(Also known as a Fractured Fibula, Fractured Lateral Malleolus, Ankle Fracture, Broken Fibula)
What is a lateral malleolus fracture?
A lateral malleolus fracture is a relatively common condition characterized by a break in the bony prominence situated at the outer aspect of the ankle known as the lateral malleolus.
The lower leg comprises of two long bones, known as the fibula and the tibia, which are situated beside each other. The fibula bone lies on the outer aspect of the lower leg and forms joints with the tibia (near the knee and ankle) and the talus in the ankle. The fibula bone has a bony lump situated at the outer aspect of the ankle known as the lateral malleolus.
During certain activities such as landing from a jump, or when rolling an ankle, stress is placed on the fibula and lateral malleolus. When this stress is traumatic and beyond what the bone can withstand a break in the lateral malleolus may occur. This condition is known as a lateral malleolus fracture.
A lateral malleolus fracture is relatively common among the elderly, but can also occur in the younger patient. Often a fracture of the lateral malleolus occurs in combination with a sprained ankle or other fractures of the foot, ankle or lower leg (such as following trauma).
Lateral malleolus fractures can vary in location, severity and type including avulsion fracture, stress fracture, Potts' fracture, displaced fracture, un-displaced fracture, greenstick, comminuted etc.
Causes of a lateral malleolus fracture
A lateral malleolus fracture commonly occurs in association with a rolled ankle particularly with significant weight bearing forces. They may also occur due to an awkward landing from a jump (particularly on uneven surfaces), due to a fall or following a direct blow to the outer ankle. Lateral malleolus fractures are common in running and jumping sports involving change of direction such as football, soccer, rugby, basketball and tennis.
Signs and symptoms of a lateral malleolus fracture
Patients with this condition typically experience a sudden onset of sharp, intense outer ankle or lower leg pain at the time of injury. This often causes the patient to limp or be unable to weight bear so as to protect the ankle. Pain can occasionally settle quickly leaving patients with an ache at the site of injury that may be particularly prominent at night or first thing in the morning.
Patients with a lateral malleolus fracture may also experience swelling, bruising and pain on firmly touching the affected region of bone. Pain may also increase during certain movements of the foot or ankle or when standing or walking (particularly up hills or on uneven surfaces). In severe lateral malleolus fractures (with bony displacement), an obvious deformity may be noticeable.
Diagnosis of a lateral malleolus fracture
A thorough subjective and objective examination from a doctor is essential to assist with diagnosis of a lateral malleolus fracture. An X-ray is usually required to confirm diagnosis and assess the severity. Further investigations such as an MRI, CT scan or bone scan may be required, in some cases, to assist with diagnosis and assess the severity of the injury.
Treatment for a lateral malleolus fracture
For those lateral malleolus fractures that are displaced, treatment typically involves anatomical reduction (i.e. re-alignment of the fracture by careful manipulation under anesthetic) followed by surgical internal fixation to stabilize the fracture (using plates and screws). This may be followed by the use of a protective boot or crutches for a number of weeks.
For those fractures that are not displaced, treatment typically involves the use of a protective boot or crutches for a number of weeks.
Evaluation of the fracture with follow up X-rays is important to ensure the fracture is healing in an ideal position. Once healing is confirmed, rehabilitation can progress as guided by the treating physiotherapist.
One of the most important components of rehabilitation following a lateral malleolus fracture is that the patient rests sufficiently from any activity that increases their pain (crutches and / or a protective boot are often required). Activities which place large amounts of stress through the lateral malleolus should also be avoided, particularly excessive weight bearing activity such as running, jumping, standing or walking excessively (especially up hills or on uneven surfaces). Rest from aggravating activities allows the healing process to take place in the absence of further damage. Once the patient can perform these activities pain free, a gradual return to these activities and weight bearing forces is indicated provided there is no increase in symptoms. This should take place over a period of weeks to months with direction from the treating doctor.
Ignoring symptoms or adopting a 'no pain, no gain' attitude is likely to cause further damage and may slow healing or prevent healing of the lateral malleolus fracture all together.
Patients with a fractured lateral malleolus should perform pain-free flexibility, strengthening and balance exercises as part of their rehabilitation to ensure an optimal outcome. This is particularly important, as balance, soft tissue flexibility and strength are quickly lost with inactivity. The treating therapist can advise which exercises are most appropriate for the patient and when they should be commenced.
In the final stages of rehabilitation, a gradual return to activity or sport can occur as guided by the treating therapist provided there is no increase in symptoms.
Prognosis of a lateral malleolus fracture
Patients with a fractured lateral malleolus usually make a full recovery with appropriate management (whether surgical or conservative). Return to activity or sport can usually take place in weeks to months and should be guided by the treating therapist and specialist. In patients with severe injuries involving damage to other bones, soft tissue, nerves or blood vessels, recovery time may be significantly prolonged. In patients with only very minor fractures that are un-displaced (such as an avulsion fracture) return to sport can sometimes occur in as little as 6 weeks as guided by the treating physiotherapist.
Physical therapy for a lateral malleolus fracture
Physical therapy treatment is vital in all patients with this condition to hasten healing and ensure an optimal outcome. Treatment may comprise:
- soft tissue massage
- joint mobilization
- electrotherapy (e.g. ultrasound)
- taping or bracing
- the use of a protective boot
- the use of crutches
- exercises to improve strength, flexibility and balance
- activity modification
- a graduated return to activity plan
Other intervention for a lateral malleolus fracture
Despite appropriate therapy management, some patients with this condition do not improve adequately and may require other intervention. The treating doctor can advise on the best course of management when this is the case. This may include further investigations such as X-rays, CT scan, MRI or bone scan, periods of plaster cast immobilization or referral to appropriate medical authorities who can advise on any intervention that may be appropriate to improve the fractured lateral malleolus. Occasionally, patients may require surgery to stabilize the fracture and a bone graft to aid fracture healing.