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.
There are numerous causes of acquired Adult Flatfoot, including, trauma, fracture, dislocation, tendon rupture/partial rupture or inflammation of the tendons, tarsal coalition, arthritis, neuroarthropathy and neurologic weakness. The most common cause of acquired Adult Flatfoot is due to overuse of a tendon on the inside of the ankle called the posterior tibial tendon. This is classed as – posterior tibial tendon dysfunction. What are the causes of Adult Acquired flat foot? Trauma, Fracture or dislocation. Tendon rupture, partial tear or inflammation. Tarsal Coalition. Arthritis. Neuroarthropathy. Neurological weakness.
Posterior tibial tendon insufficiency is divided into stages by most foot and ankle specialists. In stage I, there is pain along the posterior tibial tendon without deformity or collapse of the arch. The patient has the somewhat flat or normal-appearing foot they have always had. In stage II, deformity from the condition has started to occur, resulting in some collapse of the arch, which may or may not be noticeable. The patient may feel it as a weakness in the arch. Many patients initially present in stage II, as the ligament failure can occur at the same time as the tendon failure and therefore deformity can already be occurring as the tendon is becoming symptomatic. In stage III, the deformity has progressed to the extent where the foot becomes fixed (rigid) in its deformed position. Finally, in stage IV, deformity occurs at the ankle in addition to the deformity in the foot.
Looking at the patient when they stand will usually demonstrate a flatfoot deformity (marked flattening of the medial longitudinal arch). The front part of the foot (forefoot) is often splayed out to the side. This leads to the presence of a ?too many toes? sign. This sign is present when the toes can be seen from directly behind the patient. The gait is often somewhat flatfooted as the patient has the dysfunctional posterior tibial tendon can no longer stabilize the arch of the foot. The physician?s touch will often demonstrate tenderness and sometimes swelling over the inside of the ankle just below the bony prominence (the medial malleolus). There may also be pain in the outside aspect of the ankle. This pain originates from impingement or compression of two tendons between the outside ankle bone (fibula) and the heel bone (calcaneus) when the patient is standing.
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.
Although non-surgical treatments can successfully manage the symptoms, they do not correct the underlying problem. It can require a life-long commitment to wearing the brace during periods of increased pain or activity demands. This will lead a majority of patients to choose surgical correction of the deformity, through Reconstructive Surgery. All of the considerations that were extremely important during the evaluation stage become even more important when creating a surgical plan. Generally, a combination of procedures are utilized in the same setting, to allow full correction of the deformity. Many times, this can be performed as a same-day surgery, without need for an overnight hospital stay. However, one or two day hospital admissions can be utilized to help manage the post-operative pain. Although the recovery process can require a significant investment of time, the subsequent decades of improved function and activity level, as well as decreased pain, leads to a substantial return on your investment.