Chronic pain after total knee replacement: better post-operative prevention and management

Background and rationale Chronic pain after knee replacement is not well understood and places considerable burden on individuals, society and the NHS. With 75,000 patients undergoing total knee replacement in the NHS annually, around 15,000 patients will have chronic pain afterwards. Referral for assessment and care is patchy, and people do not necessary receive or seek care. It is hard to predict pre-operatively who will have chronic pain afterwards. The Programme will address these issues and provide evidence-based recommendations about improvements in care. Aims and objectives The Programme aims to improve outcome for patients with chronic pain three months or more after total knee replacement. The Programme will: Synthesise evidence about the effectiveness of interventions for chronic pain after knee replacement and other surgeries and identify post-surgical predictors of chronic pain after knee replacement. Characterise the long-term trajectory of chronic pain including pain characteristics, disability and resource use up to five years after knee replacement. Finalise an assessment process and a care pathway for patients with chronic pain after knee replacement. Evaluate the clinical and cost-effectiveness of a new care pathway for patients with chronic pain after knee replacement. Identify reasons for non-use of services and provide recommendations. Make recommendations about best-practice care for patients with chronic pain after knee replacement and evaluate implementation of these. Research Plan To meet the objectives we will conduct six work packages (WPs). WP1 (months 1-24): Systematic reviews and analysis of national databases 1.1: A systematic review of effectiveness of interventions for chronic post-surgical pain after diverse types of surgery. 1.2: A systematic review of post-surgical predictors of chronic pain after total knee replacement and overview of peri- and early post-operative interventions. 1.3: Analysis of data from the UK National Joint Registry linked to Hospital Episode Statistics and Patient Reported Outcomes databases to identify any post-operative predictors of chronic pain. WP2 (months 1-48): Long-term follow-up and analysis of databases 2.1: Annual follow-up of an existing cohort of total knee replacement patients (n=1581), including collection of pain, disability and resource use data for five years after surgery. 2.2: Analysis of the Clinical Practice Research Datalink linked to the Hospital Episode Statistics database to characterise the natural history of chronic pain after knee replacement, including resource use. WP3 (months 1-12): Finalisation of an assessment protocol and care pathway Nominal Group Technique with professionals (n=33) and assessment of acceptability with professionals and patients (n=30-40) will finalise an assessment protocol and care pathway. This will underpin WP4. WP4 (months 13-57): Randomised Controlled Trial A fully-powered randomised controlled trial will evaluate a new care pathway for patients with chronic pain after total knee replacement. The trial will be a multi-centre (four centres) pragmatic trial with 12 months follow-up. Pain severity and interference will be co-primary outcomes. We will recruit 380 participants. Two embedded qualitative studies will explore trial processes and acceptability of the intervention. WP5 (months 4-48): Qualitative study A qualitative interview study with people with chronic pain after knee replacement but who make little or no use of formal healthcare services (n=40) will explore reasons for non-use of services. This will provide recommendations for individuals with pain and health professionals. WP6 (months 49-60): Implementation and dissemination 6.1: Using local structures we will implement study findings with 15-20 health professionals. We will explore use of the care pathway (WP4), comparing results in WP6 with tho