But treatment in children is not the same as adults — because their growth plates are still open. Choosing the right timing and surgical method is essential for both knee stability and future growth.
How Do ACL Tears Affect Children? Kids Are Not Small Adults
A growing child is very different from a fully developed adult when it comes to knee injuries and surgery. Children have open growth plates (or physis), which means their bones are still lengthening and shaping. Any injury — or surgery — that crosses or damages these physis can change how the leg grows.
Kids also have smaller anatomy, more delicate soft tissues, and underdeveloped blood supply, all of which affect healing, ACL graft choice, and surgical precision. Beyond the physical differences, children require a different psychological approach — they need more reassurance, age-appropriate communication, and support in coping with being sidelined from sports and friends. For these reasons, pediatric ACL reconstruction is not simply a “smaller” version of the adult surgery — it is a fundamentally different operation designed specifically for the developing young athlete.
Why is Growth Plate Protection Crucial in Pediatric ACL Surgery?
In kids, the lower femur and upper tibia growth plates create 65–70% of leg length. If ACL surgery injures these plates, it can cause:
- Leg length discrepancy
- Angular deformity (Knock-knee or bow-leg deformity)
- Early arthritis later in life
That’s why pediatric ACL surgery must be growth-plate conscious (physeal-sparing).
Can We Wait or Avoid Surgery for a Child’s ACL Tear?
Parents often ask this first. Unfortunately, studies show that “waiting it out” leads to more long-term knee damage, not less.
Key Research Findings on Non-Operative Treatment:
- 75% instability in non-op vs 13.6% after surgery
- Meniscal tears 12× more common with non-operative care
- Return to sport: 0% non-op vs 85.7% after surgery
(Ramski et al., AJSM 2014)
Early vs. Delayed ACL Surgery for Young Athletes
Delaying surgery more than 12 weeks significantly increases risk of:
- Irreparable meniscal tears
- Articular cartilage damage
(Lawrence et al., AJSM 2011)
Early ACL reconstruction protects the knee long-term and improves overall prognosis.
How Do Surgeons Perform Growth Plate–Sparing ACL Reconstruction?
The operation is selected based on skeletal maturity (bone age), not just calendar age. Surgeons utilize different physeal-sparing techniques:
| Skeletal Maturity | Technique | Growth Plate Impact |
| Very Immature | Extraphyseal | Avoids growth plates entirely |
| Early Teens | All-epiphyseal | Works within epiphysis (physeal safe) |
| Mid Teens | Partial transphyseal | Minimal crossing, reduced risk |
| Near Adult | Transphyseal | Similar to adult ACL surgery |
Correct technique = stable knee + preserved growth.
ACL Rehabilitation: The Critical Path to Return to Sport
Surgery is only the first step. The success of pediatric ACL surgery is highly dependent on a committed and monitored rehabilitation program. The goal is not just to heal the surgical site, but to restore strength, stability, and neuromuscular control to the entire leg.
Phase 1 (0-6 Weeks): Protect and Restore Range of Motion
Focus: Reducing swelling, regaining full knee extension (straightening), and early muscle activation (quadriceps sets). Crutches and a brace are typically used.
Phase 2 (6 Weeks – 4 Months): Build Strength and Stability
Focus: Aggressive strengthening of the hamstrings, quadriceps, and core. Introduction of balance and light functional training (stationary bike, swimming, straight-line jogging).
Phase 3 (4-6 Months): Advanced Functional Training
Focus: Progression to agility, jumping (plyometrics), and sport-specific drills, but without cutting or pivoting. Strength training continues to be intensive.
Phase 4 (6-9+ Months): Return to Sport Clearance
Crucial Milestone: Athletes are not cleared to return to pivoting sports before 9 months post-surgery, regardless of how strong they feel. This timeline is necessary to allow the ACL graft to fully integrate and gain sufficient strength. Functional testing is used to ensure the injured leg meets criteria (usually 90% strength of the uninjured leg) before a gradual return to practice is allowed.
Expected Outcomes
With modern, growth-friendly techniques:
96–99% knee stability
6–7% graft rupture rate (similar to adults)
Very low growth disturbances
(Kocher et al., JBJS 2018)
Majority of patients achieve a successful return to sport with excellent function.
What Parents Should Take Away: The Best Approach for a Child’s ACL Tear
Early surgery = fewer meniscal and cartilage injuries
Growth plate–sparing techniques are safe and effective
Rehabilitation must be followed for 9+ months to protect the new graft
Kids return to sport with excellent long-term knee function
Frequently Asked Questions (FAQ) about Pediatric ACL Tears
While modern techniques are very safe, the primary risks are:
Growth Plate Injury: Although rare with specialized, physeal-sparing techniques, any surgery near an open growth plate carries a small risk of affecting bone growth (leading to a leg length difference).
Graft Re-Tear: The risk of tearing the new ACL or tearing the ACL in the opposite knee is higher in young athletes than in adults, often due to returning to sport too soon or high-risk athletic maneuvers.