Differential scanning calorimetric examination of the human skeletal muscle in a compartment syndrome of the lower extremities

The compartment syndrome—conditions of elevated intramuscular pressure—is one of the most serious complications of the injuries of the lower extremities. Early diagnosis is important, as delayed treatment leads to significant complications. The diagnosis of compartment syndrome is most commonly made by clinical examination and direct measurement of the intra-compartmental pressure. Our hypothesis was that in different stages of compartment syndrome there is a clear pathological abnormality in the tissue elements of the affected muscles, which is responsible for seriousness of the disease, and could be monitored besides the classical histological methods by differential scanning calorimetry. The thermal denaturation of different parts of human samples was monitored by a SETARAM Micro DSC-II calorimeter. All the experiments were performed between 0 and 100 °C. The heating rate was 0.3 K/min. DSC scans clearly demonstrated significant differences between the different types and conditions of samples (control: T_m = 55.5; 59.9 °C and ΔH_cal = 0.52 J/g, Gr. I.: T_m = 58.1; 62.2 °C and ΔH_cal = 0.28 J/g, Gr. II.: T_m = 57.45; 61.5 °C and ΔH_cal = 0.24 J/g, Volkmann’s ischemic contracture T_m = 57.75; 61.8; 65.8 °C and ΔH_cal = 0.74 J/g). These observations could be explained with the structural alterations caused by the biochemical processes. The heat capacity change between native and denatured states of muscle samples was significant, indicating significant water loosing during denaturation, but independent from the structural alterations.