Mechanism of Chronic Pain of Symptomatic Hip Osteoarthritis by Association of its Distribution, Nociceptive, Neuropathic, Nociplastic, or Mixed-pain Screening, and the Prevalence of Lumbar Spinal Stenosis

Abstract

Objectives: The pain of hip osteoarthritis (OA) is generally recognized as nociceptive in origin because of the local pathology. However, some patients with OA experience a neuropathic pain component as an essential part of some nociplastic pain subtype. Here, we sought to examine the mechanism of chronic pain of symptomatic hip OA by the association of its distribution, complex pain mechanism screening, and the prevalence of lumbar spinal stenosis. Materials and Methods:We conducted a prospective cross-sectional study of 100 hips in 100 patients with symptomatic hip OA in a chronic state. We examined all baseline clinical characteristics including clinical and functional score, location of pain and numbness, and pain score (PainDETECT questionnaire and the Leeds Assessment of Neuropathic Symptoms and Signs), and magnetic resonance imaging of the hip and lumbar spine. Results:The PainDETECT questionnaire and Leeds Assessment of Neuropathic Symptoms and Signs revealed that 23% of the patients had a neuropathic pain component. There were 24 variations of the pain pattern. By contrast, the pain localized around the hip joint was only 15%. Pain distal to the thigh and any numbness was significantly more frequent in the group with neuropathic pain (P < 0.001). Lumbar spinal stenosis grade was not significantly different between patients with nociceptive pain and those with neuropathic pain. Pain score was significantly correlated with the pain in clinical and functional scores.Discussion: Among patients with symptomatic hip OA, the distribution of pain was various, and about 23% of patients had neuropathic, nociplastic, or mixed pain as a possibility for somatosensory system disturbances.

The Psychosocial Characteristics and Somatosensory Function of Children and Adolescents Who Meet the Criteria for Chronic Nociplastic Pain

“…A study on adults with multiple sclerosis and chronic pain identified that 50% had nociplastic pain with or without neuropathic pain, 34 while a study on adults with symptomatic hip OA observed that 23% of their cohort displayed neuropathic, nociplastic, or mixed pain. 35 Nevertheless, 40% of our sample were classified as possible nociplastic pain. Studies in pediatrics with chronic pain conditions in which nociplastic pain may be present, such as fibromyalgia, complex regional pain syndrome and irritable bowel syndrome, have provided evidence of altered nociceptive processing in these conditions through quantitative sensory testing.…”

Neuropathic-like pain in knee osteoarthritis: exploring differences in knee loading and inflammation. A cross-sectional study

“… 37 However, pain in OA is a complex phenomenon that involves different mechanisms. 38 Some patients show altered nociception along with no evidence of actual tissue damage or lesion of the somatosensory system (requirement to define pain as neuropathic), fulfilling the recently introduced term of “nociplastic” pain. 39 It is challenging to differentiate if one type of pain prevails on the others as these different pathophysiological mechanisms of pain often occur in combination.…”

Clinical Assessment of Osteoarthritis Pain: Contemporary Scenario, Challenges, and Future Perspectives

“…Patients with OA, rheumatoid arthritis, and other nociceptive pain diseases have a high incidence of nociplastic pain states, such as fibromyalgia [ 5 ]. Patients with nociplastic pain might experience concurrent pain, which makes its management very challenging [ 24 ].…”