Hypersensitivity reactions to metals in spine surgery

Hypersensitivity to orthopedic devices is a rare condition with an underestimated incidence due to the lack of diagnostic guideline and ambiguous clinical manifestations. Although hypersensitivity to metal is common, a few cases of hypersensitivity reactions have been reported after spinal instrumentation. Spinal fusion and stabilization require a wide range of devices such as screws, wires, bands, and artificial disk replacement devices. Spinal instrumented surgeries are different from total joint arthroplasty in several aspects such as degree and pattern of motion, loading environment, and adjacent tissues with distinct characteristics. The interval for hypersensitivity reactions to occur after spinal metallic implantation is usually weeks to months. The present review covers the topic of hypersensitivity reactions that have been reported after spinal surgeries with the focus on cutaneous presentations.