Impact of bone health on the mechanics of plate fixation for Vancouver B1 periprosthetic femoral fractures.

Autor: Chen X; Center for Orthopaedic Biomechanics, University of Denver, Denver, CO, USA., Myers CA; Center for Orthopaedic Biomechanics, University of Denver, Denver, CO, USA., Clary CW; Center for Orthopaedic Biomechanics, University of Denver, Denver, CO, USA., Varga P; AO Research Institute Davos, Davos, Switzerland., Coombs D; DePuy Synthes, West Chester, PA, USA., DeWall RJ; DePuy Synthes, West Chester, PA, USA., Fritz B; DePuy Synthes, West Chester, PA, USA., Rullkoetter PJ; Center for Orthopaedic Biomechanics, University of Denver, Denver, CO, USA. Electronic address: paul.rullkoetter@du.edu.
Jazyk: angličtina
Zdroj: Clinical biomechanics (Bristol, Avon) [Clin Biomech (Bristol, Avon)] 2022 Dec; Vol. 100, pp. 105801. Date of Electronic Publication: 2022 Oct 23.
DOI: 10.1016/j.clinbiomech.2022.105801
Abstrakt: Background: Condyle-spanning plate-screw constructs have shown potential to lower the risks of femoral refractures after the healing of a primary Vancouver type B1 periprosthetic femoral fracture. Limited information exists to show how osteoporosis (a risk factor for periprosthetic femoral fractures) may affect the plate fixation during activities of daily living.
Methods: Using total hip arthroplasty and plate-implanted finite element models of three osteoporotic femurs, this study simulated physiological loads of three activities of daily living, as well as osteoporosis associated muscle weakening, and compared the calculated stress/strain, load transfer and local stiffness with experimentally validated models of three healthy femurs. Two plating systems and two construct lengths (a diaphyseal construct and a condyle-spanning construct) were modeled.
Findings: Osteoporotic femurs showed higher bone strain (21.9%) and higher peak plate stress (144.3%) as compared with healthy femurs. Compared with shorter diaphyseal constructs, condyle-spanning constructs of two plating systems reduced bone strains in both healthy and osteoporotic femurs (both applying 'the normal' and 'the weakened muscle forces') around the most distal diaphyseal screw and in the distal metaphysis, both locations where secondary fractures are typically reported. The lowered resultant compressive force and the increased local compressive stiffness in the distal diaphysis and metaphysis may be associated with strain reductions via condyle-spanning constructs.
Interpretation: Strain reductions in condyle-spanning constructs agreed with the clinically reported lowered risks of femoral refractures in the distal diaphysis and metaphysis. Multiple condylar screws may mitigate the concentrated strains in the lateral condyle, especially in osteoporotic femurs.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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