Survey of arthroscopy performed by rheumatologists

The preferred technique for knee synovium biopsy and synovial fluid arthrocentesis

For knee osteoarthritis and related conditions, analysis of biomarkers hold promise to improve early diagnosis and/or offer patient-specific treatment. To compare biomarker analyses, reliable, high-quality biopsies are needed. The aim of this work is to summarize the literature on the current best practices of biopsy of the synovium and synovial fluid arthrocentesis. Therefore, PubMed, Embase and Web of Science were systematically searched for articles that applied, demonstrated, or evaluated synovial biopsies or arthrocentesis. Expert recommendations and applications were summarized, and evidence for superiority of techniques was evaluated. Thirty-one studies were identified for inclusion. For arthrocentesis, the superolateral approach in a supine position, with a 0°-30° knee flexion was generally recommended. 18-gage needles, mechanical compression and ultrasound-guidance were found to give superior results. For blind and image-guided synovial biopsy techniques, superolateral and infrapatellar approaches were recommended. Single-handed tools were preconized, including Parker-Pearson needles and forceps. Sample quantity ranged approximately from 2 to 20. Suggestions were compiled for arthrocentesis regarding approach portal and patient position. Further evidence regarding needle size, ultrasound-guidance and mechanical compression were found. More comparative studies are needed before evidence-based protocols can be developed.

Postoperative flares and peri-arthroscopic management of immunosuppressive medications in patients with rheumatic disease

PURPOSE

To determine the rate and characteristics of postoperative flares in rheumatic disease patients undergoing arthroscopic surgery, and the role of perioperative immunosuppression (IS) management in preventing or provoking these exacerbations.

METHODS

We conducted a retrospective review of arthroscopic surgeries in patients with rheumatologic disease over 11 years. Patients taking IS at baseline and those without were matched 1:1 using propensity scores on age, sex, rheumatic disease type, and procedure complexity. Patients taking IS at baseline were sub-divided into those remaining on IS perioperatively versus those who held IS before surgery. Multivariable logistic regression identified risk factors for postoperative flares for the three IS groups, and survival analysis was used to compare the probability of remaining flare-free up to 12 weeks postoperatively.

RESULTS

After matching, 428 patients (214 on various types of baseline IS, 214 not on baseline IS) were included, with 110 on baseline IS remaining on it perioperatively. Rates of postoperative flares were similar for those staying on vs holding their baseline IS (9.1% vs 9.6%) but flares were less frequent in patients not on baseline IS (1.9%). Patients who remained on perioperative IS did not have significantly less flares compared to patients taken off perioperative IS (OR 0.764 [0.267, 2.181]; p = 0.61). Patients not on baseline IS had a significantly higher probability ofremaining flare-free up to 12 weeks (p = 0.004).

CONCLUSION

Rheumatic disease patients who hold IS medication before undergoing arthroscopy, out of concern for potential infection or complications, do not significantly increase their risk of flaring their autoimmune disease whether they had been taking csDMARDs or biologic agents. Those not taking any IS at baseline have a much lower risk of post-arthroscopic flaring, though as a group they likely harbor less of an autoimmune burden.

In-Office Needle Arthroscopic Synovial Biopsy Is an Effective Diagnostic Tool in Patients With Inflammatory Arthritis

Purpose

To assess the utility, safety, and accuracy of in-office needle arthroscopic (IONA) synovial biopsy as a diagnostic tool during treatment of drug-resistant monoarticular inflammatory arthritis of the knee.

Methods

Consecutive patients diagnosed with rheumatoid or psoriatic arthritis with treatment-resistant monoarticular knee involvement who underwent in-office needle arthroscopic synovial biopsy were considered for inclusion. The exclusion criteria were any current malignancies or infection. All patients underwent systematic physical and laboratory examination. IONA was undertaken to inspect the macroscopic appearance of the joint, choose the biopsy site, and classify synovial inflammation. Once collected, synovial tissue specimens were examined histologically using the Krenn scoring system.

Results

In total, 12 patients (9 male and 3 female, median age 57 [interquartile range {IQR} 8] years, median disease duration 156 [IQR 201] months) affected by psoriatic arthritis (n = 6) or rheumatoid arthritis (n = 6) were included in this study. Median operating time was 12 (IQR 11) minutes. Three biopsies per patient were collected. The success rate of specimen collection was 97%, the median postoperative 0-10 visual analog scale pain score was 2 (IQR 3), and only one minor complication occurred.

Conclusions

Knee IONA with synovial biopsy is an effective and well-tolerated procedure that can help clinicians formulate specific treatment strategies in patients with refractory pain in the setting of rheumatoid and psoriatic arthritis.

Level of Evidence

IV, Therapeutic case series.

EULAR points to consider for minimal reporting requirements in synovial tissue research in rheumatology

BACKGROUND

Synovial tissue research has become widely developed in several rheumatology centres, however, large discrepancies exist in the way synovial tissue is handled and, more specifically, how data pertaining to biopsy procedure, quality check and experimental results are reported in the literature. This heterogeneity hampers the progress of research in this rapidly expanding field. In that context, under the umbrella of European Alliance of Associations for Rheumatology, we aimed at proposing points to consider (PtC) for minimal reporting requirements in synovial tissue research.

METHODS

Twenty-five members from 10 countries across Europe and USA met virtually to define the key areas needing evaluation and formulating the research questions to inform a systematic literature review (SLR). The results were presented during a second virtual meeting where PtC were formulated and agreed.

RESULTS

Study design, biopsy procedures, tissue handling, tissue quality control and tissue outcomes (imaging, DNA/RNA analysis and disaggregation) were identified as important aspects for the quality of synovial tissue research. The SLR interrogated four databases, retrieved 7654 abstracts and included 26 manuscripts. Three OPs and nine PtC were formulated covering the following areas: description of biopsy procedure, overarching clinical design, patient characteristics, tissue handling and processing, quality control, histopathology, transcriptomic analyses and single-cell technologies.

CONCLUSIONS

These PtC provide guidance on how research involving synovial tissue should be reported to ensure a better evaluation of results by readers, reviewers and the broader scientific community. We anticipate that these PtC will enable the field to progress in a robust and transparent manner over the coming years.

Perioperative Management of Immunosuppressive Medications in Rheumatic Disease Patients Undergoing Arthroscopy

PURPOSE OF REVIEW

This manuscript reviews relevant prior literature regarding management of immunosuppressants in patients with rheumatic diseases around the time of orthopedic surgery, highlighting important considerations specifically regarding arthroscopy.

