Interpreting Joint Pain: Quantitative Sensory Testing in Musculoskeletal Management

Abstract

Synopsis Pain is a common complaint among clients seeking physical therapy services, yet interpretation of associated sensory changes can be difficult for the clinician. Musculoskeletal injury typically results in nociceptive pain due to noxious stimuli of the damaged muscle or joint tissues. However, with progression from acute to chronic stages, altered nociceptive processing can give rise to an array of sensory findings. Specifically, patients with chronic joint injury may present with signs and symptoms typically associated with neuropathic injury, due to changes in nociceptive processing. Clinical presentation may include expansion of hyperalgesia into adjacent and remote areas, allodynia, dysesthesias, and perceptual deficits. Quantitative sensory testing (QST) may provide an objective method of examining sensation and, thereby, of recognizing potential changes in the nociceptive pathways. The purpose of this paper is to provide an overview of altered nociceptive processing and somatosensory changes that may occur following a musculoskeletal injury without associated neural injury. Recommendations are made on clinical uses of quantitative sensory testing in orthopaedic physical therapy practice, and supporting clinical and laboratory evidence are presented. Examples related to joint injury are discussed, specifically, osteoarthritis of the knee and low back pain. Quantitative sensory testing may be a useful clinical tool to aid clinical decision making and for determination of prognosis. J Orthop Sports Phys Ther 2010;40(12):818–825. doi:10.2519/jospt.2010.3314

Management of a Patient With Chronic Low Back Pain and Multiple Health Conditions Using a Pain Mechanisms–Based Classification Approach

“…The presence of allodynia strongly supports a centrally mediated pain mechanism. 20,76 While lower-limb paresthesia may be associated with neuropathic pain such as radiculopathy, the neurological exam did not demonstrate a clear pattern of nerve root pathology. 4 Pseudoradicular limb pain, a centrally mediated spread of symptoms 6 from chronic LBP, was also hypothesized.…”

“…Allodynia, the report of pain with application of a nonnoxious cutaneous stimulus, 20,76 was present in the lumbar region (FIGURE 2) and was measured statically (light touch) and dynamically (light brushing). The Leeds assessment of neuropathic symptoms and signs (LANSS) pain scale was used to assess for the presence of neuropathic pain.…”

“…7 This scale assesses for neuropathic symptoms such as spontaneous pain and dysesthesia, and includes objective tests for allodynia and pinprick threshold, which may be present in both centrally mediated and peripheral neuropathic pain. 20,32,38,40 The scores for the 7 items are summed for a composite score of 0 to 24, with a score of 12 or more indicating neuropathic pain (sensitivity and specificity of 83% and 87%, respectively). 7 The scale has been shown to be reliable and valid.…”

Long-Term Treatment of Osteoarthritis Pain: Achieving a Balance Between Efficacy and Tolerability for a Successful Chronic Therapy

“…Traditionally, osteoarthritis pain has been attributed to local tissue injury, which causes mechanical nociceptive pain (Gwilym et al, 2009;Hochman et al, 2010). However, results from several studies indicate that central sensitization (ie, increased response to stimulation mediated by amplification of signaling in the central nervous system) may also play a role in the pathophysiology of chronic osteoarthritis pain (ArendtNielsen et al, 2010;Courtney et al, 2010;Hochman et al, 2010;Kidd et al, 2007;Kosek & Ordeberg, 2000). In patients with chronic osteoarthritis, persistent joint damage, synovial inflammation, and subchondral bone changes are associated with chronic nociceptor stimulation.…”

“…In patients with chronic osteoarthritis, persistent joint damage, synovial inflammation, and subchondral bone changes are associated with chronic nociceptor stimulation. This stimulation can alter the mechanisms of nociceptive processing, resulting in modification of central pain-transmitting neurons and enhanced pain response (ArendtNielsen et al, 2010;Courtney et al, 2010;Hochman et al, 2010). Symptoms associated with central sensitization in patients with osteoarthritis include hypersensitivity to pain, skin sensitivity, and the spread of pain from the affected joint to large body areas (ie, referred pain; Arendt-Nielsen et al, 2010;Hochman et al, 2010;Hunter et al, 2008;Woolf, 2011).…”