Foot instability 

General information

Many people experience foot tucking without realizing that even a single injury to the ankle ligament leads to chronic foot instability, if not treated correctly. In this condition, the foot’s supporting function is impaired, gait instability occurs, and nerve conduction and movement control by the nervous system are impaired.

Sprains are the most common cause of ankle ligament injuries. This ligament injury often affects people who play sports. The great danger of instability is that if the disease is not detected in time, and in the absence of treatment, it can turn into an unpleasant complication – osteoarthritis. Treating osteoarthritis requires surgery to replace parts of the joint (endoprosthesis).

How chronic foot instability forms

Human mobility in space (walking, jumping, running, etc.) is only possible with the proper functioning of the ankle joint. This joint consists of the tibia, fibula, and talus. The ligaments provide stability for the position of the bones and connect the foot to the lower leg.

Repeated injuries, sprains, ankle injuries, long-term inflammation of the peroneal tendon, or other traumatic events lead to instability—the inability of the ligaments to hold the proper position of the foot during walking, jumping, or other loads. The ligaments on the outside of the foot, which extend from the fibula at one end (it is thinner), are more often affected, while the deltoid ligament on the inside of the foot is less often damaged (it is thicker).

Ankle instability is the condition of uncontrolled changes in the position of the foot during work. If left untreated, chronic instability develops, reducing quality of life and making it difficult for patients to move confidently in space.

The leading known causes of chronic foot instability are damage to the mechanoreceptors in the ankle joint, which are located in the joint capsule, ligaments, muscles, tendons, and skin, and weakening muscle strength when controlling foot turns. Destruction of sensors leads to incorrect perception by the nervous system of the foot position, movement, and pressure in the ankle joint during work, i.e., the incoming signal needs to be revised to the situation. Accordingly, the response, controlling signals from the nervous system to the muscles, must also be corrected. If the strength of the muscles is weakened, the balance between their work during foot turns is disturbed, and instability develops.

Signs of foot instability

The appearance of instability in the ankle joint is accompanied by the following symptoms:

• pain that increases with prolonged loading of the ankle,
• limited mobility of the joint,
• involuntary painful twisting of the foot during walking or other activities, especially when walking on bumpy surfaces,
• swelling in the traumatized area,
• bruises,
• localized increase in skin temperature,
• painful sensations in the area of the lesion when palpated.

Chronic foot instability has three degrees of severity:

• I: selective damage to fibers in the ligaments, the functionality of the ankle joint is fully preserved, there is mild pain or discomfort with loads, slight swelling, rare instability,
• II: fragmentary rupture of ligaments, there is regular instability and moderate swelling in the ankle joint, mobility of the leg is limited, pain sensations may occur even in the absence of load,
• III: Complete rupture of the ligament. A pronounced pain syndrome develops with any movement, and the painful area is significantly swollen.

Diagnosis of foot instability

Initially, the doctor collects an anamnesis, records complaints, and asks questions about the time and circumstances of ankle injuries, frequency of subluxations, etc. The most common complaint of people with foot instability is difficulty moving on uneven surfaces, and the cause of its development is trauma to the foot.

Next, the doctor carefully examines the entire foot, noting changes (swelling, redness, bruising, mobility, etc.) and palpating the ankle joint. During the examination, the doctor evaluates the strength of pain and mobility of the joint.

After the examination, the doctor performs tests to clarify the degree of instability and functionality of the ankle joint and the nervous system. With the help of tests, it is necessary to assess instability, leg muscle strength, identify symptoms of weakness of foot ligaments (for example, in the talus tilt test), possible damage to the ligament apparatus of other joints of the leg (weakness of the cruciate ligaments of the knee, etc.).

As methods of instrumental diagnostics to assess the state of tissues inside the ankle joint, their visualization is used magnetic resonance imaging of the ankle joint (MRI). The integrity of the bones in chronic foot instability is checked with a joint radiologic examination.

Conservative treatment of foot instability

The wrong choice of treatment measures for foot instability, which the patient himself most often carries out, entails quite severe consequences: lameness, osteoarthritis, and other joint diseases may develop.

The choice of treatment methods for foot instability is determined by the severity of the ligament damage. Conservative treatment is preferable if the degree is small or the injury is recent. The ankle joint is fixed with a bandage (plaster, polymer, or other). For quality recovery, it is initially necessary to provide rest to the joint. To reduce inflammation, pain, and swelling, ice is applied to the injured joint, and non-steroidal anti-inflammatory drugs (NSAIDs) may be prescribed.

After the bandage is removed, special devices, such as bandages and orthoses, are used to support the ankle joint, and taping is an alternative method of support. Together with supportive structures, a course of restorative therapeutic physical therapy is prescribed, with exercises gradually complicated and increased load. The course may include exercises on special equipment for balance training and evaluation of recovery progress.

Surgical treatment

In the case of chronic instability, if the necessary results from conservative methods are not achieved, surgical treatment is prescribed.

In case of timely referral to a surgeon, it is possible to use a minimally invasive method – arthroscopy. In this case, the damaged ligaments are stitched together under the control of a video camera, which is inserted together with special manipulators through a small incision inside the ankle joint. Along with arthroscopic surgery, the structure and condition of the ankle joint can be visualized and studied, allowing other problems within it to be repaired right at the time of surgery. After arthroscopic surgery, the recovery period is the shortest. It lasts up to 3 weeks.

If the ligamentous apparatus is significantly damaged and the above measures are not effective for foot instability, surgical restoration of the ligaments by endoprosthetic methods (using a graft to replace part of the joint) is necessary. This is a serious operation, and recovery can take up to 1.5 months.

One of the most important activities during the recovery period is physical therapy. The exercise program is developed individually for each patient and includes exercises for strengthening and stretching muscles and loading and developing the ankle. In addition to an individual training and ankle rehabilitation program, the doctor may prescribe additional physiotherapy.

For the first time after surgery, patients must move around with crutches to minimize the load on the ankle joint. After a month, the plaster cast may be replaced with an ankle support orthosis. After a few weeks, the patient can safely load the ankle joint after surgery with an adequately selected recovery program.

All these treatment options are available in more than 760 hospitals worldwide (https://doctor.global/results/diseases/foot-instability). For example, Foot arthrodesis can be performed in following countries:

Turkey$2.9 K in 29 clinics

United States$11.6 K – 22.8 K in 23 clinics

China$11.6 K in 6 clinics

Germany$11.7 K in 45 clinics

Israel$25.7 K in 16 clinics.