Affiliation:
1. Institute of Traumatology and Orthopedics, National Academy of Medical Sciences of Ukraine
2. Republican Scientific and Practical Center of Traumatology and Orthopedics
3. Institute for Problems of Strength by G.S. Pisarenko. National Academy of Sciences of Ukraine
Abstract
Bone geometry, density, and thickness of the cortical layer of the femoral neck (FN) contribute to the mechanical strength in osteosythesis of femoral neck fractures (FNF) in young adults. The available techniques for fracture fixation of the FN are reviewed with respect to the biomechanical stability.A biomechanical study of the osteosynthesis stability of the FNF with three cannulated screws was carried out using synthetic models of the proximal part of the femoral bone (FB). The experimental models were divided into 4 groups. Each group related to the configuration of screws in the FN. The vertical and horizontal FNF stability was assessed using two series of load. In series I, models were loaded with forces in the longitudinal axis to the FB and in series II, forces acted in the perpendicular direction to the FB axis. The loading forces were evaluated when the displacement of 2 mm fragments was achieved. The highest stability strengths were obtained in group I in the both series ‒ 1898 N with a vertical load and 1046 N with a horizontal load. Further, in decreasing order, the results of stability were obtained in groups II, III and IV.In this study, it was found that the consideration of the position of screws according to architectonics of the FN is crucial for fragment stability. The triangular position of screws with three points of contact with the compact bone ensures the maximum stability of the construct in osteosynthesis of the FN fractures, which is comparable to the normal walking load conditions.We hypothesize that osteosynthesis of FN fractures with three screws in a triangular manner could provide a better stability when inserted into the dense tissues of the proximal FB with relation to bone architectonics. To ensure a maximum stability, each screw should have three points of contact with the compact bone – the lateral cortical wall of the subtrochanteric region of the FB, the inner wall of the FN, and the compact part of the FB head. New triangular configuration of screws’ placement could have a better neutralization of share forces in FN fractures.
Publisher
Publishing House Belorusskaya Nauka
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