Background The CORKA study was developed in response to a commissioned call by the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme for research into a functional home based rehabilitation programme for patients who may be at risk of poor outcome after knee arthroplasty.

Design The CORKA trial is a prospective individually randomised controlled trial with blinded outcome assessment at baseline, 6 and 12 months. The study will also include a qualitative and a health economic analysis. Participants will be randomised to one of two arms, 'home-based rehabilitation' or 'Usual Care'. Those in the usual care arm will receive a minimum of 1 and a maximum of 6 sessions of physiotherapy as delivered locally, e.g. class, one to one, etc. Those in the intervention arm will receive 7 sessions of a functional rehabilitation programme over a 12 week timescale. The intervention will be delivered using physiotherapists and physiotherapy assistants in the participants' home. Participants will be followed up at 6 months and 12 months

Inclusion Criteria:

Participant is willing and able to give informed consent for participation in the study Male or Female, aged 55 years or above Primary unilateral KR as a scheduled procedure Deemed by study screening tool developed to be at risk of poor outcome Happy to allow physiotherapy teams to attend their home to deliver the Community based rehabilitation programme if randomised to the intervention arm.

Exclusion Criteria:

Any absolute contraindications to exercise Severe cardiovascular or pulmonary disease (New York Heart Association III-IV) Severe dementia, assessed using the hospital dementia screening tool Rheumatoid arthritis Further lower limb arthroplasty surgery planned within 12 months. Serious perioperative complications