Pain Centre Versus Arthritis Christmas Research Seminar Meeting 2021
Presentation Abstracts
Michelle Hall - Development of an optimal physiotherapy intervention for arthrofibrosis following TKR
Background: Arthrofibrosis (knee stiffness due to scar tissue) after total knee replacement (TKR) is the 2nd most common reason for hospital re-admission following TKR. It severely restricts knee movement, causes pain and interferes with everyday activities. There are no guidelines as to how best to treat this complication. Most people will have additional physiotherapy but it is not clear exactly what this should involve.
People who don’t improve will usually undergo manipulation under anaesthetic (MUA), where the knee is forcefully flexed to release the stiff joint. Longer term these people are more likely to have poorer outcomes and need a repeat knee replacement.
This research aims to develop an optimal physiotherapy intervention for people with arthrofibrosis (stiffness) after total knee replacement (TKR).
Methods: We will develop the intervention by conducting:
- A review of the evidence to identify what components should be included
- Interviews with patients with arthrofibrosis to understand the impact it has on their life and what outcomes are important to them.
- Interviews with healthcare professionals (HCPs) who treat patients with arthrofibrosis to understand their experiences and opinions of available treatment.
- A survey with a larger group of HCPs and patients to reach a consensus on what the optimal intervention should include.
- A workshop with patients, HCPs and health-care commissioners to finalise the intervention.
At the end of this study, we will have an intervention that has been agreed by patients and HCPs that can then be tested to see if it can work in practice, and if a larger trial can be conducted.
Patient and Public Involvement (PPI): Patients who have had knee arthrofibrosis after TKR have told us this is an important topic to research. They experienced variations in their care and felt that improving treatment for arthrofibrosis would benefit patients and the NHS, particularly if MUA could be prevented. PPI will be actively involved throughout the project to ensure the study remains patient-focussed.
Dissemination: We will share the findings of this study with patients, healthcare professionals and healthcare commissioners locally through meetings and magazine/ internet articles and more widely by presenting at conferences, publishing in academic journals and on social media.
This study has been funded by the NIHR Research for Patient Benefit starting in Mar 2022 and completing in Sept 2023. Research team: Dr Michelle Hall (PI), Prof Cath Sackley (Co-PI), Dr Fiona Moffatt, Dr Ben Smith, Dr Joanne Socks and Dr Katie Sheehan (Kings College London).
Vasileios Georgopoulos - Can Self-reported Outcome Measures in Populations with Knee Pain be Harmonised?
Background: Osteoarthritis and knee pain following knee trauma are highly prevalent. Several patient-reported outcome measures (PROMs) address knee pain severity. Their harmonisation would facilitate data pooling between studies.
Methods: We undertook a systematic literature review (SLR) of Patient Acceptable Symptom State scores (PASS) and performed individual patient data (IPD) analysis of score distributions from concurrently completed PROM pairs. Questionnaires were standardised to 0 to 100 (worst) scales. PROM scores of individuals were compared using data from four distinct studies.
Results: SLR identified 18 studies reporting PASS in people with knee pain. Pooled standardised PASS was 27 (95%CI: 21 to 35; n=6339). PASS was statistically similar for each standardised PROM PASS scores were lowest in ligament rupture (12, 95%CI: 11 to 13), but similar between knee osteoarthritis (31, 95%CI: 26 to 36) and meniscal tear (27, 95%CI: 20 to 35). In individual data, standardised PROMs demonstrated similar mean scores and prevalence of acceptable pain, but scores within individuals diverged between PROMs.
Conclusion: Different standardised PROMs give similar PASS thresholds in group data. PASS thresholds may be affected more by patient and treatment characteristics than between PROMs. However, different PROMs give divergent scores within individuals, reflecting different experiences of pain.
Harrison Lewis - Knee pain and multimorbidity – what counts? The association of central mechanisms of knee pain with multimorbidity:
Discussed a study which explored a potential association between multimorbidity and central mechanisms of knee pain. Cross-sectional analysis of self-report data from 736 participants who reported knee as their most bothersome joint pain or aching feeling over the previous month. Two indirect measures capable of suggesting central mechanisms involvement in knee pain, pain intensity (0-10 numerical rating scale) and CAP-Knee score (0-16 scale), were utilized as dependent variables. Comorbidities were assigned either "painful comorbidity" or "non-painful comorbidity" status based on IASP classification of chronic pain criteria. Multivariable linear regression models were employed to explore associations of multimorbidity measures with pain intensity and CAP-Knee score. Comorbidity count had positive associations with pain intensity and CAP-Knee score. When included in the same regression models, painful comorbidity count and non-painful comorbidity count each had positive associations with pain intensity and CAP-Knee score. In summary, the employed multimorbidity measures were each positively associated with indirect measures of central mechanisms of knee pain, suggesting a potential positive association between multimorbidity and central mechanisms of knee pain. Both painful and non-painful comorbidities may play a role in knee pain pathophysiology.
Prof V Chapman: “Opioids & OA Pain: Mechanistic studies of opioid-induced exacerbation of chronic pain responses”
Opioids, like morphine, are very good at treating short-term pain, but side-effects outweigh benefits in long-term pain conditions like osteoarthritis (OA). Prior use of opioids can even worsen the effects of future injury, leading to more pain and worse outcomes following joint-replacement surgery in OA patients, for example. Despite this, many people are still being prescribed opioids for OA pain.
We aim to understand why prior opioid use worsens future pain and to identify the biological mechanisms, using a rat model of OA.
OA is more prevalent and severe in women, and opioid prescription rates are also higher than for men. However, most animal studies of OA use male rats only. To address this, we used female rats in our studies. We show that repeated morphine treatment loses the ability to block pain in female rats, and also leads to worse pain when the knee joint is later injured, mimicking what is seen in people with OA. In our future work, we will find out why this happens, using microscopes and recording techniques to pinpoint underlying changes in key pain signalling regions, identifying which signals cause these changes, and whether blocking these signals can prevent or reduce OA pain.