Adult acquired flatfoot
deformity (AAFD or AAF) is a progressive, symptomatic deformity
resulting from gradual stretch of the posterior tibial tendon as well as other ligaments supporting the arch of the foot. AAFD develops after skeletal maturity, May also be referred to as posterior
tibial tendon dysfunction (PTTD), although due to the complexity of the disorder AAFD is more appropriate. Significant ligamentous rupture occurs as the deformity progresses. Involved ligaments
include the spring ligament, the superficial deltoid ligament, the plantar fascia, and the long and short plantar ligaments. Unilateral AAFD is more common than bilateral AAFD.
As discussed above, many different problems can create a painful flatfoot. Damage to the posterior tibial tendon is the most common cause of AAFD. The posterior tibial tendon is one of the most
important tendons of the leg. It starts at a muscle in the calf, travels down the inside of the lower leg and attaches to the bones on the inside of the foot. The main function of this tendon is to
support the arch of your foot when you walk. If the tendon becomes inflamed or torn, the arch will slowly collapse. Women and people over 40 are more likely to develop problems with the posterior
tibial tendon. Other risk factors include obesity, diabetes, and hypertension. Having flat feet since childhood increases the risk of developing a tear in the posterior tibial tendon. In addition,
people who are involved in high impact sports, such as basketball, tennis, or soccer, may have tears of the tendon from repetitive use. Inflammatory arthritis, such as rheumatoid arthritis, can cause
a painful flatfoot. This type of arthritis attacks not only the cartilage in the joints, but also the ligaments that support the foot. Inflammatory arthritis not only causes pain, but also causes the
foot to change shape and become flat. The arthritis can affect the back of the foot or the middle of foot, both of which can result in a fallen arch. An injury to the tendons or ligaments in the foot
can cause the joints to fall out of alignment. The ligaments support the bones and prevent them from moving. If the ligaments are torn, the foot will become flat and painful. This more commonly
occurs in the middle of the foot (Lisfranc injury), but can also occur in the back of the foot. Injuries to tendons of the foot can occur either in one instance (traumatically) or with repeated use
over time (overuse injury). Regardless of the cause, if tendon function is altered, the forces that are transmitted across joints in the foot are changed and this can lead to increased stress on
joint cartilage and ligaments. In addition to tendon and ligament injuries, fractures and dislocations of the bones in the midfoot can also lead to a flatfoot deformity. People with diabetes or with
nerve problems that limits normal feeling in the feet, can have collapse of the arch or of the entire foot. This type of arch collapse is typically more severe than that seen in patients with normal
feeling in their feet. In addition to the ligaments not holding the bones in place, the bones themselves can sometimes fracture and disintegrate without the patient feeling any pain. This may result
in a severely deformed foot that is very challenging to correct with surgery. Special shoes or braces are the best method for dealing with this problem.
Patients often experience pain and/or deformity at the ankle or hindfoot. When the posterior tibial tendon does not work properly, a number of changes can occur to the foot and ankle. In the earlier
stages, symptoms often include pain and tenderness along the posterior tibial tendon behind the inside of the ankle. As the tendon progressively fails, deformity of the foot and ankle may occur. This
deformity can include progressive flattening of the arch, shifting of the heel so that it no longer is aligned underneath the rest of the leg, rotation and deformity of the forefoot, tightening of
the heel cord, development of arthritis, and deformity of the ankle joint. At certain stages of this disorder, pain may shift from the inside to the outside aspect of the ankle as the heel shifts
outward and structures are pinched laterally.
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
The adult acquired flatfoot is best treated early. Accurate assessment by your doctor will determine which treatment is suitable for you. Reduce your level of activity and follow the RICE regime. R -
rest as often as you are able. Refrain from activity that will worsen your condition, such as sports and walking. I - ice, apply to the affected area, ensure you protect the area from frostbite by
applying a towel over the foot before using the ice pack. C - compression, a Tubigrip or elasticated support bandage may be
applied to relieve symptoms and ease pain and discomfort. E - elevate the affected foot to reduce painful swelling. You will be prescribed pain relief in the form of non-steroidal antiinflammatory
medications (if you do not suffer with allergies or are asthmatic). Immobilisation of your affected foot - this will involve you having a below the knee cast for four to eight weeks. In certain
circumstances it is possible for you to have a removable boot instead of a cast. A member of the foot and ankle team will advise as to whether this option is suitable for you. Footwear is important -
it is advisable to wear flat sturdy lace-up shoes, for example, trainers or boots. This will not only support your foot, but will also accommodate orthoses (shoe inserts).
For patients with a more severe deformity, or significant symptoms that do not respond to conservative treatment, surgery may be necessary. There are several procedures available depending on the
nature of your condition. Ligament and muscle lengthening, removal of inflamed tendon lining, transferring of a nearby tendon to re-establish an arch, and bone realignment and fusion are examples of
surgical options to help with a painful flatfoot condition. Surgery can be avoided when symptoms are addressed early. If you are feeling ankle pain or notice any warmth, redness or swelling in your
foot, contact us immediately. We can create a tailored treatment plan to resolve your symptoms and prevent future problems.