Lymphocyte Transformation Testing (LTT) in Cases of Pain Following Total Knee Arthroplasty: Little Relationship to Histopathologic Findings and Revision Outcomes.

Background: The utilization of lymphocyte transformation testing (LTT) has increased for diagnosing metal sensitivity associated with total knee arthroplasty (TKA), but its validity for the diagnosis of TKA failure due to an immune reaction has not been established. In this study, we sought to characterize the relationship of a positive LTT result to histopathologic findings and clinical and functional outcomes.

Methods: This was a retrospective study of 27 well-fixed, aseptic, primary TKA cases in which the patient had persistent pain and/or stiffness and underwent revision due to a suspected metal allergy to nickel, as determined on the basis of positive LTT.