Adult Aquired Flat Foot

Overview

A more serious condition, according to ACFAS, is adult-acquired flatfoot, often cause by posterior tibial tendon dysfunction (PTTD). In this case, the tendon that supports the arch weakens and fails, leading to a rigid flatfoot where the arch stays flat even when you aren’t standing. It can lead to a loss of range of motion in the foot and ankle and pain in the arch. The ACFAS clinical guideline recommends that flatfoot caused by PTTD can be treated with custom shoe orthotics, soft casts, walking boots, physical therapy and non-steroidal anti-inflammatory medications. If there is no relief or the condition worsens, then the patient may be referred to surgery.Flat Feet


Causes

As the name suggests, adult-acquired flatfoot occurs once musculoskeletal maturity is reached, and it can present for a number of reasons, though one stands out among the others. While fractures, dislocations, tendon lacerations, and other such traumatic events do contribute to adult-acquired flatfoot as a significant lower extremity disorder, as mentioned above, damage to the posterior tibial tendon is most often at the heart of adult-acquired flatfoot. One study further elaborates on the matter by concluding that ?60% of patients [presenting with posterior tibial tendon damage and adult-acquired flatfoot] were obese or had diabetes mellitus, hypertension, previous surgery or trauma to the medial foot, or treatment with steroids?.


Symptoms

Pain along the inside of the foot and ankle, where the tendon lies. This may or may not be associated with swelling in the area. Pain that is worse with activity. High-intensity or high-impact activities, such as running, can be very difficult. Some patients can have trouble walking or standing for a long time. Pain on the outside of the ankle. When the foot collapses, the heel bone may shift to a new position outwards. This can put pressure on the outside ankle bone. The same type of pain is found in arthritis in the back of the foot. Asymmetrical collapsing of the medial arch on the affected side.


Diagnosis

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

Conservative treatment also depends on the stage of the disease. Early on, the pain and swelling with no deformity can be treated with rest, ice, compression, elevation and non-steroidal anti-inflammatory medication. Usually OTC orthotic inserts are recommended with stability oriented athletic shoes. If this fails or the condition is more advanced, immobilization in a rigid walking boot is recommended. This rests the tendon and protects it from further irritation, attenuation, or tearing. If symptoms are greatly improved or eliminated then the patient may return to a supportive shoe. To protect the patient from reoccurrence, different types of devices are recommended. The most common device is orthotics. Usually custom-made orthotics are preferable to OTC. They are reserved for early staged PTTD. Advanced stages may require a more aggressive type orthotic or an AFO (ankle-foot orthosis). There are different types of AFO’s. One type has a double-upright/stirrup attached to a footplate. Another is a gauntlet-type with a custom plastic interior surrounded be a lace-up leather exterior. Both require the use of a bulky type athletic or orthopedic shoes. Patient compliance is always challenging with these larger braces and shoes.

Flat Foot


Surgical Treatment

When conservative care fails to control symptoms and/or deformity, then surgery may be needed. The goal of surgical treatment is to obtain good alignment while keeping the foot and ankle as flexible as possible. The most common procedures used with this condition include arthrodesis (fusion), osteotomy (cutting out a wedge-shaped piece of bone), and lateral column lengthening. Lateral column lengthening involves the use of a bone graft at the calcaneocuboid joint. This procedure helps restore the medial longitudinal arch (arch along the inside of the foot). A torn tendon or spring ligament will be repaired or reconstructed. Other surgical options include tendon shortening or lengthening. Or the surgeon may move one or more tendons. This procedure is called a tendon transfer. Tendon transfer uses another tendon to help the posterior tibial tendon function more effectively. A tendon transfer is designed to change the force and angle of pull on the bones of the arch. It’s not clear yet from research evidence which surgical procedure works best for this condition. A combination of surgical treatments may be needed. It may depend on your age, type and severity of deformity and symptoms, and your desired level of daily activity.

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