Orthopaedic implant cobaltism from spinal instrumentation

Area of Science:

• Orthopaedic Surgery
• Toxicology
• Biomaterials Science

Background:

• Cobaltism is a known complication of cobalt-chromium (CoCr) implants, typically hip and knee arthroprostheses.
• Spinal implants made of CoCr alloys have not been previously associated with cobaltism.
• Orthopaedic implant cobaltism (OIC) severity correlates with cobalt levels in blood and urine and implant wear/corrosion.

Purpose of the Study:

• To report the first case of OIC resulting from failed spinal instrumentation.
• To highlight the potential for CoCr spinal components to cause systemic cobalt toxicity.
• To demonstrate the reversibility of OIC following revision surgery.

Main Methods:

• Case report of a patient with scoliosis instrumentation failure.
• Analysis of peri-implant fluid and tissue for cobalt levels and metallosis.
• Clinical assessment of neurological and visual symptoms.
• Revision surgery to remove CoCr implants and replace them with non-cobalt containing components.

Main Results:

• The patient presented with tremors, cognitive decline, insomnia, and visual changes.
• High cobalt levels (>4800 mcg/L) in peri-implant fluid and evidence of metallosis confirmed OIC.
• Post-revision surgery, the patient's symptoms resolved, and blood-cobalt normalized.

Conclusions:

• Cobalt-chromium spinal implants can cause OIC, a spectrum illness with potentially severe neurological and visual symptoms.
• This case demonstrates that OIC secondary to spinal implants is reversible upon removal of the offending components.
• This is the first reported instance of OIC originating from spinal implants.