Chronic posterior tibial tendon insufficiency can result in acquired adult flatfoot deformity
. This is a chronic foot
condition where the soft-tissues (including the posterior tibial tendon, deltoid and spring ligaments) on the inside aspect of the ankle are subject to repetitive load during walking and standing.
Over time these structures may become painful and swollen ultimately failing. When these supporting structures fail the result is a change in the alignment of the foot. This condition is typically
associated with a progressive flatfoot deformity. This type of deformity leads to increased strain on the supporting structures on the inside of the ankle and loading through the outer aspect of the
ankle and hind-foot. Both the inside and outside of the ankle can become painful resulting significant disability. This condition can often be treated without surgery by strengthening the involved
muscles and tendons and by bracing the ankle. When non-operative treatment fails, surgery can improve the alignment replace the injured tendon. Alignment and function can be restored, however, the
time to maximal improvement is typically six months but, can take up to a year.
Adult acquired flatfoot is caused by inflammation and progressive weakening of the major tendon that it is responsible for supporting the arch of the foot. This condition will commonly be accompanied
by swelling and pain on the inner portion of the foot and ankle. Adult acquired flatfoot is more common in women and overweight individuals. It can also be seen after an injury to the foot and ankle.
If left untreated the problem may result in a vicious cycle, as the foot becomes flatter the tendon supporting the arch structure becomes weaker and more and more stretched out. As the tendon becomes
weaker, the foot structure becomes progressively flatter. Early detection and treatment is key, as this condition can lead to chronic swelling and pain.
Pain and swelling behind the inside of your ankle and along your instep. You may be tender behind the inner ankle where the posterior tibial tendon courses and occasionally get burning, shooting,
tingling or stabbing pain as a result of inflammation of the nerve inside the tarsal tunnel. Difficulty walking, the inability to walk long distances and a generalised ache while walking even short
distances. This may probably become more pronounced at the end of each day. Change in foot shape, sometimes your tendon stretches out, this is due to weakening of the tendon and ligaments. When this
occurs, the arch in your foot flattens and a flatfoot deformity occurs, presenting a change in foot shape. Inability to tip-toe, a way of diagnosing Posterior Tibial Tendon Dysfunction is difficulty
or inability to ?heel rise? (stand on your toes on one foot). Your tibialis posterior tendon enables you to perform this manoeuvre effectively. You may also experience pain upon attempting to perform
a heel rise.
Starting from the knee down, check for any bowing of the tibia. A tibial varum will cause increased medial stress on the foot and ankle. This is essential to consider in surgical planning. Check the
gastrocnemius muscle and Achilles complex via a straight and bent knee check for equinus. If the range of motion improves to at least neutral with bent knee testing of the Achilles complex, one may
consider a gastrocnemius recession. If the Achilles complex is still tight with bent knee testing, an Achilles lengthening may be necessary. Check the posterior tibial muscle along its entire course.
Palpate the muscle and observe the tendon for strength with a plantarflexion and inversion stress test. Check the flexor muscles for strength in order to see if an adequate transfer tendon is
available. Check the anterior tibial tendon for size and strength.
Non surgical Treatment
A patient who has acute tenosynovitis has pain and swelling along the medial aspect of the ankle. The patient is able to perform a single-limb heel-rise test but has pain when doing so. Inversion of
the foot against resistance is painful but still strong. The patient should be managed with rest, the administration of appropriate anti-inflammatory medication, and immobilization. The injection of
corticosteroids is not recommended. Immobilization with either a rigid below-the-knee cast or a removable cast or boot may be used to prevent overuse and subsequent rupture of the tendon. A removable
stirrup-brace is not initially sufficient as it does not limit motion in the sagittal plane, a component of the pathological process. The patient should be permitted to walk while wearing the cast or
boot during the six to eight-week period of immobilization. At the end of that time, a decision must be made regarding the need for additional treatment. If there has been marked improvement, the
patient may begin wearing a stiff-soled shoe with a medial heel-and-sole wedge to invert the hindfoot. If there has been only mild or moderate improvement, a longer period in the cast or boot may be
Surgery should only be done if the pain does not get better after a few months of conservative treatment. The type of surgery depends on the stage of the PTTD disease. It it also dictated by where
tendonitis is located and how much the tendon is damaged. Surgical reconstruction can be extremely complex. Some of the common surgeries include. Tenosynovectomy, removing the inflamed tendon sheath
around the PTT. Tendon Transfer, to augment the function of the diseased posterior tibial tendon with a neighbouring tendon. Calcaneo-osteotomy, sometimes the heel bone needs to be corrected to get a
better heel bone alignment. Fusion of the Joints, if osteoarthritis of the foot has set in, fusion of the joints may be necessary.