THE OFFICIAL NEWS SOURCE OF ACR CONVERGENCE 2022 • NOVEMBER 10-14



Anatomy courses offer chance to improve pain management

Ingrid Möller, MD, PhD
Ingrid Möller, MD, PhD

While many rheumatologists recognize that pain is highly dependent on the physical structure of joints and supporting tissues, not everyone has the detailed anatomical knowledge of the ankle and foot, upper extremities, and shoulder needed to accurately assess pain or treat it appropriately.

“Ankle and midfoot disorders are very prevalent, complex, and multifactorial in origin,” said Ingrid Möller, MD, PhD, Assistant Professor of Anatomy, Instituto Poal de Reumatologia Barcelona, University of Barcelona, Spain. “They are a challenge in daily clinical practice and may affect both mobility and quality of life for our patients. The structure and function of the ankle and midfoot is poorly understood by the rheumatologist. It will help to journey through the clinically relevant anatomy and sonographic anatomy.”

Dr. Möller will lead the first of three anatomy and sonography symposia at ACR, Anatomy for the Clinician I: Anatomy of the Ankle & Midfoot: The Source of Ankle Pain on Sunday from 11:00 am –
 12:00 pm in Room 28 A-E. Subsequent sessions on Monday and Tuesday will explore the anatomy of the lower extremities and shoulder.

The complex anatomy and biomechanics of the ankle and midfoot make assessment difficult, and causes of pain can be difficult to localize. Adding sonography to the physical exam can add clinically significant detail and improve the clinician’s ability to treat pain.

“Ankle and midfoot problems are very frequent in rheumatology,” Dr. Möller said. “The foot is involved in almost 90 percent of patients with rheumatoid arthritis. The subtalar joints are more commonly affected than the ankle, especially in patients with longstanding disease.”

Ankle and foot pain is also common in other arthropathies, including spondyloarthritis, metabolic arthropathies, and osteoarthritis. Rheumatologists also see a variety of soft-tissue musculoskeletal disorders, including plantar fasciitis, heel fat pad damage, chronic ankle instability, and Achilles tendonopathy.

“Joint disease or soft tissue changes in this region, which must withstand a significant mechanical burden throughout life, can further augment symptoms and disease progression,” she said. “When evaluating pain in this region, a multifactorial etiology needs to be considered. In many cases, input from podiatry, physiatry and/or rheumatology is essential.”

So is ultrasound.

Results from Europe have shown that musculoskeletal ultrasound can bring significant added value to the rheumatology exam, Dr. Möller said. The foot, like the hand, is functionally dependent on superficial soft tissue components such as muscles, tendons, nerves, ligaments, and supporting retinacula and fascia that must work in unison.

Ultrasound offers better resolution than other imaging modalities and can easily be performed in the office or at the bedside and can be used while moving the affected structures or applying stress. Imaging structures while under stress and comparing results to contralateral structures can provide diagnostic and therapeutic insights not possible with other imaging modalities.

It can be clinically difficult to distinguish between an edematous ankle versus ankle synovitis, but ultrasound makes it possible to visualize arthritis. Ultrasound can also help rule out heel fat pad lesions, plantar venous thrombosis, fascia ruptures, or nerve compression lesions in dealing with plantar pain at the heel level. Doppler ultrasound can detect abnormal vascularization associated with disease activity and worse structural prognosis.

Deeper abnormalities such as bone and bone marrow uptake as a result of fractures, congenital and developmental conditions such as tarsal coalition, bone infections, osteochondral abnormalities, neoplasms, avascular necrosis, and others may require sectional imaging by MRI or CT.

Carlo Martinoli, MD
Carlo Martinoli, MD

Ultrasound is similarly helpful in diagnosing and treating upper extremity and shoulder pain. Carlo Martinoli, MD, Associate Professor of Radiology at the University of Genoa, Italy, will lead two relevant symposia. Anatomy for the Clinician II: Neuroanatomy Upper EXT: Nerve Entrapment to Nerve Blocks takes place Monday in Room 30 E from 11:00 am – 12:00 pm, and Anatomy for the Clinician III: Shoulder Pain: Practical Anatomy & Evaluation on Tuesday takes place from 11:00 am – 12:00 pm in Room 30E.

“Ultrasound is able to demonstrate the nerve and soft tissue anatomy in very great detail, ” Dr. Martinoli said. “Ultrasound has higher spatial resolution than MR imaging to depict subtle abnormalities of small sensory nerves and terminal branches. Any tunnel entrapment in the upper extremity, including the carpal tunnel for the median nerve, the cubital and Guyon tunnels for the ulnar nerve, the supinator canal for the posterior interosseous nerve, and even smaller structures, can clearly be seen and traced on ultrasound.”

The primary advantages of ultrasound include time effectiveness, low cost, availability, and ease of examining and evaluating long nerve segments in a single study. Ultrasound is also a dynamic technique, able to provide information on the nerve status during joint motion and contraction of the muscles.

“In a few seconds, ultrasound lets you see the state of the nerve throughout the upper extremity,” he said. “Ultrasound is clearly the technique of choice in evaluating nerve entrapments.”

Knowledge of anatomy is the key to successful ultrasonography. There are plenty of anatomic landmarks to help locate and identify nerves, and all must be properly identified. Otherwise, the branching nerve system can become extremely complex and confusing to the uneducated eye.

“Ultrasound can also help guide the needle when you are performing a nerve block,” Dr. Martinoli added. “Ultrasound lets you very precisely inject anesthetics and corticosteroids around even the smallest of nerves, which can be a great help in regional pain syndromes.”

In the shoulder, a physical exam can suggest the origin for some shoulder abnormalities, but adding ultrasound gives an even better picture of what has gone wrong and how to address the problem.

“Many rheumatologists have learned to perform ultrasound, but not everyone,” Dr. Martinoli said. “The reality is that ultrasound may be the perfect complement to a clinical exam to get a more precise idea of the condition affecting your patient — and to guiding you to the most effective treatment.”