Issue: 2016, Vol. 21, No. 3
THE PECULIARITIES OF ELASTIC DEFORMATION ZONES DISTRIBUTION IN THE AREA OF FEMUR PROXIMAL SEGMENT AND SURGICAL PREVENTION OF LOW ENERGETIC FRACTURES IN EXPERIMENT
- Keywords
- femur proximal segment, prophylactic reinforcement, implants, mathematic simulation
- Abstarct
- Objective - to study experimentally the peculiarities of elastic zones distribution under loads in the area of femur proximal segment which resulted in fractures; to estimate femur proximal segment durability in prophylactic reinforcement with using of original implant constructions. Material and methods. Mathematic simulation was performed with using the model of femur proximal segment. The parameters of cortical and sponge bone layers were estimated by laser scanning technique. Original patent implant constructions in 8 various variants were virtually introduced in the bone. Stand tests of 4 variants of reinforcement (pin, screw-corkscrew, three pins, screw-corkscrew + pin) were carried out using 27 samples of cadaver bones and artificial femur bones until complete system destruction. Results. By mathematic simulation it was established that under load in cranial and caudal parts of femur neck the tension was increased and it stipulated fractures in critical points. In this case the line of fracture was directed from periphery to inside where the maximal tension was appeared. The results of stand tests testified to the fact that under vertical load at whirlbone along femur shaft axis the durability of reinforced neck was increased to 22,7- 72,6% and under horizontal one - to 27-93% in dependence on introduced implants combination. Conclusions. Implants in femur proximal segment should be located nearer to the cortical layer and far from the central femur shaft axis; in this case the tension of external deformation load was partially redistributed into reinforcement element. All studied reinforcement variants increased the durability of bone-implant system both under vertical and under horizontal load; the best effect was demonstrated while using the systems with the most contact square (screw-corkscrew).
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