With 28 bones in each foot, each of which contacts another bone or two or three (we call this a joint) - you can imagine that joint pain in the foot is fairly common. While there are some more commonly seen causes of joint pain in the feet, the puzzling instances of joint pain that is difficult to treat can often be related to underlying systemic disease. While most people have heard of rheumatoid arthritis, not all people understand the condition and furthermore there are a great number of people that may not realize there are multiple ‘rheumatological’ conditions outside of rheumatoid arthritis that may be the underlying cause of pain.
Joint pain caused by a condition called osteoarthritis (DJD) is the most common cause of pain in a joint. This is the ‘wear and tear’ arthritis. Its cause results from the mechanics of the foot structure, the way that two or more bones interact with surrounding structures. There are many instances of mechanical arthritis that may have stemmed from a previous injury - whether it be repeated ankle sprains or even a fracture of a bone which invades the joint space.
This type of arthritis is usually isolated to the overused joints and many times may affect only one foot or the other. That being said, if foot mechanics are typically symmetrical, pain may occur on both feet but worse on one side due to favoring that one side. DJD often worsens slowly over time. However, there are instances whereby a very advanced arthritis experiences ‘flare ups’ due to overdoing it one day or another or (in the instance of feet) if unsupportive shoes are worn for extended periods of time.
Gout is another commonly seen condition in the feet. It will typically occur in just one joint - most often the great toe joint or the ankle, on one side of the body. Having gout attacks on both feet simultaneously is exceedingly rare. Gout is an arthropathy (condition of the joint) whereby there is crystals deposit in and around the joint causing attacks that seem to come out of nowhere. Patients that we see with gout can many times relate to having a relative (grandparent or parent) who had gout. So where are these crystals coming from and what are they?
In classic gout, the ‘crystals’ we speak of are uric acid. Uric acid is a biproduct of protein breakdown in the body. Everyone produces uric acid, but those who suffer from gout either overproduce this uric acid OR undersecrete it. In these situations the crystals leave the bloodstream and deposit into joints. This results in extreme redness, pain and swelling. Often motion is terribly painful as these tiny crystals rub against the joint surface and have caused increased fluid in the joint. True, classic gout is more often seen in men and can be treated with change in diet or medication. Oral medications to control gout are most often prescribed by a primary care doctor or rheumatologist. In instances of gout attacks, podiatrists prescribe strong anti-inflammatories to reduce the painful attack, but while it offers relief while the attack subsides it does not correct the underlying cause.
A condition called pseudogout is the one which is more commonly seen in females. This condition is named as it is because the symptoms also come on suddenly and cause redness, extreme pain and swelling of a joint. The crystal type differs from that of classic gout. In pseudogout (also called CPPD) the crystal causing pain is calcium pyrophosphate. In pseudogout, smaller joints are often affected more often than in classic gout. Diagnosing gout and pseudogout will often involve some blood tests, one of which actually measures uric acid levels in the bloodstream. The most definitive way to diagnose either condition is through a procedure called aspiration. This procedure requires use of a needle and syringe to pull the inflammatory fluid form the joint and it is then sent for analysis at a lab. Aspiration biopsies are also very helpful in diagnosis of rheumatological conditions that will be described below.
Rheumatoid arthritis is a systemic arthritis, meaning that more than just the feet are typically affected. The true cause is often unknown. In rheumatoid arthritis, symptoms include pain and swelling of symmetrical joints. Blood tests will reveal a positive rheumatoid factor. Rheumatoid arthritis in the feet can be seen as development of pain in the joints in the balls of the feet and over time, deformities can occur. The condition causes weakening of the medial joint capsule which causes the toes to drift toward the pinky toe side. Rheumatoid arthritis can also cause the development of rheumatoid nodules. These nodules occur around affected joints and are tough, thick tissue that is embedded in the joint capsule - making removal of these lesions tricky.
There are criteria in rheumatoid arthritis that need to be considered. If three of these criteria are true for a certain patient, the likelihood is that they have RA. If there are five of these present, there is definite RA. These criteria include morning stiffness, pain on motion through 1 joint, swelling in 1 joint, swelling of another joint, symmetrical (same on both sides of the body) joint swelling, subcutaneous nodules, positive RA test, x-ray changes, pathological changes to the synovium (joint lining), and pathological changes within the nodules tested.
