Paediatric and Adolescent ACL Reconstruction

Courtesy: Dr Kunal Kalra
Children’s Hospital of Michigan Pediatric Emergency Department, Michigan, USA
www.chmpem.com

Introduction

•  Increasing incidence of ACL injuries in children and adolescents.
•  Historically managed nonoperatively due to fear of physeal damage.
• Modern shift toward early surgical intervention due to high rates of instability and secondary injuries with conservative care.
•  The article focuses on anatomical, diagnostic, and surgical considerations in treating skeletally immature patients.

Applied Anatomy

• ACL provides anterior and rotational stability.
• Rapid growth during childhood and adolescence:
• Length increases from ~18.4 mm (age 1) to ~35.7 mm (age 15).
• The ACL lies close to growth plates, especially the distal femoral and proximal tibial physes.

Anatomical changes with age:

• ACL becomes more vertical as the child matures.
• Tibial attachment migrates posteriorly.

 Assessment of Skeletal Maturity

Vital for surgical planning.

Methods:

• Chronologic age (inaccurate alone)
• Tanner staging (pubertal development)
• Greulich & Pyle atlas (hand radiograph)
• Knee MRI for growth plate status

Classification:

• Prepubescent: >2 years growth remaining – Physeal-sparing
• Pubescent: 1–2 years growth remaining – Physeal-respecting
• Skeletally mature: <1 year growth -Transphyseal (adult-type)

Risk Factors for ACL Injury

Nonmodifiable:

Female sex, younger age, narrow intercondylar notch, increased tibial slope.

Modifiable:

• Poor neuromuscular control
• Early sport specialization
• Inadequate strength/balance training
• Female athletes in pivoting sports are at higher risk.

 Nonoperative vs Operative Management

Nonoperative treatment associated with:

• 75% rate of instability
• High rates of meniscal/chondral damage
• Delayed surgery leads to worse outcomes
• Early operative treatment is now preferred to prevent joint degeneration.

ACL Repair

• BEAR (Bridge-Enhanced ACL Repair): biological scaffold repair technique
• Promising in adults but has high failure rates in children.
• Not recommended as standard treatment for skeletally immature patients.

ACL Reconstruction Techniques

-Physeal-Sparing

• ITB Over-the-Top (Kocher–Micheli):
• No tunnels or hardware
• Best for children <11 years

-All-Epiphyseal:

• Epiphyseal tunnels only
• Anatomic but technically demanding

-Physeal-Respecting

• Partial Transphyseal:
• Tibial tunnel only crosses physis
• Femoral tunnel epiphyseal or over-the-top

Full Transphyseal:

• Both tunnels through growth plates
• Safe in older adolescents with precautions

Graft Selection

Preferred:

• Hamstring tendon: widely used, size-dependent
• Quadriceps tendon: growing popularity, larger size, low morbidity
• ITB autograft: best for young children, used in over-the-top reconstructions

Avoid:

• BTB (bone-patellar tendon-bone): bone plugs can arrest growth
• Allografts: high failure rates in active 10 mm: ~2.1%
• Prevention: small tunnels, soft-tissue grafts, fluoroscopy-guided technique, avoid screws across physes

Concomitant Procedures

Lateral Extra-articular Tenodesis (LET):

• Reduces rotational stress on the ACL graft
• Beneficial in high-risk patients: pivoting athletes, hyperlaxity
• Safe when fixed distal to the femoral physis

Growth Modulation

• Temporary hemiepiphysiodesis with plates/screws to correct/prevent deformity
• Especially in patients with valgus deformity or mechanical axis deviation

Prevention Programs

Focused on:

• Neuromuscular training
• Plyometrics
• Balance and strength training
• Best results in female athletes 11–18 years
• Proven to reduce ACL injury rates by 52–88% when implemented properly

Programs:

• FIFA 11+
• PEP
• KIPP

Conclusion

• Pediatric ACL injuries require individualized, growth-sensitive management.
• Early reconstruction is preferred over nonoperative care.
• Surgical technique selection depends on skeletal maturity.
• Physeal-sparing for younger, transphyseal acceptable in near-mature adolescents.
• LET and growth modulation improve outcomes in select patients.
• Prevention programs are essential, especially for young female athletes.