Updated May 2026. Written by the Upwell Health Collective clinical team. Clinically reviewed May 2026. Next review due November 2026. For educational purposes only — not a substitute for individual clinical assessment or surgical advice.
Your 13-year-old lands awkwardly from a mark at football training. Your 15-year-old pivots in netball and hears a pop. Your 11-year-old runs off the field and cannot straighten their knee. You are sitting in an emergency department or a GP's office being told the words “ACL tear” — and everything you thought you knew about ACL injuries — which was probably about adult athletes — suddenly needs to be reconsidered.
ACL injuries in children and adolescents are fundamentally different from ACL injuries in adults. The growth plates. The surgical options. The timing of treatment. The re-injury risk. The psychological burden. The school. The sport. The parent navigating all of it. Every aspect of this injury in a young person requires specific knowledge — and most families walk out of initial consultations with far more questions than answers.
This article answers every question that matters.
Yes. The rate of ACL injuries in children and adolescents is increasing, and in Australia it has increased substantially over the past two decades.
Victorian data published in the International Journal of Environmental Research and Public Health (2017) found that ACL injuries in 5 to 14-year-olds increased by 147.8% over a 10-year period from 2005 to 2015 — from 2.74 per 100,000 population to 6.79 per 100,000. The overwhelming majority (96.9%) of those injured were aged 10 to 14. Over 80% of the hospital-treated cases received ACL reconstruction as their primary procedure.
Nationally, the annual incidence of ACL reconstruction in Australia rose 43% from 2000 to 2015 and by 74% among those under 25. The incidence of ACLR was increasing most rapidly in the 5–14-year-old age group (Zbrojkiewicz et al., Med J Aust, 2018).
The reasons are well-understood: more children participating in organised sport, earlier specialisation in single sports, year-round competitive schedules with reduced rest periods, and increased recognition and diagnosis of ACL injuries in younger patients who would previously have been managed as a sprain. These trends show no signs of reversing.
The central anatomical difference in ACL injuries in skeletally immature patients is the growth plate — the physis — which exists at the end of each long bone and is the site of longitudinal bone growth throughout childhood and adolescence.
The distal femur (lower thigh bone) and proximal tibia (upper shin bone) each have a physis that lies very close to the attachment points of the ACL. This creates a critical surgical challenge: conventional ACL reconstruction techniques drill tunnels across or near these growth plates to anchor the graft. In a skeletally mature patient, this causes no problem. In a child with open growth plates and significant growth remaining, drilling through the physis can disrupt the growth plate, potentially causing:
Growth disturbances occur in 2.6–24% of ACL reconstructions in the pediatric population across the literature, though this wide range reflects significant variation in technique, patient age, and growth remaining (The Double-Edged Sword: ACL Reconstructions in Adolescent Patients, PMC11728393, 2024). Fortunately, the actual risk of clinically significant growth disturbance — leg length discrepancy greater than 10mm — is much lower: approximately 2.1% of cases (PMC11728393). Angular deformities occur in approximately 1.3% of cases, with femoral valgus malalignment being most common.
The risk is real but, in experienced hands using appropriate techniques, manageable. Understanding the risk is the starting point for making informed decisions about timing and technique.
For many years, the standard approach to ACL tears in young children was to wait until skeletal maturity before operating — avoiding any surgical risk to the growth plates. This seems conservative and protective on the surface. The evidence shows it is not.
An ACL-deficient knee is an unstable knee. In a child who continues to play sport with an untreated ACL tear, every session on the field is a session of the medial and lateral menisci bearing loads they are not designed to manage without the ACL's stabilising support. The consequences are measurable and severe:
The clinical decision is therefore not “surgery vs no surgery.” It is a balance of two risks: the risk of growth plate damage from early surgery versus the risk of progressive meniscal and chondral damage from delay. For most active, young athletes with complete ACL tears and growth remaining, the evidence now strongly favours early physeal-sparing reconstruction over prolonged conservative management or waiting for skeletal maturity.
