I perform the entire operation myself with a surgical assistant general practitioner who assists me. It takes 60-80 minutes (depending on the unique challenges of your TKR).

All of those in theatre who are in close proximity to your knee (this includes myself, the assistant and the scrub sister) wear a so-called “exhaust suit”. This ensures that no organism from our bodies can shed into the operating field.

The thickness of the new surface on the femur is 9mm. As a healthy joint surface is 3mm thick, it effectively means we need to remove 6mm of bone to create the 9mm space for the new surface. The tibia joint surface is replaced with polyethylene (a type of plastic) that is supported by a metal tray. The patella (knee cap) joint surface is also resurfaced with a polyethylene button if deemed necessary. Each component is cemented in place with bone cement forming a very strong bond between the prosthesis and the bone.

During the operation the anterior cruciate ligament (ACL) is always removed, but the design of the prosthesis compensates for the loss thereof. The posterior cruciate ligament (PCL) is usually retained. If it is necessary to remove the PCL then the design of the prosthesis compensates for the absence of the PCL. Your knee will be stable after the TKR.

You may have encountered the term “custom knee replacement”. At present in commercially available prostheses all that is being customized is the so-called “cutting blocks”. Cutting blocks are a standard part of any knee replacement system. In a conventional system (as I use) these cutting blocks are positioned by referencing from certain anatomical landmarks. The resection of the joint surfaces is guided by the slots in the cutting block. To customize the cutting blocks a CT scan and/or MRI scan of your knee must be done beforehand which adds to the total cost of the TKR. These are then used to manufacture cutting blocks that fit onto the bone and joint surfaces. The same standard prosthesis is then inserted after the bone cuts are made. Customization of knee prostheses itself is not available as yet. I have been involved in research in the development of customized cutting blocks. I did not find that it produced any significant advantage to justify the increased cost and radiation exposure to the patient. As technology is advancing it is foreseeable that in the future a true unique customized knee replacement can be rapidly manufactured for each patient.

I also have experience with computer-assisted surgery and will use this in selected cases to guide me with the positioning of the cutting blocks. A computer system uses infra-red sensors to guide the surgeon in the placement of the cutting blocks. In severe deformities or where the standard referencing techniques cannot be used this becomes essential. I use the Brainlab system currently.

Robotically-assisted surgery has become possible. These “robots” guide the surgeon in shaping the bones to fit the prosthesis based on pre-operative CT or MRI. I have investigated the systems currently available and to my mind currently they offer no benefit and increase the operating time (which increases the risk of infection). This concurs with the scientific literature evidence. If it becomes possible to manufacture a true customized prosthesis then the robotically-assisted surgery principals may become advantageous.

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