Treatment of torn ACL knee joints in children and adolescents

treat one right anterior cruciate ligament (ACL) tears are critical for restoring knee stability. Given the improved techniques for repairing this band of tissue, surgery is a common treatment after an ACL injury — even in young adults.

Research has shown that repairing the ACL is better than waiting, which itself may further damage growth plates — areas of active bone growth in children. However, the methods used may differ from adults.

This article explains the types of ACL surgery available for children and adolescents and why it is recommended. It also looks at strategies that can help your child heal after ACL surgery.

ACL Treatment Options

ACL injuries range from relatively minor sprains to complete tears that cause knee instability. Treatment depends on the severity of the injury.

The decision on how to treat an ACL injury depends on a physical examination, which may include several tests to assess stability and movement. Healthcare providers will also look at X-rays and magnetic resonance imaging scans to better understand the extent of ACL damage.


One of the key criteria in deciding whether surgery is required is the degree of damage to the ACL. Injury grades range from 1 (minor sprain) to 3 (complete ACL tear).

If your child has a grade 3 tear, surgery is almost always needed to repair the ACL and the unstable knee.

Surgery for a complete ACL tear is often the best option for people who:

  • Young and active like most teens and children
  • Participate in sports that involve a lot of jumping, turning, and rapid or directional changes (e.g. football, basketball)
  • Experiencing severe knee instability

Partial grade 2 ACL tears are rare, but in some cases surgery may be the best course of action. Grade 1 injuries do not require surgery.

non-surgical treatment

Nonsurgical treatment options are more appropriate for low-grade injuries.

The first is the RICE method. This involves:

  • Rest: Avoid weight bearing on the injured knee
  • Ice: Use an ice pack to help reduce pain and swelling
  • Compression: Use an elastic bandage or compression wrap around the knee
  • Elevation: Lie down and support the injured knee

These interventions may be all that is needed, or they may be initial care given to your child before a healthcare provider can further treat the ACL injury.

READ ALSO:  Open fractures and fractures (compound fractures)

If needed, a brace at the joint can keep the knee stable while the ACL injury heals. This is given or prescribed by a doctor after your child has been evaluated.

In some cases, physical therapy (PT) may also help. Treatment of relatively minor ACL injuries may be sufficient. It may also be appropriate if your child is advised to have surgery but you decide not to, or if your child is unable to undergo surgery for some reason (e.g., poor overall health).


Not all ACL injuries require surgery, but a complete tear of the ACL almost always does.

What to do if you are injured while exercising

type of surgery

In most cases, ACL repair is not technically a repair at all. They involve rebuilding or replacing the affected tendon with a new tendon. In children and adults, this is usually done as an arthroscopic procedure.

Instead of making a large incision so they can see the ACL directly, surgeons make small incisions in the knee joint. A tiny camera is passed through these openings so that the surgeon can view the ACL on a monitor. Long, thin surgical tools are also inserted.

Additionally, the surgeon will drill small holes to replace the damaged ACL and reconnect the joint.

There are two types of surgeries used to place new tendons: autografts and allografts. Each has its advantages and disadvantages.

In either case, ACL repair is considered a minimally invasive procedure. It can usually be done within a few hours of an outpatient clinic (meaning no overnight stay is required).

autologous transplantation

In an autograft procedure, the ACL is replaced with a tendon taken from your child’s own body. This tendon most often comes from the knee, hamstring (back of the thigh), or quadriceps (front of the thigh).

Because the tendon is your child’s own, the risk of infection is reduced.

Recovery tends to be smoother, but takes longer because the body needs not one but two surgical sites to heal.

Autologous transplants tend to be less expensive than allogeneic transplants.


For allograft surgery, the tendon used to repair the ACL comes from an organ donor.

On the one hand, this means shorter operative times and less painful initial recovery.

On the other hand, it usually takes longer for the body to integrate the donor tendon into the newly repaired joint than with an autologous graft.

autologous transplantation

  • Taken from the patient’s tendon

  • lower risk of infection

  • wider recovery


  • tendon from donor

  • shorter operation time

  • The body takes longer to integrate

Do you need arthroscopic knee surgery?

Modifications to protect growth plates

Children and adolescents are considered skeletal immature until their bones stop growing.

In the past, surgeons have been hesitant to perform ACL repair in young adults because existing techniques used in adults are insufficient to protect growth plates. (These areas of bone growth only close in mid-to-late teens.)

This is no longer a major issue. Research shows that surgery is the better option in most cases, and newer techniques help protect tissue that is still growing.

Today, surgeons often perform so-called Transepiphyseal anterior cruciate ligament reconstruction to young people. This means they only drill small holes in partially active growth plates to protect them as much as possible.

That said, some researchers suggest that a more standard transtibial technique, with better protection of the growth plate using drilled angles, may be safer for young adults undergoing ACL repair surgery.

While more research is needed to better understand the differences in adolescents and children, it’s important to discuss with your surgeon what techniques they plan to use and why.


Surgeons often use slightly different techniques for children than for adults. This is to preserve bone tissue that is still growing.

Postoperative treatment

Especially children and adolescents who are eager to return to sports and other activities after an ACL injury. They may think surgery is the end point of their treatment, but it is not.

Most young adults will need physical therapy to regain as much function as possible, but there are differences compared to what adults need to achieve this.

For example, it may take longer for a young person to exercise the front thigh muscles than an adult. Goals at different times can vary widely in terms of range and duration of motion.

Guidelines set by the Children’s Hospital of Philadelphia call for maintaining knee support and managing pain for the first week after surgery. Thereafter, activity levels and goals should be increased during recovery. The therapist will develop a specific plan for your child.

PT is an important commitment that usually lasts for weeks and months. If you are considering surgery for your child’s ACL tear, be sure to discuss PT requirements with their healthcare provider and let your child know about the next chapter of their recovery.

Many factors will be key to your child’s success, but perhaps nothing is more important than family support.

Physical therapy for anterior cruciate ligament sprains


The prognosis for adolescents and children who have ACL surgery is usually good. One study found that 96% of child athletes who underwent ACL reconstruction were able to return to sports at the same skill level after 9 to 12 months of recovery.

Reinjury to the ACL is possible, but the risk of meniscus tears and cartilage damage may be higher due to an unstable, unrepaired injury to the knee.

The holes drilled during surgery may affect the growth plate of the affected knee joint. This can result in slightly different leg length or angle deformities, which can lead to knee joints (knee valgus) and bowed legs (knee varus).

These conditions gradually worsen with further growth and can lead to an increased risk of problems such as joint damage and arthritis.


Surgery is generally considered safe for teens and children with ACL tears that need repair. It may not be required in all cases, but if it is, there is a good chance that knee function will return.

The procedure is much the same as for adults, but with changes in the way it is done to protect the still-growing bone as much as possible.

However, ACL repair is not the end of the road. In some ways, this is just the beginning. Once the procedure is complete, your child’s recovery may require physical therapy, which may take most of a year, depending on the PT’s recommendations.

VigorTip words

When considering surgery for your child due to a torn ACL, it’s important to remember that surgery carries risks because their bones are still growing. However, if you wait, there may be more serious risks. Talk to your healthcare provider before making a decision.