[Mechanical impedance: a new noninvasive method for measuring tissue pressure in anterior compartment syndrome. II. Results of clinical measurements in patients with tibial trauma].

In acute compartmental syndrome, it is difficult to decide on the basis of clinical criteria alone whether fasciotomy is indicated or not. Reliable and objective parameters are required before a treatment schedule can be devised. We tested mechanical impedance as a parameter for the pressure inside the tissue. The technique and associated apparatus for measuring mechanical impedance of the skin overlying the anterolateral compartment of the lower leg are described in detail. We performed the non-invasive measurement in 25 patients with leg injuries. There were 2 patients with acute compartmental syndrome and 5 with imminent compartmental syndrome. In normal legs, the mechanical impedance was between 2 and 6.5 kg/s, with an average of 3.83 kg/s. After the impedance is increased to 10 kg/s or higher, there is acute or imminent compartmental syndrome. Once the compartment has been decompressed by unilateral parafibular fasciotomy, the mechanical impedance decreases to normal values. Clinically relevant results were obtained by this method and they correlated well with the other clinical findings.