Compartment syndrome of the upper extremity is an uncommon clinical entity. In one review, only 18.4% of all fasciotomies performed were in the upper extremity and the vast majority of these were in the forearm.143 As an isolated compartment syndrome of the arm is so rare, the presence of a documented compartment syndrome in the arm mandates assessment of the forearm.
Arm.144 The 2 anatomic compartments of the arm are the anterior (flexor) and posterior (extensor). The 2 compartments are separated by the medial and lateral intermuscular septi. The anterior compartment contains the biceps brachii (long and short heads; shoulder and elbow flexion, forearm supination) and brachialis muscles, the musculocutaneous, me-dian and ulnar nerves, and the brachial artery and its venae comitantes.
The posterior compartment contains the triceps brachii muscle (long, lateral, and medial heads; shoulder and elbow extension, arm adduction), the radial nerve, and the radial collateral and middle collateral arteries.
To decompress the musculofascial compartments of the arm, the entire upper extremity is prepared and draped from the mid-clavicular area to the fingernails (in case the musculofascial compartments of the forearm need decompression as well).
Fasciotomy of the Anterior and Posterior Compartments of the Arm Using 1 Skin Incision. A 15-cm skin incision is made over the medial intermuscular septum, carefully avoiding the underlying neurovascular bun-dle. Using rake retractors and the electrocautery device, skin and subcutane-ous tissue flaps are raised anteriorly and posteriorly. The fascia over the anterior compartment is then opened midway between the anterior border of the biceps muscle and the medial intermuscular septum for the length of the skin incision. The fascia over the posterior compartment is then opened midway between the posterior border of the triceps muscle and the medial intermuscular septum for the length of the skin incision.
Fasciotomy of the Anterior and Posterior Compartments of the Arm Using 2 Skin Incisions. A 15-cm skin incision starting medial to the bicipital sulcus is extended up the anteromedial arm to the acromion and through the fascia to decompress the anterior compartment. A 15-cm skin incision starting at the tip of the olecranon is extended up the posterolat-eral arm and through the fascia to decompress the posterior compartment.
Forearm.144-151 The 3 anatomic compartments of the forearm are the volar (flexor), dorsal (extensor), and lateral (mobile wad). The volar compartment lies anterior to the lateral intermuscular septum, radius, interosseous membrane, ulna, and medial intermuscular septum and is separated from the lateral compartment by the superficial radial nerve and radial artery and vein. It contains a superficial group of muscles including the flexor carpi radialis, palmaris longus, flexor carpi ulnaris (FCU), FDS superficialis and pronator teres as well as a deep group of muscles including the FDS profundus, flexor pollicis longus, and pronator quad-ratus (some authors consider this to be a separate compartment).149,150 Other contents depending on the level include the median and ulnar nerves, the deep branch of the radial nerve, the radial artery and vein, the ulnar artery and vein, and the anterior interosseous nerve, artery, and vein.
The dorsal compartment lies posterior to the lateral intermuscular septum, radius, interosseous membrane, ulna, and medial intermuscular septum. It contains a superficial group of muscles including the extensor digitorum communis, extensor carpi ulnaris, and extensor digiti minimi as well as a deep group of muscles including the abductor pollicis longus, extensor pollicis brevis and longus, extensor indicis, and the supinator. Other contents include the posterior interosseous nerve, artery, and vein. The lateral compartment lies superior to the lateral intermuscular septum and
is separated from the volar compartment by the superficial radial nerve and radial artery and vein. It contains the brachioradialis and extensor carpi radialis longus and brevis muscles, but no other major nerves or blood vessels.
To decompress the musculofascial compartments of the forearm, the entire upper extremity is prepared and draped from the mid-clavicular area to the fingernails (in case the musculofascial compartments of the arm need decompression as well). Because of the difficulty surgeons have in remem-bering the direction of the skin incision in the “Henry” approach to decompression of the volar compartment of the forearm, the senior author uses and teaches the volar-ulnar approach in his academic surgical practice (Fig 15).
