Your posterior tibial tendon is an extension of your tibialis posterior muscle, a muscle that runs down the back of your lower leg, under the ankle bone on the inside aspect of your foot, or medial malleolus, and attaches to your navicular bone and other bones in the middle part of your foot. When this muscle and tendon contract, your foot inverts, or moves in and up relative to your ankle. Your posterior tibial tendon helps support your foot arch and prevents your foot and arch from undergoing excessive pronation.
Posterior tibial tendinitis is a relatively uncommon condition in which your posterior tibial tendon sustains direct injury or micro-trauma that causes pain and difficulty walking. Posterior tibial tendon dysfunction, or PTTD, is a chronic, or long-term, musculoskeletal problem that may be caused by posterior tibial tendinitis and involves changes in your foot arch, resulting in flattening of your affected foot. This condition occurs most frequently in women over the age of 50.
PTTD, also known as acquired flat foot, is one of the leading causes of flat feet among adults. PTTD usually occurs in only one foot, though some people may experience this health problem in both feet. This condition is often progressive and requires immediate treatment to help prevent complications.
PTTD occurs when your tibialis posterior muscle and tendon become sufficiently weakened or stretched so that they can no longer resist arch collapse. When arch collapse occurs, you may find it difficult to raise up on your toes on your affected side or you may feel excruciating pain in your arch.
PTTD causes a maximally pronated, flattened, collapsed foot in which the back of your foot shifts toward your body’s midline while your forefoot shifts away from midline. Feet affected by this problem are difficult to fit in shoes. A PTTD-affected foot often becomes a more difficult problem to treat the flatter and more deformed your foot becomes.
Causes and Symptoms
Posterior tibial tendon overuse is one of the most common causes of PTTD. PTTD-related symptoms usually develop following activities such as stair climbing, hiking, walking, and running. PTTD may also be caused by a tendon abnormality.
Possible risk factors for this health problem include:
- Elevated blood pressure
- Previous trauma (e.g. certain types of ankle fracture)
- Rheumatoid arthritis, psoriasis, and other inflammatory conditions
- Steroid injections
PTTD causes numerous signs and symptoms, including:
- Mid-foot tenderness that is worse during certain activities
- Arch collapse and flat foot on your affected side
- Pain and swelling on the inside aspect of your ankle
- Foot and ankle weakness
- Impaired ability to stand on your toes
- Pain that gradually develops on the outer aspect of your foot or ankle
Certain conservative care methods—including protection, rest, ice, compression, and elevation—may be beneficial in treating your PTTD. Your podiatrist may also perform taping procedures to temporarily splint your foot, ankle, and lower leg in an inverted position. This position allows your posterior tibial tendon to rest and recover. Topical or oral anti-inflammatory agents are commonly used in treating this health problem.
Other conservative treatment measures include:
- Toe realignment: Use of a toe-spacing appliance, such as Correct Toes, may be beneficial
- Immobilization: A short-leg cast or boot can allow your tendon to heal
- Physical therapy: Ultrasound therapy and certain exercises may help rehabilitate your tendon
- Footwear modifications: Appropriate footwear may help reduce your chances of recurrence
Footwear that possesses a flat, flexible sole and a toe box that is wide enough to accommodate Correct Toes helps reposition your big toe to its normal anatomical position, creating natural arch support and reducing the burden on your posterior tibial tendon.
Steroid preparations (cortisone-like medicines) such as dexamethasone can be applied locally on their own or used in conjunction with iontophoresis—a physical therapy modality that uses electrical current to help your body absorb topical medicines. Injectable steroids (corticosteroids) are usually not recommended, as they may lead to complete rupture of your inflamed and weakened tendon.
You require immediate attention if your foot collapses. Failure to seek immediate care may limit your treatment options for PTTD. Advanced cases of PTTD often require the use of restrictive braces or surgical procedures to straighten your foot and elevate your arch. Some of these procedures involve the use of arthrodesis, or fusion techniques, that join two or more bones with hardware, such as screws, plates, pins, or wire to eliminate your painful joint. The subtalar and midtarsal joints are the most commonly fused joints for this health purpose.
Examples of surgical options for PTTD, besides arthrodesis, include:
- Tendon transfer
- Lateral column lengthening
Regular foot checkups and proper awareness of your family’s foot history can help you prevent this debilitating foot deformity.
In his 18 years as a podiatrist, Dr. Ray McClanahan has learned that most foot problems can be corr...