Prosthetic reconstruction of the arthritic knee: considerations for limb alignment, geometry and soft tissue reconstruction

The function of the replaced knee joint is influenced by many factors, including implant design, material properties, fixation and surgical techniques. General surgical approaches have changed in tandem with design developments, but within them various technical elements of knee surgery are strongly adhered to (conservation) whilst others are vigorously debated (variation). The merits of debate are beyond dispute, but it is problematic to surgical patients that variations in surgical technology can beget variations in the performance of knee implants. One can make a strong argument for standardisation of techniques to keep abreast of advances in the fundamental knowledge of the anatomy and kinematics of the human knee. This paper considers an approach to restore normal knee function and kinematics through resurfacing of bone parts, developed from an appreciation of the derangements induced by disease processes on limb alignment and soft tissue restraints. The location and orientation of the implanted parts, optimally sized, is based on the functional axes of the knee, an approach which uses the bony attachment points of the essential ligamentous structures as the principle guides.