RECENT FINDINGS

Utilization rates of arthroscopic surgery in patients with rheumatic diseases are on the rise, as immunosuppressive treatment options enable them to lead more active lives and hence experience more injuries. Physicians regularly manage patients' glucocorticoids and conventional synthetic and biologic disease modifying antirheumatic drugs around the time of orthopedic surgery, aiming to minimize infection risk while optimizing disease control. However, there is a paucity of randomized controlled trial data for orthopedic surgery-and specifically nothing in the literature pertaining to arthroscopic surgery. Recent guidelines for rheumatic disease patients undergoing elective total hip and knee arthroplasty recommend that most immunosuppressive medications should be held perioperatively, citing the high-risk profile of arthroplasty cases and arthroplasty patients. While 2017 societal guidelines for perioperative immunosuppression during arthroplasty currently serve as a guide for physicians, they may not be applicable to arthroscopy. The less aggressive arthroscopic surgeries span a broader range of patient ages and risk profiles, indications for surgery, and procedural complexity and associated risks. Given these considerations, the majority of routine arthroscopic patients may not require holding of their immunosuppressive medications in the perioperative period.

Ultrasound-Guided Synovial Biopsy: A Review

Ultrasound-guided synovial biopsy is a safe, well-tolerated, and effective method to collect good-quality synovial tissue from all types of joints for clinical and research purposes. Although synovial biopsy cannot be used to distinguish between types of inflammatory rheumatic disease, analysis of synovial tissue has led to remarkable advances in the understanding of the pathobiology of rheumatoid arthritis and other inflammatory rheumatic diseases. Synovitis is the hallmark of these diseases; hence, accessing the core of the pathological process, synovial tissue, provides an opportunity to gather information with potential diagnostic and prognostic utility.

Arthroscopic Guided Synovial Biopsies

Synovial tissue can be safely and reliably collected for research and clinical purposes using arthroscopy. This technique offers the obvious advantage of allowing direct visualization, and targeted biopsy of specific areas of interest within the joint, as well as for the collection of tissue which will include a lining layer. Much has been learnt by studying the synovium retrieved using this technique concerning the pathobiology of inflammatory arthritis. Furthermore, recent evidence suggests that the tissue retrieved may enable the identification of unique pathotypes that will allow for a precise approach to treatment selection in individual patients. Although ultrasound guided techniques for sampling synovial tissue have gained in popularity over the last decade, both methodologies are expected to compliment each other, each having unique benefits and drawbacks. We present here a detailed description of the arthroscopy technique reporting on our collective experience at two centers in Europe.

Synovial biopsies in clinical practice and research: current developments and perspectives

Synovial biopsy techniques have developed and widely expanded over the past few years, in particular due to the development of ultrasound-guided procedures. This article reviews the different techniques, clinical applications, and the latest advances in translational research as well as current challenges and perspectives. The first part focuses on different techniques available for biopsy, along with their feasibility, success rate, tolerance, and training requirements. In the second part, clinical applications are described. Data on diagnostic performances are reported, especially regarding septic arthritis. Translational research applications are described and explained in the final part, from the early histological studies and the first description of pathotype to more recent technologies involving -omics. Latest developments involving single-cell RNA sequence analysis have allowed the discovery of new cell subpopulations with remarkable roles in RA pathophysiology. These studies pave the ground for the discovery of new therapeutic targets and the implementation of personalized therapy in RA.

Key Point •This review provides an overview of synovial biopsy techinques and applications especially in clinical and translational research.

Arthroscopy in rheumatology: where have we been? Where might we go?

The aim of our manuscript is to illustrate the past, present and future role of rheumatologists performing arthroscopy. Doctors first began adapting endoscopes to inspect joints to assess synovial conditions that concern rheumatologists. Rheumatologists were among the pioneers developing arthroscopy. Students of the father of modern arthroscopy, Watanabe, included rheumatologists, who taught others once home. Rheumatologists assessed the intra-articular features of their common diseases in the 60s and 70s. Improvements in instrumentation and efforts by a few orthopaedists adapted a number of common joint surgical procedures for arthroscopy. Interest from rheumatologists in arthroscopy grew in the 90s with ‘needle scopes’ used in an office setting. Rheumatologists conducting the first prospective questioning arthroscopic debridement in OA and developing biological compounds reduced the call for arthroscopic interventions. The arthroscope has proven an excellent tool for viewing and sampling synovium, which continues to at several international centres. Some OA features—such as calcinosis—beg further arthroscopic investigation. A new generation of ‘needle scopes’ with far superior optics awaits future investigators.

Synovial Biopsy in the Diagnosis of Crystal-Associated Arthropathies

BACKGROUND/ OBJECTIVE

This study seeks to assess the utility of synovial biopsy in the diagnosis of crystal-associated arthropathies (CAAs) in a clinical setting.

METHODS

In this retrospective study, we reviewed biopsy reports involving synovial tissue between 1988 and 2015. We then reviewed the records of patients where the biopsy was performed for a clinical suspicion of CAA-the clinical group-and calculated the frequency of a positive diagnosis. The t test, Mann-Whitney-Wilcoxon test, and Fisher test were used to compare clinical characteristics of patients with and without a tissue diagnosis of CAA. We also reviewed cases of unexpected detection of crystalline disease involving synovial tissue-the incidental group.

RESULTS

Among 2786 biopsies involving the synovium, we identified 65 cases in the clinical group and 33 cases in the incidental group. In the clinical group, a relevant diagnosis was obtained from synovial tissue in 36.9%, and a CAA was diagnosed in 20%. Restricting analysis to clinical biopsies performed for a primary suspicion of CAA, a relevant diagnosis was obtained in 61.3%, and a CAA was diagnosed in 38.7%. The incidental group comprised 1.2% of all synovial biopsies and included 7 mass lesions. Basic calcium phosphate was not reported on any biopsy in the study period.

CONCLUSIONS

Synovial biopsy is a diagnostic option when suspected CAA is resistant to conventional modes of diagnosis. Crystalline diseases should be considered in the differential diagnosis of musculoskeletal mass lesions mimicking neoplasms.

