Orthopaedic implant cobaltism from spinal instrumentation

Cobaltism is a well-defined common complication of cobalt-chromium arthroprosthetic implants but has not been previously reported from cobalt-chromium spinal components. Orthopaedic implant cobaltism (OIC) is a spectrum illness, and its severity relates to the magnitude of cobalturia and cobaltaemia and duration of implantation of the wearing or corroding cobalt-chromium component. This case report demonstrates a patient with OIC from failed scoliosis instrumentation using cobalt-chromium rods that both corroded at multiple interfaces with titanium alloy pedicle screws and fractured at the lumbosacral pseudoarthrosis. This patient's symptoms included tremors, cognitive decline, insomnia and visual changes. The diagnosis of OIC was confirmed when peri-implant fluid returned a cobalt greater than 4800 mcg/L and peri-implant tissue showed obvious signs of metallosis. Following the revision surgery without cobalt-containing implants, the patient's symptoms improved and the blood-cobalt has returned to near-normal values. This is the first reported case of reversible OIC from spinal implants.