Subjects will then be followed for one year post surgery for infection, as defined by Appendix 1, at intervals of 2 weeks, 6 weeks, 3 months, and one year from the date of surgery. During these visits patients will receive standard post operative care which includes infection screening. If an infection is clinically suspected with symptoms such as warmth and erythema over the joint, reduced mobility of the joint, and increasing pain at the joint, then infection data will be collected which will consist of a Erythrocyte Sedimentation Rate, C-Reactive Protein levels and a synovial fluid sample will be taken for white blood cell count and bacterial culture.