[Changes in the knee joint synovial membrane and articular cartilage during shin lengthening by autodistractor at increased daily rate].

Light microscopy and computerized morpho- and stereometry were used to examine the changes in the knee joint articular cartilage and synovial membrane studied during experimental canine shin lengthening by 15% of initial length by autodistraction at increased rate - 3 mm per day with switching on the automatic device 120 times. By the end of distraction period (10 days) the destructive changes in articular cartilage were more marked in the superficial and deep zones, synovitis of moderate and mild degree was observed accompanied by the destructive changes in the blood vessels and nerves of the subsynovial layer. Regeneration of articular cartilage was incomplete, and regressive neurovascular changes persisted in synovial membrane 30 days after the device removal. Comparison of these results with the previous data obtained using the distraction rate of 3 mm applied 180 times, leads to the conclusion, significant for functional prognosis, of the worsening the parameters of structural cartilage recovery in case of distraction pitch increase from 0.017 mm to 0.025 mm.