The solution to the growth plate dilemma is physeal-sparing ACL reconstruction — surgical techniques specifically designed to restore knee stability without drilling through or across the open growth plates. Three main approaches exist:
The most protective technique for children with the most growth remaining. Both the femoral and tibial tunnels are drilled entirely within the epiphysis (the bony segment between the growth plate and the joint surface), keeping the graft and fixation completely within the epiphyseal zone and away from the growth plate. A 2025 systematic review and meta-analysis (Elnewishy et al., Cureus, PMC12600025) found that all-epiphyseal ACL reconstruction demonstrated significant improvements in Lysholm and Pedi-IKDC scores, with no cases of growth arrest or angular deformity reported across pooled data.
The limitation is technical complexity — drilling entirely within the epiphysis requires precise surgical planning using MRI-based skeletal maturity assessment and intraoperative fluoroscopic guidance.
For adolescents approaching but not yet at skeletal maturity, partial transphyseal techniques spare the femoral physis (the more vulnerable of the two) while allowing the tibial tunnel to cross the tibial growth plate. This is generally considered appropriate for patients in Tanner Stage 3–4 (mid-to-late puberty) where the risk of significant growth disturbance from a small-diameter tibial tunnel is very low.
The standard adult technique, used in older adolescents approaching skeletal maturity (Tanner Stage 4–5, typically age 15–16+ for girls and 16–17+ for boys) where physeal closure is imminent and the residual growth risk is minimal. Many surgeons use this technique in the older adolescent group as the physeal risk becomes comparable to the instability risk from delay.
The appropriate technique is determined by the child's skeletal maturity — assessed through Tanner staging, bone age X-rays, and MRI appearance of the growth plates — not by chronological age alone. A 13-year-old in early puberty may require all-epiphyseal surgery, while a 14-year-old in late puberty may be appropriate for a near-standard transphyseal approach.
A 2025 KSTA paper (Grassi et al.) proposed an age-specific “over-the-top” approach with lateral tenodesis adapted for three growth stages: extra-physeal for prepubescents, supra-physeal for young adolescents, and near-standard for older adolescents approaching skeletal maturity — providing a practical framework that matches technique to biology rather than calendar age.
Graft selection in skeletally immature patients follows broadly similar principles to adult graft selection, with several important differences:
Hamstring autograft is most commonly used in physeal-sparing techniques because the softer graft can be routed through the epiphysis or over the top of the femur without the bone plug requirements of BTB or quadriceps tendon grafts. The hamstring graft is used in the all-epiphyseal technique in most large series.
Allograft is strongly contraindicated in young active athletes. The pooled failure rate of 25.5% for allograft in patients under 19 — nearly 4 times higher than autograft (OR 3.87; PMID 34322650) — is a risk that cannot be ethically accepted when autograft tissue is available in a growing child who will carry the reconstruction through a decade or more of high-demand sport.
Graft diameter matters more in young patients. Small graft diameters in adolescents are associated with meaningfully higher failure rates. Pre-operative MRI assessment of hamstring tendon diameter is standard practice in high-volume centres to determine whether the planned graft will meet diameter targets (≥8mm) and to plan accordingly.
LET augmentation should be considered in young athletes meeting the STABILITY trial criteria (Grade 2 pivot shift, high-risk sport, generalised laxity — any two of three). The evidence for LET in adolescents is accumulating: a multicenter RCT (Rezansoff et al., 2024) found no graft failures in the LET group at 25-month follow-up, and a 2025 study (Mioc et al., J Exp Orthop) found low graft failure and good functional outcomes in under-20 athletes with ACLR + LET at nearly 50-month follow-up.
Young athletes are the highest-risk group for ACL re-injury after reconstruction. This is one of the most important facts for parents and athletes to understand — because it directly shapes the rehabilitation approach, the return-to-sport timeline, and the prevention programme that should follow.
The re-injury rates in young athletes are substantially higher than in the general ACLR population:
For a 14-year-old with an ACL reconstruction who returns to football at seven months, the re-injury risk is not a small number. It is the most important clinical fact in the room.
Some families, understandably, want to avoid surgery in a child and ask whether conservative management — rehabilitation, bracing, activity modification — is a viable alternative.
The honest answer: it can be, for some patients, in specific circumstances. But it is not appropriate for most active young athletes who wish to return to pivoting sport, and the evidence strongly supports this conclusion.
