Posterior Tibial Tendon Dysfunction (PTTD)
- Acquired Adult Flat Foot
What is posterior tibialis tendon?
The posterior tibialis tendon starts as a muscle behind the shin bone (posterior to tibia) and then becomes a tendon as it courses along the inside ankle bone and inserts underneath the arch of the foot. Along with other soft tissue structures, the posterior tibialis tendon is the main supporting structure that holds up the inside arch of the foot.
What is posterior tibialis tendon dysfunction?
Posterior tibialis tendon dysfunction (PTTD) occurs when the tendon can no longer provide adequate support for the arch, resulting in arch collapse or flattening of the foot. This condition is generally an overuse injury, meaning the tendon gradually weakens over time versus a sudden acute injury.
PTTD is usually progressive, meaning it will keep getting worse, especially if it is not treated early. PTTD is often called “adult acquired flat foot” because it is the most common type of flat foot developed during adulthood. Even though it may be a common foot deformity, it is a very serious one which can greatly impact your quality of life.
PTTD usually follows a course from initial strain and minor degeneration of the tendon to complete rupture. It is now known that the problem is caused by a degenerative tendinosis rather than inflammation.
What are the signs & symptoms?
- Pain in the arch and pain and swelling behind the inside of the ankle (course of the tendon). Pain and trigger points will also be felt in the muscle belly of the posterior tibialis.
- Burning, shooting, tingling pain may also be felt on the inside of the ankle because the posterior tibialis nerve is inflamed inside the tarsal tunnel (tarsal tunnel syndrome).
- Pain may also develop on outside of ankle, especially as the foot becomes more mis-shapen.
- Pain and swelling is worse with walking and exercise, and usually gets worse as day progresses.
- Unable to perform tip-toe raise on affected side (indicating dysfunction of posterior tibialis tendon).
- Characteristic development of a flat foot (arch collapse) on affected side.
- Usually occurs in one foot, however can occur in both.
What causes PTTD?
Overuse of the posterior tibial tendon is often the cause of PTTD. The tendon can no longer cope with the load being placed on it, therefore becomes weakened and degenerative.
- Excessive over-pronation (arch collapse)
- Sudden increase in activities that involve the tendon – such as running, walking, hiking or climbing stairs
- Poor footwear, hard surfaces, weight gain
How can it be treated?
Because of the progressive nature of PTTD, early treatment is integral. If treated early enough, your symptoms may resolve without the need for surgery and progression of your condition can be arrested.
When the foot is acutely painful, you will need to avoid all high intensity activities (running, jumping, dancing etc). Ice packs, anti-inflammatory medication and gels and rest are also very important in the inflamed stages. A moon boot which immobilises the foot and ankle and allows the tendon to heal is often recommended in the initial stages.
Customised foot supports (orthotics) made from a more rigid material and incorporating a large medial flare to support the inside ankle is a necessity. This must be worn with supportive footwear to achieve greatest control around the inside ankle. In cases of severe flat foot, a Richie brace (ankle-foot orthoses) may be required to provide extra ankle support.
Will I require surgery?
If PTTD is left untreated, or treated too late, conservative treatment may no longer be of benefit and surgery may be the only option. Surgery could involve tendon transfers and osteotomies to improve the position of the rearfoot and attempt to recreate the fallen inside arch.
Where the foot has been severely neglected and a fixed (rigid) deformity is present, a fusion of one to three joints of the foot may be required. This helps to stop pain in the arthritic joints and to realign the arch as best as possible, however the patient then has a rigid foot which makes many daily activities such as climbing stairs, squatting and walking on uneven surfaces very difficult.
Without early treatment, PTTD could leave you with an extremely flat foot, painful arthritis in the foot and ankle, very altered gait causing pain in other areas such as knees and hips, and increasing limitations on walking, running, or other daily activities.