Comparison of the mechanical performance of three types of external fixators: linear, circular and hybrid

Effects of Construct Stiffness on Healing of Fractures Stabilized with Locking Plates

“…On the basis of actuator displacement, construct stiffness of femoral locking plates has been reported to range from 63 N/mm 21 to 159 N/mm 22 . This stiffness is comparable with that of external fixators (50 to 400 N/mm [23][24][25] ), which are known to promote fracture-healing by callus formation. However, investigators who have measured the actual fracture-site motion at the far cortex (opposite the plate) have reported a more than tenfold higher stiffness (833 N/mm 26 to 2100 N/mm 27 ) for locked femoral bridge-plate constructs.…”

“…The 19% of the femoral fractures that became nonunions exhibited less callus formation, while stable implant alignment was maintained. This suggests that callus inhibition, rather a: Conventional (CP) and locked-plate (LP) constructs were comparably stiff and were approximately one order of magnitude stiffer than external fixators (ExFix) [23][24][25] . b: Axial loading caused plate bending and asymmetric gap closure, whereby interfragmentary motion (IFM) at the near cortex was minimal.…”

Design, analysis and testing of an external fracture fixation device manufactured from composite materials

“…In the case of a fracture of the tibia, the fixator is loaded by a compressive axial force in the direction of the tibia [15]. In [3], the static load capacity of three types of external fixators was analyzed, and the maximal axial force was determined to be 889 N. In [5], the maximal axial force during cyclic loading of five unilateral fixators and 10 000 cycles was evaluated to be 220 N. In [6], the fixators were tested with a static force of 700 N, which was considered to be the average gravitational force of a patient (which is directly proportional to the patient's weight). In [20], a multiplanar (circular) fixator for the tibia was measured in vivo during treatment.…”

Outcome of bilateral circular fixators in complex lower limb fractures

“…[5][6][7] These fixators are attractive for the management of complex injuries due to their minimal invasive application and inherent threedimensional stability that affords early functional rehabilitation. [8][9][10][11] The modularity of circular fixators further allows for frame designs specific for each patient and fracture configuration as well as the ability to address post-traumatic bone loss and limb length discrepancies.…”