Can effusion-synovitis measured on ultrasound or MRI predict response to intra-articular steroid injection in hip osteoarthritis?

OBJECTIVES: Intra-articular steroid injection (IASI) is an effective therapy for hip osteoarthritis (OA), but carries risks and provides significant pain relief to only two thirds of patients. We attempted to predict response to IASI in hip OA patients using baseline clinical, ultrasound, and MRI data. METHODS: Observational study of 97 subjects with symptomatic hip OA presenting for IASI. At baseline and 8 weeks we obtained hip MRI, grayscale and Doppler ultrasound, clinical range of motion (ROM), timed-up and go test (TUG) scores, and self-reported Western Ontario and McMaster Universities Osteoarthritis (WOMAC) pain, stiffness, and function scores. Bone-capsule distance (BCD) measurements of inflammation on hip ultrasound and MRI were measured at three locations: the proximal-most uncovered portion of the femoral head, the superficial-most (apex) portion of the femoral head, and the largest fluid pocket at the femoral neck. RESULTS: Ultrasound and MRI BCD correlated with each other significantly and strongly at the apex and neck. Power Doppler findings did not correlate significantly with any other imaging indices. Eight weeks post-injection, WOMAC pain, function, and stiffness scores significantly improved and TUG time improved nearly to the level of significance, but there were no significant changes in ultrasound, MRI, or Doppler indices. Baseline variables were not significantly different between responder and nonresponder WOMAC pain or TUG time cohorts. CONCLUSION: Basic measures of inflammation on ultrasound and MRI are highly related to each other, but provide little insight into patient function and pain after IASI. Other mechanisms to explain improvement in patient status after IASI are likely at work.

Pain expectations in neuropathic pain: Is it best to be optimistic?

BACKGROUND: Pain expectancy may be an important variable that has been found to influence the effectiveness of treatments for pain. Much of the literature supports a self-fulfilment perspective where expectations for pain relief predict the actual pain experienced. However, in conditions such as neuropathic pain (NeP) where pain relief is difficult to attain, expectations for pain relief could be unrealistic. The objective of this study was to investigate the relationship between realistic/unrealistic expectations and 6-month, post-treatment outcomes. METHODS: We performed a retrospective analysis of a large cohort of patients with NeP (n = 789) attending tertiary care centres to determine the association between unrealistic (both positive and negative) and realistic expectations with outcomes after multidisciplinary treatment. An expectation variable with three categories was calculated: realistic expectations were those whose expected reduction in pain was similar to the observed mean group reduction in pain, while optimistic and pessimistic expectations were those who over- or under-estimated the expected response to treatment, respectively. The association between baseline realistic/unrealistic expectations and 6-month pain-related disability, catastrophizing and psychological distress was assessed. RESULTS: Univariable analyses suggested that realistic expectations were associated with lower levels of disability, catastrophizing and psychological distress, compared to unrealistic expectations. However, after adjustment for baseline symptom severity, multivariable analysis revealed that patients with optimistic expectations had lower levels of disability, than those with realistic expectations. Those with pessimistic expectations had higher levels of catastrophizing and psychological distress at follow-up. CONCLUSIONS: These findings are largely congruent with the self-fulfilment perspective to expectations. SIGNIFICANCE: This study defined realistic pain expectations with patient data. Examining the relationship between expectations between pain and disability in a large cohort of patients with neuropathic pain.

Validity evidence for the back beliefs questionnaire in the general population.

BACKGROUND: Despite common usage of the back beliefs questionnaire (BBQ) in a variety of studies, important validity evidence is missing. The objective of this study was to examine the validity of the BBQ in the general population. METHODS: A population-based, cross-sectional study design was used. Adult residents in two Canadian provinces were randomly sampled. To examine structural validity, items from the BBQ were subjected to factor analysis. Construct validity was tested by examining two hypotheses: BBQ scores would be most pessimistic in those with a recent history of back pain and in those who utilized passive treatments for back pain. Multiple linear regression was used to analyse the two hypotheses. RESULTS: Complete data were available for 6171 subjects. The best structure for the BBQ was to use eight or nine of the 14 items for scoring, which is consistent with the structure reported by the BBQ developers. BBQ scores varied based on participants' history of low back pain (LBP) and depended on pain severity. Those with severe pain and a recent history of LBP had the most pessimistic BBQ scores. In addition, participants who utilized passive management behaviours such as bed rest and activity avoidance had more pessimistic BBQ scores compared with those that did not. CONCLUSIONS: This study provides strong validity evidence supporting the current structure and scoring of the BBQ. In addition, construct validity was evidenced by the behaviour of BBQ scores in a manner congruent with our hypotheses, further supporting use of the BBQ in the general population.