Ankle dislocations occur when the bones in the lower leg (tibia and fibula) are twisted or pushed away from the talus bone in the foot. A great deal of force is required to separate these bones, and usually dislocations occur with fractures (see Ankle Fracture). Most commonly, the malleoli (the bony lumps on either side of your ankle) are fractured during dislocation.
The rare occasions of ankle dislocation without fracture are usually due to high-impact sports or car accidents. In these situations, the very strong ligaments surrounding the ankle are stretched or torn. This may effect the medial ligaments on the inside surface of your ankle, the lateral ligaments on the outer surface (see image below), or the strong syndesmosis that holds the two bones in the leg (tibia and fibula) together.
Dislocations in the ankle are extremely painful, and the rapid swelling that follows can be very dangerous. For this reason, the first-aid treatment of ankle dislocation includes elevating the foot and applying ice. The doctor or surgeon at the hospital will need to rapidly put the bones back in place to prevent long-term to your foot.
Rehabilitation after dislocations usually lasts 6-9 weeks and is a key component to recovery. Despite this, dislocations around the ankle can cause long-term problems, including instability and arthritis.
Symptoms
A dislocation can be obvious, with the foot at an obviously abnormal angle to the leg. There is often rapid swelling and severe pain, sometimes extending from the ankle into the foot or calf. The pain and weakness in the ankle will make it very difficult if not impossible to put any weight through the foot.
Symptoms of tingling, numbness or changes in the colour of the toes or foot are serious signs, and you should seek help immediately.
Causes
The ankle is generally a very stable joint. The bones fit closely together and the supporting ligaments and tendons are very strong.
The ankle is designed to be most stable when it is carrying your weight, allowing it to transmit large forces while you run. When your ankle is relaxed and not carrying your weight, the ligaments are looser, making dislocation more likely. For this reason, dislocation tends to occur when the ankle is plantar flexed (with toes pointing down) and large twisting force pushes the foot inwards (‘inversion’).
The image on the right shows an inverted and flexed foot.
There are two common situations when this occurs, namely car accidents and high impact sports like football or basketball where players make sudden turns or are likely to collide at high speed.
Alternatively, a person with already loose ligaments (for example, someone who has chronic ankle instability) can develop a dislocation from a severe twist of the ankle. This form of dislocation tends to be less obvious with milder symptoms.
Risk Factors
Ankle dislocations tend to be more common among:
- Men, especially young male athletes
- People with a history of ankle sprains, ankle instability or a loose ankle (‘hypermobility’)
- Weak or unbalanced muscles around the ankle
Investigations
Your doctor will need to carefully examine your foot for signs that the nerves and blood vessels are not endangered. If he or she is satisfied your foot is not in immediate danger, you will be sent to get X-Rays of your ankle to rule out any fractures.
Sometimes, more sophisticated imaging like CT scans or MRI are used to look for damage to the cartilage, tendons and ligaments.
Complications
At the time of the injury, there are a number of complications that can develop:
- Dislocation of the ankle can only occur when the surrounding ligaments have been severely stretched or torn. Injury to the ligaments causes the ankle to feel loose or unstable, making walking and running difficult. If the ligaments are severely damaged or fail to heal, you may require repair surgery (see Lateral Ankle Reconstruction and Ankle Stabilisation).
- When the injury has also affected the skin and soft tissue around the joint, infection, bleeding and skin damage may be severe. Your surgeon may need to wash and even ‘debride’ (clean away irreversibly damaged muscle or tendon) the wound. You may also need antibiotics and stitches.
- Bone and cartilage damage. The doctors will take X-Rays to make sure your ankle has not been broken. X-Rays however do not tell the doctors if the cartilage lining the ankle has been significantly damaged.
- Blood vessel and nerve injury. The rapid swelling following ankle dislocation can compress the blood vessels and nerves running around the ankle. If the swelling is not relieved quickly, loss of blood supply can result in complications in the toes and foot. If the nerves are sufficiently compromised, there may be numbness, tingling or weakness in the foot for some time after the injury.
Long-term complications of dislocations include:
- Arthritis. This is unfortunately common in the decades following an ankle dislocation.
- Ongoing weakness in the ankle ligaments and a tendency to sprain the ankle.
- Residual stiffness of the ankle.
Treatment
The initial treatment for an ankle dislocation is too keep it as still as possible. If swelling is severe, the first-aid physician (eg paramedics) may need to adjust the position of your foot to prevent loss of blood supply or damage to nerves.
Once you reach the hospital, the surgeons and doctors in emergency will need to realign your ankle as quickly as possible. If your foot is in serious danger (for example, your blood vessels are compressed) your foot may be realigned in the emergency department. Otherwise, the doctors will send you to the operating theatre where you can be put to sleep (general anaesthesia) while your ankle is relocated.
