ACL Surgery in Adolescents – Growth Plate Considerations

Anterior cruciate ligament (ACL) injuries are becoming increasingly common in adolescents due to early sports specialization and high levels of athletic activity. Treating ACL tears in growing children and teenagers is more complex than in adults because of the presence of open growth plates. These growth plates, also known as physes, are areas of developing cartilage near the ends of long bones and play a crucial role in bone growth.

ACL surgery in adolescents requires careful planning to restore knee stability while protecting future bone growth. Understanding growth plate considerations helps parents and patients make informed decisions and avoid long-term complications.

Understanding Growth Plates in the Knee

Growth plates are located near the ends of bones and allow bones to lengthen as a child grows. In the knee, major growth plates are present at the lower end of the femur and the upper end of the tibia. These plates remain open until late adolescence and gradually close as skeletal maturity is reached.

Any surgical procedure that crosses or damages these growth plates carries a risk of growth disturbance, limb length differences, or angular deformities. This is why ACL surgery in adolescents requires specialized techniques.

ACL Injuries in Adolescents

ACL tears in adolescents often occur during sports involving jumping, pivoting, or sudden direction changes. Common sports include football, basketball, cricket, gymnastics, and skiing.

Symptoms in adolescents are similar to adults and may include:

• Knee swelling and pain
• Feeling of knee instability or giving way
• Difficulty returning to sports
• Reduced confidence in knee movement

Because children may continue to play despite injury, delayed diagnosis is common and can lead to secondary knee damage.

Why Early Treatment Matters

Leaving an ACL tear untreated in a growing adolescent can result in repeated episodes of instability. These episodes increase the risk of meniscus tears and cartilage damage, which can cause long-term knee problems and early arthritis.

Historically, surgery was delayed until growth plates closed. However, modern evidence suggests that delaying surgery may cause more harm than early, well-planned intervention.

Non-Surgical Management in Adolescents

When Non-Surgical Treatment Is Considered

Non-surgical treatment may be considered for partial ACL tears or in patients with stable knees and low activity demands. This approach includes:

• Activity modification
• Structured physiotherapy
• Knee bracing

However, compliance can be challenging in young athletes, and non-surgical management often fails in highly active adolescents.

When ACL Surgery Is Recommended

Surgery is usually recommended for adolescents with complete ACL tears and ongoing instability. The goal is to restore knee stability while minimizing the risk to growth plates.

Indications for Surgery

• Repeated episodes of knee giving way
• Desire to return to sports
• Associated meniscus or cartilage injury
• Failure of non-surgical treatment

Surgical Techniques and Growth Plate Protection

Physeal-Sparing Techniques

Physeal-sparing procedures avoid drilling tunnels across the growth plates. These techniques are often used in younger children with significant growth remaining.

Partial Transphyseal Techniques

In this approach, tunnels are carefully placed to minimize damage to the growth plate. Soft tissue grafts are commonly used to reduce risk.

Transphyseal ACL Reconstruction

For older adolescents nearing skeletal maturity, standard ACL reconstruction techniques may be used with careful tunnel placement. Studies show minimal risk of growth disturbance when performed correctly.

Graft Choice in Adolescents

Graft selection is critical in adolescents. Hamstring and quadriceps tendon grafts are commonly preferred because they reduce the risk of growth plate injury. Patellar tendon grafts are generally avoided in younger patients due to higher risk of growth-related complications.

Post-Surgical Rehabilitation

Rehabilitation after ACL surgery in adolescents focuses on gradual restoration of strength, balance, and movement control. Special attention is given to neuromuscular training to reduce the risk of re-injury.

Return to sports is typically allowed after 9 to 12 months, depending on recovery progress and psychological readiness.

Potential Risks and Complications

Although modern techniques are safe, potential risks include:

• Growth disturbances (rare)
• Re-injury of the ACL
• Muscle weakness
• Delayed return to sports

Close follow-up until growth completion is essential.

Long-Term Outcomes

Studies show that adolescents who undergo timely ACL reconstruction with growth plate–respecting techniques achieve excellent stability and return to sports. Early intervention reduces the risk of meniscus damage and improves long-term knee health.

Conclusion

ACL surgery in adolescents requires a careful balance between restoring knee stability and protecting growth plates. Modern surgical techniques allow safe and effective reconstruction even in growing patients.

Early evaluation by a pediatric or sports orthopedic specialist is crucial. With proper planning, appropriate graft selection, and structured rehabilitation, adolescents can safely return to sports while preserving normal growth and long-term knee function.