Session III - Clinically Relevant Research

*Necrotic Muscle at Fasciotomy

Greg Hill, J. L. Marsh, MD, J. Buckwalter, MD

University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA

Purpose: The purpose of this study was to determine if the presence of necrotic muscle at the time of fasciotomy for treatment of established compartment syndrome, predisposes to poor outcome and to identify clinical factors which predict the presence of necrotic muscle.

Methods: Between January 1979 and September 1995, seventy patients with seventy-three extremities had a fasciotomy performed for an acute compartment syndrome resulting from lower extremity trauma. Two groups were identified based on the presence (Group I) or absence of (Group II) necrotic muscle at the time of fasciotomy, defined as debrided muscle and/or muscle which was non-contractile, of poor color, or non-bleeding. These two groups were compared for pre-release factors possibly predictive of muscle necrosis which included: time from initial symptoms of neuromuscular ischemia to fasciotomy, intracompartmental pressure measurements, pre-fasciotomy laboratory values (arterial pH, CO2, HCO3, K+, BUN, Cr, LDH, AST, CK and urinalysis), classification of fractures as open vs. closed, the presence or absence of associated neurovascular injuries. The incidence of occurrence of the following adverse clinical outcomes were compared between the two groups: 1) infection in the compartment, 2) fracture nonunion, 3) amputation, 4) repeated muscle debridement, 5) the occurrence of any of the previous adverse outcomes.

Results: Eleven extremities with necrotic muscle present at the time of fasciotomy formed Group I and sixty-two extremities without necrotic muscle formed Group II. There were no significant differences between the two groups for the following prefasciotomy data: age, gender, mechanism or injury, open vs. closed fracture, paresthesia, pallor, prolonged capillary fill, pulselessness by Doppler, or painful passive dorsiflexion as initial symptoms of neuromuscular ischemia, individual intracompartmental pressure or maximum intracompartmental pressures, or laboratory values. Significant differences were demonstrated between the two groups for: a history of crush injury (p<0.001); paresis as an initial symptom of neuromuscular ischemia (p<0.05), and the average time from the initial symptoms of neuromuscular ischemia to fasciotomy, 20 hours in Group I vs. 3 hours in Group II (p<0.001).

Infection in a fasciotomized compartment developed in fourteen extremities. Repeated debridement of necrotic muscle was required in nine with an average of 2.5 debridements per extremity. Fractures in seven legs developed nonunions which required further intervention. Five extremities eventually required amputation.

All of the dependent variables were significantly different, with Group I having more adverse outcomes in all categories: infection of a fasciotomized compartment (p<0.001), fracture nonunion (p<0.01), amputation (p<0.01), repeated necrotic muscle debridement (p<0.01) and the occurrence of any adverse outcome (p<0.01).

Discussion: This study indicates that patients with lower extremity trauma and compartmental syndrome who have a history of a crush injury, paresis on exam, and particularly patients with a long delay from the onset of symptoms to compartment release are likely to have necrotic muscle at the time of fasciotomy. When necrotic muscle is identified, there is a high risk for complications of treatment, particularly infection, which may lead to disastrous outcomes.

Fasciotomy that exposes necrotic muscle converts a closed compartment into an open one. Immediate skin closure of the fasciotomy incision site might decrease the susceptibility of these patients for developing wound infections. With the successful prophylaxis and treatment of myoglobinuric renal failure (mannitol-alkaline diuresis), repeated debridements to excise all necrotic muscle is no longer an essential part of compartment syndrome treatment. In some cases where the delay prior to release has been extensively long, consideration should be given to not releasing the compartments.