Benefits of Ilizarov automated bone distraction for nerves and articular cartilage in experimental leg lengthening

AIM To determine peculiarities of tissue responses to manual and automated Ilizarov bone distraction in nerves and articular cartilage.METHODS Twenty-nine dogs were divided in two experimental groups: Group M-leg lengthening with manual distraction(1 mm/d in 4 steps), Group A-automated distraction(1 mm/d in 60 steps) and intact group. Animals were euthanized at the end of distraction, at 30 th day of fixation in apparatus and 30 d after the fixator removal. M-responses in gastrocnemius and tibialis anterior muscles were recorded, numerical histology of peronealand tibialis nerves and knee cartilage semi-thin sections, scanning electron microscopy and X-ray electron probe microanalysis were performed.RESULTS Better restoration of M-response amplitudes in leg muscles was noted in A-group. Fibrosis of epineurium with adipocytes loss in peroneal nerve, subperineurial edema and fibrosis of endoneurium in some fascicles of both nerves were noted only in M-group, shares of nerve fibers with atrophic and degenerative changes were bigger in M-group than in A-group. At the end of experiment morphometric parameters of nerve fibers in peroneal nerve were comparable with intact nerve only in A-group. Quantitative parameters of articular cartilage(thickness, volumetric densities of chondrocytes, percentages of isogenic clusters and empty cellular lacunas, contents of sulfur and calcium) were badly changed in M-group and less changed in A-group.CONCLUSION Automated Ilizarov distraction is more safe method of orthopedic leg lengthening than manual distraction in points of nervous fibers survival and articular cartilage arthrotic changes.

Assessment of palmar subcutaneous tissue vascularization in patients with Dupuytren's contracture

AIM To investigate the structural and functional characte-ristics of palmar hypodermal tissue vascularization in Dupuytren's contracture patients of different agegroups.METHODS Eighty-seven Dupuytren's contracture patients underwent partial fasciectomy. Twenty-two of them were less than 55 years old(Y-group, n = 22); the others were 55 and older(O-group, n = 65). In surgically excised representative tissue samples, a histomorphometric analysis of the perforating arteries of the palmar aponeurosis and stereologic analysis of hypodermis vascularity were performed. The method of laser flowmetry estimated the microcirculation of the skin of the palm.RESULTS Frequency of cases with rapid development of contracture(less than 5 years) was 13.6% in the Y-group and 40% in the O-group, P < 0.05. The external and luminal diameters of perforating arteries in palmar fascia were decreased more severely in Y. The thickness of intima increased three times compared with healthy control, and the intima/media relation also increased, especially in O. Increased numerical and volumetric micro-vessel densities in hypodermis, percentage of large vessels(more than 12 μm in diameter), and percentage of vessels with signs of periadventitial inflammatory infiltration were noted in Y. The percentage of vessels with adventitial fibrosis was greater in O than in Y. Base capillary flow in Y was increased compared to healthy control subjects and to O, and peak capillary flow was increased in comparison with control.CONCLUSION Compared to the O-group, Y-group patients exhibited more severe constrictive remodeling of palmar fascia perforating arteries supplying hypodermis but more expressed compensatory changes of its capillarization.