Two-Stage Revision Total Knee Arthroplasty for Suspected Periprosthetic Joint Infection and Metal and Bone Cement Hypersensitivity.

Hypersensitivity to implant components and periprosthetic joint infection should be detected before all revision arthroplasty, as misdiagnosis can lead to replacement loosening and the need for further revision procedures. We describe the case of a 69-year-old woman presenting a history of a painful cemented total knee replacement. Postoperative investigations showed loosening of X-ray components, suspected periprosthetic joint infection, and patch test hypersensitivity to nickel sulfate and methyl methacrylate. Two months later, a more specific patch test indicated non-allergy to the solid scratch of one bone cement. The patient underwent a two-stage revision with prosthesis removal and the temporary application of a specific cement spacer followed by the successful reimplantation of a cemented revision prosthesis. All candidates for the revision arthroplasty procedure must be investigated for hypersensitivity to metal and bone cement in order to avoid complications related to prosthesis intolerance and the need for further revision surgery; in the presence of hypersensitivity to bone cement and periprosthetic joint infection with a two-stage revision indication, the patient must be submitted to further patch tests with scratches of solid bone cement.