Have you noticed that the medial arch of your foot is becoming flatter when you walk? You may be developing adult acquired flat foot. This condition is typically caused by a problem with a tendon on the medial side of your foot called the Posterior Tibial Tendon that is not functioning well. You may experience pain in the inner side of your foot when you walk. The affected foot appears to roll outwards (the sole of the foot is trying to face outwards) when you walk. This is called over-pronation of the foot. The back of your heel may start to point outwards (heel valgus). Over time you may lose the ability to tip toe on that foot as the posterior tibial tendon stretches out and it may eventually tear.
Women are affected by Adult Acquired Flatfoot four times more frequently than men. Adult Flatfoot generally occurs in middle to older age people. Most people who acquire the condition already have flat feet. One arch begins to flatten more, then pain and swelling develop on the inside of the ankle. This condition generally affects only one foot. It is unclear why women are affected more often than men. But factors that may increase your risk of Adult Flatfoot include diabetes, hypertension, and obesity.
Your feet tire easily or become painful with prolonged standing. It's difficult to move your heel or midfoot around, or to stand on your toes. Your foot aches, particularly in the heel or arch area, with swelling along the inner side. Pain in your feet reduces your ability to participate in sports. You've been diagnosed with rheumatoid arthritis; about half of all people with rheumatoid arthritis will develop a progressive flatfoot deformity.
Clinicians need to recognize the early stage of this syndrome which includes pain, swelling, tendonitis and disability. The musculoskeletal portion of the clinical exam can help determine the stage of the disease. It is important to palpate the posterior tibial tendon and test its muscle strength. This is tested by asking patient to plantarflex and invert the foot. Joint range of motion is should be assessed as well. Stiffness of the joints may indicate longstanding disease causing a rigid deformity. A weightbearing examination should be performed as well. A complete absence of the medial longitudinal arch is often seen. In later stages the head of the talus bone projects outward to the point of a large "lump" in the arch. Observing the patient's feet from behind shows a significant valgus rotation of the heel. From behind, the "too many toes" sign may be seen as well. This is when there is abducution of the forefoot in the transverse plane allowing the toes to be seen from behind. Dysfunction of the posterior tibial tendon can be assessed by asking the patient to stand on his/her toes on the affected foot. If they are unable to, this indicates the disease is in a more advanced stage with the tendon possibly completely ruptured.
Non surgical Treatment
Orthoses (insoles, functional orthoses, ankle supports, braces, ankle foot orthoses (AFOs)) - are usually custom-made to increase the functional stability of the foot and improve the mechanical properties of the tendon as well as reducing the actual degree of strain on the tendon. This reduces pain and inflammation. Physiotherapy - exercises and physiotherapy are often used to increase mobility, strengthen the tendon itself, stretch your Achilles tendon as well as reduce pain. Once the tendon has been stretched (stage one), the heel starts rolling outwards. Total immobilisation in a cast may help the symptoms to subside and prevent progression of the deformity in a smaller percentage of patients. Long-term use of orthoses may help stop progression of the deformity and reduce pain without surgery. Non-surgical treatment is unlikely to prevent progression to stage three and four but may be chosen by some patients who either are unsuitable for surgery or prefer not to have surgery.
Many operations are available for the treatment of dysfunction of the posterior tibial tendon after a thorough program of non-operative treatment has failed. The type of operation that is selected is determined by the age, weight, and level of activity of the patient as well as the extent of the deformity. The clinical stages outlined previously are a useful guide to operative care (Table I). In general, the clinician should perform the least invasive procedure that will decrease pain and improve function. One should consider the effects of each procedure, particularly those of arthrodesis, on the function of the rest of the foot and ankle.