Total knee arthroplasty (TKA) revisions occur in up to 10% of patients within ten years, yet identifying the cause of persistent postoperative pain remains challenging. This retrospective review evaluates whether local anesthetic injections (“Lidocaine Challenge”) can help identify patients who may benefit from revision TKA. Among 273 screened individuals, 21 met criteria for inclusion. All patients reported some degree of pain relief from anesthetic injection, suggesting high sensitivity for detecting an intra-articular pain generator. However, imaging–intraoperative concordance was modest (48%), with radiology frequently equivocal in identifying aseptic loosening, the most common revision etiology in the cohort. Demographic data reflected a homogeneous population, and variability in documentation limited consistency of pain-relief characterization. Despite limitations, findings indicate that diagnostic injections may help “rule in” candidates for revision but perform poorly in ruling out alternative causes of TKA failure. Ongoing data collection and standardized imaging–injection protocols may improve accuracy and guide future diagnostic algorithms.