[Somatometric and impedance measurements of the lower extremities in orthopedics]

The objective was to demonstrate the contribution of somatometry and vascular impedance measurement to the evaluation of somatic status and nutrition, particularly the state and function of the vascular system of lower extremities, in patients with arthropathy of the weight-bearing joints.

Impedance plethysmography and impedance phlebography appeared to be the best methods for assessment of vascular hemodynamics; pulse oxymetry, carried out on toes, was most convenient for measurement of haemoglobin saturation with oxygen (HbO2). The state of vessels was determined according to the CEAP classification. Somatometric methods included measurement of the circumference and volume of calves, and assessment of body height, at the anthropometric wall, and weight to calculate the body mass index (BMI).

The lower extremities affected by arthropathy were compared with the unaffected ones by means of CEAP classes and related to the body mass values of patients. It was found that only 15 men and 26 women had normal body mass. The rest of the patients were overweight or obese (grade I and II). Only 14 men and 17 women were free of signs of vascular insufficiency, the others were classified in the range of C1 to C4 of the CEAP system. Impedance measurements showed lower mean values for affected extremities and for overweight or obese patients. A comparison of the parameters of arterial and venous hemodynamics between the affected and unaffected extremity by means of the paried t-test gave statistically significant results in patients with higher BMI grades and higher classes of vascular insufficiency, regardless of their gender. The results of HbO2 saturation measurement showed normal values in both men and women.

To meet the requirements of orthopaedists, the Biophysical Laboratory carried out non-invasive measurements of somatometric parameters and vascular impedance values in patients with arthropathy of the weight-bearing joints of lower extremities. The results were similar to those of a large Framingham cohort study on knee arthropathy and obesity. The data derived from measurement of basic impedance, specific impedance and pulse-related impedance changes show that it is important to record and evaluate skin lesions and oedema because they are related to vascular disease. The finding that an increasing volume the calf was indirectly related to a decreasing basic impedance of calf vessels was confirmed by our results. This information is important for the evaluation of impedance measurement results in order to make diagnosis in individual patients.

Our results showed that, in the group investigated, (i) there was a high proportion of overweight and obese patients; (ii) assessment by CEAP classification revealed higher grades of vascular insufficiency; (iii) affected extremities showed a significant decrease in arterial and venous haemodynamics, particularly in women with higher-grade vascular insufficiency; (iv) there was no difference in HbO2 saturation measured on toes.