The time has come to incorporate more teaching and formalized assessment of skills in synovial fluid analysis into rheumatology training programs


Arthrocentesis with synovial fluid analysis can directly dictate the diagnosis and management of previously unexplained joint effusions (1). In addition to its obvious value in confirming the diagnosis of crystal-induced arthritis, fluid analysis can help differentiate among other causes of polyarthritis. This is now particularly relevant, given the potential of overdiagnosing rheumatoid arthritis (RA) using the newer diagnostic algorithms that seem to emphasize sensitivity over specificity (2–4) in order to appropriately encourage the early aggressive therapy of RA. We previously analyzed the accuracy of diagnosis in a series of patients using the 1987 American College of Rheumatology (ACR) criteria for the classification of RA, and noted that the diagnostic specificity could be improved by including synovial fluid analysis (5). In our analysis, 19 of 157 patients diagnosed with RA would have been alternatively classified if synovial fluid findings had been utilized in the diagnostic process. Yet, the 2010 ACR/European League Against Rheumatism classification criteria for the early diagnosis of RA (6), a major international effort that notes the need to exclude other causes of synovitis, do not recognize the diagnostic value of joint aspiration with synovial fluid analysis. We believe that an underemphasis on synovial fluid analysis in clinical training has contributed to an underutilization of the test in clinical practice and an underemphasis in academic writings and practice guidelines.

Microscopic examination of synovial fluid for crystals remains the gold standard for the diagnosis of gout and clinically relevant calcium pyrophosphate deposition disease (7–10). Synovial fluid analysis can alter the clinical diagnosis (1, 11). Although the concern regarding the inconsistent quality of fluid examination is well-founded (12–15), this can be rectified at least for rheumatologists with appropriate training and a requirement for the demonstration of competency prior to certification.

Synovial fluid analysis has been a valuable component of rheumatologic practice for a half-century. It is a skill that is expected by the Accreditation Council for Graduate Medical Education (ACGME) to be learned during rheumatologic training. Yet, only some fellowship programs have well-defined performance measures to assess the skills of their graduating fellows, and synovial fluid analysis is not rigorously assessed on the rheumatology certification examination. An informal survey of program directors and direct observation of our own and other programs indicate that many programs do not explicitly define “competency” to perform synovial fluid analysis. No consensus has been reached on a standardized method for training and evaluating fellows (and staff) in the performance of fluid analysis, nor have outcomes of various utilized teaching approaches been fully evaluated. A number of challenges exist in trying to incorporate a rigorous synovial fluid analysis module into fellowship training (including the lack of experienced mentors in some programs), particularly if it is desired to have uniformity between programs and a shared definition of competency. However, we believe that these challenges can be systematically overcome if the resolve is present.

Several educational programs to teach synovial fluid analysis and assess the skills of trainees have been described. For example, we distributed short multiple-choice quizzes on synovial fluid analysis at ACR workshops, but the validity of the quiz and the lasting educational value of the workshop have not been rigorously assessed. A similar quiz (available at was developed at the University of Pennsylvania. The questions were designed to assess not only basic knowledge on the use of a microscope with polarized light, but also to test interpretive skills. We have provided our pilot quiz to incoming fellows and performed posttraining retesting at the end of their fellowship. The fellows' performance on this quiz clearly increased after 2 years in our program (University of Pennsylvania), but improvement was not uniform and performance was not linked to graduation or certification of competency in synovial fluid analysis.

In a separate program (16), we utilized a structured synovial fluid analysis self-assessment activity in an effort to enhance skills in synovial fluid analysis and promote self-directed learning. First, a multiple-choice test on synovial fluid analysis was administered and the learners completed an answer sheet. These questions were designed with the expectation that a fellow will not know all of the answers (the mean correct response rate was 68% for second-year fellows). The answer sheets of the fellows or staff were marked by the preceptor to indicate which questions were answered incorrectly, and the fellows or staff then searched the literature to find the correct answers on their own. This process was followed by a group discussion of the questions and answers, with additional material provided by the preceptor. The surveys performed at programs following the completion of this activity invariably (100% of responses in almost all programs) indicated that the fellows desired more formal teaching about synovial fluid analysis in their program, and that they had an improved perception of their skills and knowledge after the activity. Nonetheless, not all programs modified their teaching of synovial fluid analysis after receiving the survey results.

Lumbreras et al reported training at one site with fresh wet specimens (17). Four fellows without previous experience received instruction from an established expert over 3 months and achieved significant skill. This educational program had an emphasis on identification of calcium pyrophosphate dehydrate (CPPD) crystals by shape, because they may exhibit very weak (or no) birefringence. The long-term outcomes from this educational initiative have not been reported. Several additional creative approaches to teaching synovial fluid analysis have been implemented within training programs; we hope that these will be presented and discussed at national meetings or at ACR rheumatology program director retreats.

