The articular cartilage was studied under conditions of experimental osteoarthrosis with tunnelization of the subchondral zone and injection of autologous bone marrow into the channels. Histomorphological studies showed that tunnelization of the subchondral zone with injection of autologous bone marrow into the channels stimulated reparative regeneration of the chondral tissue by inhibiting destruction of the joints.

No abstract

AIMTo determine peculiarities of tissue responses to manual and automated Ilizarov bone distraction in nerves and articular cartilage.METHODSTwenty-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 30th 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 peroneal and tibialis nerves and knee cartilage semi-thin sections, scanning electron microscopy and X-ray electron probe microanalysis were performed.RESULTSBetter 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.CONCLUSIONAutomated Ilizarov distraction is more safe method of orthopedic leg lengthening than manual distraction in points of nervous fibers survival and articular cartilage arthrotic changes.

The role of subchondral bone in the restoration of the articular cartilage was determined in experiments on mongrel dogs subjected to gonarthrosis modeling followed by subchondral zone tunneling and introduction of bone marrow suspension into the canal. Light microscopy, computer histomorphometry, and electron probe microanalysis showed that stimulation of functional activity of chondrocytes was achieved via correction of homeostasis of the cartilage and subchondral bone and improvement of tissue trophic. Restoration of the microarchitecture of the subchondral bone and improving its vascularization after tunneling with the introduction of bone marrow suspension into the drill holes enhances chondrocyte metabolism and recovers their functionality.