Using the Lymphocyte Transformation Test to Diagnose Early Knee Arthroplasty Failures from Metal Hypersensitivity and Multidirectional Instability.

This study aims to determine the etiology of knee arthroplasty failures from multidirectional instability (MDI) and chronic synovial inflammation. The cohort consisted of 304 patients with MDI, which was diagnosed using routine preoperative testing and physical examination. Metal-LTT was performed to diagnose metal hypersensitivity (MH). Five hypoallergenic prostheses were utilized during revision treatment (Groups 1 - 5). The prevalence of MH was 85.52% (260/304). The prosthesis most successful at resolving symptoms of failure was the Titanium and Niobium Nitride-coated constrained hinge with polyethylene augments (94.6% successful resolution of symptoms). Complication rates were excessive across all groups (44.9%), primarily due to loosening (37.7%) and infections (25%). TKA failures from MDI and chronic inflammation may need to be worked up for MH and treated with revision to a coated hypoallergenic prosthesis. MH patients demonstrated unusually high complication rates. (Journal of Surgical Orthopaedic Advances 35(3):166-171, 2026).