Cobalt chromium sublaminar wires for spinal deformity surgery

Area of Science:

• Spinal surgery
• Biomedical engineering
• Orthopedic surgery

Background:

• Sublaminar wires are crucial anchors in spinal deformity surgery.
• Stainless steel wires (Luque wires) allow retightening for deformity correction.
• Titanium wires are unsuitable for sublaminar use due to their mechanical properties.

Purpose of the Study:

• To evaluate the mechanical properties of cobalt chromium alloy wires.
• To assess the clinical efficacy of cobalt chromium alloy wires as sublaminar implants for spinal deformity correction.

Main Methods:

• Comparative tensile testing of cobalt chromium alloy and stainless steel wires.
• Retrospective chart review of 22 posterior spinal fusions for idiopathic scoliosis using cobalt chromium alloy wires.

Main Results:

• Cobalt chromium alloy wires exhibited 66% higher yield and 60% higher ultimate tensile loads than steel wires.
• Significant correction of thoracic (67%) and lumbar (68%) curves in idiopathic scoliosis patients.
• No instances of instrumentation failure, neurological complications, or infections were reported.

Conclusions:

• Cobalt chromium alloy wires offer enhanced tensile strength and titanium compatibility over steel wires.
• Solid cobalt chromium alloy wires are effective as sublaminar implants in titanium spinal instrumentation.
• Excellent clinical outcomes were achieved using cobalt chromium alloy wires in spinal deformity correction.