The use of orthopedic implants is booming, largely a result of an aging population with comorbid conditions such as obesity and inflammatory arthritis. Most implants are metal alloys, containing combinations of common contact allergens (e.g., nickel, cobalt, palladium, gold, and chromium). It has long been suspected that patients with hypersensitivity to 1 or more of these metals would experience a higher incidence of post implant complications, including dermatitis (localized and generalized), pruritus, joint loosening, edema, and pain. Previous studies have singled out patients with a clinical history of metal allergy, concluding that these individuals benefit most from patch testing before a metal-containing implant is placed. In addition, patients with chronic dermatitis, pruritus, joint loosening, or pain may benefit from removal and/or replacement of their prostheses. This is especially true if patch testing confirms hypersensitivity to 1 or more components, but such decisions should be made on a case-by-case basis.