Synovial biopsies in inflammatory arthritis: precision medicine in rheumatoid arthritis

Introduction: Synovial tissue (ST) is composed of a lining and sublining layer and is the target tissue involved in the inflammatory arthritides (IA), in which there is lining layer hyperplasia, inflammatory cell influx, macrophage recruitment and change in number and behavior of lining fibroblasts. Understanding synovial pathology has been critical in providing insights into pathogenetic mechanisms of disease and therapeutics. Pathobiological insights into ST have been underpinned by progress in molecular analytic methods; research in this area holds promise in individualizing treatment and optimizing response.Areas covered: We explore ST in IA and cover in-depth the utility of synovial biopsy and ST heterogeneity. We review recent advances in ST research and discuss implications with regards to therapeutic response. Finally, we provide perspectives on the identification of new drug targets and new diagnostic and prognostic markers.Expert opinion: ST holds the potential to individualize therapy by detecting biomarkers of diagnosis, therapeutic choice, and treatment modification in IA. Advances in molecular biology including high-throughput omics are likely to provide information that has hitherto remained unknown. ST analyzes pre- and post-treatment needs to be standard of care; only by routinely collecting and analyzing ST will we achieve the precision medicine outcomes described herein.

Ultrasound-Guided Biopsies: Medium and Large Joints

Ultrasound-guided needle synovial biopsies are useful for clinical practice and research in rheumatology. With the emergence of personalized medicine for the treatment of inflammatory rheumatic diseases, it is predicted that this technique will be increasingly used in the near future. Standardized characterization of the technical aspects of ultrasound-guided needle synovial biopsies is needed in order to produce solid evidence on the safety and effectiveness of the technique.

Synovial Tissue Biopsy Research

Synovial tissue is a key structure in diarthrodial joints and is the primary target of inflammation in autoimmune arthritis. The study of synovial tissue has developed significantly in the last two decades as arthroscopic and ultrasonographic techniques have allowed visualization and access to synovial biopsy. Further progress in synovial tissue processing and analysis has improved studies of disease pathogenesis, biomarker discovery, and molecular therapeutic targeting with increasingly specialized analytical and technological approaches. In September 2018 the first course on Synovial Tissue Biopsies was convened in Brussels, in this Mini Review these approaches will be described and I will summarize how synovial tissue research advanced.

Synovial Tissue Sampling in Rheumatological Practice-Past Developments and Future Perspectives

Synovial biopsies are performed in routine clinical care in order to refine diagnosis as well as within a research setting. Progress in the development of minimally invasive synovial sampling methods in the last century has accelerated and facilitated novel insights into disease pathogenesis. This review discusses the development of synovial biopsy techniques as well as examining the three currently most commonly used approaches: arthroscopic, blind needle biopsy and ultrasound guided approaches. It also highlights major research advances driven through synovial research and considers future developments.

Standardisation of synovial biopsy analyses in rheumatic diseases: a consensus of the EULAR Synovitis and OMERACT Synovial Tissue Biopsy Groups

Background

The aim of this global collaboration was to develop a consensual set of items for the analysis of synovial biopsies in clinical practice and translational research through the EULAR Synovitis Study Group (ESSG) and OMERACT Synovial Tissue Biopsy Group.

Methods

Participants were consulted through a modified Delphi method. Three sequential rounds occurred over 12 months. Members were sent a written questionnaire containing items divided into two parts. Items were identified and formulated based on a scoping review. The first part of the questionnaire referred to synovial biopsies in clinical practice including five subsections, and the second part to translational research with six subsections. Every participant was asked to score each item on a 5-point Likert scale. Items with a median score above 3.5 and a ≥ 70% agreement were selected for the next round. The last round was conducted orally at EULAR in June 2017.

Results

Twenty-seven participants from 19 centers were contacted by email. Twenty participants from 17 centers answered. Response rates for next rounds were 100%. For the first part relating to clinical practice, 20/44 items (45.5%) were selected. For the second part relating to translational research, 18/43 items (41.9%) were selected for the final set.

Conclusions

We herein propose a consensual set of analysis items to be used for synovial biopsies conducted in clinical practice and translational research.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1762-1) contains supplementary material, which is available to authorized users.

Patient-reported outcomes and safety in patients undergoing synovial biopsy: comparison of ultrasound-guided needle biopsy, ultrasound-guided portal and forceps and arthroscopic-guided synovial biopsy techniques in five centres across Europe

Background

We present a European multicenter study, comparing safety data and patient-reported outcomes (PRO) from patients undergoing synovial biopsy using ultrasound-guided needle biopsy (US-NB), ultrasound-guided portal and forceps (US-P&F) or arthroscopic-guided (AG) procedures.

Objectives

To describe safety and PRO data on joint indices of pain, stiffness and swelling before and after biopsy, procedural discomfort, joint status compared with before biopsy and willingness to undergo a second biopsy for each technique and compare the three techniques. To evaluate the impact on PRO and safety data of corticosteroid therapy as part of the biopsy procedure and sequential biopsy procedures.

Methods

Data were collected on the day of biopsy and 7-14 days postprocedure. Joint pain, swelling and stiffness indices were recorded as 0-100  mm Visual Analogue Scale; qualitative outcome variables on five-point Likert scales. Groups were compared with linear regression, adjusting for disease activity, corticosteroid therapy and prebiopsy PRO value and accounting for repeated measurements.

Results

A total of 524 synovial biopsy procedures were documented (402 US-NB, 65 US-P&F and 57 AGSB). There were eight adverse events (1.5%) with no difference between biopsy methods (p=0.55). All PROs were improved 2  weeks postprocedure, and there were no differences in postbiopsy change in PROs between biopsy methods. Corticosteroid administration, whether intramuscular (n=62) or intra-articular (n=38), did not result in more adverse events (p=0.81) and was associated with reduction in postbiopsy swelling (p<0.01). Sequential biopsy procedures (n=103 patients) did not result in more adverse events (p=0.61) or worsening in PRO data.

Conclusion

Overall, our results do not suggest a significant difference in safety or patient tolerability between US-NB, US-P&F and AGSB sampling. Further, corticosteroid therapy as part of the biopsy procedure and sequential biopsies is safe and well tolerated in patients.

A Multicenter Retrospective Analysis Evaluating Performance of Synovial Biopsy Techniques in Patients With Inflammatory Arthritis: Arthroscopic Versus Ultrasound-Guided Versus Blind Needle Biopsy

OBJECTIVE

To evaluate whether the choice of synovial biopsy technique (arthroscopy, blind needle [BN] biopsy, ultrasound [US]-guided portal and forceps [P&F], or US-guided needle biopsy [NB]) translates to significant variation in synovial tissue quality and quantity, with the aim of informing recommendations for the choice of synovial sampling technique within clinical trials.

