Tibialis posterior muscle is located in the inner most aspect of the leg; the muscle then travels and inserts on bones that are located in the midfoot region. The function of Tibialis posterior muscle is to allow the foot to point down (plantarflex) and allow outward tilting of the foot (supination). This muscle also helps to support the arch of the foot. Like any muscle, it can be damaged due to overuse and trauma. One type of pathology involving this muscle is called Posterior Tibial Tendon Dysfunction (PTTD), which is also known as Adult Acquired Flatfoot. There are different stages of PTTD, which have been classified using the Johnson and Strom Classification System. The stages are identified as follows:
- Stage 1: There is normal tendon length; however, there is mild breakdown and weakness of the tendon. Symptoms may include pain and/or swelling on the inside of the foot and/or ankle.
- Stage 2: The arch of the foot begins to fall due to increasing length and decreased strength of the Tibialis posterior tendon.
- Stage 3: There is an even greater increase in length, decrease in strength, and decrease in the arch; there is usually some arthritis present in the rearfoot and ankle.
Most patients with Stage 1 PTTD will usually not come into the clinic for evaluation during this stage, since many patients will just try deal with the pain. What many patients do not realize is that PTTD is a progressive deformity and without podiatric treatment, little can be done to prevent the progression and symptoms. Stage 2 and Stage 3 are more commonly seen since patients realize that despite their efforts the pain and/or swelling is increasing, and there is a flattening of their arch noted. There are several non-invasive physical exam tests that can be performed to diagnose PTTD. Some of these tests include:
- Too many toes sign: This sign will be positive in Stage 2 and Stage 3. This test is performed by the podiatrist having the patient stand in front of them in a relaxed position. If more than the 4th and 5th toes are seen from the behind the patient, it indicates that the arches are collapsing.
- Heel raise test: The podiatrist will have the patient try to stand on their toes. If the patient is unable to do this, it is a positive test and may indicate that the Tibialis posterior tendon has ruptured. This sign is commonly seen in Stage 2 and Stage 3.
- Hubscher maneuver also called the Jack test: The podiatrist will have the patient stand and they will try to move the big toe up. The test is positive if the big toe cannot be raised, and the arches will be very flat or non-existent. This sign can be seen in Stage 2, but is more commonly seen in Stage 3.
Risk factors for PTTD include: women age 40 and older, obesity, traumatic injuries to the foot and ankle, and exercises that cause overuse of the tendon, such as long distance running, hiking, and step aerobics.
There is treatment for PTTD. Some treatment options include: oral non-steroidal anti-inflammatory medications in conjunction with icing, physical therapy targeted to help increase the strength of the tendon, custom-made orthoses to help the foot function better and in a more correct position, the ankle can also be braced to help maintain support, and surgery as a last resort. However, as with any deformity, the further advanced the more difficult it is to successfully treat, so if you are having pain in your foot or ankle, visit the Platte Valley Foot and Ankle Clinic for further evaluation.