refers to a deformity that develops after skeletal maturity is reached. Adult flatfoot should be differentiated from constitutional
flatfoot, which is a common congenital non-pathologic foot morphology. There are numerous causes of acquired adult flatfoot, including fracture or dislocation, tendon laceration, tarsal coalition,
arthritis, neuroarthropathy, neurologic weakness, and iatrogenic causes.
Posterior tibial tendon dysfunction is the most common cause of acquired adult flatfoot deformity. There is often no specific event that starts the problem, such as a sudden tendon injury. More
commonly, the tendon becomes injured from cumulative wear and tear. Posterior tibial tendon dysfunction occurs more commonly in patients who already have a flat foot for other reasons. As the arch
flattens, more stress is placed on the posterior tibial tendon and also on the ligaments on the inside of the foot and ankle. The result is a progressive disorder.
Many patients with this condition have no pain or symptoms. When problems do arise, the good news is that acquired flatfoot treatment is often very effective. Initially, it will be important to rest
and avoid activities that worsen the pain.
There are four stages of adult-acquired flatfoot deformity (AAFD). The severity of the deformity determines your stage. For example, Stage I means there is a flatfoot position but without deformity.
Pain and swelling from tendinitis is common in this stage. Stage II there is a change in the foot alignment. This means a deformity is starting to develop. The physician can still move the bones back
into place manually (passively). Stage III adult-acquired flatfoot deformity (AAFD) tells us there is a fixed deformity. This means the ankle is stiff or rigid and doesn???t move beyond a neutral
(midline) position. Stage IV is characterized by deformity in the foot and the ankle. The deformity may be flexible or fixed. The joints often show signs of degenerative joint disease
Non surgical Treatment
Nonoperative treatment of stage 1 and 2 acquired adult flatfoot deformity can be successful. General components of the treatment include the use of comfort shoes. Activity modification to avoid
exacerbating activities. Weight loss if indicated. Specific components of treatment that over time can lead to marked improvement in symptoms include a high repetition, low resistance strengthening
program. Appropriate bracing or a medial longitudinal arch support. If the posterior tibial tendon is intact, a series of exercises aimed at strengthening the elongated and dysfunctional tendon
complex can be successful. In stage 2 deformities, this is combined with an ankle brace for a period of 2-3 months until the symptoms resolve. At this point, the patient is transitioned to an
orthotic insert which may help to support the arch. In patients with stage 1 deformity it may be possible to use an arch support immediately.
When conservative care fails to control symptoms and/or deformity, then surgery may be needed. The goal of surgical treatment is to obtain good alignment while keeping the foot and ankle as flexible
as possible. The most common procedures used with this condition include arthrodesis (fusion), osteotomy (cutting out a wedge-shaped piece of bone), and lateral column lengthening. Lateral column
lengthening involves the use of a bone graft at the calcaneocuboid joint. This procedure helps restore the medial longitudinal arch (arch along the inside of the foot). A torn tendon or spring
ligament will be repaired or reconstructed. Other surgical options include tendon shortening or lengthening. Or the surgeon may move one or more tendons. This procedure is called a tendon transfer.
Tendon transfer uses another tendon to help the posterior tibial tendon function more effectively. A tendon transfer is designed to change the force and angle of pull on the bones of the arch. It's
not clear yet from research evidence which surgical procedure works best for this condition. A combination of surgical treatments may be needed. It may depend on your age, type and severity of
deformity and symptoms, and your desired level of daily activity.