Rigidity of unilateral external fixators—A biomechanical study

Abstract

Introduction: External fixation is the primary choice of temporary fracture stabilisation for

Management of Osteomyelitis-Induced Massive Tibial Bone Defect by Monolateral External Fixator Combined with Antibiotics-Impregnated Calcium Sulphate: A Retrospective Study

“…Therefore, we preferred to use monolateral external fixation because its impact on the soft tissue is limited compared with conventional internal fixation. Moreover, the stable and flexible fixation provided by monolateral external fixation not only achieve greater mechanical stability and callus formation [25], but also reconstruct the limb alignment and reduce the risk of pin and screw loosing [26]. Although circular external fixation is also commonly used for managing bone defect, we focused on monolateral external fixation because it is much easier for surgeons to learn and can be rapidly applied with minimal equipment, and its relatively lower price and less cumbersome burden can be better accepted by patients [27].…”

The Effect of External Fixator Configurations on the Dynamic Compression Load: An Experimental and Numerical Study

“…The aim of our study was to investigate the viability of the Orthofix Limb Reconstruction System (LRS) ® in the dynamic compression mode. Although it is well accepted that the Orthofix ProCallus fixator was designed to incorporate controlled axial compression at the fracture site [1,25], the LRS external fixator it is also often used in the dynamic compression mode. Actually, the LRS fixator is especially indicated for bone correction through the techniques of bone transport, compression-distraction, partial acute shortening and transport, multifocal surgery, and bifocal lengthening [5,13,15,16].…”

“…Therefore, these results show that there are at least two parameters that should be included on the external fixation comparisons purpose, the average bending span of Schanz screws and the weight of patient, i.e., the maximum load that is self-imposed. In fact, these two parameters should be accounted for, because the early weight bearing and bony union capabilities that are achieved with one external fixator are not only related to the geometric characteristics of the device (components of the fixator) or even with the psychological effect of those characteristics on patients, but also to their static or dynamic characteristics at several loads and fixator configurations (the number and spread of the pins along the bone segments, the distance between the main body of fixator and the bone) [1,25,34,35]. Nonetheless, the dynamic compression of the callus, which was induced by releasing one of the clamps from the fixator rail and the patient weight bearing, seems to be more sensitive to variations of the distance between axes of the fixator and the nylon bar than to the fixator configuration, see Table 4.…”

“…External fixation is one method of treatment for fractures, especially for patients who are at high risk for systematic complications [1]. They are frequently applied for combat and disaster related casualties [2][3][4], but also to manage bone defects [5].…”

Computer-aided surgical planner for a new bone deformity correction device using axis-angle representation

“…Thus, as in previous literature [13,[32][33][34][35], we simulated the mechanical tests with the fixator in straight configuration with all joints zeroed. Since unilateral fixators are known to deform linearly with increasing load [13], stiffness is evaluated using a single loading force value of 100 N [13,36,37,38] at each loading point. Our fixator design has a longer moment arm and thus a greater bending moment on the pins in the inferior bone fragment.…”