The Role of Patient Specific Instrumentation in Arthroplasties of the Knee Arthroplasties

Different concepts have been developed to improve implants positioning in total knee arthroplasty (TKA) such as navigation very popular during the last decade and more recently personalized cutting jigs ("Patient Specific Instruments" PSI). Several studies demonstrated the role of navigation to improve accuracy in TKA particularly concerning coronal alignment. Navigation however has potential drawbacks and demonstrated limitations concerning the rotation and the sagittal positioning of the implants. Recently, PSI has been introduced as a new solution to improve implants positioning. PSI is based on custom-made cutting jigs obtained after a 3-D segmentation of the MRI or CT images of the patient’s knee. Following the segmentation process, the surgeon is performing a surgical planning and can valid his planning to start the jigs production. In this paper, we reported the results of our study evaluating the accuracy of the guides. The radiological and clinical results obtained after TKA with this technique were then compared with the results obtained with the conventional instrumentation. Other applications of PSI such as for unicompartimental arthroplasty or post-traumatic arthritis are also presented in this paper. This technology is interesting and in a near future may help to reduce the need for ancillaries. Surgeon control at every steps of the process from the planning to the surgery remains the key. A cost-efficiency analysis and new thinking process in TKA regarding the need for ancillaries should be evaluated. The actual extra-cost related to the PSI may be largely compensate in a near future if these ancillaries may help to reduce the need for conventional ancillaries.