High Time to Upgrade the Clinical Joint Examination with Complementary Musculoskeletal Ultrasound -From the Clinician's Finger to the Ultrasound Transducer.

In this issue of Internal Medicine, Shimizu et al. reported a case of sporotrichal tenosynovitis diagnosed helpfully by musculoskeletal ultrasonography (MSUS) (1). Sporotrichosis, which is also known as “rose gardener's disease”, is a disease caused by infection with the fungus Sporothrix schenckii. I would like to comment on their findings as a rheumatologist, not as an infectious disease specialist.

Based on the appearance of the patient's wrist in the present case, an experienced rheumatologist should be able to distinguish typical joint synovitis from rheumatoid arthritis. However, for non-specialists, such as the local orthopedist in the present case, such a conclusion may be difficult to draw, and they may suspect it of being early rheumatoid arthritis. The accurate clinical examination of joints is, like other skills in a clinical examination, dependent on the clinicians' experience, their knowledge of anatomy and the pathologies. Consequently, there are always limitations with a classic routine physical examination using the five senses.

Several steps have been taken throughout history to overcome these limitations. For example, the stethoscope was invented in France in 1816 by René Laennec at the Necker-Enfants Malades Hospital in Paris (2). The stethoscope imbued users with powerfully advanced diagnostic knowledge and medical capabilities in those days. However, with the rapid development of medical equipment aiding physicians in their decision-making, even stethoscopes are becoming old-fashioned, and some physicians believe that they will soon be obsolete.

Ultrasonography (US) is a safe and effective form of imaging that has been used by many specialists for over half a century to aid in the diagnosis and guide procedures. Over the past two decades, US equipment has become more compact, higher quality, and less expensive to manufacture. In 2004, a conference on compact US hosted by the American Institute of Ultrasound in Medicine (AIUM) concluded that “the concept of an ‘ultrasound stethoscope’ is rapidly moving from the theoretical to reality.” There are numerous reports comparing the reliabilities of the stethoscope vs. US probe (3) or a physical examination vs. US (4). In most cases if not all, the winner is US.

The situation in the field of rheumatology is no different. Within the past decade, MSUS has become an established imaging technique for the diagnosis and follow-up of patients with rheumatic diseases. MSUS is most commonly used in the assessment of soft tissue disease or detection of fluid collection and can also be used to visualize other structures, such as cartilage and bone surfaces. MSUS can be used to detect pathologies that cannot be evaluated by conventional radiography, such as synovitis and synovial fluid. In addition, it is more sensitive than radiography in detecting bone erosions. Compared to MRI and CT, MSUS is noninvasive, cheap, immediately available, applicable to several articular sites, easy to repeat and, above all, suitable for dynamic studies. However, regarding its drawbacks, MSUS has been described as operator-dependent and time consuming. There is now accumulating evidence that MSUS improves the accuracy of the clinical diagnosis and the intervention skills. High-resolution US is superior to a clinical examination in the diagnosis and localization of joint and bursal effusion and synovitis. MSUS is becoming popular among rheumatologists, but not necessarily among general physicians. The present case reported by Shimizu et al. reminds us of the importance and utility of MSUS in clinical practice.

However, we should always keep in mind that the indiscriminate use of ultrasonography may lead to further unnecessary testing, unnecessary interventions in the case of false positive findings or inadequate investigation of false negative findings. For example, in a recent study, incorporating US information into strategic treatment decisions and targeting therapy towards imaging remission (abrogation of inflammation as visualized by US) in rheumatoid arthritis did not lead to improved outcomes (5). The authors concluded that the application of US imaging remission as a treatment target in rheumatoid arthritis may lead to overtreatment and inefficient use of healthcare resources. As is always the case, more imaging may simply lead to increased expense without added benefit, or might even be harmful. These results do not deny the important roles of MSUS in the detection of subclinical synovitis, subradiographic bone erosions or in the differential diagnosis of rheumatic diseases and in procedures such as intra-articular injections.

In rheumatology, a clinical examination using manual palpation is still and will always be the most important method for evaluating joint diseases. However, as there are some limitations to a clinical examination, we should aggressively and reasonably use MSUS, a rheumatologists' magic stethoscope, as a complementary procedure to a systematic clinical evaluation. MSUS is not only useful for rheumatologists but also for general practitioners. Don't let the rheumatologists alone use this wonderful imaging tool; instead, encourage its widespread use, which benefits more patients.

The author states that he has no Conflict of Interest (COI).