Orthopaedic surgeons are currently faced with an overwhelming number of choices surrounding total knee arthroplasty (TKA), not only with the latest technologies and prostheses, but also fundamental decisions on alignment philosophies. From ‘mechanical’ to ‘adjusted mechanical’ to ‘restricted kinematic’ to ‘unrestricted kinematic’ — and how constitutional alignment relates to these — there is potential for ambiguity when thinking about and discussing such concepts. This annotation summarizes the various alignment strategies currently employed in TKA. It provides a clear framework and consistent language that will assist surgeons to compare confidently and contrast the concepts, while also discussing the latest opinions about alignment in TKA. Finally, it provides suggestions for applying consistent nomenclature to future research, especially as we explore the implications of 3D alignment patterns on patient outcomes. Cite this article:
There is a trend towards the use of double-bundle techniques for the reconstruction of the anterior cruciate ligament. This has not been substantiated scientifically. The functional outcome of these techniques is equivalent to that of single-bundle methods. The main advantage of a double-bundle rather than a single-bundle reconstruction should be a better rotational stability, but the validity and accuracy of systems for the measurement of rotational stability have not been confirmed. Despite the enthusiasm of surgeons for the double-bundle technique, reconstruction with a single-bundle should remain the standard method for managing deficiency of the anterior cruciate ligament until strong evidence in favour of the use of the double-bundle method is available.