[Dynamics of acoustic properties of skin integument and hydroxyproline content during surgical treatment of congenital limb malformation].

The aim of the work was to examine mechanical and acoustic properties of the skin and collagen metabolism in patients with congenital and developmental malformation (CDM) of extremities. Acoustic tests were performed in 39 patients with forearm CDM and in 30 with leg CDM aged 4-18 years using an ASA-4 apparatus (Russia and Yugoslavia). Mean radial and ulnar lengthening was 6.4 +/- 1.0 (5.5-8) cm, tibial and fibular lengthening 5.0 +/- 1.2 (3-8) cm, and femoral lengthening 6-12 cm. Longitudinalvelocity of sound 1 and 2 months after distraction was 42.3% and 62.9% respectively higher than the preoperative value (p < 0.05). A similar increase (36.8 and 58.4% respectively) was recorded with the ASA-4 sensor in the transverse position. Acoustic inhomogeneity in the thigh skin also increased during distraction. Maximum free to protein-bound hydroxyproline ratio in blood was measured in the end of distraction (0.58 +/- 0.04) and in the beginning of fixation (0.6 +/- 0.01). Its subsequent decrease reflected structural and metabolic changes related to proliferative and biosynthetic processes in the skin, fibrillogenesis, and altered homogeneity patterns.