Cyclic long-term loading of a bilateral fixed-angle plate in comparison with tension band wiring with K-wires or cannulated screws in transverse patella fractures

Abstract

The bilateral fixed-angle plate and cannulated lag screws with anterior tension wiring preserved a constantly reduced fracture gap over 10,000 tensile cycles in contrast to modified anterior tension wiring, which exhibited significant widening of the gap after initial loading. Results of in vitro testing indicate that bilateral fixed-angle plates provide sustainable fixation stability offering a promising new option in the treatment for transverse patella fractures.

Biomechanical comparison of pin and tension-band wire fixation with a prototype locking plate fixation in a transverse canine patellar fracture model

“…The design of this study was similar to that described in a number of biomechanical studies of patellar fracture fixation techniques in human cadavers (3,9,11,13,23,32,33). In the majority of human experimental biomechanical studies evaluating patellar fracture repair methods, a failure criterion of ≥2 mm fracture gap increase was chosen (23,24,32). This criterion has been used in numerous human studies based on the belief that a gap of 2-3 mm increases the risk of development of postoperative osteoarthritis and a poor outcome (3,34,35).…”

“…Biomechanical stability of a pin/TBW fixation in human cadavers has been shown to depend on the amount of tensioning, on how well the cerclage wire can be secured directly against the bone surface, and on the size of the implants (3,23,24,32). This characteristic of an initial tightening of the anterior tension wire with a subsequent distraction of the fracture gap under axial tension has previously been reported in several cadaveric biomechanical analyses (5,11,23,24,36). With full knee extension, a tension band wire system does not function adequately and may even lead to further fracture distraction (3,11,36).…”

“…Additionally, there is a shared opinion among many surgeons (unpublished) that this technique is not successful in the dog, despite the success reported in humans. A number of problems and complications with pin/TBW fixation in humans have nevertheless been reported (21)(22)(23)(24)(25). As a result, alternative fixation with plates has been evaluated experimentally and clinically, and they appear to provide improved stability (5,(23)(24)(25)(26).…”

Inframammary fold reconstruction – a biomechanical analysis

“…This value is often used in orthopedic surgery as dehiscence should not exceed 2 mm without impairing, for example, osteosynthesis stability. 8,11,14 As one would expect, 2-mm displacement loads also favor anchor implementation by a factor of approximately 10. This again was to be expected because a 2-mm displacement load is a calculated value directly proportional to stiffness.…”

Frakturversorgung der Patella

“…Wild et al haben als Erste den Einsatz einer winkelstabilen Plattenosteosynthese an der Patella beschrieben [41][42][43][44][45]. Diese polyaxiale Platte wird bilateral an der medialen und lateralen Patellakante angelegt.…”