Treatment of an ACL rupture in children differs from the standard treatment for an ACP rupture in an adult. A child or adolescent knee varies anatomically and physiologically from an adult knee and thus the treatment needs to be adjusted accordingly.
The main difference is the growth plates or epiphysis in a child’s knee. These are regions at the end of the femur and tibia of developing tissue and provide the majority of the growth of the leg. These sections are usually the weakest part of the knee. The same injury that would tear a ligament or cartilage in a mature knee is much more likely to fracture the bones through the growth plate in a child.
The complication in children is the growth plates in the knee are directly in the path of where the surgical holes would be drilled in the bone to attach the new ligament. A standard ACL reconstruction in a growing child or adolescent without any consideration for this factor can cause a growth abnormality leading to leg length inequality or to angulatory deformity at the knee. The younger the child the higher the risk of this occurring.
Thus, non-operative treatment is usually suggested initially. This involves strapping the leg and undertaking strengthening exercises as well as abstaining from activity.
When a child stops growing, the growth plate hardens (ossifies) along with the rest of the bone. Girls tend to stop growing earlier than boys; their growth plates usually close around ages 14 or 15, while boys' growth plates close later, at around 16 or 17.
If the adolescent is close to skeletal maturity the risks are small and a standard ACL reconstruction is usually performed.
In a younger child, alternative techniques have been developed to reduce the possibilities of growth complications. These techniques involve placing the ligament graft in a non-anatomic position or one that does not quite duplicate normal ligament function. This is done by either drilling holes that go around rather than through the growth plates or by avoiding drilling holes altogether and instead wrapping the graft around the bone. Growth abnormalities can still occur but the incidence is much less than with standard techniques.
These procedures are designed to be a temporary measure to control symptoms until skeletal maturity when a traditional reconstruction can then be performed. Such treatments have proven to be quite successful with many children returning to sports and not needing a second procedure later on.
Rehab and Recovery
Recovery from ACL surgery is a lengthy process and physiotherapy is required to restore full range of motion and function of the knee.
A full rehab program complete with daily strengthening exercises will be prescribed and the child will be on crutches for four to six weeks post surgery.