Review Article Acute Compartment Syndrome of the Upper Extremity Abstract Mark L. Prasarn, MD Acute compartment syndrome occurs when pressure within a fibro- Elizabeth A. Ouellette, MD osseous space increases to a level that results in a decreased perfusion gradient across tissue capillary beds. Compartment syndromes of the hand, forearm, and upper arm can result in tissue necrosis, which can lead to devastating loss of function. The etiology of acute compartment syndrome in the upper extremity is diverse, and a high index of suspicion must be maintained. Pain out of proportion to injury is the most reliable early symptom of impending compartment syndrome. Diagnosis is particularly difficult in obtunded patients and in young children. Early recognition and expeditious surgical treatment are essential to obtain a good clinical outcome and prevent permanent disability. ompartment syndrome was first most frequent causes of compart- Cdescribed in 1881 by Richard ment syndrome in the upper extrem- von Volkmann.1 The etiology, patho- ity.1,2 Compartment syndrome is a physiology, and management of clinical diagnosis, and it can be diffi- compartment syndrome and the as- cult to make in certain patient popu- sociated complications have been ex- lations, such as persons who are ob- tensively described. Acute compart- tunded and children.2-5 Emergent ment syndrome (ACS) occurs with surgical treatment is required; the elevation of interstitial pressure in a most important determinant of out- closed fascial compartment, resulting come is early recognition and expedi- in microvascular compromise. This tious surgical intervention.3,5-9 Re- From the Department of causes the perfusion gradient to fall constructive procedures can be Orthopaedics, University of below a critical value, leading to is- performed to improve the function Rochester, Rochester, NY chemia of the tissues within this con- of the affected upper extremity in the (Dr. Prasarn), and Physicians for patient with Volkmann contracture; The Hand, Miami, FL (Dr. Ouellette). fined space. In the upper extremity, the dorsal and volar compartments however, return of normal function Dr. Ouellette or an immediate family should not be expected.10-16 member serves as a paid consultant of the forearm are the most com- to or is an employee of Stryker. monly affected. Upper extremity Neither Dr. Prasarn nor any ACS can lead to devastating loss of immediate family member has Anatomy received anything of value from or function, including Volkmann ische- owns stock in a commercial mic contracture, neurologic deficit, The upper extremity contains 15 company or institution related infection, amputation, and death. compartments. The upper arm con- directly or indirectly to the subject of A wide range of causes of ACS in this article. sists of a flexor (ie, volar) compart- the upper extremity has been re- ment and an extensor (ie, dorsal) J Am Acad Orthop Surg 2011;19: ported, and a high index of suspicion 49-58 compartment. The forearm is divided must be maintained. Distal radius into three compartments: volar, dor- Copyright 2011 by the American fracture in adults and supracondylar sal, and lateral (ie, mobile wad) (Fig- Academy of Orthopaedic Surgeons. humerus fracture in children are the ure 1). The hand has 10 compart- January 2011, Vol 19, No 1 49 Acute Compartment Syndrome of the Upper Extremity Figure 1 this membrane lie the flexor digito- rum profundus, flexor pollicis lon- gus, and pronator quadratus mus- cles. Some consider the pronator quadratus to lie within an additional compartment of the distal volar fore- arm, separate from the flexor ten- dons at this level.20 These deep volar muscles are the most commonly damaged muscles in forearm com- partment syndrome. The remaining, more superficial flexor muscles are less prone to ischemia than their deeper counterparts. The finger and wrist extensors lie on the posterior aspect of the forearm. Isolated exercise-induced compartment syn- dromes of the extensor carpi ulnaris muscle have been noted in case re- ports.21,22 The mobile wad, which consists of the brachioradialis, flexor carpi radialis longus, and flexor carpi radialis brevis tendons, is rarely Cross section at the junction of the proximal and middle thirds of the forearm involved.12 The antebrachial fascia, demonstrating the compartments and the important neurovascular structures. The volar compartment contains the flexor muscles of the wrist and digits, which is a continuation of the bra- including the flexor digitorum superficialis (FDS), flexor carpi radialis (FCR), chial fascia, envelops the compart- flexor pollicis longus (FPL), flexor digitorum profundus (FDP), and flexor carpi ments and muscles in the forearm. ulnaris (FCU), as well as the ulnar nerve (UN), ulnar artery (UA), median nerve (MN), median artery (MA), radial artery (RA), superficial branch of the The compartments of the hand are radial nerve (RN), anterior interosseous artery (AIA), and anterior divided by the carpal bones, metacar- interosseous nerve (AIN). The dorsal and volar compartments are separated pals, and individual investing fascial by the interosseous membrane. The dorsal compartment contains the finger layers. Pressures within the carpal tun- and thumb extensors and the long thumb abductor as well as the posterior interosseous artery (PIA), posterior interosseous nerve (PIN), extensor carpi nel may become elevated in cases of ulnaris (ECU), extensor pollicis longus (EPL), and extensor digitorum hand or volar forearm compartment communis (EDC). The mobile wad, which is often considered to be a third syndrome. Release of the transverse compartment, is composed of the extensor carpi radialis brevis and longus carpal ligament is often necessary in muscles (ECR) and the brachioradialis (BR). (Reproduced with permission from Ouellette EA: Compartment syndromes in obtunded patients. Hand Clin addition to release of the other in- 1998;14[3]:431-450.) volved compartments. The digital fas- cial compartments are bound by the Cleland ligament and the Grayson lig- ments: hypothenar, thenar, and tal fasciotomy is necessary in some ament, and elevated pressure may oc- adductor pollicis as well as four dor- cases19 (Figure 3). cur in individual digits (Figure 3). sal interosseous and three volar in- In the upper arm, the medial and Compartment syndrome of the hand terosseous17 (Figure 2). The volar the lateral intermuscular septa sepa- typically necessitates carpal tunnel re- forearm is the most commonly af- rate the flexor compartment from lease and dorsal interosseous compart- fected compartment in the upper ex- the extensor compartment. The bra- ment releases; however, any compart- tremity. Compartment syndrome in chial fascia is a dense fibrous sheath ment may be involved and may require this area typically occurs following that surrounds the muscles in each of release. The decision regarding the fracture of the distal radius, supra- the two compartments. In the fore- number and location of incisions condylar humerus, or diaphysis of arm, the stiff interosseous membrane should be based on the clinical findings the radius or ulna.2,17,18 Any compart- bridges the distance between the ra- and on intraoperative pressure mea- ment can be affected, however. Digi- dius and the ulna. Just anterior to surements.3 50 Journal of the American Academy of Orthopaedic Surgeons Mark L. Prasarn, MD, and Elizabeth A. Ouellette, MD Etiology Figure 2 ACS of the upper extremity is caused by a myriad of factors, including fracture, bleeding disorders, constric- tive dressing and casting, arterial in- jury, extravasation of intravenous or intraosseous infusion, and regional anesthesia3-5,23-35 (Table 1). Anything that causes increased volume within the confined fascial space (eg, bleed- ing, edema, purulent material, extra- neous fluids) or restricts the com- partment from expanding (eg, burn, casting, dressing, tourniquet) can cause ACS. It is difficult to estimate the true incidence of compartment syndrome of the upper extremity, but most Cross section at the level of the metacarpal shafts demonstrating the 10 cases occur in the setting of fracture. compartments of the hand: hypothenar, thenar, and adductor pollicis as well McQueen et al17 analyzed 164 pa- as four dorsal interosseous and three volar interosseous. (Reproduced with permission from Ouellette EA: Compartment syndromes in obtunded tients with traumatic ACS. In 69% patients. Hand Clin 1998;14[3]:431-450.) of cases, compartment syndrome was associated with fracture. The most frequent fracture types observed fractures of the distal end of the ra- to decreased arteriolar pressure and were of the tibial diaphysis (36%), dius is substantially higher with con- possibly closure of end arterioles, the distal radius (9.8%), and the di- comitant ipsilateral elbow injury leading to a further decrease in tissue aphysis of the forearm bones (7.9%). than with distal radial fracture perfusion4 (Figure 4). Only 2.5% occurred following hand alone.36 fracture, and the incidence was 0.6% Ischemia occurs when a critical each for elbow fracture-dislocation threshold is reached in the local arte- and humeral fracture. Soft-tissue in- Pathophysiology riovenous gradient and when circula- jury without fracture was the second tion is compromised to the point that most common cause of injury Compartment syndrome is caused by blood flow is insufficient to meet the (23.2%). Incidence in the forearm an elevation of pressure within a metabolic demands of the tissue.4 and hand was 5.5% and 0.6%, re- fibro-osseous