Precision Medicine in Rheumatology: The Promise of Ultrasound-Guided Synovial Biopsy, Barriers to Its Implementation in the United States, and Proposed Solutions

PURPOSE OF REVIEW

In the clinical evaluation of inflammatory arthritis and the research into its pathogenesis, there is a growing role for the direct analysis of synovial tissue. Over the years, various biopsy techniques have been used to obtain human synovial tissue samples, and there have been progressive improvements in the safety, tolerability, and utility of the procedure.

RECENT FINDINGS

The latest advancement in synovial tissue biopsy techniques is the use of ultrasound imaging to guide the biopsy device, along with evolution in the characteristics of the device itself. While ultrasound guided synovial biopsy (UGSB) has taken a strong foothold in Europe, the procedure is still relatively new to the United States of America (USA). In this paper, we describe the expansion of UGSB in the USA, elucidate the challenges faced by rheumatologists developing UGSB programs in the USA, and describe several strategies for overcoming these challenges.

What Bedside Skills Could the Modern Rheumatologist Possess? Part II. "Certain Technical Procedures"

ABSTRACT

Rheumatologists have never been reluctant to adopt procedures that might enhance their diagnostic or therapeutic powers. Their propensity to penetrate the joints of the patients they were treating set them apart from the general internist. Since the 1980s, when a chance to look inside the joints they were treating attracted a few rheumatologists, other things that could be done at the bedside emerged with now an array of bedside procedures that could be part of a rheumatologist's skill set. Besides gains in diagnosis and/or therapy, each constitutes a chance to restore the physical contact between physician and patient, riven by factors of the last decade, such as electronic medical records and COVID. With such contact so important to satisfaction of the patient and physician alike, acquisition of proficiency in certain technical procedures described herein offers one path to begin restoring rheumatology to the richly fulfilling practice it once was.

Best practices for ultrasound-guided synovial biopsy in the United States

The target organ in many forms of inflammatory arthritis is the synovium. However, synovial tissue has historically been perceived as either difficult to obtain or of little practical value. Ultrasound-guided synovial biopsy [UGSB] is a safe and well-tolerated bedside procedure that is established in Europe and rapidly growing in popularity in the United States. The technique can be mastered by rheumatologists who are already experienced in ultrasound-guided procedures such as joint aspirations. The USGB procedure allows the proceduralist to access small, medium, and large joints and is inexpensive and less invasive compared to surgical alternatives. The relative ease of obtaining this tissue, along with recent research suggesting that synovium may have more clinical and investigational utility than previously thought, has led clinicians and researchers to a new appreciation of the role of synovial biopsy in both the clinical and research setting. In this manuscript, the authors present recommendations on best practices for ultrasound-guided synovial biopsy in the United States, based on our initial training with well-established experts overseas and our own subsequent collective experience in performing numerous synovial biopsies in the United States over the past 7 years for both clinical and research indications. We envision a future where UGSB is more frequently incorporated in the standard diagnostic workup of arthritis and drives novel research initiatives.

The application of a novel hydrodynamic cavitation device to debride intra-articular monosodium urate crystals

INTRODUCTION

Efficient and complete debridement of intra-articular deposits of monosodium urate crystals is rarely achieved by existing arthroscopic tools such as shavers or radiofrequency ablation, while cavitation technology represents a prospective solution for the non-invasive clearance of adhesions at intra-articular interfaces.

METHODS

Simulation modeling was conducted to identify the optimal parameters for the device, including nozzle diameters and jet pressures. Gouty arthritis model was established in twelve rats that were equally and randomly allocated into a cavitation debridement group or a curette debridement group. A direct injection nozzle was designed and then applied on animal model to verify the effect of the cavitation jet device on the removal of crystal deposits. Image analysis was performed to evaluate the clearance efficiency of the cavitation device and the pathological features of surrounding tissue were collected in all groups.

RESULTS

To maximize cavitation with the practical requirements of the operation, an experimental rig was applied, including a 1 mm direct injection nozzle with a jet pressure of 2.0 MPa at a distance of 20 mm and a nitrogen bottle as high-pressure gas source. With regards to feasibility of the device, the clearance rates in the cavitation group were over 97% and were significantly different from the control group. Pathological examination showed that the deposition of monosodium urate crystals was removed completely while preserving the normal structure of the collagen fibers.

CONCLUSIONS

We developed a promising surgical device to efficiently remove intra-articular deposits of monosodium urate crystals. The feasibility and safety profile of the device were also verified in a rat model. Our findings provide a non-invasive method for the intraoperative treatment of refractory gouty arthritis.

Regarding Arthroscopy: Can Orthopedists and Rheumatologists Be Friends?

BACKGROUND/OBJECTIVE

Rheumatologists' interest in arthroscopy began before the 1980s, when many era practitioners began to take up the procedure in earnest. Some of the important players in pre-World War II explorations of arthroscopy were rheumatologists, and the father of modern arthroscopy Makei Watanabe counted many rheumatologists among his postwar students, who were publishing about arthroscopic insights into rheumatic conditions in the 1960s and 1970s. We chose to review this evolution to demonstrate the diverging interests of rheumatologists and orthopedists in arthroscopy and emphasize the chances for reconciliation and cooperation. Methods involve our personal recollection and review of the literature.

RESULTS

Guidelines for the practice of arthroscopy were published by the American Rheumatism Association (now the American College of Rheumatology) 7 years before similar guidelines appeared from the Arthroscopy Association of North America. American rheumatologists ceased arthroscopy when controlled trials showed no effect in osteoarthritis beyond placebo and biologics for synovitis virtually eliminated situations in which synovectomy might be considered. The research potential of arthroscopy has been realized mainly by European rheumatologists, although the ultrasound-guided biopsy is supplanting arthroscopy as means to secure synovium for investigation, despite the advantages of the latter, such as the ability to obtain larger amounts of tissue, select tissue based on macroscopic appearance, sample multiple area in the same joint, and deliver the potentially therapeutic effect of washout. New miniscopes suitable for office use could restore some of the lagging interest in arthroscopy for investigation. Orthopedists have generally been resistant to rheumatologists doing arthroscopy but would not be sharing any turf with rheumatologists using the miniscope.

CONCLUSIONS

We hope that we orthopedists and rheumatologists could be friends as we enter this new phase of arthroscopy as we use the technique for different purposes.

Will rheumatologists ever pick up the arthroscope again?

Conditions prompting physicians and surgeons first adapting endoscopes to peer into joints were mainly the sort of synovial conditions that would concern today's rheumatologists. Rheumatologists were among the pre-World War II pioneers developing and documenting arthroscopy. The post-War father of modern arthroscopy, Watanabe, found rheumatologists among his early students, who took back the technique to their home countries, teaching orthopedists and rheumatologists alike. Rheumatologists described and analyzed the intra-articular features of their common diseases in the '60s and '70s. A groundswell of interest from academic rheumatologists in adapting arthroscopy grew considerably in the '90s with development of "needle scopes" that could be used in an office setting. Rheumatologists helped conduct the very trials the findings of which reduced demand for their arthroscopic services by questioning the efficacy of arthroscopic debridement in osteoarthritis (OA) and also developing biological compounds that greatly reduced the call for any resective intervention in inflammatory arthropathies. The arthroscope has proven an excellent tool for viewing and sampling synovium and continues to serve this purpose at several international research centers. While cartilage is now imaged mainly by magnetic resonance imaging, some OA features - such as a high prevalence of visible calcinosis - beg further arthroscopy-directed investigation. A new generation of "needle scopes" with far superior optics awaits future investigators, should they develop interest.