Introduction
As many as 40% of young to middle-aged adults report chronic hip-related groin pain (HRGP).1–3 HRGP can be attributed to conditions such as femoroacetabular impingement syndrome, acetabular dysplasia and acetabular labral tears,4 and can result in significant pain and activity limitation. Structural factors5 and patient-specific factors such as psychological impairment,6–11 pain with movement12 13 and somatosensory disturbances14 contribute to the relationship of pain and the patient’s perception of their mobility limitations and can confound the clinical assessment of pain. Understanding the relationship of these factors and functional limitations is imperative for the provider to optimise recovery in patients with pain.15
Up to 50% of patients with HRGP present with a psychological impairment,16 17 depression among the most common.16 Psychosocial factors such as symptoms of depression or central sensitisation are associated with worse patient-reported function among patients with HRGP seeking a surgical consult.6–11 A 2020 systematic review by Cheng et al9 found that greater baseline psychological impairment in patients with FAI was associated with worse postoperative clinical outcomes after hip arthroscopy. Less is known about the relationship between psychosocial factors and hip-related function among patients seeking non-operative management. It is important to understand the multiple variables, including psychosocial variables, that may be associated with treatment outcomes in these patients in order to develop personalised care and maximise clinical outcomes.
Assessment of movement evoked pain (MEP) and pain pressure threshold (PPT) may provide additional information regarding the patient’s pain perception. Clinical assessment of the severity of a patient’s pain level can be challenging. Pain questionnaires often involve recall of pain at rest and may not accurately reflect pain related to movement.18 Therefore, allowing a patient to report pain levels occurring with specific movements may provide a more accurate measure of movement-related pain.19 Evaluating MEP along with performance-based measures of function and patient-reported outcomes provides a more comprehensive evaluation of the patient with chronic pain.19 PPT, a quantitative sensory test,20 assesses pressure hypersensitivity. Low PPT values at the painful site may indicate a heightened local nociceptive response and a low threshold for pain; however, low PPT values at a remote, non-painful site may indicate a more generalised response suggestive of nociplasty.21 The independent relationship of MEP and PPT values to patient-reported function in people with HRGP is unknown.
The goal of the current study was to determine if depressive symptoms, central sensitisation symptoms, MEP, pressure hypersensitivity and activity level were associated with hip-specific, patient-reported function quantified by the International Hip Outcome Tool (iHOT-33).22 Determining the relationship between personal factors and patient-reported function may influence decision-making regarding the treatments offered to those who present with HRGP. In this secondary analysis, we hypothesised that among patients with HRGP seeking non-operative management, greater depressive symptoms, greater central sensitisation, higher MEP ratings, greater local and remote pressure hypersensitivity, and lower activity level would be associated with lower perceived hip-related function.