EXPERIMENTAL RESEARCH ON FIXATION PROPERTIES OF EXTERNAL OSTEOSYNTHESIS DIFFERENT BIOMECHANICAL OPTIONS IN TREATING THE TIBIAL PLATEAU SPLIT FRACTUREAUTHORS

BACKGROUND: In surgical practice there are various biomechanical options of bone and cartilage fragments fixation, such as resting on bone transplant by means of subchondral wires reinforcement, or applying osteosynthesis based both on fork-like fixators and special plates, with the bolts installed just under the joint surface fragments. The authors take advantage of subchondral strained reinforcement method.

AIM: To compare fixation properties of osteosynthesis different biomechanical options in treating split intra-articular fractures, basing on the models made of porcine tibia.

MATERIALS AND METHODS: An unblinded single-center indented study was conducted. The research object included two types of models characterised by the similar fractures, bone defects and non-strained wires reinforcement. Model A got bone defects filled with transplant, while Model B — did not. There were also analysed the results of osteosynthesis (Models A and B): 1) osteosynthesis by means of external plate with the joint surface resting on the bone transplant, option A-I; 2) osteosynthesis by means of the external plate with the joint surface resting on both the external plate fixation elements and the bone transplant, option A-II; 3) osteosynthesis by means of the external plate with joint surface splits fixed with the help of П-shaped strained wires, option B-III; 4) osteosynthesis by means of the joint surface fixation with the help of strained subchondral wires in the  module external fixing device, option B-IV. The given research was conducted on porcine tibia proximal metaepiphysis, basing on the method of static indentation.

RESULTS: The authors observed options B-III and B-IV demonstrate more effective fixation properties of strained subchondral reinforcement in comparison with non-strained wires reinforcement (Model A). Among four biomechanical options, the options with strained subchondral reinforcement, B-III and B-IV, demonstrated the best strength properties. Option A-II analysis showed worse resistance properties against the vertical load, compared to those in options B-III and B-IV. Option A-I proved to have the poorest results of all.

CONCLUSIONS: The authors assumed that the option with strained subchondral reinforcement with the help of П-shaped wires (B-III) and the one using the module external fixing device (B-IV) without additional support in the form of the bone autotransplant, demonstrated the best efficiency.