A comparison of knee replacement surgery and knee joint distraction for treating osteoarthritis of the knee

INTERVENTION: This is a pragmatic, non‐blinded, multi‐centre randomised controlled trial designed to establish the clinical and cost‐effectiveness of KJD in an NHS setting. 344 participants will be recruited from secondary care orthopaedic outpatient clinics following referral by their GP for symptoms of knee osteoarthritis. Potential participants will be identified by the local trial team and approached in clinic by their treating surgeon and given a participant information sheet. They will be given as long as possible to consider the trial before consenting to take part, ideally a minimum of 24 hours but this will not be imposed if a participant wants to consent sooner, is fully informed and has had sufficient time to consider the trial. Those who choose not to consent will have their non‐identifiable information, including age, gender and reason for non‐consent, added to the non‐registration log. Participants who wish to take part will attend a trial visit up to 6 weeks before their planned date of surgery. At this visit informed consent will be taken by the PI or delegated member of the trial team and the participant will complete a questionnaire pack and have their knee function assessed for research purposes. This will be done with a timed up and go test (which involves standing from a sitting position, walking three metres and then returning to a sitting position) and range of motion assessment (involved the leg being extended as far as possible and the angle measured, and then flexing the leg as far as possible and having the angle measured again). They will be randomised to an arm of the trial and will be informed of their treatment. They will also have an x‐ray of their knee with the leg bent, which will be used in both groups to assess the CONDITION: Osteoarthritis ; Musculoskeletal Diseases ; Osteoarthritis PRIMARY OUTCOME: Knee Injury & Osteoarthritis Outcomes Score (KOOS) pain component measured at 12 months following surgery INCLUSION CRITERIA: 1. Age > = 18 years and < = 65 years at the time of signing the Informed Consent form 2. Symptoms (pain and/or reduced function) severe enough to warrant knee replacement, in the opinion of the treating clinician 3. Pre‐operative leg alignment not requiring correction, in the opinion of the treating clinician 4. Intact collateral knee ligaments, in the opinion of the treating clinician 5. Fixed flexion deformity < = 10 degrees of the involved knee SECONDARY OUTCOME: ; 1. Patient reported outcomes and Quality of life outcomes (KOOS, Pain VAS, Oxford Knee Score) at baseline and 3, 6, 12, and 24 months after surgery; 2. Objective assessment of knee function (Active range of movement and a timed up and go test) at baseline and 3, 12, and 24 months post‐surgery; 3. Incidence of complications (intra‐operative, post‐operative and any unplanned surgical interventions on the affected knee) at 3, 12, and 24 months post‐surgery; 4. Joint space width (assessed quantitatively from standardised radiographs) at 3, 12, and 24 months post‐surgery; 5. Cost‐effectiveness (EQ‐5D‐3L and Health Resource Utilisation and Private Costs Questionnaire) at 3, 6, 12, and 24 months post‐surgery; 6. Implementation processes and intervention fidelity (assessed quantitatively using a surgical CRF and assessments of radiographs, and assessed qualitatively) in the first 12 months of recruitment; 7. Qualitative evaluation of participant experiences measured using interviews after discharge from hospital and 3 months later;