A painful flat foot, or adult acquired flatfoot deformity, is a progressive collapsing of the arch of the foot that occurs as the posterior tibial tendon becomes insufficient due to various factors. Early stages may present with only pain along the posterior tibial tendon whereas advanced deformity usually results in arthritis and rigidity of the rearfoot and ankle.
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.
Some symptoms of adult acquired flat foot are pain along the inside of the foot and ankle, pain that increases with activity, and difficulty walking for long periods of time. You may experience difficulty standing, pain on the outside of the ankle, and bony bumps on the top of the foot and inside the foot. You may also have numbness and tingling of the feet and toes (may result from large bone spurs putting pressure on nerves), swelling, a large bump on the sole of the foot and/or an ulcer (in diabetic patients). Diabetic patients should wear a properly fitting diabetic shoe wear to prevent these complications from happening.
Starting from the knee down, check for any bowing of the tibia. A tibial varum will cause increased medial stress on the foot and ankle. This is essential to consider in surgical planning. Check the gastrocnemius muscle and Achilles complex via a straight and bent knee check for equinus. If the range of motion improves to at least neutral with bent knee testing of the Achilles complex, one may consider a gastrocnemius recession. If the Achilles complex is still tight with bent knee testing, an Achilles lengthening may be necessary. Check the posterior tibial muscle along its entire course. Palpate the muscle and observe the tendon for strength with a plantarflexion and inversion stress test. Check the flexor muscles for strength in order to see if an adequate transfer tendon is available. Check the anterior tibial tendon for size and strength.
Non surgical Treatment
There are many non-surgical options for the flatfoot. Orthotics, non-custom braces, shoe gear changes and custom braces are all options for treatment. A course of physical therapy may be prescribed if tendon inflammation is part of the problem. Many people are successfully treated with non-surgical alternatives.
Surgical intervention for adult acquired flatfoot is appropriate when there is pain and swelling, and the patient notices that one foot looks different than the other because the arch is collapsing. As many as three in four adults with flat feet eventually need surgery, and it?s better to have the joint preservation procedure done before your arch totally collapses. In most cases, early and appropriate surgical treatment is successful in stabilizing the condition.
A more serious condition, according to ACFAS, is adult-acquired flatfoot, often cause by posterior tibial tendon dysfunction (PTTD). In this case, the tendon that supports the arch weakens and fails, leading to a rigid flatfoot where the arch stays flat even when you aren’t standing. It can lead to a loss of range of motion in the foot and ankle and pain in the arch. The ACFAS clinical guideline recommends that flatfoot caused by PTTD can be treated with custom shoe orthotics, soft casts, walking boots, physical therapy and non-steroidal anti-inflammatory medications. If there is no relief or the condition worsens, then the patient may be referred to surgery.
Overuse of the posterior tibial tendon is often the cause of PTTD. In fact, the symptoms usually occur after activities that involve the tendon, such as running, walking, hiking, or climbing stairs.
In many cases, adult flatfoot causes no pain or problems. In others, pain may be severe. Many people experience aching pain in the heel and arch and swelling along the inner side of the foot.
The diagnosis of posterior tibial tendon dysfunction and AAFD is usually made from a combination of symptoms, physical exam and x-ray imaging. The location of pain, shape of the foot, flexibility of the hindfoot joints and gait all may help your physician make the diagnosis and also assess how advanced the problem is.
Non surgical Treatment
Treatment will vary depending on the degree of your symptoms. Generally, we would use a combination of rest, immobilization, orthotics, braces, and physical therapy to start. The goal is to keep swelling and inflammation under control and limit the stress on the tendon while it heals. Avoidance of activities that stress the tendon will be necessary. Once the tendon heals and you resume activity, physical therapy will further strengthen the injured tendon and help restore flexibility. Surgery may be necessary if the tendon is torn or does not respond to these conservative treatment methods. Your posterior tibial tendon is vital for normal walking. When it is injured in any way, you risk losing independence and mobility. Keep your foot health a top priority and address any pain or problems quickly. Even minor symptoms could progress into chronic problems, so don?t ignore your foot pain.
If initial conservative therapy of posterior tibial tendon insufficiency fails, surgical treatment is considered. Operative treatment of stage 1 disease involves release of the tendon sheath, tenosynovectomy, debridement of the tendon with excision of flap tears, and repair of longitudinal tears. A short-leg walking cast is worn for 3 weeks postoperatively. Teasdall and Johnson reported complete relief of pain in 74% of 14 patients undergoing this treatment regimen for stage 1 disease. Surgical debridement of tenosynovitis in early stages is believed to possibly prevent progression of disease to later stages of dysfunction.