Predictors of Placebo Response to Local (Intra-Articular) Therapy In Osteoarthritis: An Individual Participant Data Meta-Analysis

OBJECTIVE

We undertook this study to evaluate potential predictors of placebo response with intra-articular (IA) injections for knee/hip osteoarthritis (OA) using individual participant data (IPD) from existing trials.

METHODS

Randomized placebo-controlled trials evaluating IA glucocorticoid or hyaluronic acid published to September 2018 were selected. IPD for disease characteristics and outcome measures were acquired. Potential predictors of placebo response included participant characteristics, pain severity, intervention, and trial design. Placebo response was defined as at least a 20% reduction in baseline pain. Logistic regression models and odds ratios were computed as effect measures to evaluate patient and pain mechanisms and then pooled using a random effects model. Generalized mixed-effect models were applied to intervention and trial characteristics.

RESULTS

Of 56 eligible trials, 6 shared data, and these were combined with the existing 4 OA Trial Bank studies, yielding 10 studies with IPD of 621 placebo participants for analysis. In the total placebo population, at short-term follow-up, the use of local anesthetic and ultrasound guidance were associated with reduced odds of placebo response. At midterm follow-up, mid- to long-term trial duration was associated with increased odds of placebo response, and worse baseline function scores were associated with reduced odds of a placebo response.

CONCLUSION

The administration of local anesthetics or ultrasound guidance may reduce IA placebo response at short-term follow-up. At midterm follow-up, participants with worse baseline function scores may be less likely to respond to IA placebo, and mid- to long-term trial duration may enhance the placebo response. Further studies are required to corroborate these potential predictors of IA placebo response.

Recommendations for rheumatology ultrasound training and practice in the UK

OBJECTIVE

The aim of this paper is to present a UK-based consensus of principles and recommendations to guide rheumatology US training and practice.

METHOD

A Delphi process was conducted involving 19 US experts representing each of the 14 regions of the UK. A working group of experienced British Society for Rheumatology Ultrasound Special Interest Group (BSRUSSIG) members made seven proposals that were presented to the whole group for further discussion. This resulted in minor modifications and seven preliminary recommendations. Members were then asked to anonymously agree or disagree with each recommendation using an electronic ballot. A threshold of 75% was used to determine consensus agreement. Results were collated by an independent chairperson and presented to the BSRUSSIG in a face to face meeting where agreement for each recommendation was ratified and an action plan agreed for dissemination of the results and future development work.

RESULTS

Using a validated process, experts in rheumatology US have worked through an iterative process and have unanimously agreed seven recommendations for rheumatology training and practice. These cover a hierarchy of practice indications, education and training, including the need for practitioners to demonstrate lifelong learning, as well as a commitment to support mentors and trainers through the BSRUSSIG.

CONCLUSION

These are the first specific education and practice recommendations for rheumatology US in the UK and have been developed and endorsed by the BSRUSSIG. We intend that these proposals will help to support and validate rheumatology US practice and inform the development of future rheumatology training curricula and education programmes.

The OA Trial Bank: meta-analysis of individual patient data from knee and hip osteoarthritis trials show that patients with severe pain exhibit greater benefit from intra-articular glucocorticoids

OBJECTIVE

To evaluate the efficacy of intra-articular (IA) glucocorticoids for knee or hip osteoarthritis (OA) in specific subgroups of patients with severe pain and inflammatory signs using individual patient data (IPD) from existing trials.

DESIGN

Randomized trials evaluating one or more IA glucocorticoid preparation in patients with knee or hip OA, published from 1995 up to June 2012 were selected from the literature. IPD obtained from original trials included patient and disease characteristics and outcomes measured. The primary outcome was pain severity at short-term follow-up (up to 4 weeks). The subgroup factors assessed included severe pain (≥70 points, 0-100 scale) and signs of inflammation (dichotomized in present or not) at baseline. Multilevel regression analyses were applied to estimate the magnitude of the effects in the subgroups with the individuals nested within each study.

RESULTS

Seven out of 43 published randomized clinical trials (n = 620) were included. Patients with severe baseline pain had a significantly larger reduction in short-term pain, but not in mid- and long-term pain, compared to those with less severe pain at baseline (Mean Difference 13.91; 95% Confidence Interval 1.50-26.31) when receiving IA glucocorticoid injection compared to placebo. No statistical significant interaction effects were found between inflammatory signs and IA glucocorticoid injections compared to placebo and to tidal irrigation at all follow-up points.

CONCLUSIONS

This IPD meta-analysis demonstrates that patients with severe knee pain at baseline derive more benefit from IA glucocorticoid injection at short-term follow-up than those with less severe pain at baseline.

A modular, flexible training strategy to achieve competence in diagnostic and interventional musculoskeletal ultrasound in patients with hip osteoarthritis

OBJECTIVE

This study sought to establish a model of training and an assessment of competency in musculoskeletal ultrasound (MSUS) diagnosis of hip synovitis and/or effusion and in MSUS-guided injection of the hip.

METHODS

The 'trainee' (no previous experience in MSUS) was trained by an 'expert' [a rheumatologist who is a trainer on the European League Against Rheumatism (EULAR) MSUS course] using a modular approach focused on hip ultrasound only. This consisted of (i) a 1.5 h initial tutorial and practical demonstration and (ii) indirectly supervised non-continuous scanning of 40 hips over 5 h. Competency was assessed in three ways: (i) ability to obtain standard EULAR reference MSUS images of the hip of sufficient image quality, (ii) accuracy in diagnosis of synovitis or hip effusion by measurement of the anterior femur-capsule distance, and (iii) accuracy in ultrasound-guided hip aspiration and injection.

RESULTS

After a period of scanning of 75 min (10 hips), the images obtained by the trainee were consistently graded as acceptable for routine clinical use. Next, blinded triplicate measurements of the anterior femur-capsule distance performed by the trainee and expert showed agreement regarding diagnosis of hip effusion (>7 mm thickness) in 16/17 cases of hip arthritis (kappa 0.876). The trainee performed 40 MSUS-guided hip injections (seven directly supervised followed by 33 indirectly supervised). After 10 consecutive MSUS-guided hip injections, the novice achieved a subsequent accuracy rate of 25/26 (96%) confirmed by radiographic localization of radiopaque contrast.

CONCLUSIONS

Using a modular approach, a learner-centred curriculum and a self-directed learning strategy with a minimum of direct supervision, a trainee achieved competence in MSUS diagnosis of hip effusion/synovitis and in MSUS-guided hip aspiration/injection.

Caffey's disease: an unusual cause for concern

BACKGROUND

Caffey's disease or infantile cortical hyperostosis is a rare cause of irritability, bone pain, soft tissue swelling and fever in the infant.

AIMS

To review the presentation and diagnosis of an 8-week old infant with focal tenderness of the tibia.

METHODS

The symptoms, signs, laboratory work-up and radiology are reviewed.

RESULTS

The child presented with focal bony tenderness and pyrexia. Laboratory work-up was inconclusive. The diagnosis of Caffey's disease was made following a skeletal survey to outrule non-accidental injury, which showed similar changes of cortical thickening in the mandible as well as the affected tibia.

CONCLUSIONS

With our increasing immigrant population, an increasing number of differential diagnoses must be considered when evaluating patients presenting to our emergency rooms. Caffey's disease is an unusual cause of bone pain in the infant. Symptoms and signs are subtle and the diagnosis is generally made with plain X-rays.