It is assumed that all training programs have access to a high-quality polarizing microscope, and hands-on experience is generally agreed to be an essential part of learning synovial fluid analysis. Comfort and proficiency with handling specimens and microscopes are necessary practical skills in the performance of synovial fluid analysis and must be practiced. The lack of available fresh fluid specimens has been a voiced limitation to the development of uniform teaching programs, but fluid specimens can be stored for teaching purposes in capped syringes, and a method to preserve crystal-containing specimens in Permount mounting medium (Fisher) (18) has been published. These crystal-containing slides remain stable for weeks, and we have regularly used them at ACR Annual Scientific Meeting workshops. Standard testing specimens of whole synovial fluid have also been shipped in small vials to laboratories by the American College of Pathologists. Although useful for teaching and testing crystal analysis skills, there will be death of cells with both of these methods, and crystal–cell relationships and cell types cannot be fully appreciated. Specific experience with interpreting crystal–cell relationships and identifying cell structures (i.e., distinguishing refractile granules versus small crystals) will need to be provided utilizing digitized images, as well as supervised real-time fluid analyses during clinical training. The latter remains an indispensable component of a fellow's training and must be tracked by their program.

Can a documented skill in synovial fluid analysis be ensured at the completion of fellowship training? Is this important, or is the status quo acceptable? We believe that the creation of a standardized program to train fellows to be competent in synovial fluid analysis is both important and achievable. Therefore, we propose a general approach that the ACR (or a consortium of training programs) can pursue to ensure that all fellows receive uniform and appropriate instruction and can consistently demonstrate that they are able to perform synovial fluid analysis in an acceptable manner by the time they graduate.

We propose the following teaching approaches. 1) During the first 4 months of fellowship training, each program should present to their fellows a standardized program on synovial fluid analysis built around core didactic presentations. Didactic standardized material will include components on arthrocentesis, fluid handling, the basics of performing regular and polarized light microscopy, and examples of common crystals and artifacts. These core presentations will be followed by standardized supervised microscope practice using the rheumatology program's equipment. Faculty facilitators may be trained, if desired, at a similar session offered for faculty (before or after the ACR annual meeting). Specimens may include fluids obtained locally, but will be supplemented by small wet aliquots previously examined by at least 3 recognized experts. Specimens will come from a central source and will include one or more samples containing artifacts, no crystals, CPPD, monosodium urate monohydrate (MSU), basic calcium phosphate (BCP), depot corticosteroid, and cholesterol crystals. The fellows will prepare the specimens, and set up and use their departmental microscope. The fellows will then record their synovial fluid analysis findings and provide interpretation on a standardized report form (a written or electronic form ideally appropriate for use in their clinical practice).

2) Each program will be expected to have their fellows examine (with supervision) all fluids obtained during their training, maintaining a log sheet with mandatory staff evaluation and feedback on all aspects of the procedure. After approximately 1 year of fellowship, an evaluation of the fellows' skill in synovial fluid analysis will be performed. This evaluation could be linked to the currently administered in-training examination. Administration of this evaluation will be supervised by local faculty (but scored centrally) and will include: a) analysis using the program's microscope of standardized specimens (these initially could be sent from the University of Pennsylvania and the Philadelphia VA Medical Center, but it will likely be necessary that there are additional reference laboratories). These specimens will be small wet aliquots in tubes from large-volume effusions so that optimal standardization can be ensured. The samples will include at least 2 MSU and CPPD, a synovial fluid with artifacts but no crystals, a dilute depot corticosteroid, and a BCP. Repeated centralized blinded testing of the specimens by 3 experts will ensure specimen reliability. The findings at each training site for each fellow will be recorded and mailed to an evaluation center orchestrated through the ACR (or consortium of program directors). b) A short-answer quiz (ultimately online) designed to test critical principles taught originally, but with slightly reformatted questions, will be offered, with the expectation that all answers should be known by the fellows before graduation. These quiz responses will also be scored at the central center. c) The results from a) and b) above will be returned to each program director with any suggestions for revision of their training program or remedial training of individual fellow(s). Successful completion of the wet crystals identification and written test will define appropriate completion of the ACGME expectation for competency in synovial fluid analysis, and will be a requirement for graduation from a rheumatology training program, in addition to successful documentation of multiple synovial fluid analyses performed in the clinical setting as attested by the program director.

3) An additional self-assessment activity can be made available to second-year fellows to reinforce and extend their knowledge of synovial fluid analysis and its clinical correlations. This activity will be a series of questions, some testing knowledge beyond what might be expected from fellows with basic level competency in fluid analysis, which the senior fellows are expected to research and answer.

4) Given the importance of synovial fluid analysis, at least the didactic components of this proposal (points 1, 2b, and perhaps 3) could also be incorporated into the recertification process.

We believe, as recognized by the ACGME, that synovial fluid analysis should be a core competency acquired by all rheumatology fellows during training. We propose that programs should have access to a standardized teaching/learning program that facilitates the acquisition of this skill. We believe that the time is long overdue for the ACR, as the leading academic organization for rheumatologists in the US and the formal organized voice for US rheumatology program directors, to develop and promote such an educational initiative.


All authors were involved in drafting the article or revising it critically for important intellectual content, and all authors approved the final version to be published.