METHODS

In total, 159 procedures from 5 academic rheumatology centers were evaluated. Hematoxylin and eosin-stained, paraffin-embedded synovial tissue sections from patients with inflammatory arthritis were assessed in order to determine the proportion of graded synovial fragments, total area of graded synovial tissue, and synovitis score per procedure. RNA quantity (μg of RNA) and quality (RNA integrity number) per procedure were also assessed in the synovial samples.

RESULTS

In this study, 84 of the 159 procedures performed on large joints at baseline (25 arthroscopic, 35 US-P&F, 11 US-NB, and 13 BN biopsies), 41 of the 159 procedures performed on small joints at baseline (11 US-P&F, 20 US-NB, and 10 BN biopsies), and 34 sequential biopsy procedures were evaluated. Compared to all other techniques evaluated in the small and large joints, fewer small joint BN biopsies and a significantly lower proportion of large joint BN biopsies yielded graded synovial tissue. No significant difference in either the proportion of graded tissue samples or total graded synovial tissue area between the US-NB and arthroscopic large joint procedures was demonstrated. Among the sequential biopsy procedures evaluated (small joint US-NB, large joint arthroscopy, US-P&F biopsy, and BN biopsy), no significant difference in the proportion of graded synovial tissue or total graded synovial tissue area was demonstrated. All procedures yielded RNA of significant quality and quantity for subsequent transcriptomic analysis.

CONCLUSION

These data support the integration of US-guided methods along with arthroscopic biopsy for clinical trial protocols in which sequential sampling of synovium from the large and small joints is needed for both histologic and molecular analysis. BN biopsy may be considered if graded synovial tissue is not required for subsequent analyses.

Success Rate and Utility of Ultrasound-guided Synovial Biopsies in Clinical Practice

OBJECTIVE

The utility of synovial biopsy in increasing our understanding of the pathogenesis of inflammatory arthropathies, as well as in evaluating treatments, is well established. Ultrasound (US) allows synovial assessment and therefore assists in biopsying synovial tissue in a safe and well-tolerated manner. This study's objectives were to (1) determine the rate of success in retrieving synovial tissue using US guidance, (2) describe the indications for US-guided synovial biopsies in the clinical setting, (3) determine how frequently the synovial biopsy can lead to a clear diagnosis, and (4) assess the quality of the synovial tissue obtained using this technique.

METHODS

Synovial biopsies of small and large joints were performed under US guidance between February 2007 and December 2014 using a semiautomatic core biopsy needle. The biopsy procedure was considered successful if synovial tissue was found at histological examination.

RESULTS

Seventy-four patients with undifferentiated arthritis underwent 76 synovial biopsies. The success rate in retrieving synovial tissue was 81.6% (62/76). One patient taking acetyl salicylic acid at 75 mg at the time of the biopsy presented with hemarthrosis 48 h after the procedure, which resolved following simple arthrocentesis. A definitive diagnosis was achieved in 16% of the patients where synovial tissue was sampled successfully.

CONCLUSION

US-guided synovial biopsies in clinical practice can be performed safely on patients with undifferentiated arthritis and with heterogeneous presentations. The rate of success in acquiring synovial tissue is high. The procedure usually retrieves quality tissue and leads to a definite diagnosis in a significant minority of patients.

Is there a role of synovial biopsy in drug development?

Rheumatoid arthritis (RA) is an autoimmune disease which causes significant pain, joint deformity, functional disability. The pathological hallmark of RA is inflammation of the synovium characterized by involvement of inflammatory and resident stromal cells, soluble mediators and signalling pathways leading to irreversible joint destruction. The treatment goal in RA has evolved over the last decade towards a target of disease remission that is achieved in less than a third of patients in clinical trials. The lack of therapeutic response to current treatments is suggestive of alternative drivers of RA pathogenesis that might serve as promising therapeutic targets. There are data to justify the use of synovial tissue in early drug development. Synovial tissue represents an appropriate compartment to be studied in patients with inflammatory arthritis and provides information that is distinct from peripheral blood. Modern techniques have made the procedure much more accessible and ultrasound guided biopsies represent a safe and acceptable option. Advances in analytic technologies allowing transcriptomic level of analysis can provide unique inside to target organ/tissue following the exposure to investigational medicinal product. However, there are still caveats with regard to both the choice of technique and analytical methods. Therefore the significance of synovial biopsy remains to be determined in future clinical trials. The aim of the current debate is to explore the potential for accessing and evaluating synovial tissue in early drug development, to summarize lessons we have learned from clinical trials and to discuss the challenges that have arisen so far.

Evaluation of Minimally Invasive, Ultrasound-guided Synovial Biopsy Techniques by the OMERACT Filter--Determining Validation Requirements

OBJECTIVE

Because limited data currently support the clinical utility of peripherally expressed biomarkers in guiding treatment decisions for patients with rheumatoid arthritis, the search has turned to the disease tissue. The strategic aim of the Outcome Measures in Rheumatology (OMERACT) synovitis working group over the years has been to develop novel diagnostic and prognostic synovial biomarkers. A critical step in this process is to refine and validate minimally invasive, technically simple, robust techniques to sample synovial tissue, for use both in clinical trials and routine clinical practice. The objective of the synovitis working group (SWG) at OMERACT 12 (2014) was to examine whether recently developed ultrasound (US)-guided synovial biopsy techniques could be validated according to the OMERACT filter for future clinical use recommendation.

METHODS

The SWG examined whether current data reporting US-guided synovial biopsy of both large and small joints addressed the OMERACT filters of truth, discrimination, and feasibility.

RESULTS

There are currently limited data examining the performance of US-guided synovial biopsy, mainly from observational studies. Thus, it remains critical to evaluate its performance, within the clinical trials context, against the current gold standard of arthroscopic biopsy, with particular reference to: (1) synovial tissue yield, (2) capacity to determine treatment response as measured by a validated synovial biomarker, and (3) tolerability of the procedure.

CONCLUSION

We summarize the discrete work packages agreed to as requirements to validate US-guided synovial biopsy and therefore lead to a global consensus on the use of synovial biopsy for research and clinical practice.

Ultrasound-guided synovial biopsy: a safe, well-tolerated and reliable technique for obtaining high-quality synovial tissue from both large and small joints in early arthritis patients

OBJECTIVE

To determine the tolerability, safety and yield of synovial tissue in an early arthritis cohort using a minimally invasive, ultrasound (US)-guided, synovial biopsy technique in small, medium and large joints.

