Figure 13

Figure 14

Figure 15

Figure 16

Because we use our feet continually, tendinitis in the foot is a common problem. One of the most frequently affected tendons is the posterior tibial tendon. (Figure 13: picture of patient with bilateral flatfeet)

Anatomy

The posterior tibial tendon runs behind the inside bump on the ankle (the medial malleolus), across the instep, and into the bottom of the foot. The tendon is important in supporting the arch of the foot and helps turn the foot inward during walking.

Problems with the posterior tibial tendon seem to occur in stages. Initially, irritation of the outer covering of the tendon, called the paratenon, causes a peritendinitis. This simply indicates that there is inflammation around the tendon as it runs through the tunnel behind the medial malleolus. As we age, the tendon is subject to degeneration within the substance of the tendon. This creates a situation in which the tendon becomes thickened, possibly to the extent that a nodule forms within the tendon. The normal arrangement of the fibers of the tendon (similar to strands of a nylon rope) becomes jumbled and the tendon loses strength. This condition is called tendinosis. In many cases, the two conditions are present simultaneously. The weakened, degenerative tendon sets the stage for the possibility of actual rupture of the posterior tibial tendon (Figure 14: picture of patient with pain on inner ankle).

Symptoms

The symptoms of tendinitis of the posterior tibial tendon include pain in the instep area of the foot and swelling along the course of the tendon. In some cases the tendon may actually rupture due the weakening of the tendon by the inflammatory process. Rupture of the tendon leads to a fairly pronounced flatfoot deformity that is easily recognizable.

Medical Treatment

Treatment of posterior tibial tendinitis begins with a good supportive arch support, decreased activity, and anti-inflammatory medications such as ibuprofen or aspirin. If the condition has been present for a long time, a brace known as an AFO (Ankle Foot Orthosis) can be very helpful. (Figure 15: picture of a patient with an AFO on)

Surgery

If the above methods of medical treatment fail to resolve the problem, surgery may be required to remove the thickened tissue around the tendon. This is done to try and decrease the symptoms of pain and to prevent rupture of the tendon.

If the tendon has ruptured, surgery may be required to either repair the ruptured tendon or to reconstruct it with a tendon transfer. Most tears cannot be repaired simply unless they occurred recently. Usually, another tendon in the foot, such as the tendon that flexes the four lesser toes (bends them down), is used as a tendon graft to replace the function of the posterior
tibial tendon.

In cases that have been neglected and there is a fixed flatfoot deformity, surgery on the bones of the feet is required to realign the deformed foot. Usually this involves cutting the heel bone and shifting it to make the foot more straight. (Figure 16: picture of heel osteotomy)

Finally, if the condition has been present for a very long time and the foot has severe deformity with arthritis, a fusion (or arthrodesis) of the foot may be required. A fusion is an operation where a joint between two bones is removed and the two bones on either side of the joint are allowed to grow together, or fuse. This type of operation is used to stop pain from joints that are worm out and can be used to realign the bones when the normal mechanisms for maintaining normal alignment are deficient, such as when the tendon and ligaments no longer work properly. Usually, several joints must be fused to control the flatfoot deformity occurring after posterior tibial tendon rupture.

Following surgery, you will most likely be placed in some sort of brace or cast if the tendon has been repaired or grafted. You will porbably be in a cast for 8 to 12 weeks if a fusion has
been performed.