What should I do if my ankle sprain fails to heal? After regular physical rehabilitation, about 10% of severe ankle sprains do not heal. There are three common conditions: ankle instability, articular cartilage damage, and impingement. These conditions usually occur in conjunction with each other and are generally categorized as “ankle instability”. Ankle instability is caused by ligamentous laxity and usually begins with an ankle sprain, sometimes several years after the sprain occurred. Patients may feel weakness in the ankle joint and sprain easily, and some patients may sprain even when walking on a wide sidewalk gap. The biggest problem with ankle instability is that repeated sprains can cause arthritis. 2, articular cartilage damage Articular cartilage is a very smooth bone covering the end of the bone, and other corresponding cartilage together constitute the joint. Articular cartilage can bear the weight of the body, so that the joint becomes a joint, rather than two pieces of bone rubbing against each other. If the articular cartilage is gone, it is equivalent to having “arthritis”. In an ankle sprain, the two large bones that make up the ankle joint (tibia and talus) come together and may become partially damaged in the articular cartilage. This localized damage to the cartilage is often called an “osteochondral injury” and is often located on the cartilage side of the talus, hence the name “talar cartilage injury”. You may read this diagnosis on an MRI report. When the area of articular cartilage damage becomes larger and larger, it evolves into ankle arthritis. 3. Ankle impingement Impingement means that the bones are squeezed together with the bones. When a bone spur develops in the bone around the joint (commonly in the front of the ankle), it causes ankle pain and decreased range of motion in ankle dorsiflexion (crossing the back of the foot). Typical symptoms are pain when running and walking up hills, and when squatting the patient will stand on his heels because of the pain. This condition, also known as “soccer foot”, can occur spontaneously, but most cases are still associated with ankle sprains. What is the natural course of an ankle sprain if left untreated? If left untreated, ankle sprains often develop into ankle arthritis at a later stage. 3. How to diagnose ankle instability? 1. Medical history: Most patients have symptoms such as ankle pain, swelling, and tenderfoot. 2. Physical examination: Although muscle spasm can easily mask the signs, ligamentous laxity can often be found during physical examination. In patients with impingement, pressure pain can be felt along the front of the ankle joint line, while there is a decrease in joint dorsiflexion mobility. In cases of articular cartilage damage, there may be joint swelling and deep joint tenderness. (1) X-rays: Bone growths may be seen when there is joint impingement. Sometimes these bone spurs can only be seen on special anterior internal oblique films, which requires the experience of the doctor taking the film. Radiographs can also detect arthritis that has developed, but X-rays cannot detect only early arthritic changes. Ligament damage or joint instability can also be diagnosed by special stress-position radiographs, but this is usually not necessary. (2) CT: CT can detect occult joint impingement and occult damage to the subchondral bone of the joint, but is not usually necessary. (3) MRI: It can detect most cases of cartilage lesions and ligament damage, but if the ligaments are only slightly lax, the MRI may not be diagnostic. MRI can also detect other diseases such as talar necrosis, infection, and tumors. 3. Arthroscopy: Arthroscopy is the best diagnostic method. It allows access to the inside of the ankle joint to examine the ligaments of the ankle joint. It also allows the use of a probe to examine the condition of the articular cartilage, which sometimes appears normal on the surface but separates from the underlying subchondral bone when pushed with the probe.