How is a child’s ankle fracture treated?
Pediatric ankle fractures are generally classified based on several factors, including:
- The location of the fracture
- The degree of damage to the growth plate
- The position of the foot at the time of injury, such as pronation (Lauge-Hansen classification system)
- The direction of the force at the time of the injury, such as external rotation (Lauge-Hansen classification system)
When planning treatment, your doctor will take these factors into account. He or she will also consider the degree of bone displacement. In a displaced fracture, the broken ends of bone are separated and do not line up. These types of fractures often require surgery to put the pieces back together.
Perhaps the most widely used classification system for growth plate fractures is the Salter-Harris system. There are several types of fractures and treatment options including:
Salter Harris I and II Fractures
Type I fractures break through the bone at the growth plate, separating the bone end from the bone shaft. Type II fractures break through part of the bone at the growth plate and crack through the bone shaft, as well. Both of these types of fractures are unlikely to impact growth.
First, your doctor will put the pieces of broken bone back into place, called a closed reduction. This is typically done while your child is under sedation or anesthesia. A cast will keep the bones in place while they heal, and is usually needed for 4 to 6 weeks.
In some cases, closed reduction is unsuccessful. This occurs most often because soft tissue, like muscle, gets in between the healing bones. If this happens, surgery is required. During the procedure — called an open reduction — the soft tissue is removed, the bones are realigned and usually held in place with internal fixation (such as pins and screws).
Salter-Harris III Fractures
These fractures affect part of the growth plate and break off a piece of the bone end. They often damage the growth plate. If the joint does not heal properly then it will grow to be uneven, leading to a crooked ankle.
Your doctor will first align the broken bones during a closed reduction procedure. If after the closed reduction there is more than 2 millimeters of displacement between the broken bones, your doctor will recommend surgery using screws or pins to fix the broken ends in place.
Salter-Harris IV Fractures
These fractures break through the bone shaft, the growth plate, and the end of the bone.
Patients with these fractures are usually treated with closed reduction and a long-leg cast and told not to put any weight on that leg. After the bone has healed, they’ll get a short-leg walking cast. However, in some cases, surgery is necessary. Open reduction and pins and/or screws can more precisely line up the broken pieces and reduce damage to the articular cartilage that protects the end of the bone.
Salter-Harris V Fractures
These fractures result from a crushing injury to the growth plate. They are rare fractures that are sometimes difficult to diagnose. Growth problems are a major concern with Type V fractures.
In many cases, these fractures are diagnosed months or years after the injury when the length of the leg is affected or a deformity has already developed. Treatment at this point aims to correct leg-length discrepancy or deformity.
Distal Fibular Fractures
When just the fibula is injured in the ankle, it is most often a Salter-Harris Type I or II fracture. These isolated fractures most often result from low-energy trauma, such as a fall. Isolated distal fibular fractures generally heal well when treated with a short-leg walking cast.
Special Distal Tibial Fractures
The growth plate at the ankle end of the tibia (called the distal end of the tibia) matures and goes away in girls at about 14 years of age, and in boys at about age 16. This occurs over an 18-month transitional period. During this time, the growth plate first begins to close and harden in the center of the bone, then outward toward the front, then toward the back, and finally all around the outside of the bone.
It is during this period that "transitional fractures" of the maturing growth plate can occur. Two common transitional fractures of the distal tibia are triplane fractures and Tillaux fractures.
Triplane fractures. If the fracture extends away from the growth plate in both directions (into the distal tibia as well as into the joint) it is a triplane fracture. Triplane fractures extend through the epiphysis, physis (growth plate), and metaphysis of the bone.
Treatment of triplane fractures depends on the amount of displacement between the broken bones. Minimally displaced fractures (less than 2 millimeters) and non-displaced fractures can be treated with a long-leg cast.
Tillaux fractures. Ankle fractures occurring in the front and outside area of the distal tibia in adolescents are named after the French surgeon Tillaux. This is a Salter-Harris Type III fracture which extends through the growth plate and joint. Tillaux fractures account for 3% to 5% of pediatric ankle fractures