A lateral ligament ankle sprain occurs when the ligaments on the outside of the ankle are stretched beyond their limits. Injury to these ligaments causes pain and swelling in the ankle. Generally, most lateral ligament ankle sprains are minor and will get better with simple treatments. However, more severe cases can weaken the ankle leading to repeated sprains and chronic ankle pain. So, how do you diagnose a tear of the ankle ligaments and what do you do?

What are the lateral ligaments? 

Ligaments are strong fibrous structures that connect bones to other bones. There are three ligaments connecting the top and bottom of the ankle joint on the outside of the ankle. In general, spraining the ankle damages one or more of these ligaments.


A Lateral ligament ankle sprain occurs when the ankle rolls inwards or twists. Generally, your ankle twists during many activities such as walking or running on uneven surfaces, playing sport involving change of direction, or an unexpected fall.

Usually, the more times you sprain your ankle, the more likely you’ll sprain it again.

Clinical findings of a lateral ligament ankle sprain

In general, a sprained ankle causes pain on the outside of the ankle. Other symptoms include:

  • a pop or crack sound at the time of the injury
  • swelling which forms immediately or overnight
  • bruising
  • stiffness due to inflammation, which is worse in the morning and improves with activity
  • instability of the ankle joint – this may occur with complete tearing of the ligaments
  • tenderness at the ligaments

Usually, your doctor will diagnose an ankle sprain by careful examination of the ankle and foot. As a rule, it is important to make sure that you don’t have a break (fracture) or cartilage injury. Often, an X-ray, ultrasound, or MRI is needed to confirm a lateral ligament tear and rule out other injuries.

Treatment of lateral ankle ligament sprain

ankle exercises for ankle sprain

Almost all ankle sprains can be treated without surgery. Even complete ligament tears get better with treatment such as bracing and physiotherapy. Overall, just because you tear your ligaments doesn’t mean you need surgery.

In general, we suggest a three-phase process to get you back to sport:

  • Phase 1 includes rest from sport, compression, and regular icing to limit swelling. A short course of ibuprofen can help. Also, a small cast boot may provide extra support.
  • Phase 2 includes range of motion exercises, stretching, and calf strengthening. Balance exercises are important to prevent a recurrence.
  • Phase 3 involves complex exercises and gradual return to running and change of direction activity. Your therapist will introduce agility drills to test the ankle.

Ankle sprain getting worse and not better: what to do 

On average, about 10% of ankle sprains do not get better with simple treatments. In these cases, it may be useful to see your doctor and explore imaging to confirm the diagnosis. Generally, we need ultrasound or MRI to diagnose other problems such as a tendon tear or ankle cartilage damage.

Examples of other damage to the ankle include:

  • breaks in the small bones of the ankle such as the anterior process of calcaneus, base of 5th metatarsus or os trigonum
  • cartilage damage in the ankle joint

Every so often, an injection is useful to help with therapy. For example, a common cause of ankle pain after a sprain is persistent inflammation in the ankle joint. A cortisone injection directed to this inflammation can reduce pain and allow for more rehab. Generally, we perform injections with ultrasound to improve accuracy. A small needle is inserted into the area of inflammation. Ultrasound allows us to avoid important nerves and blood vessels.

Occasionally, surgery is needed to remove the inflammation or reconstruct the ligaments. Normally, we refer to surgery for cases that fail rehab.

Commonly asked questions about ankle sprains:

Why do I keep twisting my ankles? 

Generally, repeated ankle twists lead to more damage to the outside ligaments meaning that you’re more likely to twist again.  Therefore, we stress the importance of seeing a therapist after a sprain to prevent future sprains.

Why won’t my ankle heal after a sprain? 

Not all sprained ankles involve just ligament damage. Sometimes, rolling your ankle can damage other structures such as tendons or cartilage. In these cases, we recommend you see an experienced doctor who can sort out the reason for your ongoing ankle problems.

Can torn ankle ligaments heal without surgery? 

Yes. Even in tears of all the ligaments on the outside of the ankle, the ankle can regain full function without surgery. We suggest a short period of rest in a walking boot followed by slow physiotherapy.

Deltoid ligament sprain: Do we treat it differently? 

The deltoid ligament on the inside of the ankle is much larger and stronger than the lateral ligaments. Therefore, a tear of the deltoid ligaments is in fact a more serious injury that requires longer rehab. In complete tears of the deltoid ligament, we recommend a surgical repair.

Final word from Sportdoctorlondon

Not all ankle injuries are benign and settle with physiotherapy. You should see an expert sports doctor to correctly diagnose and manage your difficult ankles.

Other foot and ankle conditions:

Dr. Masci is a specialist sport doctor in London. 

He specialises in muscle, tendon and joint injuries.

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