METHODS

93 sequential biopsy procedures were assessed from a total of 57 patients (baseline and 36 repeat biopsies at 6 months) recruited as part of the 'Pathobiology of Early Arthritis Cohort' study. Patients completed a tolerability questionnaire prior to and following the synovial biopsy procedure. The synovial biopsy was performed under US guidance with US images of the joint recorded prior to each procedure. Synovial tissue was harvested for immunohistochemistry and RNA extraction.

RESULTS

Five different joint sites were biopsied (knee, elbow, wrist, metacarpal phalangeal and proximal interphalangeal). No significant complications were reported following the procedure. No difference in pain, swelling and stiffness of the biopsied joint from before and after the procedure was demonstrated. A median of 14 biopsy samples was retrieved from each procedure with 93% of biopsy procedures yielding good quality tissue. RNA yield was good in all joints and in repeat biopsies. Multivariant analysis demonstrated a significantly greater yield of RNA and graded tissue in relation to a high prebiopsy, grey-scale synovitis score (0-3, semiquantitative).

CONCLUSIONS

A minimally invasive approach to synovial tissue harvesting, using US guidance, is both safe and well-tolerated by patients. Tissue quality/RNA yield is preserved in subsequent biopsies following therapeutic intervention. A high US grey-scale synovitis score is a predictor of good quality/quantity of tissue and RNA.

New learnings on the pathophysiology of RA from synovial biopsies

PURPOSE OF REVIEW

To critically appraise the literature related to the pathophysiology of rheumatoid arthritis (RA) focusing on the contribution of synovial tissue pathology (synovitis) in determining diverse clinical outcome/therapeutic response.

RECENT FINDINGS

RA synovitis is highly heterogeneous with diverse cellular and molecular signatures (pathotypes) emerging as potential taxonomic classifiers of disease phenotypes.The challenge is to understand mechanistically the sophisticated interplay between systemic disease 'initiators' and joint-specific 'localizing/perpetuating' factors leading to disparate coupling of inflammation/tissue-destructive pathways and disease outcome. Synovial tissue analysis has been instrumental in enhancing understanding of R0A pathogenesis and developing targeted DMARD-biologic therapies. The next step is to elucidate the relationship of different synovial pathotypes/molecular signatures with therapeutic response/resistance in randomized clinical trials in order to develop effective therapies for 'resistant' patients. The development of ultrasound-guided synovial biopsy as a rapid, safe and well tolerated procedure that enables synovial tissue collection from most joints/patients will facilitate such studies.

SUMMARY

RA is a heterogeneous clinical and pathobiological entity. Specific pathways within synovial tissues are emerging as associated with diverse clinical evolution and therapeutic response/resistance that, if confirmed in randomized clinical trials, may lead to the development of synovial tissue analysis as a potential clinical tool for patient stratification.

How to perform and analyse synovial biopsies

Although most of the rheumatologic diseases can be diagnosed based on clinical examination combined with additional laboratory and radiographic tests, histological examination of synovial tissue may lead to the correct diagnosis and adjustment of therapy when neoplastic or granulomatous disease, deposition disease or infection in spite of negative synovial fluid culture is suspected. For research purposes synovial tissue analysis is used to investigate the pathological changes of the synovium in studies aimed at elucidating the aetiology and pathogenetic mechanisms involved in arthritis. In addition, the use of synovial biomarkers has been shown to be instrumental in the developmental process of new therapeutics. In this chapter, several minimally invasive techniques for acquiring synovial tissue samples, handling of the tissue and the analysis thereof are described.

Bacillus species infective arthritis after knee arthroscopy

BACKGROUND

Bacillus species infection of the joints is a very rare occurrence, with sporadic reports in the medical literature.

CASE REPORT

A 67-year-old woman with osteoarthritis developed infection in the knee joint after arthroscopy. Percutaneous needle aspiration of articular fluid performed post-operatively showed a positive culture for Bacillus species. The diagnosis of septic arthritis was, however, not confirmed as the results were considered contamination. Failure of treatment with beta-lactam antibiotics on two occasions and successful cure of infective arthritis by long-term administration of a fluoroquinolone confirmed iatrogenic clinical joint infection with Bacillus species.

CONCLUSION

Any clinically suspected joint infection must be treated as septic arthritis until proved otherwise.

Utility of synovial biopsy

Synovial biopsies, gained either by blind needle biopsy or minimally invasive arthroscopy, offer additional information in certain clinical situations where routine assessment has not permitted a certain diagnosis. In research settings, synovial histology and modern applications of molecular biology increase our insight into pathogenesis and enable responses to treatment with new therapeutic agents to be assessed directly at the pathophysiological level. This review focuses on the diagnostic usefulness of synovial biopsies in the light of actual developments.

Intravascular Ultrasound (IVUS): A Potential Arthroscopic Tool for Quantitative Assessment of Articular Cartilage

Conventional ultrasound examination of the articular cartilage performed externally on the body surface around the joint has limited accuracy due to the inadequacy in frequency used. In contrast to this, minimally invasive arthroscopy-based ultrasound with adequately high frequency may be a better alternative to assess the cartilage. Up to date, no special ultrasound transducer for imaging the cartilage in arthroscopic use has been designed. In this study, we introduced the intravascular ultrasound (IVUS) for this purpose. An IVUS system with a catheter-based probe (Ø approximately 1mm) was used to measure the thickness and surface acoustical reflection of the bovine patellar articular cartilage in vitro before and after degeneration induced by enzyme treatments. Similar measurement was performed using another high frequency ultrasound system (Vevo) with a probe of much larger size and the results were compared between the two systems. The thickness measured using IVUS was highly correlated (r = 0.985, p < 0.001) with that obtained by Vevo. Thickness and surface reflection amplitude measured using IVUS on the enzymatically digested articular cartilage showed changes similar to those obtained by Vevo, which were expectedly consistent with previous investigations. IVUS can be potentially used for the quantitative assessment of articular cartilage, with its ready-to-use arthroscopic feature.

Evaluation of arthroscopy and macroscopic scoring

INTRODUCTION

Arthroscopy is a minimally invasive technique for retrieving synovial biopsies in rheumatology during the past 20 years. Vital for its use is continual evaluation of its safety and efficacy. Important for sampling is the fact of intraarticular variation for synovial markers. For microscopic measurements scoring systems have been developed and validated, but for macroscopic evaluations there is a need for further comprehensive description and validation of equivalent scoring systems.

