A Comparison of Patients Receiving a Total Knee Replacement With Robotic Assistance or With Conventional Instrumentation

A Prospective, Multi-Centre, Randomised Controlled Study to Evaluate the Clinical, Health Economic and Patient Reported Outcomes Following Total Knee Arthroplasty With a Robotic Assisted Technique

A total knee replacement is the removal of parts of the knee joint, that have become damaged due to osteoarthritis, and replacing these with artificial implants. The placement of these artificial implants and how they are aligned with each other is important because they can impact overall knee function and the long-term survival of the implant. It is reported that up to 34% of all patients following total knee replacement (TKR) have poor outcomes functionally.

There have been significant developments in knee replacement surgery over recent years. In particular, the introduction of robotic surgical systems, such as the NAVIO and CORI systems (Smith+Nephew Plc). The NAVIO and CORI Surgical Systems are hand-held devices which can support the surgeon with the knee replacement procedure, the systems are image-free and do not require the patient to undergo any scans (such as CT scans). During the surgery, the surgeon uses the NAVIO/CORI hand-held device to map specific landmarks within the knee joint and determines the desired alignment using associated computer software. The tools to remove the bone and place the implants are controlled by the surgeon with the guidance of the NAVIO/CORI software.

Comparisons of robotic systems to conventional instruments have demonstrated that robotic platforms produce fewer positioning errors in total knee replacement. This can result in more precise knee alignment and better outcomes following surgery. With both the NAVIO and CORI Surgical Systems there is a reduction in radiation exposure due to them being image-free.

At present, there is some evidence available for the long-term outcomes of total knee replacement implanted using robotic assistance (i.e. 2-10 years) however this study is designed to look at the early outcomes following TKR. There is no literature to date to show that robotic-assisted TKR is superior to conventional methods, within the early post-operative period (up to 12 months).

This study is designed to show that the NAVIO/CORI surgical systems are better than conventional methods for TKR. The hypothesis is that they will be cost-effective, will reduce the time a patient spends in hospital following their surgery, will improve patient satisfaction during the early recovery period and will improve the patient's early post-operative mobility and function.

Inclusion Criteria:

• Subject must provide written informed consent
• Subject must be aged 18 years or older at the time of surgery
• Subject is listed for a primary total knee replacement (TKR)
• The indication for the TKR is primary arthritis of the knee joint involving one or more compartments
• The subject agrees to give informed consent to participate in the study including consenting to any incidental findings being reported to their general practioner (GP)
• The subject agrees to consent to and to follow the study visit schedule
• The subject plans to be available throughout the 1-year post-operative period
• Routine radiographic assessment is possible

Exclusion Criteria:

• The subject undergoes a robotic-assisted TKR on the index joint as a revision for a previously failed surgery, or there is a need for complex implants, or any other implant than a standard total knee arthroplasty (TKA)
• Subject is listed for a simultaneous bilateral TKR
• Subject does not understand written or spoken English used in the informed consent form
• Subject has active infection or sepsis
• Subject is to have a Smith+Nephew Journey II BCS implanted by non-robotic conventional instrumentation
• Subject is not available throughout the 1-year post-operative period
• Subject, in the opinion of the investigator, has a neuromuscular disorder that prohibits control of the index joint
• Subject is undergoing the surgery as a private patient
• Patients who, in the opinion of the clinical staff, do not have capacity to give consent
• Women who are pregnant
• Subjects with a medical or physical condition that, in the opinion of the investigator, would preclude safe subject participation in the study