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.

Anatomy
The posterior tibial tendon runs behind the inside bump on the ankle, 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. Initially, irritation of the outer covering of the tendon causes inflammation around the tendon as it runs through the tunnel behind the inside bump of the ankle. As we age, the tendon is subject to degeneration within the tendon. The normal arrangement of the fibers of the tendon becomes jumbled and the tendon loses strength. This condition is called tendinosis.

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.

Diagnosis
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) or a lace up ankle brace can be very helpful. If the tissue thickening is severe or it has ruptured, surgery may be required to repair or reconstruct the tendon. This is also the case when neglected tendinitis/rupture has caused a fixed flatfoot deformity or deformity from arthritis.