After the dislocation is treated, your ankle will be placed in a special cast (back-slab) then changed to a below knee cast or walking boot once the swelling has gone down. Your surgeon will be able to discuss whether you can carefully put weight through your foot, or if you will need to use crutches during the first few weeks of your recovery.
During this period, you should try to keep your ankle elevated as often as possible. This can include sleeping with your foot supported on many pillows, and always keeping your foot on a chair when you’re sitting.
Rehabilitation | Physiotherapy
During your rehabilitation period you will have follow-up X-Rays your ankle has not moved. If your surgeons are satisfied your ankle is healing well and is not likely to redislocate, you will be allowed to start moving your ankle. If the X-Rays show that your ankle has moved, you may have serious injury in the ligaments around your ankle. Surgery is sometimes necessary to repair this (see Lateral Ankle Reconstruction and Ankle Stabilisation).
Your physiotherapists will show you a range of exercises to build up the strength and motion in your ankle, and discuss how far you should push yourself. You may also need to perform exercises to keep the other joints and muscles in your leg flexible and strong. These exercises may include:
- Active movement of the ankle, for example pointing your foot down then up repeatedly.
Your physiotherapist can prescribe the kind of exercises and the number of times your should repeat these during the day.
Over the course of your rehabilitation period your exercises will change as your ankle heals. Together, you will focus on exercises that promote the flexibility and range of movement in your ankle, as well as gradually increasing the degree of strengthening exercises you perform.
You must not force yourself beyond the exercises recommended by your physio – doing so can re-injure your ligaments and undo your work!
When you are ready, your physiotherapist will help you return to your normal activities. They may recommend taping of your ankle during sports to prevent re-injury.
Special Cases…
When the skin around your ankle has been broken, you may need to have a series of operations to wash out the joint and remove any severely damaged tissues. This helps prevent infection developing in the soft tissues or the bone.
If the cartilage in your ankle has been sheared off during the injury, you may need arthroscopy to wash away the loose cartilage fragments floating in your joint.
Seeking Advice
If you think you have an ankle dislocation, you should seek help immediately – the faster your ankle is returned to its normal position the better it will heal.
If your unsure if your ankle is dislocated or just sprained, using first-aid treatment of rest, ice, compression and elevation is appropriate. Over the counter anti-inflammatories (NSAIDs) like ibuprofen can also be helpful in controlling pain and swelling.
You should seek help immediately if:
- Your ankle remains swollen, or continues to swell
- Your injury has caused significant damage to your skin
- You are unable to bend and stretch your toes
- Your foot or toes start tingling, changing colour or go numb
If your symptoms are mild, you can see your local healthcare professional (GP or physiotherapist) rather than going to the emergency department.
Prevention
Wearing shoes that are well-fitting and supportive is helpful in reducing injuries to the ankle.
If you have chronic ankle instability there are a number of exercises physiotherapists can show you to strengthen the muscles around your ankle. Alternatively, if you have weak ankles and play high-risk sports (soccer, football, basketball etc) you can tape your ankles to prevent straining the ligaments. A physiotherapist can discuss whether you need taping or not.
F.A.Q. | Frequently Asked Questions
How will my ankle feel long-term?
When the ankle is relocated quickly and rehabilitation is initiated, the ankle will generally feel virtually ‘normal’ within months of the injury.
In the months to years following your injury, you may notice the injured ankle has a slightly smaller range of movement than the uninjured ankle, or may have some degree of instability, however these complications are rarely severe enough to impact function significantly.
What should I do for pain?
This should be discussed with your doctor, however over the counter anti-inflammatory medications are very useful in controlling pain. Your physiotherapist will also be able to talk to you about strategies like icing and elevation of your ankle.
References
Dlimi, F., et al., ‘Open medial ankle dislocation without associated fracture: A case report’, Foot and Ankle Surgery, 2011, <www.elsevier.com/locate/fas>.
Kiefer, E., et al., ‘Ankle Dislocation Without Fracture: An On-Field Perspective’, Clinical Journal of Sports Medicine, Vol. 16, No. 3, May 2006, pp. 269-270.
Larsen, J. et al., ‘Ankle Dislocation without Fracture in a Young Athlete’ , The Journal of Foot and Ankle Surgery, Vol. 37, No. 4, 1998, pp. 334-338.
Moriatis Wolf, K., ‘Impact of Joint Laxity and Hypermobility on the Musculoskeletal System’, Journal of American Academy of Orthopaedic Surgeons, Vol. 9, No. 8, 2011, pp. 463-471.
Rios-Luna, A., et al., ‘Isolated dislocation of the ankle: two cases and a review of the literature’, European Journal of Orthopaedic Surgery and Traumatology, Vol. 17, 2007, pp. 403–407.