One of the most common ankle joint injuries is the “ankle sprain.” Ankle sprains are a very common athletic injury. In basketball players ankle sprains account for 45% of injuries suffered. An inversion injury of the ankle with sprain of the lateral ankle ligaments is the single most common injury seen in sports. Because they are so common, there is a tendency to underestimate the severity of the injury as “just an ankle sprain.”
Lateral ankle sprain
This occurs when the foot inverts, or turns inward. A sprain denotes an injury to a ligament. Three ligaments are commonly injured. These ligaments are (in the order most commonly injured):
- anterior talofibular (ATF)
- calcaneofibular (CF)
- posterior talofibular (PTF)
The diagnosis of lateral ankle sprain is primarily clinical, with a history of turning in of the foot, occasionally with a ‘pop’ heard or felt. Swelling and bruising occur shortly after the injury. It is often difficult to bear weight immediately after, but it may be accomplished shortly afterward. This history with careful examination of the region determines which ligaments are injured. Ruling out other injuries is critical to full recovery. Often the injury is severe enough to limit initial physical examination. Repeat examination after a short period to let swelling and pain subside may be necessary. X-rays may taken immediately to rule out a broken bone.
A common classification applicable to all ligament injuries classifies sprains according to degree of severity into:
- Grade I ligament stretch (microscopic tear)
- Grade II ligament partly torn
- Grade III ligament completely torn
Medial ankle sprain
This occurs when the ankle turns outward or rotates. The medial ankle ligaments form a strong complex ligament called the deltoid ligament. These injuries are less common, but often involve tendon or bone requiring a period of immobilization.
Injuries related to ankle sprains: Occult injuries
There are a number of other structures about the ankle joint that may be injured with the same mechanism as an ankle sprain. These injuries can be a challenge to diagnose and may be initially masked by pain from the classically involved ligaments. When standard sprain treatments do not provide the patient with relief, occult or hidden injury should be suspected. Other injuries that may occur are:
Several bones may be injured in an ankle injury. A common misconception is that if a bone is broken one cannot bear weight. This is not true in the foot and several fractures have been associated with ankle sprains: 5th metatarsal, anterior process of the calcaneus, navicular, cuboid, tibia, fibula and talus.
Other ligamentous sprains
There are many ligaments that may be injured with the same mechanism either isolated or in addition to the common structures. These structures may not respond to regular ankle sprain treatment and may require immobilization or even surgical management to stabilize the bones while the ligaments heal.
Tendons may also be injured in a typical sprain mechanism. They may not completely tear, but may actually split lengthwise. This often results in a chronic condition that requires surgical repair if it does not respond to other treatments.
Nerve injuries can occur when the nerves stretch. This is called neuropraxia and may result in numbness and pain. These injuries may take long periods of time to heal
Chronic conditions as a result of ankle sprain
Chronic instability of ankle or subtalar joints, osteochondral fracture, adhesions or intra-articular hyalinized lesions as a result of intra-articular bleeding, meniscoid lesions, synovial impingement and loose bodies, and post-traumatic arthritis.
What You Can Do
- Start initial treatment including protection, rest, ice, compression, and elevation (PRICE).
- Slight sprains will respond quickly. Seek a professional opinion for significant injuries.
What Your Doctor May Do
- Careful history and physical examination.
- X-rays and other imaging studies (bone scan, CT, MRI) where necessary.
- Use immobilization and non-weightbearing for significant injuries.
- Prescribe anti-inflammatory drugs
- Prescribe physical therapy.
- Use local anesthetic blocks to diagnose injury.
- Surgery is rarely indicated immediately after an ankle sprain, but complete tears
- Other related injuries and chronic conditions may respond well to surgery.