From the Clinic: Not Every Painful Rheumatoid Foot Is an Arthritis Flare
When someone has rheumatoid arthritis (RA), it's easy to assume that every new ache or swollen joint is caused by inflammation.
In reality, many patients develop entirely separate mechanical problems that require very different treatment. Recognising the difference can be the key to restoring mobility and avoiding unnecessary escalation of rheumatology medication.
This recent case is a good example.
The Presentation
The patient was referred following assessment by her rheumatology team because her symptoms appeared to be more mechanical than inflammatory.
She had lived with rheumatoid arthritis for more than 11 years, which was generally well controlled with methotrexate. Despite this, she had developed gradually worsening pain affecting both ankles and heels.
Only months earlier she had comfortably walked four to five miles. By the time she attended clinic, she struggled after just 15–20 minutes.
Her ankles had always been the joints most affected by her rheumatoid arthritis, making it understandable to suspect another inflammatory flare.
Fortunately, an MRI had already been arranged.
What Did the MRI Show?
The scan revealed several important findings:
Mild plantar fasciitis
Bilateral tarsal coalition
Early osteoarthritis affecting the ankle and talonavicular joints
Rather than showing widespread active inflammatory disease, the MRI demonstrated structural mechanical problems that explained her symptoms remarkably well.
Understanding Tarsal Coalition
Many people have never heard of a tarsal coalition.
It is a congenital condition where two bones within the foot are joined together, either by bone, cartilage or fibrous tissue. Although present from birth, many people remain symptom-free until adulthood.
As activity levels increase or arthritis develops around the abnormal joint, pain can begin to appear.
The coalition restricts the normal movement between the bones, meaning surrounding joints are forced to work harder. Over time this commonly leads to:
Early osteoarthritis
Reduced side-to-side movement
Recurrent ankle pain
Difficulty walking on uneven ground
Fatigue during prolonged activity
On examination she demonstrated the characteristic reduction in side-to-side hindfoot movement, particularly on the left side, matching the MRI findings.
Why This Matters
Patients with rheumatoid arthritis are certainly more prone to inflammatory joint pain.
However, they are not immune from developing common mechanical problems.
In fact, attributing every symptom to inflammatory disease risks missing treatable structural conditions.
This case highlights the importance of treating the patient—not simply treating the diagnosis.
The MRI allowed us to confidently identify the dominant pain generators rather than assuming the rheumatoid arthritis was responsible.
Our Treatment Plan
Because the symptoms were primarily mechanical, treatment focused on reducing joint stress rather than escalating immunosuppressive medication.
Initial management included:
Ultrasound-guided viscosupplementation with a low-dose corticosteroid into the left ankle and talonavicular joint
3D-printed custom foot orthoses designed from bespoke casts
Footwear advice to reduce loading through the affected joints
Activity modification during the initial recovery period
The aim was to improve joint lubrication, reduce mechanical irritation and optimise foot biomechanics to minimise stress across the affected joints.
Early Follow-Up
At review several weeks later, the improvement was encouraging.
She reported approximately 70% improvement in her previously painful left ankle. Although not completely pain-free, only occasional discomfort remained at the front of the ankle.
Importantly, the right ankle was no longer painful.
Her custom 3D-printed orthoses were fitted to provide long-term mechanical support and reduce loading through the affected joints.
As the right ankle was comfortable on the day of review, we proceeded with viscosupplementation alone, avoiding the steroid component because there was no active pain requiring its anti-inflammatory effect.
The left ankle did not require repeat injection, allowing the orthoses time to provide their full biomechanical benefit.
Why Combine Orthoses and Injection?
Neither treatment is a magic bullet.
An injection can calm an irritated joint and improve lubrication, allowing patients to become more active.
Custom orthoses then help maintain those improvements by reducing abnormal loading and improving foot mechanics during everyday walking.
Used together, they often provide longer-lasting symptom control than either treatment alone.
Key Learning Points
This case reinforces several important lessons:
Not every painful foot in rheumatoid arthritis is caused by inflammation.
MRI can be invaluable in distinguishing inflammatory disease from mechanical pathology.
Tarsal coalition is frequently under-recognised in adults and can contribute to early osteoarthritis.
Mechanical causes of pain require mechanical solutions.
Combining image-guided injections with bespoke orthotic therapy can significantly improve walking ability and quality of life.
Final Thoughts
Foot pain in patients with rheumatoid arthritis is often complex, with multiple conditions existing side by side.
Careful assessment, appropriate imaging and an understanding of biomechanics allow treatment to be directed at the true source of symptoms rather than simply assuming inflammation is to blame.
In the patient's case, identifying the mechanical contributors to her pain has already resulted in a substantial improvement in function, with further gains expected as her custom orthoses continue to support her feet over the coming weeks.
Mr L Stapleton MSc PGDip PGc(IP) PGc(PSM) FFPM RCPS(Glas) FRCPodM
Consulting Prescribing Podiatrist & Specialist in Podiatric Sports Medicine
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