Ankle Sprains | Overview, Causes, Diagnosis & Treatment

Ankle sprains are very common injuries. Most people, have had an ankle sprain or two in their lifetime. Most ankle sprains do not require surgery and will resolve within 2-6 weeks with good quality rehabilitation. But not all ankle sprains are the same, and some patients will require surgery to achieve the best outcome.

Ankle Sprains Explained

Your ankle joint is made up from 3 different bones. You can think of the ankle joint, in simple terms, as being a connection between your leg and your foot.

Your leg has 2 bones inside it. The largest leg bone is called the tibia (or the shin bone). The end of the tibia is responsible for forming the knuckle, or bump, on the inner side of your ankle. The smaller bone on the outside of the leg is called the fibula, this is what causes the knuckle on the outer side of your ankle.

The ligaments on the inner side, or medial aspect, of the ankle joint are called the Deltoid ligament complex.

The ligaments on the outer side, or lateral aspect, of the ankle joint are called the anterior talo-fibular ligament, and also the calcaneofibular ligament. Now in order to avoid getting too tongue tied, we usually just refer to them as simply the ATFL and the CFL.

You can think of the Deltoid, ATFL and CFL as being the main ligaments that connect the leg bones to the ankle bone and foot. These are the ligaments that most people would associate with an ankle sprain.

The tibia and the fibula are held together by a number of very strong ligaments. These ligaments prevent the two bones from separating apart.  All together, these ligaments are known as the syndesmosis. The syndesmosis continues from the top of your ankle joint, all the way up your leg.

Ankle Injuries and Ankle Sprains

Ankle Sprain Types

To help patients understand their injury, and treatment options, I tend to divide ankle sprains into 3 main categories; simple ankle sprains, complex ankle sprains and syndesmosis injuries, and chronic ankle sprains.

Simple Ankle Sprains

Simple ankle sprains usually involve a lower grade injury to only the ATFL, CFL or Deltoid ligaments. But the syndesmotic ligaments are not injured, and there is no associated cartilage injury or fracture.

Usually the injury mechanism is minor, such as tweaking your ankle during sports practice or your ankle giving way when walking on uneven ground. Patients don’t usually hear or feel a ‘pop’ within their ankle as the injury occurs. In general, you are not in horrible pain and you can continue to walk on your ankle. There can be swelling and bruising, but this is not usually major.

Within hours to days after your injury you should be walking more comfortably, with minimal pain. Yes, you might still be a bit sore and swollen, but overall things start to improve quite rapidly.

Complex Ankle Sprains and Syndesmosis Injuries

Complex ankle sprains involve higher grade injuries to the ATFL, CFL or Deltoid ligament. Commonly, they also involve damage to the syndesmosis ligaments and there is associated bone and cartilage injury. Complex ankle sprains are less likely to recover without surgery, or they may require longer periods of non-operative management compared to simple ankle sprains.

The injury mechanism for a complex ankle sprain and syndesmosis injury is often more severe, such as a significant sporting injury, falling from a bike at high speed or even slipping over in high heels. However, it is also true that a complex ankle sprain can also occur with a relatively minor injury. Sometimes you can just be unlucky. Pain and swelling are significant, and in the days that follow there can be major bruising around the ankle and foot.

In this situation I would recommend an appointment with a podiatrist, general practitioner or sports doctor, and it is likely they will arrange an x-ray.

In general, unstable syndesmotic injuries, where the two legs bones have separated, have very poor long-term results if managed without surgery. The leg bones heal slightly separated, and this creates uneven stress through your ankle joint, and there is a high risk of on-going pain and arthritis.

If you have a severe syndesmosis injury, we then need to hold these bones together securely, so that the ligaments can heal back in the normal position. We do this with a technology called a ‘tight rope’.

A tight rope is a very strong piece of suture material with a small, metal button at each end. We drill a small tunnel between the two leg bones, then thread the tight rope between them. The tight rope is then tightened in place over the metal buttons. It is extremely strong and holds the leg bones in their normal position.

The ruptured syndesmotic ligaments will then heal during the next 6-8 weeks. Once the ligaments have healed, the tight-rope has finished its job – it’s a temporary holding device until those ligaments heal.

Syndesmotic injuries should ideally be discussed with an orthopaedic surgeon, so they can examine your ankle, view your scans and explain the pros and cons of surgery.

Chronic Ankle Sprains

Even though many patients recover fully from a simple ankle sprain without surgery, there are a number of patients who will not. In these patients, the ankle continues to give way, or they repeatedly sprain their ankle, even months or years after the original injury.

If you are continually spraining your ankle, then it is likely that you have sustained a major injury to the ATFL and the CFL. These ligaments are the main restraint to your ankle giving way and turning in without warning. In chronic ankle instability, the ATFL and CFL are like over-stretched elastic bands. They can no longer provide normal support to your ankle.

The muscles and tendons around the ankle joint are also very important to preventing your ankle from giving way. This is why rehabilitation to strengthen these is crucial after an ankle sprain. But sometimes, even the best rehabilitation isn’t enough to compensate for badly torn and stretched out ankle ligaments.

Fortunately, surgery for on-going ankle instability is a reasonably small operation, with minimal risks and a high success rate. Surgery should only be considered if non-operative management has failed.

I’ve Just Sprained My Ankle- What Now?

Simple Ankle Sprains

In this situation, I would recommend making an appointment with a good sports physiotherapist or podiatrist. They can assess you, and in most situations, you probably won’t even require an x-ray or any other scans. The key thing is that you should feel continued improvement day by day and week by week. A return to full activities does vary, but you should be back doing everything within 2-6 weeks.

Even if there is significant damage to the ATFL, CFL or Deltoid ligament, these can often heal up with scar tissue, and don’t always require surgical repair.

Quality rehabilitation is absolutely essential in recovering from a simple ankle sprain. The main goal is to prevent your simple ankle sprain from turning into a chronic ankle sprain that requires surgery.

Don’t fall into the trap of thinking that because you’re already improving that this isn’t necessary. You will put your ankle at much higher risk of re-injury when you return to normal activities. A few sessions with a sports physiotherapist or podiatrist, and them prescribing you a quality rehabilitation program, is a very worthwhile investment.

Some patients will not fully recover from a simple ankle sprain, and it may become a chronic ankle sprain. On-going pain, swelling, or their ankle giving way are common symptoms. If these don’t settle within 6-12 weeks, you may have a had a complex ankle sprain which requires further investigation. If this happens, then arrange an appointment with your GP or Sports doctor for some further advice.

Complex Ankle Sprains

In this situation I would recommend an appointment with a podiatrist, general practitioner or sports doctor, and it is likely they will arrange an x-ray. This will help to exclude any major fractures.  Even though we can’t see cartilage and ligaments on an x-ray, major injuries of these structures will often change the alignment of the ankle bones, and we can see that on an x-ray. An x-ray is a very valuable tool for assessing all complex ankle sprains.

If there is a suspicion of a cartilage or syndesmosis injury, then an MRI scan is usually very valuable, as this does shows us all the ligaments, bone and cartilage in your ankle joint.

If an MRI scan excludes major cartilage or major syndesmotic injuries, then often we can still attempt a period of non-surgical management. But this will be a lot slower recovery than a simple ankle sprain. You may need to walk in a moon boot for 4-6 weeks, and full recovery may be 3-6 months or longer. Your rehabilitation will need to be closely overseen by an experienced sports physiotherapist or podiatrist, otherwise your outcome will be poor.

Cartilage or syndesmotic injuries should ideally be discussed with an orthopaedic surgeon, so they can examine your ankle, view your scans and explain the pros and cons of surgery.