An ankle sprain, a common injury, occurs when the strong ligaments supporting the ankle are stretched or torn. While many anticipate a quick recovery, persistent pain months after an initial sprain can be unsettling. This prolonged discomfort often indicates an underlying issue.
Normal Recovery Versus Persistent Pain
The healing process for an ankle sprain typically progresses through several stages. An acute phase involves inflammation, pain, and swelling, usually lasting a few days. This is followed by a subacute phase where the body begins to repair damaged tissues and form scar tissue. A rehabilitation phase then focuses on restoring strength and range of motion.
Mild sprains (Grade 1) often allow walking without pain within one to two weeks, with a return to activities in three to four weeks. Moderate sprains (Grade 2) may take two to three weeks for comfortable walking, with full activity resuming in six to eight weeks. Severe sprains (Grade 3), involving complete ligament tears, can require twelve weeks or longer for full recovery. Pain that continues beyond three to six months after the initial injury is classified as persistent or chronic post-sprain pain.
Common Causes of Lingering Ankle Pain
Persistent ankle pain often stems from issues where the initial injury did not fully resolve. Chronic ankle instability is a frequent cause, developing when ligaments do not heal properly, leading to a feeling of the ankle “giving way.” This instability can result in recurrent sprains and ongoing discomfort.
Ankle impingement occurs when soft tissues or bone spurs become pinched within the ankle joint during movement. This can occur at the front (anterior) or back (posterior) of the ankle, causing pain, especially during activities like walking uphill or pointing the toes. Repeated ankle sprains are a common cause of anterior soft tissue impingement due to inflammation and scarring.
Peroneal tendinopathy involves inflammation or damage to the tendons located on the outside of the ankle. These tendons can become irritated due to altered walking mechanics or overuse following a sprain. Excessive scar tissue, known as arthrofibrosis, can also cause persistent pain and stiffness by limiting joint motion. While some scar tissue is normal, too much can restrict movement and irritate nerves.
Nerves around the ankle can be stretched, compressed, or torn during a sprain, leading to persistent pain, numbness, or tingling. Severe sprains, particularly Grade 3 injuries, have a higher incidence of nerve involvement, which can prolong rehabilitation.
Less Common or Related Conditions
Other conditions can contribute to prolonged ankle pain after a sprain. Osteochondral lesions occur when the cartilage and underlying bone on the talus are damaged during the injury. These lesions can cause persistent pain, clicking, or a sensation of locking in the joint, often exacerbated by activity. Approximately 50-70% of acute ankle sprains are associated with osteochondral lesions.
Stress fractures can also develop, sometimes as a result of altered gait or increased stress on other bones due to the initial sprain. These tiny cracks in the bone can cause localized pain that worsens with activity. Post-traumatic arthritis may also develop, particularly after severe or repeated ankle sprains, where the joint surface is damaged. This can lead to the gradual breakdown of cartilage and pain. The ankle joint is particularly susceptible, with up to 90% of ankle arthritis cases being post-traumatic.
Tarsal tunnel syndrome, a condition similar to carpal tunnel syndrome, involves the compression of the posterior tibial nerve. Swelling or scar tissue from a sprain can compress this nerve, leading to pain, numbness, or tingling in the foot.
What to Do Next
If ankle pain, swelling, or instability persists for several months after a sprain, seek medical attention. A healthcare professional, such as an orthopedic specialist or physical therapist, can diagnose the underlying cause. Diagnosis begins with a physical examination to assess the ankle’s range of motion, stability, and tenderness.
Imaging studies are often used. X-rays can help rule out fractures, while magnetic resonance imaging (MRI) is valuable for visualizing soft tissue damage, cartilage issues, and bone marrow edema. Treatment options are then tailored to the specific condition.
Conservative management is often the first approach, including physical therapy to strengthen the ankle, improve balance, and enhance proprioception (the body’s awareness of its position in space). Bracing, RICE (rest, ice, compression, and elevation), and nonsteroidal anti-inflammatory drugs (NSAIDs) may also be recommended. In some cases, injections might be considered. Surgical intervention is generally reserved for severe cases that do not respond to conservative treatments, such as severe instability or persistent impingement. Consistent physical therapy after any treatment helps regain strength, flexibility, and stability, which can prevent future issues.