Comparing the clinical and cost-effectiveness of robotic assisted total hip replacement to conventional total hip replacement in the management of adults with osteoarthritis of the hip

INTERVENTION: Conventional total hip replacement and robotic‐assisted total hip replacement, using the Mako Robotic system (Stryker, USA) Randomisation will be completed using a secure online web system and will be performed on the day of surgery. Both treatment arms will receive additional scans in the form of a pre‐operative CT scan and up to three pre‐operative X‐Rays, as well as a post‐operative CT scan 3 months after surgery. The participants who are allocated to the robotic assisted surgery group will undergo surgery using the Stryker Mako robotic arm system, using Stryker implant constructs. This can either be hybrid or cemented construct. In order to use the Mako surgical robot, three marker pins are required to be placed around the hip to enable the robot system to orientate the anatomy of the hip joint. The result of this is three additional incisions where the markers pins have been placed. The participants who are allocated to the conventional total hip replacement will be delivered using conventional instruments and the same Stryker implants, using either a hybrid or cemented construct. The implant construct will be confirmed prior to randomisation to ensure the same implants would be used in both intervention and control groups. In order to keep the allocation blinded, the conventional hip replacement group will receive three small sham incisions where the marker pins would have been placed. All other care, including the choice of anaesthetic and post‐operative analgesia will be according to usual care. The rehabilitation programme will be standardised between groups, but this is expected to be consistent with usual practice across all sites. CONDITION: Adults with osteoarthritis of the hip joint for which, in the opinion of the treating clinician, warrants a total hip replacement. ; Musculoskeletal Diseases ; Hip osteoarthritis PRIMARY OUTCOME: Joint awareness measured using the Forgotten Joint Score Hip‐12 (FJS‐12) at 12 months post‐surgery INCLUSION CRITERIA: 1. Osteoarthritis of the hip with pain, disability and radiological changes that, in the opinion of the treating clinician, warrants a total hip replacement 2. Conservative therapy has been unsuccessful, as judged by the treating clinician SECONDARY OUTCOME: ; Peri‐operative outcomes:; 1. Mean pain intensity, using an 11‐point numerical rating scale for "pain right now" and "pain since yesterday" on the morning of each of the first three days following surgery and at baseline; 2. Estimated blood loss calculated using Brecher's formula, based on pre‐ and post‐operative Haematocrit measurements from routinely collected clinical blood measurements, and volume, if any, of blood transfused; 3. Opioid use to the end of day three measured using patient records; 4. Hours from surgery to hospital discharge measured using patient records; ; Outcomes collected at baseline, three and six months and one, two, five and ten years post‐operation:; 1. Overall hip pain and function measured using FJS‐12; 2. Overall hip pain and function measured using Oxford Hip Score; 3. Health utility measured using EQ‐5D‐5L (also collected at 6 weeks); 4. Satisfaction with total hip replacement, measured using a five‐point Likert scale; 5. Resource use using patient questionnaires; 6. Re‐operations; ; Process and Fidelity measures:; 1. Time from skin incision to final dressing measured using patient records; 2. Alignment measures at three months on a focused low‐dose CT: rotation of femoral and acetabular components, leg length and offset compared to pre‐operative plan; ; Safety outcomes:; 1. Adverse events relating to the operation, the anaesthetic or rehabilitation measured using patient records;