Fibula Fracture: Types, Healing Time and Recovery

01Anatomy

The fibula and what it does

Cambridge University Hospitals (CUH) explains that the fibula is the bone on the outside of the lower leg. It carries little of the body's weight, but it is an important attachment for the ligaments of the knee and ankle. The tibia (shinbone) is the larger bone that carries most of the load.

AAOS describes the ankle joint as the meeting point of the tibia, the fibula and the talus, a small bone above the heel. The lower end of the fibula forms the bony bump on the outside of the ankle, called the lateral malleolus. A second joint, the syndesmosis, links the lower ends of the tibia and fibula and is held together by ligaments; it gives the ankle its stability.

02Causes

How fibula fractures happen

CUH notes that fibula fractures commonly happen as part of an ankle injury, with a mechanism similar to a bad sprain. AAOS lists the injuries that can cause an ankle fracture:

• Twisting, rotating or rolling the ankle while walking or running.
• Tripping, or falling from a height such as a ladder.
• An impact during an accident, such as a road traffic collision.

Symptoms include immediate pain, swelling, bruising and tenderness to touch. Some people cannot put any weight on the foot, and there may be deformity if the joint is dislocated. Pain that builds up gradually with training, without a single injury, is a different problem; see our guide to stress fractures. For ankle injuries without a fracture, see our guide to sprained ankle recovery time.

03Location

Fractures by location: near the knee, shaft and ankle

Where the fibula breaks changes how the injury is managed. The sources describe:

• Lower end (ankle): AAOS calls a fracture of the lower end of the fibula a lateral malleolus fracture, a type of ankle fracture. It may happen alone or with breaks of the tibia (bimalleolar or trimalleolar fractures) and ligament damage.
• Shaft (middle): CUH covers fractures of the fibula shaft, which also commonly occur as part of an ankle injury.
• Near the knee: the fibula also anchors knee ligaments. The NHS and AAOS sources used here do not give specific advice for breaks at the top of the fibula, so these need individual assessment by a trauma team, who may also check the ankle and knee for associated injuries.

AAOS adds that doctors may X-ray the leg and foot as well as the ankle to make sure there are no other injuries.

04Stability

Stable vs unstable injuries

AAOS classifies fractures by how far the bone pieces have moved. In a nondisplaced fracture the bones stay in place and surgery may not be needed. In a displaced fracture the fragments are separated, and the ankle joint may also be dislocated; most ankle fractures with dislocation need surgery. An open fracture, where bone breaks through the skin, is an emergency because of the risk of infection.

Stability also depends on the ligaments. AAOS explains that many isolated lateral malleolus fractures are stable enough to bear weight, while bimalleolar fractures are often unstable. A syndesmosis injury that combines a ligament sprain and a fracture requires surgery to fix both the bone and the syndesmosis.

05Diagnosis

Diagnosis

AAOS describes a careful examination of the ankle, lower leg and foot after a history of how the injury happened. Most ankle fractures are diagnosed with X-rays, which show where the bone is broken, whether pieces are out of place and how many fragments there are.

Depending on the fracture, a stress X-ray taken while standing on the ankle can help show whether the fracture is stable or unstable. A CT scan can show the extent of the injury and help plan surgery, and an MRI, rarely needed, can show ligament injuries. A doctor decides which tests you need.

06Walking

Walking and weight-bearing as advised

For stable fractures, both NHS leaflets encourage walking. CUH advises putting weight through the leg in the walking boot as pain allows, using crutches if needed, and University Hospitals Coventry and Warwickshire (UHCW) explains that early movement and early weight-bearing help healing. UHCW suggests relative rest for the first 24 to 72 hours, not complete stillness, with ice wrapped in a damp cloth for up to 20 minutes at a time and the leg raised above the hips to control swelling.

This advice is not universal. AAOS warns that after some fractures, especially after surgery, you may be told not to put weight on the leg, and that weight-bearing too early can make the fragments move, leading to a bone that does not heal or heals in the wrong position. Being able to walk does not mean a fracture is stable: always follow the instructions of the team treating you.

07Treatment

Boots, casts and when surgery is needed

CUH treats stable shaft fractures with a walking boot for 6 weeks, which can be removed at night, at rest and for washing. In the UHCW leaflet for stable fractures of the outer ankle bone, the boot is for comfort only and is not needed for healing: it is used for walking in the first 2 weeks, gradually left off between weeks 2 and 4, and no longer used from week 4 to 6.

AAOS explains that nondisplaced lateral malleolus fractures can often be treated with a short leg cast or walking boot. Surgery is needed for fractures that make the ankle unstable, using a plate and screws, a rod or screws, and for syndesmosis injuries with fractures, where screws or a suture button may be used. The choice is made by the trauma surgeon.

08Healing

Healing time and lingering swelling

UHCW says a stable fibula fracture usually heals in about 6 to 8 weeks, but pain and swelling can last 3 to 6 months, often worse at the end of the day. For ankle fractures in general, AAOS gives at least 6 weeks for early healing and 10 to 12 weeks for complete healing, with ligaments and tendons sometimes taking longer, and most people returning to normal activities within 3 to 4 months.

Smoking delays healing, according to UHCW. Contact the team that treated you if, at 6 weeks, you still have significant pain or swelling or cannot manage without the boot, or, as CUH advises, if you are not improving. Do not miss any fracture clinic appointment you have been given.

09Sources

Where the sources differ

The NHS leaflets describe stable fibula fractures managed with a boot, early weight-bearing and exercises, and healing in about 6 to 8 weeks. AAOS covers the whole range of ankle fractures and is more cautious: weight-bearing may be restricted, rehabilitation often starts once the boot or cast is removed, and full recovery can take months, sometimes up to 2 years.

The two NHS leaflets also differ on the boot: CUH recommends wearing it for 6 weeks, while UHCW, for stable injuries of the outer ankle bone, uses it only for comfort and weans off it after 2 to 4 weeks. These differences reflect different injuries and services, which is why the plan should come from the team that has seen your X-rays.

10Summary

In summary

A fibula fracture ranges from a stable break that heals with a boot in 6 to 8 weeks to an unstable ankle injury that needs surgery. Location, displacement and ligament damage decide the treatment and how much weight you can put on the leg.

UHCW recommends gentle exercises from the start, such as moving the foot up and down and spreading the toes, adding a towel calf stretch from week 2, with a return to normal activity guided by pain and swelling. CUH advises avoiding high-intensity or contact sports for at least 6 weeks, and AAOS notes that return to sport may take longer and that a brace may be recommended for several months. After assessment by the trauma team, our physiotherapy practice in Bilbao can guide rehabilitation for adults (consultations are in Spanish).