Prostheses option in revision total knee arthroplasty, from the bench to the bedside: (1) basic science and principles

The number of primary and revision total knee arthroplasties (rTKAs) continues to increase annually. To date, most of the literature has focused on the surgical technique and outcome of revision prostheses. Thanks to the contributions of surgeons, engineers, and researchers, the design of prostheses has reached a prominent milestone. However, very limited discussion regarding the design, rationale and constitution of prostheses has been documented at present. An electronic search of four online databases (Embase, MEDLINE, PubMed, and Google Scholar) was conducted to identify eligible resources. Forty-four review articles were acquired by searching the terms ‘prosthesis selection’, ‘prosthesis option’, and ‘prosthesis determination’ in rTKA. Sixty-eight research articles investigating the factors affecting prosthesis options in rTKA were screened and integrated with the authors’ perspective to reach a final recommendation. This article first discusses the pathological, individual, and other factors affecting prosthesis options in rTKA and further illustrates the classification, geometry, biomechanics, and constitution of the revision system from the authors’ perspective. An evidence-based recommendation in the form of a matching algorithm was formulated. This review offers special value for decision-making regarding prosthesis options in rTKA. Particularly, it presents specific recommendations regarding unclear practical issues, such as the optimal level of constraint, individualized design, length, and fixation of extension stem, as well as the pros and cons of modularity.