There are some unfortunate patients that not only have rheumatoid arthritis, but also have concurrent conditions. If a patient with RA also has enlargement of the spleen and granulocytopenia has Felty’s syndrome. These patients are at risk for leg ulcers as well as bacterial infection. Sjogren’s syndrome is when a patient has an overall finding of drying out of mucous membranes. This often results in recurrent infections. 90% of patients suffering Sjogren's are female.
Juvenile rheumatoid arthritis is when this condition begins before the age of 16 years old. This is more commonly seen in females than males and while it has similar findings to traditional RA there are some distinctions. In JRA, the disease is particularly severe. The peak of this disease occurs in ages 2-5 years and 9-12 years. These children have high fevers, they are very sickly and suffer from polyarthralgia and they are said to have fevers of unknown origins. Half of these children will have growth and developmental abnormalities. In JRA, a positive rheumatoid factor is only seen in 10-20% of those undergoing blood test.
As rheumatoid arthritis is a progressive disease, those who find themselves facing a surgical procedure will face a different range of surgical options. In addition, because of medications used to manage RA, many need to be adjusted prior to surgery. Steroids and other medications aim to reduce the inflammatory processes in the body and this impedes a person’s ability to heal from surgery. In addition, many surgeries require anesthesia and if general anesthesia is anticipated, cervical spine x-rays must be performed to evaluate for instability that could cause complications with regards to intubation.
Another commonly seen condition is psoriatic arthritis. This is referred to as one of the seronegative diseases. This condition typically involves the small joints within the fingers and toes. Psoriatic can be harder to diagnose than rheumatoid arthritis due to the labwork. Once diagnosed, psoriatic arthritis is treated with anti-inflammatories (NSAIDS) as well as medications which lower the immune system. Therefore patients with psoriatic arthritis who are being treated can have an increased risk of infection. When psoriatic arthritis has been present for a period of time, x-rays may reveal an appearance to the bones in the tips of the toes that they are disappearing (we call this osteolysis). Joint findings on x-rays will give the appearance of a pencil in cup.
Reiter’s syndrome is a disease in which the eyes, joints and urinary tract is affected. Conjunctivitis or inflammation of the eyes as well as swelling and pain in small bones and joints can occur. Difficulty with urination in combination with these other two symptoms merits a work-up to rule out Reiter’s syndrome. If Reiter’s is seen on x-ray, it will be seen as a fluffy appearance to the bone in the back of the foot, called the calcaneus. Inflammatory markers will be elevated in blood testing.
A condition called ankylosing spondylitis is when there is pain primarily to the joints of the hips, spine and very low back. In this condition, the affected joints are in a process of fusing themselves and the goal of treatment is to allow fusion of these joints in a straight alignment. In ankylosing spondylitis, patients experience low back pain, stiffness that ascends up the back as well as heel pain. Fatigue can also occur and some patients will experience vision difficulties and may even lead to glaucoma and blindness. On x-rays of the spine, the spine will look like bamboo due to the process of fusions occurring around joints.
Septic arthritis is a dangerous condition in which joint pain is due to a bacterial infection within the joint. This most commonly is caused by the Gonococcal disease (a sexually transmitted disease) and is seen in otherwise healthy, sexually active young adults. The septic joint caused by non gonococcal disease if more often seen in adults with previous joint damage and compromised immune systems. If septic joint is suspected, the joint has to be aspirated and the fluid analyzed and cultured. Blood tests can also assist in the diagnosis of septic arthritis. This condition is serious and necessitates a hospital admission for expedited treatment and eradication of the infection. Intravenous antibiotics and also surgical incision with surgical cleansing of the joint is required.
As you can see, pain in the joints of the feet can be very straightforward - or may be a much more complicated issue. Don’t write off pain that you have in the joints. Our office has digital x-rays which assist in your initial evaluation to determine the most likely cause of your pain. We do aspirations in the office when necessary and work closely with rheumatology and your primary care doctor if the problem you are facing stems from a more systemic illness. Don’t let foot pain get you down. Call our office for an evaluation today!