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

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SECTION ONE • Fundamentals of Pediatric Fracture Care

that overtreatment may be the result of operating based on pres sure thresholds alone. 27 Risk factors that may delay diagnosis are altered level of consciousness, associated nerve injury, polytrauma, and altered pain perception. Delay in diagnosis may also be related to longer elapsed time between the initial injury and peak compartment pressures in the pediatric setting. 11 Extended close monitoring after injury is recommended when there is concern for develop ment of compartment syndrome in children.

osteomyelitis and ruptured subperiosteal abscess 37 as well as a severe ankle sprain with injury to a branch of the peroneal artery. 31

EXERCISE-INDUCED OR EXERTIONAL COMPARTMENT SYNDROME

Exercise-induced compartment syndrome, or chronic compart ment syndrome, is a transient increased compartment pressure and reversible tissue ischemia caused by a noncompliant fas cial compartment that does not accommodate muscle expan sion occurring during a repetitive exercise such as running. It has been described in both the upper and lower extremities. 3,50 Exertional compartment syndrome can be relieved with cessa tion of the offending activity or fasciotomies of affected com partments for refractory cases. A case series of 155 patients and 250 legs with chronic exertional compartment syndrome found that adolescent female running athletes were at highest risk. Fasciotomy allowed for return to play in 79.5%. Significantly, when compared to four-compartment release, anterior and lat eral (two) compartment release increased the odds of reopera tion by 3.4 times. 3 NEONATAL COMPARTMENT SYNDROME Neonatal compartment syndrome is caused by limb ischemia presenting at birth or in the postnatal period. It is character ized by skin lesions that can be confused with other diagno ses. Because of this, diagnosis is usually delayed and patients develop contractures, as well as bone and nerve disturbances. 6,32 Early recognition and treatment can improve the functional out come and growth; however, established neonatal contractures cannot be improved by emergent intervention. Potentially devastating complications of compartment syn drome may be avoidable with early recognition and prompt intervention. The goal of treatment is to prevent tissue necrosis, neurovascular compromise, and permanent functional deficits. The first step is to remove all possible extrinsic causes of pressure on the affected limb, including circumferential dress ings, cast padding, and casts. A study simulating compartment syndrome in the anterior leg compartment in healthy patients was performed using a pneumatic thigh cuff to elevate pres sures in the studied leg, with the contralateral leg as control. Compartment pressures, microvascular blood flow, perfusion pressure, pH, and oxygenation were evaluated with the leg at heart level and 12 cm above heart level. Authors found that tissue oxygenation, blood flow, perfusion pressure, and pH, all decrease as compartment pressure was increased, and leg elevation caused further decreases in all outcome variables. 7 Authors argue that in patients with compartment syndrome, the affected extremity should not be dependent but also should not be elevated higher than the patient’s heart to maximize per fusion while minimizing swelling. Optimizing overall medical TREATMENT

CLASSIFICATION

COMPARTMENT SYNDROME Compartment syndrome occurs when tissue pressures rise high enough within a fascial compartment to cause tissue ischemia. IMPENDING COMPARTMENT SYNDROME Impending compartment syndrome is when pressures are ris ing in a compartment but the tissue is not yet ischemic. In these at-risk cases, the clinical indicators do not yet meet the threshold for diagnosis of compartment syndrome. The exact time of conversion to compartment syndrome from impend ing compartment syndrome is difficult to determine and varies by patient. Patients with impending compartment syndrome necessitate vigilant monitoring. FRACTURE COMPARTMENT SYNDROME Most cases of compartment syndrome are associated with a frac ture. Both high- and low-energy injuries can result in compart ment syndrome. Open fractures are associated with a higher incidence of compartment syndrome than closed injuries. 12 Open fractures are generally associated with higher-energy inju ries. Fascial disruption in these cases does not result in adequate decompression of all compartments. NONFRACTURE COMPARTMENT SYNDROME Soft tissue injury without fracture can also lead to compartment syndrome, especially in the setting of an underlying bleeding disorder or with the use of anticoagulants. Compartment syn drome in this setting has been associated with a high rate of disability. 13 A retrospective review over 16 years evaluating non fracture compartment syndrome identified 39 cases of which 29 of 39 (74%) involved the leg. In this series, compartment syndrome was most commonly caused by vascular injury, fol lowed by trauma and postoperative changes. Pain and swelling were the most common symptoms. Delay in diagnosis up to 48 hours was commonly seen and 21 of 39 (54%) had evidence of myonecrosis at time of surgery. 20 Muscle recovery is rare once myonecrosis has occurred. Rarely, IV infiltration can cause com partment syndrome. A retrospective review of compartment syndrome caused by IV infiltration found that pediatric patients constituted 40% of cases. 30 Other rare reported causes of non fracture compartment syndrome includes acute hematogenous