Most (approximately 85 percent) ankle sprains and strains are inversion injuries in which the foot twists inward, damaging the lateral ligaments on the outside of the foot. Pronation injuries to the medial ligaments on the inside of the foot, which are caused by twisting the foot outward, are less common.
Sprains are graded on a scale of 1 to 3 (mild, moderate, and severe), depending on the degree of tearing to the ligaments. In most cases, x-rays are performed to rule out a fracture or dislocation.
Treatment for ankle sprains and strains usually involves RICErest, ice, compression, and elevation:
- Rest involves keeping off the injured ankle as much as possible. Crutches may be used to enable the patient to move around when necessary, without placing weight on the injury. An air cast or splint may be used to support the ankle for support and severe sprains may require a hard cast.
- Ice is used to reduce swelling. Ice packs are usually applied for 20 minutes at a time every hour as long as swelling persists.
- Compression involves supporting the ankle and foot with a firmly (not tightly) wrapped elastic bandage, compression stocking, or gel wrap. If swelling causes the bandage to become tight, it should be loosened immediately.
- Elevation helps to minimize bruising and swelling. The foot should be kept above heart level as often as possible during the first 48 hours.
Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may help to reduce pain, swelling, and inflammation. Due to potentially severe gastrointestinal and cardiovascular side effects, NSAIDs should only be used as instructed.
In some cases, prolonged swelling caused by the formation of excessive scar tissue occurs and the physician may request x-rays to check for small, previously undetected bone fragments, or damage to the joints.
Most ankle strains and sprains heal in 2 to 6 weeks, with proper treatment. Severe injuries may take as long as 12 weeks to heal and may require physical therapy to restore full muscle balance and strength. Physical therapy may involve stretching the Achilles tendon, as well as coordination and speed exercises. During this time, the ankle may require taping or bracing to provide support until full function is regained.
Patients who experience an ankle injury are at risk for recurrent injury during and following recovery and should take precautions. Shoes that provide stability and support are a prudent investment, and supplemental bracing with a specially fitted elastic wrap may be recommended. In some cases, custom orthotics are prescribed to help provide ankle stability after an injury.
Ankle sprains rarely require surgery. However, if a person experiences persistent pain or recurrent ankle sprains, surgical repair of the ankle ligaments may be necessary. A badly torn ligament may need to be surgically reattached to the bone, for example, or a chronically unstable ankle may be strengthened by removing a piece of tendon from one side of the foot and attaching it to the weakened area for support.
These procedures usually require the foot and ankle to be placed in a cast for up to 2 months. The success rates for these procedures are high, and up to 85 percent of patients eventually return to full activity.
If chronic pain is a problem, an arthroscopic surgical procedure may be necessary to remove bone fragments, scar tissue, and damaged cartilage.