METHODS

We studied the complication rate and yield of arthroscopies performed at our clinic between 1998 and 2005. We also created and evaluated a macroscopic score set of instructions for synovitis.

RESULTS

Of 408 procedures, we had two major and one minor complication; two haemarthrosis and one wound infection, respectively. Pain was most often not a problem, but 12 procedures had to be prematurely ended due to pain. Yield of biopsies adequate for histology were 83% over all, 94% for knee joints and 34% for smaller joints. Video printer photographs of synovium taken during arthroscopy were jointly and individually reviewed by seven raters in several settings, and intra and inter rater variation was calculated. A macroscopic synovial scoring system for arthroscopy was created (Macro-score), based upon hypertrophy, vascularity and global synovitis. These written instructions were evaluated by five control-raters, and when evaluated individual parameters were without greater intra or inter rater variability, indicating that the score is reliable and easy to use.

CONCLUSIONS

In our hands rheumatologic arthroscopy is a safe method with very few complications. For knee joints it is a reliable method to retrieve representative tissue in clinical longitudinal studies. We also created an easy to use macroscopic score, that needs to be validated against other methodologies. We hope it will be of value in further developing international standards in this area.

Predicting the development of RA in patients with early undifferentiated arthritis

The rapidity with which bone and cartilage damage occurs in patients with rheumatoid arthritis (RA), and the increasing body of evidence for the effectiveness of early intervention in RA, mean that there is a great need for approaches to accurately predict the development of RA in patients with early undifferentiated arthritis. We will review developments in the prediction of outcome on the basis of clinical and laboratory features, including measures of anti-citrullinated protein/peptide antibody status. Although accurate predictions are possible in the majority of patients using recently developed predictive algorithms which utilize clinical and serological variables, there remains a group of patients for whom it is very difficult to predict the development of RA. The utility of new strategies for prediction will be discussed, including recently discovered genetic associations of RA, an assessment of material from the primary site of pathology (the joint), and assessment using the highly sensitive imaging modalities of ultrasound and magnetic resonance imaging.

Correlation between arthroscopic and histopathological grading systems of articular cartilage lesions in knee osteoarthritis

PURPOSE

Arthroscopic and particularly histopathological assessments have been used to evaluate alterations of knee cartilage in osteoarthritis (OA). The aim of this study was to examine the correlation between an arthroscopic method to grade the severity of chondropathies and the histological/histochemical grading system (HHGS) applied to the corresponding articular cartilage areas in knee OA.

METHODS

The articular cartilage surface was examined by chondroscopy using the Beguin and Locker severity criteria, analysing the lesions in 72 chondroscopic areas. Afterwards, samples were obtained by dividing the cartilage surface of the medial tibiofemoral compartment of three OA knee joints into equal squares and they were evaluated histologically using the HHGS. The correlation between both grading methods was assessed using the weighted Kappa coefficient (K(w)).

RESULTS

The results obtained with both scores showed good agreement (K(w): mean+/-standard deviation, 0.619+/-0.071). While the average HHGS scores of the chondral samples showed a better agreement with arthroscopic grades 0, I and II, the arthroscopic evaluation has a tendency to overestimate chondral lesions for histological grades III and IV. The intra- and inter-observer reliability of the HHGS evaluation of chondral lesions was excellent (Intraclass Correlation Coefficient: 0.909 and 0.941, respectively).

CONCLUSION

In this study, we found a good quantitative correlation between established arthroscopic severity and histopathological scoring systems, particularly in less advanced lesions. Our results suggest that the arthroscopic method is a valuable tool in clinical research to score chondropathies in the medial femorotibial compartment of the OA knee, although some limitations should not be overlooked.

Three-dimensional ultrasonographic application for analyzing synovial hypertrophy of the knee in patients with osteoarthritis

OBJECTIVE

The purpose of this study was to evaluate 3-dimensional (3D) ultrasonography for the visualization of intra-articular synovial hypertrophy in patients with osteoarthritis.

METHODS

Knee joints of 22 patients with osteoarthritis were examined by 3D ultrasonography, and their synovial fluids were analyzed. Ultrasonographic image patterns, vascular endothelial growth factor and transforming growth factor beta concentrations in synovial fluid, and serum inflammatory markers were analyzed.

RESULTS

It was possible to visualize the intra-articular structure by 3D ultrasonography. Three-dimensional ultrasonography revealed various interesting stereoscopic views of the synovial structures, and the patterns of synovial proliferation ranged from simple proliferations to complex shrubby structures. Patients with a more complex and proliferative pattern in the synovium tended to have higher C-reactive protein concentrations, but this difference was not significant (P = .09). The concentrations of vascular endothelial growth factor and transforming growth factor beta in synovial fluid were significantly higher in patients with complex hypertrophy (P < .05).

CONCLUSIONS

Three-dimensional technology was useful in delineating the shape of the synovium. It may have a possible impact on future imaging in rheumatology.

Arthroscopy as a research tool: a review

Arthroscopy continues to experience a growth in interest from the rheumatology community reflecting a common desire to gain better understanding of the underlying processes in inflammatory and degenerative joint diseases. Arthroscopy provides the ability to assess the internal appearances of a joint in a well tolerated and repeatable manner, to obtain tissue samples from the principle site of pathology within the joint and thus confers on it the role of "gold standard" amongst currently available imaging techniques. The evolution of arthroscopy is reviewed together with an overview of the evidence obtained from its research application in the rheumatology. Methodology for the conduct of arthroscopy and synovial biopsy is described.

Septic arthritis in Iceland 1990-2002: increasing incidence due to iatrogenic infections

Objectives:

To assess the impact of increased number of diagnostic and therapeutic joint procedures on the incidence and type of septic arthritis (SA).

Methods:

All cases of SA in Iceland from 1990–2002 were identified by thorough review of the available medical information. The results of synovial fluid cultures from every microbiology department in Iceland were checked and positive culture results reviewed, as well as patient charts with a discharge diagnosis of septic arthritis (International Statistical Classification of Diseases and Related Health Problems (ICD) code M009).

