Adult flatfoot 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.
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.
Symptoms are minor and may go unnoticed, Pain dominates, rather than deformity. Minor swelling may be visible along the course of the tendon. Pain and swelling along the course of the tendon. Visible decrease in arch height. Aduction of the forefoot on rearfoot. Subluxed tali and navicular joints. Deformation at this point is still flexible. Considerable deformity and weakness. Significant pain. Arthritic changes in the tarsal joints. Deformation at this point is rigid.
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
Flatfoot can be treated with a variety of methods, including modified shoes, orthotic devices, a brace or cast, anti-inflammatory medications or limited steroid injections, rest, ice, and physical therapy. In severe cases, surgery may be necessary.
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.