Progressive flatfoot (sometimes called adult flatfoot or posterior tibial tendon dysfunction) occurs when the tendon that connects the calf to the bones on the inside of the ankle stretches, tears, or becomes inflamed. Because the posterior tibial tendon helps hold up the arch, when it is damaged, the arch falls, causing what is commonly called a “flat foot.” Progressive flat foot can result in pain and weakness and can be caused by obesity, diabetes, high blood pressure, trauma, and other factors. The condition often worsens over time (hence the name “progressive”), causing the tendon to become rigid and resulting in painful arthritis that can permanently hinder walking.
Treatment of progressive flatfoot depends on how far the condition has progressed. This can range from drug therapy and immobilization to custom footwear or surgery.
Progressive flatfoot, also known as posterior tibial tendon dysfunction, is a common deformity of the foot and ankle. The condition occurs when the posterior tibial tendon is torn or develops inflammation. As the tendon that connects the calf muscle with the bones on the inner side of the foot, damage often results in a lack of stability and support to the arch of the foot, resulting in progressive flatfoot. Progressive flatfoot is typically a painful condition that requires medical attention to prevent it from worsening.
Causes of Progressive Flatfoot
Progressive flatfoot is most commonly found in adults over the age of 50, and it is more common among women than men. The condition may occur due to a preexisting abnormality in the tendon, though it is more often linked to the following risk factors:
- Acute injury caused by participation in sports such as basketball, tennis, soccer or hockey, which may result in a posterior tibial tendon tear
- High blood pressure
- Inflammatory disease including rheumatoid arthritis and Reiter's syndrome
- Prior foot or ankle surgery or trauma, such as an ankle fracture on the inner side of the foot
- Local steroid injections
Symptoms of Progressive Flatfoot
The symptoms of progressive flatfoot typically include:
- Gradually worsening pain on the outer side of the foot or ankle
- Tenderness within the mid-foot area
- Swelling around the inner side of the foot
- Weakness in the foot
Diagnosis of Progressive Flatfoot
Progressive flatfoot is diagnosed after a physical examination and evaluation of the patient's medical history have been conducted. During the physical examination, the foot will be assessed for signs of swelling along the posterior tibial tendon, as well as for any changes in the shape of the foot. The foot may also be moved from side to side to test its flexibility. The level of flexibility and the severity of the flatfoot will determine the type of treatment recommended for this condition.
One common diagnostic test for progressive flatfoot that may be performed is known as the "single limb heel rise" test. During this test, patients are instructed to stand on one leg and go up on their toes. Since the ability to stand on the toes requires a healthy posterior tibial tendon, a patient's inability to maintain this position typically indicates a problem with the tendon. Imaging exams, such as X-rays or MRI scans, may be taken to confirm a progressive flatfoot diagnosis.
Treatment of Progressive Flatfoot
For many patients, progressive flatfoot may be treated effectively with conservative measures. These treatments may include placing ice packs on the tendon area, taking non-steroidal anti-inflammatory medications to reduce pain and swelling, receiving cortisone injections, wearing a brace to support the joints of the back of the foot and undergoing physical therapy to help strengthen the tendon. In many cases, conservative treatments can alleviate symptoms of progressive flatfoot within six months.
Surgery for progressive flatfoot should only be considered if pain does not resolve after six months of conservative therapies. Surgical options for progressive flatfoot include:
- Gastrocnemius Recession Lengthening of the Achilles Tendon. This procedure lengthens the calf muscles, and helps prevent flatfoot from recurring. It is typically recommended for patients with a limited ability to move the ankle.
- Tendon Transfer. This procedure helps reconstruct the lost arch by removing the damaged tendon and replacing it with a tendon from another area of the foot.
- Osteotomy. This procedure involves the cutting and restructuring of the bones in the foot into an arch.
- Arthrodesis, or fusion surgery. Often recommended for patients with arthritis of the back of the foot, arthrodesis is used to fuse together two or more bones to provide greater stability and prevent the condition from progressing.
Risks of Treatment for Progressive Flatfoot
The most common risk associated with treatment for progressive flatfoot is that symptoms of the condition will not be relieved. For some patients who undergo arthrodesis, the fusion may fail, making a second surgery necessary. Poor wound healing and infection are also potential complications of surgical treatment for progressive flatfoot.
Recovery from Progressive Flatfoot Surgery
Most patients experience significant pain relief after undergoing surgery for progressive flatfoot. However, the length of recovery time varies, depending on the procedure performed and the severity of the condition. For some patients, a complete recovery may take up to one year.