Five Year Survival and Functional Assessment of the Triathlon Cementless Total Knee System Using the Tritanium Tibial Baseplate

All potential total knee arthroplasty patients from two consultant orthopaedic surgeons at the Golden Jubilee National Hospital (GJNH) will be screened in relation to the inclusion/exclusion criteria. Invitation letters and participant information sheets (PIS) will be sent out to suitable patients who have been referred to the GJNH for total knee replacement (allocated patients) prior to their pre-operative consultation with their surgeon. They will be approached at their consultation visit to seek consent to take part in the study. Patients who have been referred to the GJNH for assessment for a knee replacement (see and treat patients) will be approached only if they are deemed eligible for knee replacement by their consultant, and will be given a copy of the participant information sheet along with the invitation letter. They will be approached for consent to take part in the study at their pre-operative assessment. All patients will be given the opportunity to ask questions about the study before signing the consent form. Consent will be taken by the chief investigator or their delegate, using a signed form.

One hundred patients will be recruited to the study. They will have their surgery performed by one of the participating consultants using the study implant, the Triathlon Tritanium cementless tibial baseplate manufactured by Stryker Corporation.

Participants will receive their standard in-patient care and rehabilitation. Standard hospital care for knee arthroplasty patients is for them to return to the hospital for a post-operative review at 6 weeks and then 1 year and 7 years after operation. Study participants will also be asked to attend the GJNH for two additional research specific appointments at six months and five years. They will be also contacted by post or via telephone to complete a study questionnaire (patient satisfaction) at 3 years post operation.

During the standard care appointments, patients will be reviewed by a member of the arthroplasty team who will collect routine data on the clinical and functional outcomes and implant stability. These data include the Oxford Knee Score (OKS), EURO Quality of life questionnaire (EQ-5D 5L), patient satisfaction and standard radiographic assessment of the implant.

Detailed radiographic analysis will be carried out on radiographs collected as standard and specifically for the study. These will be post-operation at day one (standard), 6 weeks (standard), 6 months (study), 1 year (standard) and the 5 years (study) time points. Study specific radiographic assessment will consist of assessment for radiolucency and osteolysis at specific regions around the tibial and femoral components. Pre-operatively, a standard weight bearing long- leg anterior-posterior (AP) view, lateral view and a skyline view is obtained as per standard care. Post-operatively, standard care consists of a standard weight bearing long-leg AP radiograph at 6 weeks and a short AP and Lateral view at all other reviews.