Periprosthetic Tissue Reaction Independent of LTT Result and Implanted Materials in Total Knee Arthroplasty

Abstract Background An allergic reaction may rarely cause a painful and/or stiff total knee arthroplasty (TKA). However, no consensus diagnostic criteria for TKA immune failure exists. Lymphocyte transformation testing (LTT) measures immune sensitivity to various materials, but its role in diagnosing an allergic reaction to a TKA has not been established. This study compares TKA periprosthetic tissues in a) LTT positive v. negative patients, and b) patients with conventional CoCrNi v. hypoallergenic implants. Methods Periprosthetic tissues from 26 revision cases of well-fixed, aseptic, but painful/stiff TKAs were analyzed. Twelve patients LTT positive for nickel (Ni) were matched as a cohort to 6 LTT negative patients. In 4 patients LTT positive for Ni, tissue from first revision of CoCrNi implants was compared to tissue from subsequent revision of hypoallergenic implants. Histology was evaluated using the aseptic lymphocytic vasculitis-associated lesion (ALVAL) score. Results No correlation was found between LTT and any ALVAL score component. Mean total ALVAL score was 3.8 ± 1.5 for LTT negative patients and 3.3 ± 1.2 for LTT positive patients (p=0.44). The mean total ALVAL score at revision of CoCrNi implants was 3.0 ± 1.8 compared to 5.8 ± 0.5 at re-revision of hypoallergenic implants (p=0.053). Conclusions Periprosthetic TKA tissue reactions were indistinguishable between LTT positive and negative patients. LTT does not predict the periprosthetic tissue response. ALVAL scores of hypoallergenic revision implant tissue trended higher than primary CoCrNi implant tissue. A positive LTT may not indicate that a periprosthetic immune reaction is the cause of pain and stiffness post-TKA. Level of Evidence 3, Retrospective Cohort Study