A biomechanical evaluation of magnetic resonance imaging-compatible wire in cervical spine fixation.
In a bovine cervical spine model, the ultimate and fatigue strengths as well as relative magnetic resonance imaging artifact produced by titanium, cobalt chrome, and stainless-steel wires in various gauges were assessed. Single-cycle and fatigue strength of wire constructs were measured. Although larger wires generally had greater static strength, fatigue strength was mixed. Sixteen-gauge titanium, and all stainless-steel models (22-gauge braided, 18-gauge, and Songer cable) withstood 10,000 cycles without failure, whereas all other constructs rarely could withstand a similar 10,000 cycles. Magnetic resonance imaging was performed on calf cervical spines instrumented with the various materials. Titanium exhibited the least artifact, stainless-steel showed the greatest artifact, and cobalt chrome an intermediate amount. Although titanium wire produces the least amount of magnetic resonance imaging artifact, it remains a poor choice for implant fixation because its notch sensitivity reduces its fatigue resistance compared with stainless steel, which remains the more dependable choice.
Scuderi
G J
GJ
Department of Orthopaedics and Rehabilitation, University of Miami School of Medicine, Florida.
Greenberg
S S
SS
Cohen
D S
DS
Latta
L L
LL
Eismont
F J
FJ
D000818:Animals; D016477:Artifacts; D001696:Biomechanical Phenomena; D001864:Bone Wires; D002417:Cattle; D002574:Cervical Vertebrae / Q000601:surgery*; D002858:Chromium Alloys; D008279:Magnetic Resonance Imaging; D013123:Spinal Fusion / Q000295:instrumentation*; D013193:Stainless Steel; D014025:Titanium
D002858:Chromium Alloys; D013193:Stainless Steel; D014025:Titanium