The Cross Bracing Protocol (CBP) — the structured bracing intervention developed by Filbay et al. (BJSM, 2023) that has shown ACL healing on MRI in approximately 90% of cases when the brace is applied within 4 weeks of injury — is a genuinely important option for carefully selected acute injuries. However, CBP criteria apply to adults and older adolescents, and the protocol has specific eligibility requirements (injury within 4 weeks, brace within 4–21 days ideally, Grade 1–2 ACL injuries on MRI) that not all young patients meet. The EMBRACE trial (NCT06756815) is the ongoing RCT that will provide definitive CBP data, but current evidence does not yet support CBP as a standard first-line approach for the general pediatric ACL population.
For young athletes without a CBP-eligible injury who wish to return to pivoting sport, the evidence clearly shows that non-operative management carries a high rate of instability episodes and progressive meniscal and chondral damage that worsens the long-term prognosis. The cumulative meniscal damage from repeated instability episodes in an ACL-deficient knee during the years of waiting for skeletal maturity is more damaging than appropriately performed physeal-sparing reconstruction.
ACL rehabilitation in children and adolescents requires specific adaptations from adult protocols. The biology is different. The psychology is different. The school, the sport, the family, and the social context are all different. A rehabilitation programme that ignores these differences will produce inferior outcomes.
Young athletes have the same graft maturation biology as adults — ligamentisation takes 12–18 months regardless of age. The nine-month minimum for return to pivoting sport applies equally. For athletes with physeal-sparing reconstruction who are still growing, some surgeons and clinicians advocate for even more conservative timelines given the additional biological variables involved.
The re-injury risk data for young athletes — significantly higher than adult rates — argues strongly for not rushing. The extra months matter more for a 14-year-old than they do for a 24-year-old because the 14-year-old has more competitive years ahead, higher biological vulnerability during the return window, and less psychological experience managing re-injury risk in competitive contexts.
For young patients, a year-long rehabilitation is not just a physical journey. It is an enormous social and psychological one. Missing sport means missing the peer connections, the identity, the routine, and the sense of competence that sport provides. Adolescence is a developmentally critical period for identity formation and social connection, and the psychological impact of ACL injury in this age group is documented and significant.
At Upwell, ACL rehabilitation for young athletes includes explicit attention to:
Blood flow restriction (BFR) training is especially useful in young ACL patients because it provides meaningful muscle stimulus at very low absolute loads — loads that are appropriate for healing tissue in a still-growing skeleton. Young athletes can build quadriceps volume and strength safely without the high absolute loading that adult strength programmes require. BFR at Upwell is introduced as standard from Phase 1 in our young ACL patients, combined with carefully progressed OKC knee extensions in the 90–40 degree safe range.
A 13-year-old has different absolute strength targets than a 22-year-old. But the principles are identical: quad and hamstring strength symmetry above 90% LSI, absolute strength at 1.5–1.8x bodyweight for single-leg press and squat, and rate of force development within safe clinical range. The VALD force plate testing at Upwell normalises all data to bodyweight, ensuring that strength targets are appropriate and achievable for the young athlete’s stage of development.
The full MRSS 2.0 criteria — clinical knee health, patient-reported function, psychological readiness (TSK-11 below 19), hop battery above 95% LSI, sport-specific fitness, and fatigued hop testing — apply to young athletes without exception. Young athletes are the highest re-injury risk group. They need the most rigorous return-to-sport assessment, not a more lenient one.
The psychological impact of ACL injury in adolescents is substantial and largely invisible to the people around them.
Research consistently documents elevated anxiety, depression, and reduced quality of life in the months following ACL injury in young athletes. The loss of sport identity, the uncertainty about return, the fear of re-injury, and the social isolation from the team combine to create a psychological burden that extends well beyond the physical injury. Kinesiophobia — fear of movement and re-injury — is, if anything, more prevalent in young athletes than in adults, reflecting the emotional intensity with which adolescents engage with their sporting identity.
The 2025 Frontiers in Psychology study found a 28% increased odds of unacceptable ACL-RSI score for every one-point increase in TSK-11 in adolescents and young adults. This effect is large and clinically significant. A 14-year-old with a TSK-11 score of 25 is not just psychologically uncomfortable. They are, by the evidence, likely to return to sport with movement hesitation, altered biomechanics, and significantly elevated re-injury risk.
