Sternoclavicular Joint Involvement in Rheumatoid Arthritis: Fascinating Discovery of a “Neglected Joint”
About a month ago, I was fascinated by a new report on 103 “patients with Rheumatoid Arthritis” in Mexico, “Sternoclavicular Joint Involvement in Rheumatoid Arthritis: Clinical and Ultrasound Findings of a Neglected Joint.” A sternoclavicular (SC) joint is a joint at the top of the sternum that allows movement of the clavicle. We each have 2. You can view clear pictures of the SC joint on Shoulderdoc.co.uk.
How often are sternoclavicular joints affected in Rheumatoid Arthritis?
This is the first modern study on the prevalence of SC joint involvement, evaluating joints in several ways:
- Visual inspection
- Palpation (touching) during rest and movement
- Asking about history of pain or swelling
- Listening for crepitus (which can be done with a stethoscope as seen here)
If they found any of these, researchers considered the SC joint to be “clinically involved.” Their exams detected that 19% of SC joints were clinically involved, compared to only 1.9% in a healthy control group. The SC joints were also thoroughly evaluated by specialists with musculoskeletal ultrasound (MSUS). 43% of SC joints had at least one MSUS lesion, compared with 17% in the control group.
They concluded that “The sternoclavicular joint actively participates in the systemic inflammatory process of rheumatoid arthritis, as do other peripheral synovial joints,” and that ultrasound is an effective tool to identify it.
Ok, that’s interesting to know about, but why does it matter?
Why this story is valuable to patients
- The study authors acknowledge a model of a “clinically affected” or “involved” joint. It would be a significant improvement in care if this model were widely used. I’ve advocated consideration of involved joints (including any sign of involvement) because it would provide a more accurate picture of a particular patient’s disease. It is more precise than merely counting which joints appear swollen in a clinician’s opinion at a particular moment.
- Crepitus is acknowledged as a meaningful symptom. I’ve heard and read from some rheumatologists that it is not to be considered significant.
- Expert musculoskeletal ultrasound was used to detect signs of disease activity that are not always obvious. (More on that soon.) Diagnostic MSUS is very valuable if performed by a well-trained clinician, as RAW has reported, and not yet widely available in the United States.
How can there be a “neglected joint” in the first place? Why do people who live with a disease know things that experts who write textbooks don’t? After listening to experts for the past few years, I have some ideas (listed below). But first, a telling little story:
Last year, I shook hands with one of the top rheumatology experts in the world using my usual safe handshake that doesn’t allow fingers to be squeezed. Then he pleasantly explained to me that his RA handshake version was better since “RA doesn’t affect DIP joints,” and he proceeded to firmly squeeze the end half my sore fingers. With a smile, he thought he taught me something new because it never occurred to him that some people (actually most) do have DIP joints involved.
What ELSE can be learned from this study?
Look at this simple sentence: “Both the patients and healthy controls were specifically asked about the current or past presence of signs or symptoms reminiscent of SC joint involvement (i.e., pain and/or swelling).”
- More is unknown than is known about Rheumatoid Disease, as many freely admit. Therefore, it is irresponsible to tell patients “such-and-such joint is not related to RA” or “that symptom cannot be your RA,” etc. as patients often report. See also DIP joint.
- The most valuable input to assessing Rheumatoid Disease is the input of the patient who lives with it 24/7/365.
- The most important quality in a researcher is intellectual curiosity, so that she or he is open-minded to things that are not already known. Intellectual curiosity enables researchers to ask new questions or examine them in new ways, instead of protecting the existing framework. Without honest curiosity, advancement of knowledge is very slow. Intellectual curiosity is the polar opposite of dismissiveness too often seen with RD.
- Does It Matter Whether Rheumatoid Arthritis Affects DIP Joints?
- What Is the List of Rheumatoid Arthritis Joints?
- Posts on musculoskeletal ultrasound (MSUS)
- Rheumatoid Arthritis Hand – Safe Handshake
Pedro Rodríguez-Henríquez P, Solano C, Peña A, León-Hernández S, Hernández-Díaz C, Gutiérrez M, Pineda C. sternoclavicular joint involvement in rheumatoid arthritis: Clinical and ultrasound findings of a neglected joint. Arthritis Care Res. 2013 Jul [cited 2013 Jul 30];65(7):1177–1182. Available from: http://onlinelibrary.wiley.com/doi/10.1002/acr.21958/full. Abstract available from: http://onlinelibrary.wiley.com/doi/10.1002/acr.21958/abstract.
Yood RA, Goldenberg DL. Sternoclavicular joint arthritis. Arthritis & Rheum. 1980 Jan [cited 2013 Jul 30];23(2):232–239. Available from: http://onlinelibrary.wiley.com/doi/10.1002/art.1780230215/abstract
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