Technique depends on skeletal maturity. Pre-pubescent (wide open physes): physeal-sparing techniques — the graft is positioned entirely around (not through) the growth plates. Extra-articular tenodesis or all-epiphyseal tunnels are used. Adolescent (near skeletal maturity): transphyseal technique similar to adult ACL reconstruction with soft tissue graft, using smaller tunnels placed centrally to minimise physeal damage. The hamstring autograft (gracilis and semitendinosus) is most commonly used. The operation takes one to one and a half hours.
ACL reconstruction in children is recommended for complete ACL tears with symptomatic instability (giving way), meniscal tears requiring concurrent treatment, and children who wish to return to pivoting sports. Non-operative management risks further meniscal and cartilage damage from recurrent instability episodes.
Activity modification (avoiding pivoting sports), bracing, and physiotherapy. This was historically preferred due to growth plate concerns, but evidence now supports early reconstruction with appropriate technique to protect the menisci and cartilage.
MRI confirming ACL tear and assessing for meniscal injury. Bone age assessment (hand X-ray) to determine skeletal maturity. Assessment of growth remaining. The surgical technique is chosen based on skeletal maturity.
Restoration of knee stability, protection of the menisci and cartilage from further injury, and return to sport. Modern physeal-sparing and transphyseal techniques have excellent outcomes with very low rates of growth disturbance.
Knee stiffnessCommon
Temporary. Physiotherapy is essential.
Graft site discomfortCommon
Hamstring harvest site soreness.
Re-ruptureCommon
Children returning to sport have re-rupture rates of approximately 10–20% — higher than adults due to high activity levels and return to pivoting sports.
Growth disturbanceRare
Risk of growth plate damage causing leg length discrepancy or angular deformity. Risk is very low (less than 2%) with modern techniques.
Graft failureUncommon
Requiring revision reconstruction.
Contralateral ACL tearCommon
The opposite knee is also at risk. Rate approximately 10–15% in young athletes.
InfectionRare
Joint infection.
Blood clotsRare
Very rare in children.
General anaesthesia.
Crutches for two to four weeks. Brace for four to six weeks. Physiotherapy begins immediately. Running at four to six months. Return to pivoting sport at nine to twelve months. Re-injury prevention programmes (FIFA 11+, neuromuscular training) are essential.
Reviews at two weeks, six weeks, three months, six months, and one year. Standing alignment X-rays to monitor for growth disturbance. Long-term follow-up through adolescence.
Will surgery damage the growth plates?
Modern techniques are designed to minimise growth plate risk. Physeal-sparing techniques avoid the growth plate entirely. Transphyseal techniques use small soft tissue grafts through the centre of the physis. The risk of clinically significant growth disturbance is very low (less than 2%).
Should we wait until the child stops growing?
Current evidence favours early reconstruction in unstable knees rather than waiting. Recurrent instability episodes damage the menisci and cartilage, which cannot be replaced. Protecting these structures through early reconstruction is more important than the very small risk of growth disturbance.
Why is re-rupture so common in young athletes?
Young athletes return to high-risk pivoting sports at high intensity. Their re-rupture rate (10–20%) is higher than adults. Neuromuscular training programmes and graduated return to sport protocols are essential to reduce this risk.