Ankle and foot fractures

Common fractures of the foot and ankle, and what causes them

Ankle fractures involve one or more of the bones that form the ankle joint. They usually result from twisting or rolling the ankle, or from a fall.^[1]

Metatarsal fractures are breaks in the long bones of the forefoot. The fifth metatarsal, on the outside of the foot, has two well-known fracture patterns that differ in their outlook. In an avulsion fracture, a tendon or ligament pulls off a small piece of bone when the ankle rolls. A Jones fracture happens in a part of the bone with a limited blood supply, and it can be slow to heal.^[5,6]

Lisfranc injuries (see Lisfranc injuries) affect the midfoot, where the metatarsals meet the midfoot bones. They can range from a sprain of the ligaments to a break with the joints out of alignment. They can result from a simple twist or from high-energy trauma.^[7]

Stress fractures are small cracks from repeated loading rather than a single injury, and they often occur after a rapid increase in training.^[8]

Symptoms

• pain, swelling and bruising after an injury, or gradually increasing pain with activity in a stress fracture
• difficulty or inability to put weight on the foot
• visible deformity, or numbness or coolness in the foot after a serious injury
• for a Lisfranc injury, swelling and bruising on both the top and the bottom of the midfoot, and pain that worsens with standing, walking or pushing off^[1,7]

How it’s evaluated

After an ankle or midfoot injury, the examination looks for tenderness over the bones and ligaments and checks circulation and sensation. X-rays are taken when specific findings are present. The Ottawa ankle and midfoot rules, a checklist of these findings, are highly sensitive for excluding a fracture but not very specific.^[9]

• Ankle fractures: X-rays; CT for complex fractures; MRI is rarely needed but can show ligament injury.^[1]
• Lisfranc injuries: standing X-rays to show ligament injury that isn’t visible when the foot is unloaded; CT for detail and surgical planning; MRI for soft-tissue damage. A delay in diagnosis has a negative impact on the outcome, so a suspected injury with inconclusive X-rays warrants further imaging.^[7,2]
• Stress fractures: early X-rays often miss the crack, and it may not be visible until several weeks later. MRI or a bone scan can detect it earlier.^[8]

See foot and ankle imaging.

Treatment

Non-surgical treatment is used for stable fractures where the bones have not moved out of position. For ankle fractures this means a cast or walking boot with weight-bearing restrictions.^[1] Studies support non-surgical care of stable Weber B ankle fractures.^[3] Stable Lisfranc injuries can be treated in a non-weight-bearing cast or boot for six to eight weeks, followed by a gradual return to weight-bearing with regular X-rays.^[7,2] Most stress fractures heal in six to eight weeks with activity changes and protective footwear.^[8]

Surgery is generally recommended when a fracture is displaced, when the ankle is unstable or dislocated, when several bones are broken, or when a fracture does not heal.^[1,5] Surgeons realign the bones and hold them with screws, a plate and screws, or a rod or nail while they heal. A Cochrane review found only a few small trials of variable quality. In one trial followed for seven years, patient-reported symptoms did not differ significantly between surgical and non-surgical treatment. The decision therefore depends on the specific fracture pattern and stability.^[10]

• Fifth metatarsal: a limited number of studies suggest that fixing a Jones-type fracture with an intramedullary screw can shorten the time to union and the return to activity compared with a cast. The evidence base is small.^[11]
• Lisfranc injuries: unstable injuries are treated with open reduction and internal fixation or with fusion of the midfoot joints (see Lisfranc surgery). A meta-analysis of 18 studies found better pooled pain and function scores after primary fusion than after fixation. Other outcome measures favored fixation, and which approach is preferable remains debated.^[12,7]
• High-risk stress fractures (the base of the fifth metatarsal and the navicular) may need surgery, because the blood supply is limited.^[8] The navicular has the longest average time to return to sport (about 127 days) in one meta-analysis, and complications are more frequent there and at the fifth metatarsal.^[13]

For what fracture surgery involves, see surgery for ankle and foot fractures.

Recovery and complications

The timing of weight-bearing is set by your surgeon, because putting weight on a fracture too soon risks a nonunion (failure to heal) or malunion.^[1] After ankle fracture surgery, a Cochrane review found that walking on the ankle earlier (within about three weeks) probably leads to somewhat better ankle function. The difference is small and may not be clinically meaningful.^[14] Lisfranc injuries can take six months to a year to reach full activity, and arthritis may develop afterward.^[7]

Complications include stiffness, swelling, infection, arthritis and nerve or vessel injury. Diabetes roughly doubles the overall risk of complications after an ankle fracture, and the risk of infection is about three times higher, more so with surgery than without it.^[4,1] Smoking is also linked to healing problems.^[1] See recovery after foot and ankle surgery.

When to seek care

Any injury that leaves you unable to put weight on the foot, or with swelling, bruising and a deformed ankle or foot, should be evaluated promptly. Persistent pain in the forefoot or midfoot after a twisting injury also deserves an evaluation. So does pain that gradually increases with running or walking, because some fractures are not visible on the first X-ray.