Fasciotomy of the Volar and Lateral Compartments of the Forearm (Volar-Ulnar Approach). A transverse incision starting distal to the antecubital crease on the radial side of the forearm is extended to the ulnar side of the forearm and then turned 90°. The longitudinal component of the incision is extended down the ulnar side of the forearm until it reaches the wrist, where it curves medially to the mid-aspect of the volar
FIG 15.Proximal aspect of skin incision used in volar-ulnar approach to decompress the volar and lateral compartments of the forearm.
wrist. The incision is now extended and curved into the thenar crease of the palm. By dividing the underlying fascia at the transverse origin of the incision distal to the antecubital crease, the muscles of the lateral (mobile wad) compartment are decompressed. The fascia underlying the longitu-dinal and wrist components of the skin incision is opened, thereby decompressing the superficial flexor muscles of the forearm and the carpal tunnel.151The space between the FCU and FDS muscles (flexing the fingers will help differentiate these muscles) is separated with retractors, and the ulnar nerve and artery are visualized lying on the deep flexor compartment (Fig 16). The deep flexor compartment is opened longitudinally after retracting the ulnar artery and nerve laterally and ligating any small arterial branches in the area where the fasciotomy is to be performed. Ideally, the fascia over each deep volar muscle should be incised.149 If there is continued tightness at the level of the wrist, the tunnels of the median and ulnar nerves should be divided.
Fasciotomy of the Dorsal Compartment of the Forearm. Pressures in the dorsal compartment of the forearm often return to the normal range following decompression of the volar and lateral compartments. There-fore, the pressure in the dorsal compartment is reassessed at this time to
FIG 16.Access to the deep flexor compartment of the forearm by retraction of the flexor carpi ulnaris (FCU) and flexor digitorum (FDS) muscles. (Reprinted with permission from Twaddle and Amen-dola.61)
avoid an unnecessary skin incision and fasciotomy. After the forearm is pronated, a longitudinal skin incision from 2 cm lateral to and 2 cm distal to the lateral epicondyle of the humerus to the mid-aspect of the posterior wrist is made. A longitudinal fasciotomy to decompress the superficial muscles of the dorsal compartment is made between the extensor carpi radialis brevis and extensor digitorum communis muscles (extending the fingers will help differentiate these muscles).
Wrist and Hand.151-155 The carpal tunnel on the flexor aspect of the wrist is the only compartment in this location, and a carpal tunnel release is usually performed as part of the fasciotomy of the volar compartment of the forearm as described previously.151,152,155
A delay in reestablishing arterial inflow into the forearm and hand, ligation of the major veins of the arm or forearm, marked traumatic disruption of the soft tissues of the arm (traumatic near-amputation), a crush injury, or a compression syndrome may result in a compartment syndrome of the hand on rare occasions. Consultation with a hand surgeon is appropriate if one is available.
The hand has thenar, hypothenar, adductor, and 4 interossei compart-ments. An injection study published in 1980 demonstrated that the traditional 4 interossei compartments were actually divided into 3 palmar and 4 dorsal compartments, bringing the total number of compartments in the hand to 10.153Other anatomic studies have demonstrated a significant amount of variation in these 10 fascial compartments.154 Fortunately, despite the described variations, the compartments of the hand can be adequately decompressed with the traditional 4-incision fasciotomy.155
Fasciotomy of the Hand. Two 4-cm longitudinal incisions are made on the dorsum of the hand over the metacarpal bones of the index and ring fingers. Fascial incisions are then made along both sides of these metacarpals, thereby releasing the 4 dorsal interosseous muscles. The first palmar interosseous and adductor compartments are opened by blunt dissection along the ulnar aspect of the index metacarpal bone. The second and third palmar interosseous compartments are released by dissection along the radial aspect of the ring and small metacarpal bones.
A longitudinal incision is then made along the radial side of the first metacarpal bone to release the thenar compartment. A longitudinal incision is made along the ulnar aspect of the fifth metacarpal bone to release the hypothenar compartment.