Ankle Fracture (Broken Ankle)

Quick answer

An ankle fracture is a break in one or more of the three bones that form the ankle joint: the tibia (shin), the fibula (the smaller bone on the outside), or the back edge of the tibia. The same twisting injury that causes a sprain can also cause a fracture, which is why fractures are often initially mistaken for severe sprains. The number of bones broken determines treatment: one bone fractures often heal in a boot; two or three usually need surgery.

How to recognize one

• Specific moment of injury: twisting the ankle, often with a “pop”
• Severe pain that’s typically worse than a sprain
• Inability or great difficulty bearing weight (can sometimes walk on a low-grade ankle fracture)
• Rapid swelling
• Bruising that develops over hours to days, often spreading
• Tenderness over a specific bone rather than diffuse soft tissue
• Visible deformity in displaced fractures
• Possible numbness or color change in advanced injuries

Anatomy of the ankle

Three bony parts make up the ankle joint:

• Medial malleolus: the inside ankle bone (end of the tibia)
• Lateral malleolus: the outside ankle bone (end of the fibula)
• Posterior malleolus: the back edge of the tibia

Plus the syndesmosis: a ligamentous connection between tibia and fibula above the ankle joint. Injury here (“high ankle sprain”) changes the picture even without a bony fracture.

Fracture types:

• Unimalleolar: one bone broken (often lateral). Many heal without surgery.
• Bimalleolar: two bones broken. Usually unstable; surgery typical.
• Trimalleolar: all three. Almost always unstable; surgery.
• Pilon fracture: high-energy crush injury through the bottom of the tibia. Severe.

When you need an X-ray (Ottawa Ankle Rules)

You probably need an X-ray if any of these are true:

• You can’t bear weight for 4 steps right after the injury or in the ER
• Bone tenderness on the back edge or tip of either malleolus
• Bone tenderness over the navicular or fifth metatarsal base (specific midfoot bones, the rules cover both ankle and foot)

The Ottawa Rules are 95%+ sensitive for fractures and reduce unnecessary X-rays substantially.

Treatment

Stable, non-displaced fractures (often single-bone)

• Walking boot for 6–8 weeks
• Weight-bearing as tolerated in many cases
• Physical therapy for range of motion and strength
• Gradual return to activity
• Healing typically 6–12 weeks

Unstable or displaced fractures

• Surgery (open reduction with internal fixation, ORIF): plates and screws to realign the bones
• Non-weight-bearing for 6–8 weeks typical
• Cast or boot for protection
• Physical therapy afterward
• Full recovery 4–6 months, sometimes longer

Pilon fractures

• High-energy injuries with significant soft tissue damage
• Often staged surgery: initial external fixation, definitive surgery once swelling decreases
• Long recovery (12+ months for full recovery)
• High rate of long-term arthritis

Recovery expectations

Realistic timeline for typical surgically treated ankle fracture:

• Weeks 0–6: non-weight-bearing in cast or boot, swelling and bruising resolve
• Weeks 6–12: gradual weight-bearing, physical therapy starts in earnest
• Months 3–6: full weight-bearing, return to most daily activities
• Months 6–12: return to running, sports, full strength
• Years: some stiffness and weather sensitivity often persist
• Late: risk of post-traumatic arthritis (roughly 20% after operatively treated fractures, higher for severe patterns)

For non-surgical fractures, the timeline is roughly half of the above.

When to see a clinician

Same day if:

• You can’t bear weight after a twisting injury
• Severe deformity is visible
• Bone tenderness on specific spots (Ottawa rules)
• Pain or numbness suggesting nerve or vascular involvement
• Open wound near the ankle

A “bad sprain” that doesn’t improve over a week of rest, ice, and elevation is worth getting X-rayed too, some fractures are subtle.

Prevention

• Adequate strength and balance: single-leg balance training reduces fall risk
• Address chronic ankle instability: repeat sprains predispose to fractures
• Appropriate footwear for the activity
• Calcium, vitamin D, weight-bearing exercise for bone health
• Fall prevention in older adults, home modifications, vision checks, medication review
• Don’t return to sports too early after a sprain, incomplete rehab raises future fracture risk