (lacertus fibrosis), the proximal edge of the pronator teres muscle, and the proximal edge of the flexor digitorum superficialis muscle.