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Type IV Cell-Mediated Hypersensitivity Reaction Caused by Titanium Implant Following Medial Displacement Calcaneal Osteotomy and First Metatarsal-Cuneiform Arthrodesis
INTRODUCTION AND OBJECTIVES: Due to its inert character and desired biocompatibility, titanium (Ti) implants have been universally accepted as safer alternatives to the previous conventional orthopedic hardware implants. However, a recent emergence of Type IV hypersensitivity reactions to Ti have displayed symptoms that include eczema, contact dermatitis, prolonged fever, sterile osteomyelitis, and impaired fracture and wound healing. The following case presents a patient with postoperative incision dehiscence and devascularization of cortical surfaces in contact with Ti hardware after undergoing a medial displacement calcaneal osteotomy and a first metatarsal-cuneiform arthrodesis. To our knowledge, this is the only reported case of an allergic reaction to a Ti implant in the foot or ankle in the United States.
METHODS: Diagnostic tools to confirm a Ti hypersensitivity reaction include a patch test and lymphocyte transformation test. The lymphocyte transformation test can be utilized if a false negative patch test is suspected. Potential treatment options include immunosuppressants, removal or substitution of the Ti hardware, and external fixation.
RESULTS: In this case, the patient's allergy to Ti was confirmed with a patch test, and all hardware was subsequently removed with no other complications.
CONCLUSIONS: A hypersensitivity reaction to Ti should remain a differential diagnosis for a patient presenting with symptoms such as prolonged fever, contact dermatitis, sterile osteomyelitis, and impaired wound healing. Preoperative diagnostic tools, such as the patch test, can be utilized to prevent allergic reactions from occurring. Treatments for Ti hypersensitivity should be tailored to fit the patient's needs and can include removal or substitution of the Ti hardware, external fixation, and immunosuppressants.
