Background Previous research has suggested that tai chi offers a therapeutic benefit in patients with fibromyalgia. Methods We conducted a single-blind, randomized trial of classic Yang-style tai chi as compared with a control intervention consisting of wellness education and stretching for the treatment of fibromyalgia (defined by American College of Rheumatology 1990 criteria). Sessions lasted 60 minutes each and took place twice a week for 12 weeks for each of the study groups. The primary end point was a change in the Fibromyalgia Impact Questionnaire (FIQ) score (ranging from 0 to 100, with higher scores indicating more severe symptoms) at the end of 12 weeks. Secondary end points included summary scores on the physical and mental components of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). All assessments were repeated at 24 weeks to test the durability of the response. Results Of the 66 randomly assigned patients, the 33 in the tai chi group had clinically important improvements in the FIQ total score and quality of life. Mean (±SD) baseline and 12-week FIQ scores for the tai chi group were 62.9±15.5 and 35.1±18.8, respectively, versus 68.0±11 and 58.6±17.6, respectively, for the control group (change from baseline in the tai chi group vs. change from baseline in the control group, −18.4 points; P<0.001). The corresponding SF-36 physical-component scores were 28.5±8.4 and 37.0±10.5 for the tai chi group versus 28.0±7.8 and 29.4±7.4 for the control group (between-group difference, 7.1 points; P = 0.001), and the mental-component scores were 42.6±12.2 and 50.3±10.2 for the tai chi group versus 37.8±10.5 and 39.4±11.9 for the control group (between-group difference, 6.1 points; P = 0.03). Improvements were maintained at 24 weeks (between-group difference in the FIQ score, −18.3 points; P<0.001). No adverse events were observed. Conclusions Tai chi may be a useful treatment for fibromyalgia and merits long-term study in larger study populations.

Objective. To develop definitions for imaging features being considered as potential classification criteria for calcium pyrophosphate deposition (CPPD) disease, additional to clinical and laboratory criteria, and to compile example images of CPPD on different imaging modalities.Methods. The American College of Rheumatology and European Alliance of Associations for Rheumatology CPPD classification criteria Imaging Advisory Group (IAG) and Steering Committee drafted definitions of imaging features that are characteristic of CPPD on conventional radiography (CR), conventional computed tomography (CT), dual-energy CT (DECT), and magnetic resonance imaging (MRI). An anonymous expert survey was undertaken by a 35-member Combined Expert Committee, including all IAG members. The IAG and 5 external musculoskeletal radiologists with expertise in CPPD convened virtually to further refine item definitions and voted on example images illustrating CR, CT, and DECT item definitions, with ≥90% agreement required to deem them acceptable.Results. The Combined Expert Committee survey indicated consensus on all CR definitions. The IAG and external radiologists reached consensus on CT and DECT item definitions, which specify that calcium pyrophosphate deposits appear less dense than cortical bone. The group developed an MRI definition and acknowledged limitations of this modality for CPPD. Ten example images for CPPD were voted acceptable (4 CR, 4 CT, and 2 DECT), and 3 images of basic calcium phosphate deposition were voted acceptable to serve as contrast against imaging features of CPPD.Conclusion. An international group of rheumatologists and musculoskeletal radiologists defined imaging features characteristic of CPPD on CR, CT, and DECT and assembled a set of example images as a reference for future clinical research studies.

Objective Classification criteria for calcium pyrophosphate deposition (CPPD) disease will facilitate clinical research on this common crystalline arthritis. Our objective was to report on the first 2 phases of a 4‐phase process for developing CPPD classification criteria. Methods CPPD classification criteria development is overseen by a 12‐member steering committee. Item generation (phase I) included a scoping literature review of 5 literature databases and contributions from a 35‐member combined expert committee and 2 patient research partners. Item reduction and refinement (phase II) involved a combined expert committee meeting, discussions among clinical, imaging, and laboratory advisory groups, and an item‐rating exercise to assess the influence of individual items toward classification. The steering committee reviewed the modal rating score for each item (range –3 [strongly pushes away from CPPD] to +3 [strongly pushes toward CPPD]) to determine items to retain for future phases of criteria development. Results Item generation yielded 420 items (312 from the literature, 108 from experts/patients). The advisory groups eliminated items that they agreed were unlikely to distinguish between CPPD and other forms of arthritis, yielding 127 items for the item‐rating exercise. Fifty‐six items, most of which had a modal rating of +/– 2 or 3, were retained for future phases. As numerous imaging items were rated +3, the steering committee recommended focusing on imaging of the knee and wrist and 1 additional affected joint for calcification suggestive of CPP crystal deposition. Conclusion A data‐ and expert‐driven process is underway to develop CPPD classification criteria. Candidate items comprise clinical, imaging, and laboratory features.