1. Adolescent ACL rehab needs to reflect growth and development 

Anterior cruciate ligament (ACL) injury is no longer a problem just for elite adults. 

Population data shows a clear rise in ACL surgery in young people, which is a useful proxy for severe ACL injury in young people.

In Australia, the annual rate of primary ACL reconstructions (ACLR) increased 43 per cent between 2000 and 2015 and rose 74 per cent in people under 25 (Zbrojkiewicz et al 2018), with the fastest growth in children aged five to 14, particularly girls (Maniar et al 2022). 

These trends likely reflect a mix of higher sporting exposure, year-round training and early specialisation, plus improved recognition and access to imaging and surgery. 

For physiotherapists, the adolescent pathway is not just a smaller version of adult rehab. 

We must consider skeletal maturity and protect the physis; use shared decision-making with the surgeon, young person and parents; match loading to growth-related vulnerability; and expect fluctuating coordination during growth spurts. 

Progression should be criteria-based, prioritising quadriceps and hamstring strength, single leg control, landing mechanics and change of direction quality alongside cardiovascular reconditioning. 

Given the high secondary injury risk in young athletes, return to sport should be conservative and include psychological readiness, school and family support, and a plan for ongoing neuromuscular injury prevention after discharge. 

The goal is safe performance now and lifelong knee health.

2. Adding a LEAP in primary ACLR can reduce graft failure 

Current research focused on clinical outcomes suggests that lateral extra-articular procedures (LEAPs) can reduce rotational instability and graft failure rates in primary ACLRs (Kan et al 2025, Onggo et al 2022, Beckers et al 2021), though limited studies have investigated functional outcomes including patient-reported outcome measures, sports participation and physical performance (Kan et al 2025, Onggo et al 2022). 

Evidence from randomised controlled trials indicates that adding a LEAP, such as a lateral extra-articular tenodesis, to primary ACLR significantly reduces the risk of graft rupture compared with isolated ACLR. 

Patients undergoing combined procedures also demonstrate improved control of rotatory instability as commonly assessed using the pivot-shift test, suggesting that extraarticular augmentation may better restore the rotational biomechanics of the knee (Kunze et al 2021). 

Some studies do report increased early postoperative symptoms following combined ACLR and LEAP, including greater pain, temporary stiffness and quadriceps weakness, though these differences are generally confined to the early rehabilitation period (Kan et al 2025, Beckers et al 2021). 

Despite this, patient-reported outcomes and functional measures tend to equalise over time, with no meaningful disadvantages observed beyond approximately six to 12 months, suggesting that short-term comorbidity does not translate into longerterm functional deficit (Kan et al 2025, Onggo et al 2022, Beckers et al 2021). 

The reduction in graft rupture and rotatory laxity suggests that adding a LEAP may be particularly beneficial in patients at higher risk of ACL graft failure, such as young athletes returning to pivoting sports. 

However, longer-term outcomes and osteoarthritis risk require further investigation before broader recommendations can be made across all patient populations.

3. ACL grafts follow a maturation timeline

 In ACLR rehabilitation, we often prioritise functional milestones like quadricep strength and hop symmetry. 

However, we cannot overlook the biological remodelling of the graft. 

This process follows a strict chronological timeline that even the most elite rehab program cannot accelerate. 

Immediately after surgery, the graft undergoes an ‘initial breakdown’ phase as donor cells die off. 

This creates a structural vulnerability window, typically between six and 12 weeks postop, where the tissue is at its weakest and biologically most prone to failure. 

Because the graft requires significant time to recover from this vulnerable state and regain its structural integrity, the timing of return to sport (RTS) is critical. 

Research by Grindem et al (2016) highlights the fact that delaying a return to play until the nine-month mark reduces reinjury risk by 51 per cent for every month waited. 

We must educate our patients that while their muscles may feel ready at six months, the internal integration of the new ligament is only just beginning to be able to withstand the high demands of sport.

4. Different ACLR autografts have distinct strength deficit profiles 

Autograft selection for primary ACLR remains a subject of ongoing debate. 

With over 160,000 ACLRs performed in Australia between 2001 and 2020, optimising both surgical and rehabilitation decisionmaking carries considerable public health relevance (Campbell et al 2025). 

