Clamping of fine Kirschner wires in external fixators.

In Ilizarov circular (ring) external fixators, fine Kirschner wires are used to fix the bone to the fixator. Clamping of the wires to the rings with different bolt torques has been studied. However, the relation between the bolt torque and the fixation load applied to the wire was not investigated.

Effect of asymmetrical configuration of pins in the TSF external fixator used for tibial lengthening in a pediatric population.

Background: The Taylor Spatial Frame (TSF) is a relatively new circular external fixator linked with a computer program used in limb reconstruction surgery. It is routinely used in our unit (Royal Manchester Children's Hospital) for pediatric tibial lengthening.

Methods: The case notes and radiographs of 17 children who underwent 18 tibial lengthenings were reviewed.

The in vivo mechanical properties of muscular bulk tissue.

The aim of this study was to characterize the bulk modulus properties of the upper arm under relaxed and controlled contraction which is defined as 25% of the maximum voluntary contraction. A new testing machine was designed to generate a continually increasing load on the upper arm and measure the load over time. The machine consists of a device which is effectively a cuff that applies controllable pressure on a 47 mm wide band of the upper arm.

Analytical modelling of kirschner wires in Ilizarov circular external fixators using a tensile model.

Mechanical characteristics of orthopaedic fixators, such as the stiffness and stability, directly influence the mechanobiological environment in which the bone is healed. In circular external fixators, the transfixing Kirschner wires are the major contributors to the biomechanics involved. A comprehensive understanding of the mechanical behaviour of the wires is therefore the key to biomechanical analysis of the Ilizarov fixator.

Analytical modelling of Kirschner wires in Ilizarov circular external fixator as pretensioned slender beams.

Transfixing thin Kirschner wires (K-wires) are the key components of the Ilizarov fixator regarding its axial stiffness, which affects the mechanobiological environment in which bone is healed. Mechanically speaking, K-wires are slender beams that are axially tensioned, then fixed and transversely loaded. The existing solutions to such a problem either do not accommodate any axial loading prior to transverse loading, or do not account for the change in the axial load (reaction) due to transverse loading.

A mechanical model representation of the in vivo creep behaviour of muscular bulk tissue.

In vivo mechanical properties of bulk tissue have not yet been explored sufficiently. One of the major problems researchers face is the lack of agreement between the constitutive models and the standardised methodologies for experimental studies. The object of this study was to obtain bulk modulus of the upper arm under relaxed and controlled contraction that was 25% of the maximum voluntary contraction.