Results:

A total of 253 cases of SA (69 children and 184 adults) were diagnosed in Iceland in 1990–2002, giving an average incidence of 7.1 cases/100 000 inhabitants. The incidence of SA increased from 4.2 cases/100 000 in 1990 to 11.0 cases/100 000 in 2002. This rise in SA was primarily observed in adults where the incidence rose by 0.61 cases/100 000 per year (p<0.001). SA was iatrogenic in 41.8% of adults and the number of iatrogenic infections increased from 2.8 cases/year in 1990–1994 to 9.0 cases/year in 1998–2002 (p<0.01). The annual number of arthroscopies increased from 430 in 1990–1994 to 2303 in 1998–2002 (p<0.001) and there was a correlation between the total usage of intra-articular drugs in Iceland and the incidence of SA (p<0.01). The frequency of post-arthroscopy SA was 0.14% and post-arthrocentesis SA 0.037%.

Conclusions:

The incidence of SA has increased in recent years due to an increased number of arthroscopies and joint injections. Although the frequency of SA per procedure has not changed, these results emphasise the importance of sterile technique and firm indications for joint procedures.

Microscopic measurement of inflammation in synovial tissue: inter-observer agreement for manual quantitative, semiquantitative and computerised digital image analysis

OBJECTIVES

To evaluate inter-observer agreement for microscopic measurement of inflammation in synovial tissue using manual quantitative, semiquantitative and computerised digital image analysis.

METHODS

Paired serial sections of synovial tissue, obtained at arthroscopic biopsy of the knee from patients with rheumatoid arthritis (RA), were stained immunohistochemically for T lymphocyte (CD3) and macrophage (CD68) markers. Manual quantitative and semiquantitative scores for sub-lining layer CD3+ and CD68+ cell infiltration were independently derived in 6 international centres. Three centres derived scores using computerised digital image analysis. Inter-observer agreement was evaluated using Spearman's Rho and intraclass correlation coefficients (ICCs).

RESULTS

Paired tissue sections from 12 patients were selected for evaluation. Satisfactory inter-observer agreement was demonstrated for all 3 methods of analysis. Using manual methods, ICCs for measurement of CD3+ and CD68+ cell infiltration were 0.73 and 0.73 for quantitative analysis and 0.83 and 0.78 for semiquantitative analysis, respectively. Corresponding ICCs of 0.79 and 0.58 were observed for the use of digital image analysis. All ICCs were significant at levels of p<0.0001. At each participating centre, use of computerised image analysis produced results that correlated strongly and significantly with those obtained using manual measurement.

CONCLUSION

Strong inter-observer agreement was demonstrated for microscopic measurement of synovial inflammation in RA using manual quantitative, semiquantitative and computerised digital methods of analysis. This further supports the development of these methods as outcome measures in RA.

Arthroscopic estimation of the extent of chondropathy

INTRODUCTION

Arthroscopy has been used to evaluate articular cartilage (AC) pathology in osteoarthritis (OA) for outcome measurement and validation of non-invasive imaging. However, many fundamental aspects of arthroscopic assessment remain un-validated.

OBJECTIVES

This study evaluated arthroscopic estimates of extent of chondropathy.

METHODS

Serial arthroscopic assessments were performed in a group of 15 sheep before and after bilateral stifle medial meniscectomy (MMx). Post-mortem assessments were performed in un-MMx sheep and 4 and 16 weeks post-MMx. Arthroscopic assessments of the extent of each grade of chondropathy were compared with a non-arthroscopic hybrid assessment that incorporated biomechanical, thickness and macroscopic assessments.

RESULTS

Arthroscopy evaluated only 36% of AC and missed significant pathological changes, softening and chondro-osteophyte, occurring in peripheral regions. The patterns of change in arthroscopic assessments were similar to those of the non-arthroscopic assessment but there was a very strong tendency to over-estimate the extent of softened AC after MMx. In spite of these limitations arthroscopic assessments were responsive to change. Estimates of the extent of normal and softened AC were most responsive to change over time followed by estimates of superficial and deep fibrillation. Arthroscopy was as an excellent discriminator between normal and OA. Assessments of chondro-osteophyte and exposed bone were not responsive to change.

CONCLUSIONS

Arthroscopic estimates of extent of chondropathy are prone to substantial error. While experience and training may reduce these errors other approaches may more effectively improve performance.

Synovial biopsy

In patients with arthritis, synovial tissue is easily accessible for analysis. Blind needle biopsy is a simple and safe procedure. Arthroscopic biopsy is also safe, it allows access to most sites in the joint and it can provide adequate tissue for extensive laboratory investigations, both before and after successful therapy. Synovial tissue analysis has been successfully applied to the study of disease mechanisms and response to treatment. In addition, there may be an indication for diagnostic synovial biopsy in selected cases.

Arthroscopy and joint lavage

Arthroscopy is used by rheumatologists for research purposes in cases with knee osteoarthritis and inflammatory arthritis. This chapter explains the technical characteristics of 'research arthroscopy' including the simplification of the procedure, video-recording, as well as risks and training. Lavage of the knee joint is proposed as a treatment procedure for osteoarthritis and inflammatory and septic arthritis. Tidal irrigation and the two-needle technique of lavage are described. In the absence of clear predictive factors for efficacy, the indications for these techniques are a matter of debate.

Synovial tissue inflammation in early and late osteoarthritis

OBJECTIVE

To compare selected immunohistological features of inflammation in synovial tissue from patients with early and late osteoarthritis (OA).

METHODS

Synovial tissue samples were obtained from 10 patients with knee pain, normal radiographs, and arthroscopic manifestations of OA (early OA), and from 15 patients with OA undergoing knee joint arthroplasty (late OA). Conventional immunohistochemical techniques were used to measure microscopic manifestations of inflammation. The inflammatory cell infiltrate, blood vessel formation, and angiogenic factors, NF-kappaB activation, expression of tumour necrosis factor alpha (TNFalpha) and interleukin 1beta (IL1beta), and the presence of cyclo-oxygenase (COX)-1 and COX-2 were quantified. Fibroblast-like synoviocytes (FLS) were isolated from early and late OA tissue samples to compare in vitro production of prostaglandin E2 (PGE2)

RESULTS

Synovial tissue from patients with early OA demonstrated significantly greater CD4+ (p = 0.017) and CD68+ (p<0.001) cell infiltration, blood vessel formation (p = 0.01), vascular endothelial growth factor (p = 0.001), and intercellular adhesion molecule-1 expression (p<0.001). Numbers of cells producing TNFalpha and IL1beta were also significantly greater in early OA (p<0.001). Manifestations of inflammation in early OA were associated with increased expression of the NF-kappaB1 (p<0.001) and RelA (p = 0.015) subunits, and with increased COX-2 expression (p = 0.04). Cytokine-induced PGE2 production by cultured FLS was similar in both groups.

