Adult acquired flatfoot deformity (AAFD) is a painful condition resulting from the collapse of the longitudinal (lengthwise) arch of the foot. As the name suggests, this condition is not present at birth or during childhood. It occurs after the skeleton is fully matured. In the past it was referred to a posterior tibial tendon dysfunction (or insufficiency). But the name was changed because the condition really describes a wide range of flatfoot deformities. AAFD is most often seen in women between the ages of 40 and 60. This guide will help you understand how the problem develops, how doctors diagnose the condition, what treatment options are available.
Flat feet causes greater pressure on the posterior tibial tendon than normal. As the person with flat feet ages, the muscles, tendons and ligaments weaken. Blood supplies diminish as arteries narrow. These conditions are magnified for obese patients because of their increased weight and atherosclerosis. Finally, the tendon gives out or tears. Most of the time, this is a slow process. Once the posterior tibial tendon and ligaments stretch, body weight causes the bones of the arch to move out of position. The foot rotates inward (pronation), the heel bone is tilted to the inside, and the arch appears collapsed. In some cases, the deformity progresses until the foot dislocates outward from the ankle joint.
The first stage represents inflammation and symptoms originating from an irritated posterior tibial tendon, which is still functional. Stage two is characterized by a change in the alignment of the foot noted on observation while standing (see above photos). The deformity is supple meaning the foot is freely movable and a ?normal? position can be restored by the examiner. Stage two is also associated with the inability to perform a single-leg heel rise. The third stage is dysfunction of the posterior tibial tendon is a flatfoot deformity that becomes stiff because of arthritis. Prolonged deformity causes irritation to the involved joints resulting in arthritis. The fourth phase is a flatfoot deformity either supple (stage two) or stiff (stage 3) with involvement of the ankle joint. This occurs when the deltoid ligament, the major supporting structure on the inside of the ankle, fails to provide support. The ankle becomes unstable and will demonstrate a tilted appearance on X-ray. Failure of the deltoid ligament results from an inward displacement of the weight bearing forces. When prolonged, this change can lead to ankle arthritis. The vast majority of patients with acquired adult flatfoot deformity are stage 2 by the time they seek treatment from a physician.
In the early stages of dysfunction of the posterior tibial tendon, most of the discomfort is located medially along the course of the tendon and the patient reports fatigue and aching on the plantar-medial aspect of the foot and ankle. Swelling is common if the dysfunction is associated with tenosynovitis. As dysfunction of the tendon progresses, maximum pain occurs laterally in the sinus tarsi because of impingement of the fibula against the calcaneus. With increasing deformity, patients report that the shape of the foot changes and that it becomes increasingly difficult to wear shoes. Many patients no longer report pain in the medial part of the foot and ankle after a complete rupture of the posterior tibial tendon has occurred; instead, the pain is located laterally. If a fixed deformity has not occurred, the patient may report that standing or walking with the hindfoot slightly inverted alleviates the lateral impingement and relieves the pain in the lateral part of the foot.
Non surgical Treatment
PTTD is a progressive condition. Early treatment is needed to prevent relentless progression to a more advanced disease which can lead to more problems for that affected foot. In general, the treatments include rest. Reducing or even stopping activities that worsen the pain is the initial step. Switching to low-impact exercise such as cycling, elliptical trainers, or swimming is helpful. These activities do not put a large impact load on the foot. Ice. Apply cold packs on the most painful area of the posterior tibial tendon frequently to keep down the swelling. Placing ice over the tendon immediately after completing an exercise helps to decrease the inflammation around the tendon. Nonsteroidal Anti-inflammatory Medication (NSAIDS). Drugs, such as arcoxia, voltaren and celebrex help to reduce pain and inflammation. Taking such medications prior to an exercise activity helps to limit inflammation around the tendon. However, long term use of these drugs can be harmful to you with side effects including peptic ulcer disease and renal impairment or failure. Casting. A short leg cast or walking boot may be used for 6 to 8 weeks in the acutely painful foot. This allows the tendon to rest and the swelling to go down. However, a cast causes the other muscles of the leg to atrophy (decrease in strength) and thus is only used if no other conservative treatment works. Most people can be helped with orthotics and braces. An orthotic is a shoe insert. It is the most common non-surgical treatment for a flatfoot and it is very safe to use. A custom orthotic is required in patients who have moderate to severe changes in the shape of the foot. Physiotherapy helps to strengthen the injured tendon and it can help patients with mild to moderate disease of the posterior tibial tendon.
Surgical correction is dependent on the severity of symptoms and the stage of deformity. The goals of surgery are to create a more functional and stable foot. There are multiple procedures available to the surgeon and it may take several to correct a flatfoot deformity. Usually surgical treatment begins with removal of inflammatory tissue and repair of the posterior tibial tendon. A tendon transfer is performed if the posterior tibial muscle is weak or the tendon is badly damaged. The most commonly used tendon is the flexor digitorum longus tendon. This tendon flexes or moves the lesser toes downward. The flexor digitorum longus tendon is utilized due to its close proximity to the posterior tibial tendon and because there are minimal side effects with its loss. The remainder of the tendon is sutured to the flexor hallucis longus tendon that flexes the big toe so that little function is loss.