Foot & Ankle Fracture Anatomy
There are 26 bones in the foot that can be separated into 3 different areas:
- Forefoot: From the ball of the foot forward) contains phalanges (toes) and five longer bones called metatarsals.
- Midfoot: (between the heel bone and the ball of the foot) the bones that form all of the arches of the foot. The bones are called cuneiforms (you have 3), the cuboid bone, and the navicular bone.
- Hindfoot: forms the heel and bottom part of the ankle. The talus bone supports the lower leg bones (tibia and fibula). The heel bone is called the calcaneus and is the largest bone in the foot.
How Does Foot & Ankle Fracture Happen?
- Fractures can occur from a direct blow (trauma) to the foot, which may occur when kicking something, falling, twisting, or if something heavy is dropped on it.
- Fractures can also occur from repetitive high impact forces through the foot.
Types of Foot & Ankle Fractures
- Closed fractures: the skin is not broken
- Open fractures: the skin is broken and the bone is exposed. There is a high risk for infection, and should always result in seeking medical assistance immediately.
- Displaced fractures: when the two ends of the bone are not aligned. Often requires surgical intervention.
- Non-displaced fractures: when the two ends of the bone are aligned. Usually managed conservatively with immobilization.
- Pilon fractures: usually results from a compressive force where the tibia (shin bone) is driven downward into the talus (ankle bone). When this occurs, there is splintering of the end of tibia. This often has long term consequences.
Common Foot & Ankle Fractures
- Talar dome fractures: Also known as osteochondritis dissecans or flake fractures. This fracture presents with persistent swelling, pain with weight bearing, locking of ankle, and a grating sound/feeling. This fracture often presents as an ankle sprain that will not heal.
- Unimalleolar fracture: The most common type of fracture involving the ankle. Malleolus are the end of tibia and fibula and are the two “bumps, or knobs,” that you can see or feel on the side of your ankle. 85% of the time the outside one is involved without damage to the inside one. Wwhen the inside one is involved, it is rarely the only fracture.
- Bimalleolar fractures: Implies both the malleoli (“bumps” on sides of ankle) are involved. Fractures normally result in an ankle dislocation (from a severe turn out of the foot that causes the two long bones in the leg to separate and fracture. These almost always involve surgical intervention.
- Calcaneus/heel fracture: The most frequently fractured tarsal/foot bone. It accounts for over 60% of foot fractures.
- Stress fractures: Develops after repetitive submaximal loading. Most common in 2nd and 3rd metatarsal shaft and calcaneus (heel).
Other Types of Fractures
- Metatarsal shaft fracture: Occurs from a direct blow or twisting force. Usually heal well on own – may be splinted
- Fifth metatarsal fracture or “Jones fracture”: An avulsion fracture of the tuberosity (a round bony prominence where muscles or ligaments attach) caused by traction of peroneus (fibularis) brevis muscle and the lateral (outside) band of the plantar fascia. Usually occurs while the ankle in inverted (turned in) and plantarflexed (pointed). This location has poor blood supply and is at risk for delayed healing. Normally, a person will be in a cast and non-weight bearing for 6-8 weeks. If it is not healing, sometimes a screw and/or bone graft will be used.
- Lisfranc Injury with proximal 1st – 4th metatarsal fracture: Not very common, but important because of its relationship with the Lisfranc ligament complex. These ligaments hold the bones in place, maintaining the arch of the foot and anchoring the bones to the rest of the body. This is crucial and can cause many long term problems if left untreated. These injuries are caused by a direct blow, crush injury, or falling forward onto a plantarflexed (pointed) foot.
- Compensated walking or running mechanics
- Running on hard surfaces
- Improper training or sudden increase in activity
- Improper shoes
- Malalignment of lower extremity
- Muscle weakness
- Difficulty walking
- Nerve damage
- Blood vessel damage
- Foot fractures rarely require surgical intervention or can be managed conservatively with immobilization, depending on severity, location, and availability of blood flow to injured area.
- Physical Therapy focused on re-establishing mobility, strength, stability, coordination, and reaction time of muscles is an important component in recovery.