Medical engineering & physics
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This paper analyses the suitability of a system comprising a Dynamic Compression Plate (DCP) and Screw Locking Elements (SLEs) to allow sufficient interfragmentary motion to promote secondary bone healing in osteoporotic fractures. Four fixation systems were mounted on bone-simulating reinforced epoxy bars filled with solid rigid polyurethane foam. Group 1, used for comparison purposes, represents a system comprised of a Locking Compression Plate (LCP) and eight locking screws. ⋯ For group 1 (the LCP construct) the mean stiffness at 10,000 cycles was 3144±446 N mm(-1), 3.25 times higher than that of groups 2 and 3 (there being significant differences: p=0.00002), and 1.6 times higher than that of the DCP+8SLEs construct (1944±408 N mm(-1), there being significant differences: p=0.007). It is concluded that using the DCP+2SLEs construct sufficient interfragmentary motion is ensured to promote secondary bone healing. However, if too many SLEs are used the result may be, as with the LCP, an excessively rigid system for callus formation.