Chronic ankle instability (CAI) is a common orthopedic condition that occurs after multiple ankle sprains, or in some cases, one severe ankle sprain.
Approximately 30 percent of patients will develop this condition after their first ankle sprain. Each subsequent injury increases the likelihood of developing CAI. Conservative treatment has limited effectiveness for this chronic condition. Instead, surgical intervention is often required, followed by an extended period of rehabilitation.
Causes of Chronic Ankle Instability
The most common cause of CAI is a history of sprains accompanied by pain and swelling. However, if you did not seek appropriate treatment at the time, your risk of CAI increases significantly.
CAI involves the complex anatomy of lateral ankle, consisting of multiple muscles, tendons and ligaments. It is the ligaments, however, that are primarily responsible for instability, allowing the ankle to give way when weight is put upon it.
Repeated sprains weaken the muscles of the joint. When the ligaments are unable to compensate for this weakness, they lose the ability to stabilize the ankle
Chronic Ankle Instability Symptoms & Diagnosis
Most CAI patients present with localized pain, swelling and stiffness, and see their ability to participate in activities significantly reduced. Tenderness, limited range of motion and joint misalignment when bearing weight are also common symptoms, as is a persistent ache after activity.
CAI is also characterized by patient apprehension and distrust in their ankle’s ability to support them on uneven ground.
To diagnose CAI, the doctor will begin by taking a detailed medical history, focusing on prior injuries and treatment. A physical exam begins with an evaluation of the patient’s nonsymptomatic ankle to establish a baseline. The symptomatic joint is then evaluated, including alignment while bearing weight. The doctor will evaluate range of motion.
Imaging tests, including weight-bearing X-rays, ultrasound and non-contrast MRI, will assist the doctor in identifying structural problems in the joint.
Treatment & Prevention of Ankle Instability
The doctor will likely prescribe a conservative treatment to start, including ankle support while pain is present. Orthotics (supportive insoles) and stiff-soled shoes may also be recommended. Strength training and range-of-motion exercises are the keys to overcoming CAI.
Many CAI patients require surgery to correct the problem. Although surgical stabilization of the affected tendons is a common approach, this procedure does not address the underlying ligament problems that cause instability.
The specific surgical techniques required will depend on the specific tissues that are damaged. However, the surgeon may have to repair both tendon and ligament damage as well as remove scar tissue within the joint.
Following surgery for chronic ankle instability, a non-weight-bearing cast is usually required for three to six weeks, followed by an ankle brace for three additional months. Intensive rehab is necessary to restore strength and range of motion.
The most effective way to prevent CAI is to seek qualified medical treatment immediately after any ankle injury. Going to the ER or an urgent care facility is often insufficient to address the injuries related to ankle sprain. Instead, see an orthopedic specialist, sports medicine doctor or foot and ankle specialist for appropriate chronic ankle instability treatment.