Pain sensitization associated with nonresponse after physiotherapy in people with knee osteoarthritis

Abstract

In knee osteoarthritis (OA), pain sensitization has been linked to a more severe symptomatology, but the prognostic implications of pain sensitivity in people undergoing conservative treatment such as physiotherapy are not established. This study aimed to prospectively investigate the association between features of pain sensitization and clinical outcome (nonresponse) after guideline-based physiotherapy in people with knee OA. Participants (n = 156) with moderate/severe knee OA were recruited from secondary care. All participants completed self-administered questionnaires and underwent quantitative sensory testing at baseline, thereby establishing subjective and objective measures of pain sensitization. Participants (n = 134) were later classified after a physiotherapy intervention, using treatment responder criteria (responder/nonresponder). Quantitative sensory testing data were reduced to a core set of latent variables using principal component analysis. A hierarchical logistic regression model was constructed to investigate whether features related to pain sensitization predicted nonresponse after controlling for other known predictors of poor outcome in knee OA. Higher temporal summation (odds ratio 2.00, 95% confidence interval 1.23-3.27) and lower pressure pain thresholds (odds ratio 0.48, 95% confidence interval 0.29-0.81) emerged as robust predictors of nonresponse after physiotherapy, along with a higher comorbidity score. The model demonstrated high sensitivity (87.8%) but modest specificity (52.3%). The independent relationship between pain sensitization and nonresponse may indicate an underlying explanatory association between neuroplastic changes in nociceptive processing and the maintenance of ongoing pain and disability in knee OA pain. These preliminary results suggest that interventions targeting pain sensitization may warrant future investigation in this population.

Low adherence to exercise may have influenced the proportion of OMERACT-OARSI responders in an integrated osteoarthritis care model: secondary analyses from a cluster-randomised stepped-wedge trial

“…Unfortunately, this intervention was not sufficient to show a clinically meaningful difference in patient-reported outcomes and a statistically significant difference in proportion of OMERACT-OARSI responders in the intervention group compared to the usual care control group. However, the total proportion of responder in the intervention group (47%) is similar to previous RCTs applying the OMERACT-OARSI responder criteria to evaluate the effect of different physiotherapist led exercise interventions on knee OA [22][23][24].…”

Mechanistic pain profiling as a tool to predict the efficacy of 3-week nonsteroidal anti-inflammatory drugs plus paracetamol in patients with painful knee osteoarthritis

“…Recently, O'Leary et al [36] found that facilitated TSP and low PPTs were predictive of poor outcome for knee OA patients following physiotherapy. The current study further indicates that knee OA patients with facilitated TSP do not respond optimally to standard anti-inflammatory treatment, which is in line with a previous study regarding topical NSAIDs in knee OA [16].…”

“…Several studies have shown that the analgesic effects of NSAIDs plus paracetamol are superior to placebo [11,12,15,29,45]. The aim of the study was to investigate the value of mechanistic pain profiling and its predictive value after NSAIDs and paracetamol treatment as mechanistic pain profiling has previously been shown to identify poor responders to other standardized OA treatments [36,39,40,42,54]. Predicting poor NSAID treatment outcome is valuable as patients not responding adequately should not be treated with NSAIDs due the possible unwanted side effects.…”

Low adherence to exercise may have influenced the proportion of OMERACT-OARSI responders in an integrated OA care model: Secondary analyses from a cluster-randomised controlled trial

“…is similar to previous RCTs applying the OMERACT-OARSI responder criteria to evaluate the effect of different physiotherapist led exercise interventions on knee OA (22)(23)(24).…”