Locked plate constructs are not necessarily stiffer than nonlocked constructs: A biomechanical investigation of locked versus nonlocked diaphyseal fixation in a human cadaveric model of nonosteoporotic and osteoporotic distal femoral fractures.

The objective of this study was to compare the biomechanical properties of locked and nonlocked diaphyseal fixation in a model of distal femur fractures using osteoporotic and nonosteoporotic human cadaveric bone. A supracondylar osteotomy was created to mimic a fracture (OTA/AO 33A3) in osteoporotic (n = 4) and nonosteoporotic (n = 5) cadaveric distal femurs. The left and right femurs of each pair were instrumented with a distal femoral locking plate and randomly assigned to have diaphyseal fixation with either locked or nonlocked screws. The construct was cyclically axially loaded, and construct stiffness and load to failure were evaluated. In osteoporotic bone, locked constructs were more stiff than nonlocked constructs (mean 143 vs. 98 N/mm when all time points combined, Contrary to popular belief, locked plating constructs are not necessarily stiffer than nonlocked constructs. In healthy nonosteoporotic bone, locked diaphyseal fixation does not provide a stiffer construct than nonlocked fixation. Bone quality has a profound influence on the stiffness of nonlocked (but not locked) constructs in distal femur fractures.

Informations de copyright

Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Orthopaedic Trauma Association.