CONCLUSION

Increased mononuclear cell infiltration and overexpression of mediators of inflammation were seen in early OA, compared with late OA. Isolated FLS were functionally similar in both groups, consistent with microenvironmental differences in the synovial tissue during different phases of OA. These observations may have important therapeutic implications for some patients during the early evolution of OA.

Diagnostic classification of spondylarthropathy and rheumatoid arthritis by synovial histopathology: a prospective study in 154 consecutive patients

OBJECTIVE

To explore prospectively the value of synovial histopathology in comparison with the value of classic parameters for diagnostic classification of spondylarthropathy (SpA) and rheumatoid arthritis (RA) in patients with an atypical disease presentation.

METHODS

Synovial biopsy samples were obtained from 154 consecutive patients presenting for diagnostic evaluation; 67 patients fulfilled the classification criteria for RA, SpA, or other well-defined disease at the time of arthroscopy (cohort 1), and an additional 53 patients were classified after a full diagnostic reevaluation at 6 months (cohort 2). Synovial parameters with diagnostic value were identified in cohort 1 and were compared prospectively with classic diagnostic parameters in cohort 2.

RESULTS

Staining with anticitrulline, staining with monoclonal antibody 12A (recognizing HLA-DR shared epitope-human cartilage glycoprotein 39(263-275) complexes), and crystal deposition had positive predictive values (PPVs) for diagnosis of >90% in patients with an atypical disease presentation (cohort 2). Using these 3 parameters, a diagnosis was predicted by synovial histopathology in 39.6% of cohort 2 patients and turned out to be correct in 90.5% of these patients at 6 months of followup. Using a multiparameter model rather than single histopathologic parameters, even better results were obtained, with a diagnostic prediction in 79.2% of samples and a PPV of 81.0%. In comparison, a similar multiparameter model using classic diagnostic criteria rather than synovial histopathology performed poorly in cohort 2; the sensitivity was 56.6% and the PPV was 73.3%, with an inferior capacity to predict SpA. Especially for the presence of crystals and anticitrulline staining, the analysis of synovial tissue had a clear added value to the analysis of synovial fluid or serum in patients with an atypical presentation.

CONCLUSION

This proof-of-concept study indicates that synovial histopathology can contribute to the multiparametric diagnostic classification of inflammatory arthritis in patients with an atypical presentation.

Are synovial biopsies of diagnostic value?

Synovial tissue is readily accessible by closed needle or arthroscopic biopsy. These techniques provide adequate tissue for most diagnostic requirements. Examination of synovial tissue can assist in the diagnosis of some joint infections, and in several atypical or rare synovial disorders. Histological confirmation is not normally required for diagnosis of the common forms of inflammatory arthritis, including rheumatoid arthritis (RA). In patients with either established or early RA, immunohistological measures of inflammation in synovial tissue are associated with clinical measures of disease activity, may predict the clinical outcome, and change in response to treatment. Surrogate markers of disease activity and outcome that have been identified in synovial tissue include components of the cellular infiltrate, and several mediators of inflammation and matrix degradation. There is evidence that the very early introduction of disease-modifying therapy inhibits progressive structural damage maximally. Clinicians exploiting this 'window of opportunity' therefore require very early indicators of the diagnosis and outcome in patients who present with an undifferentiated inflammatory arthritis. Some immunohistological features have been described that distinguish patients who are likely to develop progressive RA and who might benefit most from early aggressive therapeutic intervention. In this regard, the inclusion of pharmacogenomic and proteomic techniques in the analysis of synovial tissue presents some exciting possibilities for future research.

Diagnostic usefulness of synovial vascular morphology in chronic arthritis. A systematic survey of 100 cases

OBJECTIVES

To assess the diagnostic usefulness of the systematic analysis of synovial vascular morphology in various inflammatory, early, and longstanding arthropathies, and to examine the validity of the vascular patterns in predicting the evolution of a group of patients with undifferentiated arthritis (UA).

METHODS

One hundred patients who underwent rheumatologic arthroscopy of a symptomatic joint (85 knees, 11 wrists, 3 elbows, 1 metacarpophalangeal joint) were evaluated. The same observer, blinded to patient diagnosis, analyzed the video recordings of the arthroscopies. Vascular morphology was classified into 3 patterns: straight, tortuous, and mixed.

RESULTS

Eighty-one patients had inflammatory arthritis: 35 rheumatoid arthritis (RA), 16 psoriatic arthritis (PsA), 13 spondyloarthropathies (SpA), and 17 UA. Forty-nine percent of patients with RA had a straight pattern, 28% a mixed, and 23% a tortuous one. The sensitivity rate of the straight pattern for RA was 77% and the specificity rate was 70%. Seventy-six percent of RA patients with a straight pattern were rheumatoid factor positive (RF+) against 25% of RA patients with a tortuous pattern. The odds ratio for RA associated to straight compared with tortuous pattern was 57.3 (95% confidence interval, 6.6 to 499.5; P <.001). Patients with PsA and SpA shared the same pattern and were analyzed as 1 group. Ninety-three percent of patients with PsA/SpA had a tortuous pattern, 4% a straight pattern, and 3% a mixed pattern. The sensitivity rate of the tortuous pattern for PsA/SpA was 61% and the specificity rate was 95%. During 2 years of follow-up, 6 of 17 patients with UA were definitely diagnosed: 4 RA (2 RF+ and straight pattern; 2 with a tortuous pattern, 1 with RF+ and HLA-B27+); 1 SpA and 1 PsA, both with a tortuous pattern. No differences in vascular patterns were observed according to disease duration. Our results indicate that vascular patterns are not modified by disease modifying antirheumatic drug (DMARD) treatment. The other 19 patients had osteoarthritis (n = 8) and calcium pyrophosphate dihydrate crystal deposition disease (n = 11) and their predominant vascular pattern was tortuous-like.

CONCLUSIONS

Arthroscopic assessment of synovial vascular changes in chronic arthritis may be of diagnostic and pathogenetic interest, although differences between published studies suggest a need for consensus in evaluating vascular patterns. A straight pattern is strongly associated with RF + RA whereas a tortuous pattern is generally associated with PsA or SpA; these associations are independent of disease duration. The vascular pattern likely does not change qualitatively with DMARD therapy. The application of this technique to the diagnosis or prognosis of patients with UA may be a complementary tool for the treatment of these patients, but larger, prospective studies are necessary to confirm this hypothesis.