Histomorphometric changes in the synovial membrane of the knee joint in combined use of the Ilizarov non-free bone plasty and the Masquelet technique (experimental study)

Relevance Defects of long bones result in anatomical and functional complex of pathologies in the entire limb. There are few fundamental studies of tissues adjacent to bone defects by using different technologies for management of long bone defects. Purpose To study the structural changes in the synovial membrane of the knee joint by modelling the conditions for tibial defect management using the Ilizarov method of non-free bone plasty in combination with the Masquelet technique. Materials and methods The conditions of post-resection defect of the tibia (from 15 % of the segment length) by lengthening the distal fragment were modeled in ten mongrel dogs. Temporarily, for 30 days, a cement spacer was implanted into the post-resection defect gap. Upon its removal, the intermediate fragment in the lower third of the leg was transported at a rate of 1 mm in 4 steps until complete contact of the bone fragments. Histomorphometric studies of the synovium were carried out at the observation stages at the end of the fixation period (60 days) and after removing the apparatus (30 days). Results Two types of changes were revealed in the synovium: changes of a destructive nature without synovitis (30 % of cases) and with signs of synovitis (70 % of cases, 3 dogs had mild synovitis and 4 dogs had severe synovitis). Changes in the microvessels of the synovial membrane in synovitis indicated impaired microcirculation, high activity of angiogenesis and the development of hypervascularization. Conclusion Experimental management of the tibial bone defect by Ilizarov method in combination with the Masquelet technique revealed signs of synovitis of the knee joint in 70 % of cases using histophorphometry methods.