Zondervan RL, et al. - Through a retrospective review conducted for patients that underwent a revision total knee arthroplasty after metal sensitivity testing, the researchers determined the improvement in outcomes in patients who presented with a painful total knee arthroplasty with a positive metal sensitivity following review to a hypoallergenic implant. Significant improvement in a range of motion after revision arthroplasty in both non-reactive and reactive patients was noted. No variation in the frequency of pain experienced, between groups and no correlation between the pain level at the time of the revision and the maximum metal lymphocyte transformation test (LTT) was observed. Overall, satisfactory reports post revision total knee arthroplasty were exhibited with no difference between positive and negative sensitivity groups. Hence, improved pain scores, walking function, and range of motion following revision to a hypoallergenic component in patients who presented with a painful knee arthroplasty and positive metal LTT were recorded. In order to provide effective and timely diagnosis and management, this study presented a treatment algorithm for painful knee replacement patients.