Arthritis in Feet

Rheumatoid arthritis is a chronic systemic inflammatory disease that affects the joints and surrounding tissues throughout the body, from the head to the feet (back, elbows, hips, knees, feet, etc.). The cause of this disease (RA) is of unknown etiology and is considered an autoimmune disease. It can occur at any age, but two-thirds of patients are women, with a higher prevalence in the elderly.
​From an epidemiological point of view, it can be said that this pathology affects 0.5% of the general population. It can occur at any age but is more common between 25 and 55 years old, and most cases (two-thirds) occur in women, although this imbalance tends to level off after the age of 60. The hallmark of a rheumatoid patient is their hands, which, despite the severe deformities, have not lost their functionality. However, the greatest pain originates from their feet. For this reason, we consider studying and treating the effects of this significant foot disease. The treatment should be part of the global medical-surgical strategy of the patient, which includes a multidisciplinary team: rheumatologist, orthopedic surgeon, podiatrist, physiotherapist, and orthopedist. The foot is the most affected area in generalized polyarthritis, with the midfoot being the most impacted, though it also damages other joints of the same ankle between 15% and 50%. Rheumatoid arthritis triggers various deformities depending on the type of anatomical foot. The nature of this disease affects not only the joints but also the tendons, bones, skin, muscles, vessels, and nerves in several ways, summarized as follows:

– Jointly: Early phase of synovitis, with secondary involvement of the joint capsule and loss of ligament properties, which would explain the ease of subluxation and dislocation of the joints. In more advanced stages, as we will discuss later, there is destruction of the cartilage and its subsequent loss of joint functionality.
– Tendon injuries: They start in the sheath and the synovitis gradually destroys the tendon until it ruptures.
– Bone: Radiologically, we observe osteoporotic tissue, and in person, a weak bone that worsens with corticosteroid use, increasing the risk of fractures. The Galmiche sign, a notch in the head of the fifth metatarsal, simulates a bite mark.
– Skin: Thin and fragile, lifeless, and tears easily, potentially causing ulcers.
– Vascularly: Vasculitis is common, affecting the smallest vessels, which will appear as small vascular spider webs under the skin. This factor is closely related to wound healing.
– Nodules: Once the vascular system is altered, small nodules may appear under the skin in areas of friction, which is very characteristic of this disease.
– Muscle lesions: Affected arterioles in the connective tissue interstitial space, combined with the lack of activity in these patients due to pain, lead to muscle atrophy.
– Neurologically: The combination of the above conditions leads to involvement of the perineurium, creating sensory or sensory-motor neuropathies. Additionally, bone deformities can lead to nerve entrapments.

The diagnosis of a rheumatic foot is based on its clinical symptoms and complementary tests such as bone scintigraphy, MRI, and conventional X-rays. However, the rheumatoid factor (RF), consisting of HLA B27 proteins and PCR and ESR, is a pathological examination of the synovial sheath for a more conventional and effective analysis, as tests may be negative in the first few months, making them less useful for early detection. These factors also occur in patients without the disease and in patients with other conditions but less frequently than in those with RA. Rheumatoid arthritis can manifest in young people, but as we mentioned earlier, its diagnosis and treatment can be effective. If diagnosed early, the podiatrist not only cares for your feet but can also help detect other diseases affecting the entire body.