The Journal of hand surgery
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Comparative Study
Biomechanical comparison of contemporary clavicle fixation devices.
Because recent studies have shown that malunited or nonunited clavicle fractures treated nonsurgically have poor outcomes, early fixation of certain clavicle shaft fractures using contemporary implants has become more common. Little is known about the physiologic loading of these implants. This study was designed to observe the biomechanical behavior and strength of implants used for fixation of the clavicle shaft. ⋯ Both locking and nonlocking constructs appear to provide similar rigid fixation under the tested mechanical conditions. The intramedullary pin can provide high resistance to failure loads in situations when rigidity and rotational stiffness are not required. Intramedullary pin fixation appears to be inadequate where rotational stiffness is required.
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To investigate the effects of motion following repair with a modified Kessler core suture and 5 different epitendinous suture designs on the gliding resistance, breaking strength, 2-mm gap force, and stiffness of flexor digitorum profundus tendons in a human in vitro model. ⋯ The cross-stitch, IHM, and running-locking epitendinous sutures had the best combination of higher strength and lower gliding resistance in this study. Although these findings suggest a potential for these suture types to be preferred as epitendinous sutures, these repairs should first be investigated in vivo to address their effect on tendon healing and adhesion formation.
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Comparative Study
Comparison between locking and non-locking plates for fixation of metacarpal fractures in an animal model.
The use of locking plates increases the primary load to failure, thereby reducing the rate of implant-related failure. The good clinical and biomechanical results of locking plates in long bones might be applicable to treatment of metacarpal fractures. The purpose of this study was to determine strength and stiffness of locking plates in a metacarpal fracture model with mono- and bicortical screw fixation in comparison to non-locking plate mono- and bicortical screw fixation, with both types of plates placed at the dorsal side of the bone. ⋯ The new generation of locking plates can be used to achieve a higher stability for fixation of metacarpal fractures. Monocortical, stable fixation can minimize flexor tendon interference and probably reduce bone and soft tissue trauma.