Evaluation of limb compartment with suspected increased interstitial pressure. A noninvasive method for determining quantitative hardness.

Six compartments in four dogs and three compartments in three anatomic specimen limbs were injected with plasma, and the intracompartmental interstitial pressure and hardness of the compartments were measured. Six patients suspected of having compartment syndromes were also studied. Of the compartments evaluated in the dog and anatomic specimen limbs, the average correlation coefficient between measurements with the two methods was 0.95 (range, 0.87 to 0.99). In six patients suspected of having compartment syndromes, the ratios of quantitative hardness of the injured to uninjured limbs closely matched the intracompartmental interstitial pressure measurement ratios (correlation coefficient, 0.95). All correlation coefficients were significant (F test, p < 0.05). There was a close correlation between the direct measurement of intracompartmental interstitial pressure with the wick catheter and quantitative hardness in compartment syndrome models in dog and anatomic specimen limbs, and in patients suspected of having compartment syndromes. The determination of surface hardness of limb compartments, which appears accurate and reproducible, offers the advantages of being noninvasive and well suited for longer-term assessments of intracompartmental interstitial pressure.