Authors

Dr Keran Sundaraj MBBS, MSc (Trauma), FRACS, FAOA

Ankle Fractures

An ankle fracture is a generic term for a break that occurs around the ankle joint. There are different types of ankle fracture patterns, with varying degrees of severity.

Ankle fractures can be confusing. The integrity of the ligaments (fibrous tissue connecting bone to bone) can be just as important as the broken bones. The most noticeable parts of X-rays are the broken bones. However, beyond what we see easily on X-rays, the ligaments provide stability to the ankle joint. In general, the more 'parts' that are broken, the more likely the ankle will be unstable. All of these elements are taken into consideration to determine what treatment is best for you.

Anatomy

The ankle joint is made up of:

• Tibia (shin bone)

• Fibula (small outer bone)

• Talus (sitting between the heel bone and the tibia and fibula)

The malleolus is the bony prominence at the end of these bones. There are three of these - medial (inner), lateral (outer) and posterior (back).

Numerous ligaments provide stability to the ankle. These include:

• Deltoid ligament

• Lateral ligaments

• Syndesmosis ligaments (distal tibiofibular ligaments)

Cause

In general, injuries are caused by twisting, rolling the ankle or trips. More severe injuries may be seen in falls or motor vehicle accidents.

Imaging Tests

X-rays

• X-rays are the most common investigation.

Stress X-ray

• In order to determine 'instability', weight-bearing X-rays (stress X-ray) may be performed. The ankle being examined must be 'stressed', which means the limb has to take most of the body weight. This helps simulate real-life walking and has been shown to be an accurate representation of when the ankle is unstable. Sometimes this investigation is delayed for one to two weeks so that this may be achieved.

• A stress X-ray may also be performed in an operating room under an anaesthetic, with the view to stabilising the ankle joint at the same time if instability is seen.

CT

• CT scans may be ordered if the fracture is difficult to see on X-ray, the pattern of injury is unclear, or surgery is being planned. These help to visualise bone in a three-dimensional picture.

MRI

• MRI scans and ultrasounds are uncommonly ordered in ankle fractures. Most of the information required can be determined from X-rays.

• MRI may be performed in the rare circumstances of unclear diagnosis or to rule out other problems.

• Ultrasound is sometimes ordered for ankle sprains. However, specific ankle clinical examinations are usually sufficient for the diagnosis of ankle sprains.

Treatment

For information on fracture healing and general management, see the link.

Treatment of ankle fractures is mainly dependent on ankle joint stability. Fractures of the lower part of the fibula (outer side) depend on the injury level.

Fracture below the syndesmotic ligaments (Weber A)

• The ligaments are not injured, and the ankle joint stable.

• These heal readily, and a walking boot is applied.

• The boot can be removed for showers and gentle exercise but is generally kept on for the rest of the time.

• Generally, the boot is worn for 6 weeks.

Fracture at syndesmotic ligaments (Weber B)

• The ligaments are not usually injured, and the ankle joint is stable. Sometimes a weight-bearing X-ray is performed at the time of the first follow-up (one to two weeks) to confirm this.

• Slight displacement and shortening of the fracture are acceptable. If within acceptable limits, there is minimal difference compared with fractures that have not shifted.

• These heal readily, and a walking boot is applied.

• The boot can be removed for showers and gentle exercise but is generally kept on for the rest of the time.

• Generally, the boot is worn for 6 weeks.

Fracture above the syndesmotic ligaments (Weber C)

• The ligaments are usually injured, and the ankle joint is unstable.

• Surgical treatment is necessary for these fractures unless medical conditions make an operation too risky.

• During the surgery, the bone is stabilised with a plate and screws. The syndesmosis is also stabilised using a screw or strong suture across the tibia and fibula. As soft tissue around the ankle is relatively thin, these implants may irritate the overlying skin around the ankle. If these cause an ongoing issue, the implants can be removed once the bone and ligaments have healed. Over many months, due to the ankle's back and forward rotating motion, the screw may break. This is normal and expected to occur. Think of this like bending a wire many times, which causes the metal to fatigue and break. By this stage, the screw is no longer required as the ligaments have healed. If this does occur and you have ongoing pain, the screw can be removed with a minor procedure.

• After the operation, you may be in a temporary cast or boot. During this time, you should be on blood thinners to prevent you from getting clots (DVTs). The cast or boot will be removed around one to two weeks to check the wound and commence some gentle physiotherapy to prevent ankle stiffness. If not already in one, a boot is applied at two weeks. You will not be able to put weight through your injured leg. You will require crutches for at least six weeks.

Medial malleolus fracture  

• Treatment for this fracture depends on the pattern and displacement. However, it is uncommon for the fracture to be undisplaced.

• Usually, these are treated with surgery - either screw or a plate, depending on the fracture configuration.

• After the operation, you may be in a temporary cast or boot. During this time, you should be on blood thinners to prevent you from getting clots (DVTs). The cast or boot will be removed around one to two weeks to check the wound and commence some gentle physiotherapy to prevent ankle stiffness. If not already in one, a boot is applied at two weeks. You will not be able to put weight through your injured leg. You will require crutches for at least six weeks.

Bi- and Tri-malleolar ankle fractures

• This is a combined injury of two or three of the malleoli. The pattern of injury is unstable and will require surgery. As the injury pattern is more severe, the recovery time is longer than the above-mentioned injuries.

• Surgery is to treat the fractured components and possibly stabilise the syndesmotic ligaments.

• After the operation, you may be in a temporary cast or boot. During this time, you should be on blood thinners to prevent you from getting clots (DVTs). The cast or boot will be removed around one to two weeks to check the wound and commence some gentle physiotherapy to prevent ankle stiffness. If not already in one, a boot is applied at two weeks. You will not be able to put weight through your injured leg. You will require crutches for at least six weeks.

What to Discuss with Dr Sundaraj

• How long can I expect off work?

• When can I start driving?

• How long before I can start putting weight on my leg?

• When can I start physiotherapy?

• What is the likely outcome from this treatment plan?

• When do I need to come back?