Addressing kinesiophobia in young athletes requires:
This is one of the most important surgical conversations parents and young athletes should have with their surgeon before ACL reconstruction.
The STABILITY trial criteria for LET consideration are: Grade 2 or greater pivot shift, returning to high-risk pivoting sport, and generalised ligamentous laxity — any two of three. Most young athletes returning to Australian football, netball, basketball, soccer, or handball will meet at least two of these criteria.
The STABILITY trial found that adding LET to hamstring ACLR reduced failure or persistent instability from 41% to 25% in patients aged 14–25 — a population that directly includes the adolescent age group. The reduction in adverse events compared to ACLR alone was not statistically significant. LET did not cause the growth concerns it was feared it might in this age group, because the LET procedure (a strip of iliotibial band) is extra-articular and does not involve the physes.
For young athletes who meet the criteria, LET is a serious conversation. The potential reduction in re-injury risk from 41% to 25% is clinically meaningful in a population with the highest re-injury risk of any ACLR subgroup. Ask your surgeon about it.
Yes — and this is one of the most important public health messages in all of youth sports medicine.
Neuromuscular training (NMT) programmes — structured warm-up protocols that include jumping, landing, change of direction, and balance training — reduce ACL injury risk in female team athletes by approximately 50% (RR=0.50, 95% CI 0.31–0.81; PMC12581765, 2025). Broader meta-analyses find ACL injury risk reduction of up to 64% across sport populations.
Modifiable risk factors for ACL injury in children aged 6–13 have been identified in systematic reviews, including neuromuscular deficits, landing mechanics, and sport specialisation patterns — all of which are addressable with appropriate training and coaching (J Sports Sci, 2023).
Programs that work:
The most impactful prevention intervention is not a programme — it is a coach who understands landing mechanics, who teaches and cues them consistently, and who runs a structured warm-up before every session. The knowledge exists. The evidence is strong. The gap is implementation.
Navigating ACL injury in a child involves multiple consultations with GPs, sports doctors, orthopaedic surgeons, physiotherapists, and exercise physiologists. Here are the questions that matter most at each stage.
At the initial surgical consultation:
At the start of rehabilitation:
At the return-to-sport decision:
Upwell’s ACL rehabilitation programme for children and adolescents recognises that young athletes are not small adults — they require specific clinical knowledge, age-appropriate psychological support, family integration, and a return-to-sport standard that accounts for their elevated re-injury risk.
Our clinical team for young ACL patients includes:
If your child has had an ACL injury — whether they are pre-operative, post-operative, or partway through rehabilitation elsewhere — contact our team or book an assessment. We are used to working with young athletes and the families navigating this with them.
ACL injuries in children and adolescents are increasing. In Victoria alone, the rate in 5–14-year-olds nearly tripled in 10 years. This is happening at your club, in your sport, to kids you know.
Surgery is often the right decision. The historical approach of waiting for skeletal maturity is increasingly recognised as harmful, because the meniscal and chondral damage that accumulates during prolonged instability is more damaging than appropriately performed physeal-sparing reconstruction.
Growth disturbance risk is real but low in experienced hands. Clinically significant leg length discrepancy occurs in approximately 2.1% of cases. Angular deformity in approximately 1.3%. These risks are manageable with appropriate technique selection based on skeletal maturity, not chronological age.
Allograft should not be used in young athletes. The 25.5% failure rate in under-19s — nearly 4 times that of autograft — is not an acceptable risk when autograft tissue is available.
Re-injury risk is higher in young athletes than in any other group. This is not a reason to avoid surgery. It is a reason to do the rehabilitation properly, to wait the full nine months minimum, and to ensure the return-to-sport assessment is comprehensive and criteria-based, not calendar-based.
Prevention is possible. Neuromuscular warm-up programmes reduce ACL injury risk by 50–64% in youth athletes. If your club’s coach is not running a structured warm-up before every session, that is the highest-leverage conversation you can have right now.
This article is for educational purposes only and does not substitute for individual clinical or surgical assessment. If your child has had an ACL injury, please seek assessment from a qualified physiotherapist and orthopaedic surgeon with experience in pediatric ACL management. Information last reviewed May 2026.