Impact of nickel allergy on total knee arthroplasty outcomes

Implants containing nickel, which are typically stainless steel and cobalt-chromium prostheses, have been previously linked to implant-induced reactions in patients with metal sensitivities. These reactions have manifested as pain, implant loosening, reduced implant survival rates, and delayed wound and bone healing. The purpose of this study was to examine the outcomes following primary total knee arthroplasty (TKA) with nickel-containing implants in patients with a known nickel allergy. This retrospective case control study included 22 patients with a documented nickel allergy who underwent a primary TKA with a nickel containing implant at a single tertiary academic center between January 2004 and October 2024. They were matched 1:2 to a control cohort of patients without a nickel allergy. Primary outcomes included wound healing complications, surgical site infections, post-operative pain, implant failure, and range of motion. Complications in the nickel allergy cohort included one patient with minimal incisional erythema, one superficial infection treated with oral antibiotics, one patient with increased wound drainage, and one manipulation under anesthesia. There were no incidences of prosthetic joint infection, revision surgery, aseptic loosening, implant failure, or wound dehiscence in the nickel allergy cohort, and no overall differences in complication rates compared to the control group. Post-operative pain levels were categorized as well-controlled (45.5 % nickel allergy versus 70.5 % control), moderately controlled (45.5 % versus 22.7 %), and poorly controlled (9.0 % versus 6.8 %) (p = 0.130). In this study, we found no significant difference in patient outcomes following TKA when comparing patients with a nickel allergy to those without.