Attenuation of psychophysical measures of augmented central pain processing and improved cervical movement imply that these processes are maintained by peripheral nociceptive input.

Purpose The aim of the study was to assess the use of the centre-edge (CE) angle in the assessment of pincer femoroacetabular impingement (FAI) for reliability and predictability in the diagnosis. Methods Between 2004 and 2008, 55 patients underwent surgical treatment for FAI. A control group of 30 was identified among patients attending the emergency department with normal radiographs. Radiographs were assessed by two independent observers both before and after the operation. Nine patients with trauma were excluded. The magnetic resonance arthrogram reports of the remaining 46 patients were assessed for pincer FAI. Nineteen patients were identified and underwent repeat radiographic assessment. All underwent surgical dislocation of hip (SDH), acetabular, with/without femoral osteochondroplasty. Acetabular depth and version were also assessed. The intraclass correlation (ICC) was used to assess reliability of the CE angle. The paired t test and independent groups t test were used to assess the difference between the pincer FAI group, both pre-op and post-op and against controls. Results The control and pincer groups were similar in demographics (p=0.1769). Coxa profunda was present in 14 patients with eight also having retroverted acetabuli. Of the rest two had retroverted acetabuli and one protrusio. The mean CE angle in the control group was 31.4°, in the pre-op pincer group 46.2°and in the post-op pincer group 38.3°. The ICC for intra-observer correlation was 0.977 and 0.992 pre-op and 0.986 and 0.974 post-op. The ICC for inter-observer correlation was 0.960 and 0.957 pre-op and 0.979 and 0.967 post-op.The p value was <0.001 between the controls, the pre-op and post-op pincer groups. The test characteristics using the CE angle ≥ 40 is a reasonably good predictor of FAI, with a sensitivity of 84.2% and a specificity of 100%. Conclusions The pincer FAI can be reliably assessed with the CE angle and can be predicted in patients presenting with FAI.

BackgroundCervical facet block (FB) procedures are often used as a diagnostic precursor to radiofrequency neurotomies (RFN) in the management of chronic whiplash associated disorders (WAD). Some individuals will respond to the FB procedures and others will not respond. Such responders and non-responders provided a sample of convenience to question whether there were differences in their physical and psychological features. This information may inform future predictive studies and ultimately the clinical selection of patients for FB procedures.MethodsThis cross-sectional study involved 58 individuals with chronic WAD who responded to cervical FB procedures (WAD_R); 32 who did not respond (WAD_NR) and 30 Healthy Controls (HC)s. Measures included: quantitative sensory tests (pressure; thermal pain thresholds; brachial plexus provocation test); nociceptive flexion reflex (NFR); motor function (cervical range of movement (ROM); activity of the superficial neck flexors during the cranio-cervical flexion test (CCFT). Self-reported measures were gained from the following questionnaires: neuropathic pain (s-LANSS); psychological distress (General Health Questionnaire-28), post-traumatic stress (PDS) and pain catastrophization (PCS). Individuals with chronic whiplash attended the laboratory once the effects of the blocks had abated and symptoms had returned.ResultsFollowing FB procedures, both WAD groups demonstrated generalized hypersensitivity to all sensory tests, decreased neck ROM and increased superficial muscle activity with the CCFT compared to controls (p < 0.05). There were no significant differences between WAD groups (all p > 0.05). Both WAD groups demonstrated psychological distress (GHQ-28; p < 0.05), moderate post-traumatic stress symptoms and pain catastrophization. The WAD_NR group also demonstrated increased medication intake and elevated PCS scores compared to the WAD_R group (p < 0.05).ConclusionsChronic WAD responders and non-responders to FB procedures demonstrate a similar presentation of sensory disturbance, motor dysfunction and psychological distress. Higher levels of pain catastrophization and greater medication intake were the only factors found to differentiate these groups.

BackgroundThe cervical zygapophyseal joints may be a primary source of pain in up to 60% of individuals with chronic whiplash associated disorders (WAD) and may be a contributing factor for peripheral and centrally mediated pain (sensory hypersensitivity). Sensory hypersensitivity has been associated with a poor prognosis. The purpose of the study was to determine if there is a change in measures indicative of sensory hypersensitivity in patients with chronic WAD grade II following a medial branch block (MBB) procedure in the cervical spine.MethodsMeasures of sensory hypersensitivity were taken via quantitative sensory testing (QST) consisting of pressure pain thresholds (PPT's) and cold pain thresholds (CPT's). In patients with chronic WAD (n = 18), the measures were taken at three sites bilaterally, pre- and post- MBB. Reduced pain thresholds at remote sites have been considered an indicator of central hypersensitivity. A healthy age and gender matched comparison group (n = 18) was measured at baseline. An independent t-test was applied to determine if there were any significant differences between the WAD and normative comparison groups at baseline with respect to cold pain and pressure pain thresholds. A dependent t-test was used to determine whether there were any significant differences between the pre and post intervention cold pain and pressure pain thresholds in the patients with chronic WAD.ResultsAt baseline, PPT's were decreased at all three sites in the WAD group (p < 0.001). Cold pain thresholds were increased in the cervical spine in the WAD group (p < 0.001). Post-MBB, the WAD group showed significant increases in PPT's at all sites (p < 0.05), and significant decreases in CPT's at the cervical spine (p < 0.001).ConclusionsThe patients with chronic WAD showed evidence of widespread sensory hypersensitivity to mechanical and thermal stimuli. The WAD group revealed decreased sensory hypersensitivity following a decrease in their primary source of pain stemming from the cervical zygapophyseal joints.

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