Rockwood, Green, and Wilkins' Fractures, 10e Package

93

CHAPTER 6 • Compartment Syndrome in Children

Preoperative therapy is also helpful in establishing a good patient and parent rapport with the therapist and in gaining an understanding of the postsurgical therapy program. A variety of surgical procedures have been used to treat Volkmann ischemic contracture. These have included both bone and soft tissue procedures. Surgical treatment should not be undertaken before soft tissue equilibrium is present. We do not recommend a shortening osteotomy of the radius and ulna and proximal row carpectomy to match the skeletal length to the shortened fibrotic muscle because the bones are already rel atively shortened by the initial ischemic insult to the growth plates. Further, the principal contracture is usually on the flexor surface. Shortening the forearm indiscriminately length ens the muscle resting length of both the flexor and extensor muscles, neglecting the predominant involvement of the con tracture within the flexor compartment. Bony reconstructive procedures for long-standing contractures or for distal recon struction required for neurologic injury include wrist fusion, trapeziometacarpal joint fusion, or thumb metacarpophalangeal joint fusion, which should be done after skeletal maturity. These may be considered in conjunction with some of the soft tissue procedures listed below. Soft tissue procedures have included excision of the infarcted muscle, fractional or z-lengthening of the affected muscles, muscle sliding operations (flexor origin muscle slide), neuroly sis, tendon transfers, and functional free tissue transfers, as well as combinations of the above procedures. Excision of scarred fibrotic nerves without distal function followed by nerve graft ing has been described to try and establish some protective sensation in the hand. Fixed contractures of the joints can be addressed with soft tissue release including capsulectomy and collateral ligament recession or excision depending on the joints involved. Full functional recovery within 6 months has been reported with timely management of compartment syndrome in the pediatric population. 2 Functional outcomes are good to excel lent in over 90% of patients. Of all compartment syndrome, upper extremity compartment syndrome and nonfracture com partment syndrome may have poorer outcomes. 21 Late diagno sis of compartment syndrome may increase the risk of severe complications, including infection, neurologic injury, need for amputation, and death. The duration of elevated tissue pres sures before definitive surgical decompression may be the most important factor in determining outcome. In adults, prolonged ischemic insult to compartment musculature greater than 8 hours increases the risk of permanent sequelae. 11 Some stud ies have shown that after traumatic upper extremity injury in pediatric patients, delayed presentation and decompression of forearm compartment syndrome after 48 hours results in signifi cant morbidity and can result in forearm muscle necrosis neces sitating reconstructive surgery with a free gracilis muscle flap or OUTCOMES

ESTABLISHED CONTRACTURE (VOLKMANN CONTRACTURE)

Volkmann ischemic contracture is the end result of prolonged ischemia with irreversible tissue necrosis. The most commonly used classification system is that of Tsuge, who classified Volkmann contracture into mild, moderate, and severe types, according to the extent of the muscle involvement. The mild type, also described as the localized type, involves the muscles of the deep flexor compartment of the forearm. It can involve all the flexor digitorum profundus and the flexor pollicis longus, although usually only involves the flexor digi torum profundus of the ring or middle fingers. Nerve involve ment is absent or mild, typically involving sensory changes that resolve spontaneously. With wrist flexion, the fingers can be fully extended. The majority of mild types result from direct trauma either from crush injury or forearm fractures and are typically seen in young adults. In the moderate type, muscle degeneration includes most or all of the flexor digitorum profundus and flexor pollicis lon gus with partial involvement of the flexor superficialis muscles. Neurologic impairment is always present. Sensory impairment is generally more severe in the median than in the ulnar nerve distribution, and the hand demonstrates an intrinsic minus pos ture. Moderate-type Volkmann contracture is most commonly the result of SCH fractures in children between ages 5 and 10. The severe type involves degeneration of all the flexor mus cles of the fingers and of the wrist. There is central muscle necrosis and varying involvement of the extensor compartment. Neurologic deficits are severe, including complete palsy of all the intrinsic muscles of the hand. Hallmarks of the severe type include fixed joint contractures, scarred soft tissue, or previ ously failed surgeries. As with the moderate cases, the severe cases were most commonly the result of SCH fractures in children. 45 Treatment of established Volkmann contracture depends on the severity of the contracture and neurologic deficits and the resultant functional losses. Nonoperative management should be instituted early in most cases of established Volkmann contracture. In children, there may be more recovery of nerve and muscle function over time than in adults, so we do not advocate immediate surgical intervention. A formal program of splinting and therapy can improve the outcome of later surgical intervention and may result in less extensive surgical corrections. Therapy should be directed toward maintenance of passive joint motion, preser vation and strengthening of remaining muscle function, and correction of deformity through a program of splinting. We prefer the use of static progressive splinting or serial casting for fixed contractures of the wrist, fingers, and thumb web space. Mild contractures with minimal to no nerve involvement can often be treated only with a comprehensive program of hand therapy and rehabilitation. For moderate to severe involvement where surgery is anticipated, therapy is indicated only as long as necessary to achieve supple passive motion of the fingers.