An axial fat saturated contrast enhanced T1-weighted magnetic resonance image of his left thigh (fig.) was obtained on postoperative day 3. There is heterogeneous muscle enhancement involving anterior, medial, and posterior compartments (predominantly adductor magnus and vastus lateralis). Central areas of lack of enhancement indicate muscle necrosis (arrows), an imaging appearance consistent with rhabdomyolysis.1
Extreme tourniquet-induced ischemia causes metabolic (anaerobic), cellular, and microvascular changes (endothelial injury), leading to muscle breakdown (rhabdomyolysis) and compartment syndrome.2
Alhough there are no tourniquet guidelines specifically pertaining to muscle injury, inflation pressure ≤100 mmHg above systolic blood pressure, inflation time ≤120 min, deflation time ≥30 min, and reinflation time ≤90 min are recommended to prevent ischemic nerve injury.3
Tourniquet pressure (300 mmHg) and duration (150 min inflation, 30 min deflation, and 100 min reinflation) in our patient exceeded guidelines. It is likely that ischemia was exaggerated by tourniquet size-mismatch due to obesity. Our case calls for strict adherence to tourniquet guidelines, prompt diagnosis, and timely intervention to prevent tourniquet related morbidity.