A comparison of standard versus robotic total knee replacement

INTERVENTION: RACER is a multi‐centre, patient‐assessor blinded, pragmatic randomised controlled trial to assess the clinical and cost‐effectiveness of robotic total knee replacement (TKR) compared to conventional TKR in the UK NHS health setting. This is the equivalent of a phase III study according to the IDEAL classification. Participants will be randomly allocated (1:1) to the two treatment groups via a central computer‐based randomisation system provided by the Warwick Clinical Trials Unit (WCTU, independent of the study team). This will be performed by minimisation with a random factor, with a 70% weighting towards balance across the whole study, stratified for age, hospital site, surgeon, BMI =35 at baseline, and primary compartment involved (medial, lateral or patellofemoral, as determined by the treating clinician). A full summary of the intervention and control procedure will be available in an accompanying RACER surgical manual, prepared following a surgical consensus meeting to which all surgical co‐investigators were invited. The intervention treatment will be total knee replacement (TKR) performed using the MAKO robotic system and Triathlon (Stryker, USA) implants, the only implant compatible with the MAKO robot. All implants will be cemented (96% of TKRs recorded on the National Joint Registry (NJR) are cemented). No uncemented implants will be used. Participants in both groups will have a CT scan according to the needs of the MAKO system (an imaging manual will be prepared, the CT also includes some imaging at hip and ankle) and a three‐dimensional plan will be made for the surgeon, isolating the effect of the robot from surgical planning. This is done at least 2 weeks prior to surge CONDITION: Osteoarthritis of the knee with pain, disability and changes on standard of care clinical images (x‐rays or MRI according to normal clinical practice) that, in the opinion of the treating clinician, warrants total knee replacement (TKR) ; Musculoskeletal Diseases ; Gonarthrosis [arthrosis of knee] PRIMARY OUTCOME: Patient awareness of their joint measured using Forgotten Joint Score (FJS) questionnaire at baseline, 3, 6, 12 months, 2, 5 and 10 years INCLUSION CRITERIA: 1. Osteoarthritis of the knee with pain, disability and changes on standard of care clinical images (x‐rays or MRI according to normal clinical practice) that, in the opinion of the treating clinician, warrants total knee replacement (TKR) 2. Conservative therapy has been unsuccessful, as judged by the treating clinician SECONDARY OUTCOME: ; In‐hospital outcomes:; 1. Mean pain intensity measured using an 11‐point numerical rating scale (NRS) questionnaire for ‘pain right now’ and ‘pain since yesterday’ on the morning of each of the first 3 days after surgery; 2. In‐patient estimated blood loss calculated using Brecher’s formula, based on pre‐ and post‐operative Haematocrit measurements obtained from reviewing patients notes post‐discharge; 3. In‐patient opioid use obtained from patient’s medical notes (total morphine equivalent, using conversion methods established in I‐WOTCH, NIHR HTA 14/224/04) to the end of day 3; 4. Hours from surgery to hospital discharge obtained from patient’s medical notes post‐discharge; ; Postoperative outcomes:; 1. Outcomes of knee osteoarthritis surgery measured using the Oxford Knee Score (OKS) questionnaire at baseline, 3, 6, 12 months, 2, 5 and 10 years; 2. Levels of activity and (social) participation measured using the Oxford Knee Score Activity and Participation Questionnaire (OKS – APQ) at baseline, 3, 6, 12 months, 2, 5 and 10 years; 3. Generic health status measured using the EQ5D‐5L questionnaire at baseline, 6 weeks, 3, 6, 12 months, 2, 5 and 10 years; 4. Pain over the last week measured using the three‐item PROMIS Pain Intensity Scale questionnaire at baseline, 3, 6, 12 months, 2, 5 and 10 years; 5. Satisfaction with the knee replacement measured using a five‐point Likert scale questionnaire at 3, 6, 12 months, 2, 5 and 10 years; 6. Activity limitations, symptoms, emotions, and overall quality of life related to the painful condition assessed using a Participant Global Impression of Change questionnaire – a seven‐point Likert scale – at 3, 6, 12 months, 2, 5 and 10 years; 7. Number of re‐operations measured using a single question ‐ Have you had a re‐operation or revision of your knee replacement – at 3, 6, 12 months, 2, 5 and 10 years; 8. Number of episodes and type of NHS services the patient has used measured using resource use questionnaire at 3, 6, 12 months, 2, 5 and 10 years;