The efficacy of multimodal physiotherapy and usual care in chronic whiplash-associated disorders with facet-mediated pain undergoing platelet rich plasma (PRP) treatment: a series of single case experimental designs (SCEDs)

Chronic whiplash-associated disorders (WAD) is a heterogeneous condition with limited effective treatment options available. This study evaluated the efficacy of multimodal physiotherapy and usual care in chronic WAD with facet-mediated pain receiving platelet-rich plasma (PRP) injections to determine if pain interference and confidence completing activities in the presence of neck pain could be improved. A multiple-baseline, single-case experimental design was used to evaluate the 6-week effect of physiotherapy or usual care in two groups of three participants each. All six participants demonstrated a significant reduction in pain interference, and three participants showed improved confidence to perform daily activities when in pain. Weighted Tau-<i>U</i> demonstrated a significant reduction of pain interference with large to very large effect sizes (&gt; 0.75) for both interventions in all participants irrespective of treatment allocation with no significant group difference demonstrated. Similar effects were demonstrated for the confidence to perform daily activities with neck pain (ES &gt; 0.46), although this was only evident in three participants (two PT and one UC). Generalisation measures also showed improvements in pain and disability, psychological and quality of life outcomes. No adverse events were reported. Both physiotherapy and usual care demonstrated improvements in pain interference and confidence to perform activities of daily living with neck pain in people with chronic WAD following cervical facet joint PRP. The trial was registered with ClinicalTrials.gov (Protocol Number: NCT03949959).