Patient Specific Instrumentation in TKR

This is a randomised control trial to assess the benefits of using patient specific instrumentation in total knee replacement surgery. Patient specific instrumentation is an individualised system for total knee replacement surgery. The system has been marketed and is already in use in some centres. The type of implant used remains the same but the sizing of the components, and alignment of the implant is expected to improve. This study assesses any improvement in implant alignment in using the patient specific instrumentation, any improved intra-operative outcomes and any long term clinical outcome improvements for patients.