Current evidence from randomised controlled trials demonstrates no significant differences in graft failure, joint laxity or patient-reported outcomes between QT (quadriceps tendon), HT (hamstring tendon) and BPTB (bone patellar tendon bone) autografts at short- to medium-term follow-up (Dai et al 2022, White et al 2025). 

QT autografts are, however, consistently associated with lower donor site morbidity than both the alternatives, particularly when compared to BPTB autografts (Kunze et al 2023, White et al 2025). 

HT autografts remain the most widely used graft in primary ACLR globally, although QT utilisation is increasing (Raj et al 2024, Tuca et al 2023). 

Each graft carries a distinct postoperative strength deficit profile. 

BPTB autografts benefit from earlier graft integration via bone-to-bone healing, though anterior knee pain and quadriceps weakness remain recognised postoperative considerations. 

QT autografts are also associated with prolonged extensor weakness, while HT autografts are associated with flexor weakness and a reduced hamstring-to-quadriceps ratio (White et al 2025). 

These differences have direct implications for rehabilitation programming and RTS planning. 

Optimal graft selection requires an individualised approach, guided by patient anatomy, activity demands, occupational requirements and rehabilitation capacity.

5. Psychological readiness is important in RTS following ACLR 

ACLR surgery is widely recognised for restoring knee stability and enabling athletes to RTS at their pre-injury level of participation. 

However, despite achieving physical recovery, up to 50 per cent of athletes are unable to successfully RTS due to psychological factors (Ardern et al 2014). 

Traditionally, decisions regarding RTS have focused primarily on physical recovery markers such as strength, functional performance and joint stability. 

Common assessment methods include hop tests and isokinetic strength testing, which are important for minimising the risk of reinjury during RTS. 

While these physical measures are essential, psychological factors – including fear of reinjury, reduced confidence in the knee and low motivation – also play a critical role in determining successful RTS outcomes (Ardern et al 2013). 

The Anterior Cruciate Ligament Return to Sport after Injury scale is a validated assessment tool used to measure psychological readiness in individuals recovering from ACL injury or reconstruction. 

It evaluates emotions, confidence and risk appraisal, with responses scored on a Visual Analogue Scale (Webster et al 2008). 

Research indicates that lower Anterior Cruciate Ligament Return to Sport after Injury scores are associated with delayed RTS and a higher risk of reinjury, whereas higher scores reflect greater confidence and psychological readiness to resume sporting activity (Ardern et al 2014). 

Athletes should therefore be monitored for psychological recovery alongside physical rehabilitation, using validated assessment tools. 

Rehabilitation programs should incorporate interventions aimed at addressing psychological barriers to optimise an athlete’s overall readiness to RTS.

>>Matthew Fels APAM is director of hospitals and connected care at Active Rehabilitation Physiotherapy in Brisbane. Matthew has a clinical focus on orthopaedic physiotherapy across multiple private hospitals and the rehabilitation continuum. He is vice chair of the Queensland branch of the APA Orthopaedic national group. 

>>Adrian Kan APAM is a physiotherapist at Gold Coast Knee Group and an orthopaedic researcher at Gold Coast Health. Adrian’s clinical and research interests focus on knee-related pathologies, particularly ACL injury, rehabilitation and knee osteoarthritis. He is a member of the Orthopaedic group. 

>>Rod Grof APAM is a director and principal physiotherapist with over 15 years of private practice experience. Rod treats musculoskeletal conditions with a range of treatment modalities, from manual therapy to exercise-based rehabilitation, collaborating with leading orthopaedic surgeons. He is the chair of the Victorian branch of the Orthopaedic group. 

>>Dr Larissa Sattler APAM is an orthopaedic physiotherapy researcher with dual appointments at Gold Coast Hospital and Health Service and Bond University. Larissa holds a PhD in total knee arthroplasty rehabilitation and is the chair of the Queensland branch of the Orthopaedic group. 

>>Emma Blake APAM is a senior orthopaedic physiotherapist at Hollywood Private Hospital and the chair of the Western Australian branch of the Orthopaedic group. Emma has 20 years of senior orthopaedic physiotherapy experience in both elective and trauma departments across the private and public sectors.

Quick links:

• References
• Download Infographic (PDF)