Sprains to the ankle are one of the most common sporting injuries. The major concern is that 70% of patients will suffer from repetitive ankle sprains and subsequent chronic ankle instability (CAI) following the initial injury. This CAI does not only limit physical activity, but more importantly leads to articular degeneration of the talus, with an increased risk of osteoarthritis.
The ankle joint is a hinge joint formed between the tibia and fibula (bones of the lower leg) and the talus (a bone of the foot) and allows the foot to bend upwards (dorsiflexion) and downwards (plantarflexion). Two bones of the foot, the talus and calcaneus (heel bone) connect to form the subtalar joint which allows the foot to rock side to side (inversion/eversion).
On the inside of the ankle (medial side), the joint is stabilised by a thick, strong fibrous ligament called the deltoid ligament. Sprains to the deltoid ligament (eversion sprains, foot twists outward) account for less than 20% of all ankle sprains.
On the outside of the ankle (lateral side), the joint is stabilised by three smaller ligaments; the anterior talofibular (at the front), the calcaneofibular (at the side) and the posterior talofibular (at the back). Sprains to any of these ligaments (inversion sprains, foot twists inward) account for more than 80% of all ankle sprains.
The most commonly injured ligament is the anterior talofibular. Injury to this ligament results in swelling and pain on the outside of the ankle. If the force is more severe, the calcaneofibular ligament is also damaged. The posterior talofibular ligament is less likely to be damaged. A complete tear of all ligaments may result in a dislocation of the ankle joint and an accompanying fracture and often requires surgical repair.
Occasionally medial ligament injuries may be seen in conjunction with a lateral ligament injury.
The greatest proven risk factor for an Ankle sprain is a previous or existing ankle injury, especially if it has been poorly rehabilitated in the past. Sports requiring jumping, turning & twisting movements ie. Basketball, netball, volleyball, football, as well as those requiring explosive changes of direction ie. Soccer, tennis & hockey place you at increased injury risk.
Proven risk factors include
Potential Risk Factors
The signs & symptoms of an ankle sprain can vary depending on the severity of the injury.
Grade | Signs & Symptoms |
1 (mild) |
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2 (moderate) |
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3 (severe) |
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