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.
The number of knee replacements taking place in the UK is continuing to rise; over 84,000 knee replacements took place in the UK during 2011 which is an increase of > 3% from 2010. Part of the reason for this increase is that knee replacements are increasingly being performed for patients who are older and with other health conditions in addition to their osteoarthritis. It is known that age is not a barrier to having a good outcome from knee replacement, with reports of successful outcome in patients aged over 90 years. However, it is also known that around 15% of patients do not report a good outcome from their knee replacement and have continuing pain and mobility problems which limit or prevent them from being able to do the activities they would like to be able to do after their knee replacement. It is thought that factors such as the amount of pain and limitation of balance and muscle strength may contribute to poorer outcome. Currently it is normal practice for patients to receive a short course (between 4-6 sessions) of post-operative physiotherapy after their surgery. This is usually delivered in a physiotherapy out-patient clinic setting. Previous research has shown that this short course of physiotherapy is not needed by all patients to help them recover after their operation. Given the increasing number of knee replacements, the relative limited physiotherapy resource available and the increasing age and frailty of patients receiving joint replacements, it is important that we concentrate our rehabilitation resources on those patients who most need help to avoid poor outcome.
We plan to run a study in two stages. In the first we aim to identify patients at risk of poor outcome using 2 methods:
1. We will systematically review the literature and use expert opinion from an online survey of rehabilitation clinicians to identify factors associated with poor outcome after knee arthroplasty.
2. We will examine data from a large study cohort of patients from the COAST study - a NIHR funded study to assess outcome following lower limb joint arthroplasty.
We will analyse all the information obtained both before people have their joint replacements and the information about their outcomes and 12 months after joint replacement. Using these sources of information we will develop a screening tool that will help us to identify those patients who are most at risk of poor outcome i.e. those patients who are most likely to have continuing pain and mobility problems and who are limited or unable to return to doing the activities they would like to be able to after their joint replacement. Secondly, we will develop and test a multidisciplinary rehabilitation exercise intervention designed to improve both the function of at risk patients, but also their participation in activities. We aim to deliver this intervention in patients own homes in order to make it accessible to those without good social support or those with physical or mental frailty.