Long-Term ACL Injury Outcomes: Sport, Arthritis and Life After Injury

When someone tears their anterior cruciate ligament (ACL), the first questions usually revolve around the immediate injury.

Will I need surgery? How long will rehabilitation take? When can I run again? Will I return to football or netball?

These are all important questions. But there is another conversation that deserves just as much attention.

What happens to the person, and their knee, five, ten or twenty years after an ACL injury?

An ACL tear can affect much more than a ligament. It can influence sporting performance, mental health, social connection, finances, future knee health and quality of life.

At RHP Physiotherapy in Kelvin Grove, Brisbane, our sports physiotherapists work with people recovering from ACL injuries across football, netball and other recreational and competitive sports.

While the initial focus is often on rehabilitation and returning to activity, we believe it is equally important to understand the potential long-term consequences of knee injury.

This article explores those outcomes, what the research tells us and where appropriate rehabilitation and ongoing physical activity may make a difference.

Understanding the Burden of ACL Injury

In sports medicine, injury burden is often calculated by combining how frequently injuries occur with the amount of time athletes lose because of them.

For example, a relatively minor muscle injury may occur frequently but resolve within a few weeks.

An ACL injury may occur less often, but its consequences can be considerably greater because of the lengthy rehabilitation and potential long-term effects.

For the individual, injury burden extends well beyond the amount of time missed from sport.

It may include:

• Time away from training and competition.
• Medical and rehabilitation expenses.
• Reduced sporting performance or participation.
• Disruption to work, study and family life.
• Changes in confidence, identity and mental wellbeing.
• The possibility of a second ACL injury.
• Long-term knee symptoms or osteoarthritis.
• Future healthcare costs and quality-of-life changes.

Understanding these outcomes changes how we think about success.

The goal is not simply to return someone to sport as quickly as possible. It is also to consider how the injury and its management might influence their future health, participation and quality of life.

1. ACL Injury Rates and the Cost of Time Away From Sport

ACL injuries are particularly relevant in sports involving rapid deceleration, pivoting, jumping, landing and changes of direction.

These include football, netball, basketball and Australian rules football.

Although an ACL rupture is not always the most common injury in these sports, its time-loss burden can be substantial.

A mild ankle sprain might keep someone out for a matter of weeks. In contrast, return to high-demand pivoting sport following ACL reconstruction commonly requires nine to twelve months of rehabilitation, sometimes longer.

That can mean an entire sporting season missed, with consequences for the individual and their team.

How Do Injuries Affect Team Performance?

Research involving elite European football clubs has demonstrated an association between lower injury burden, greater player availability and better team performance.

An influential 11-year investigation found that teams with fewer injuries tended to achieve better results in domestic and European competitions.

It does not mean that reducing injuries guarantees a championship. Stronger clubs may also have better resources, greater squad depth and more sophisticated training systems.

Nevertheless, it reinforces a useful point:

Player availability is a meaningful part of sporting performance.

An athlete cannot contribute their skills while spending a season recovering from injury.

2. The Financial Cost of ACL Injuries in Australia

ACL injuries can create considerable financial costs, even before accounting for their potential long-term consequences.

For someone recovering from an ACL tear in Brisbane, direct and indirect expenses might include:

• Initial medical appointments and diagnostic imaging.
• Orthopaedic consultations.
• ACL reconstruction surgery and hospital expenses, where required.
• Postoperative or non-surgical physiotherapy.
• Gym memberships and ongoing strength training.
• Travel to appointments.
• Time away from employment or study.
• Reduced ability to perform physically demanding work.
• Additional family or childcare responsibilities.

Some of these costs are covered or partly offset through insurance and other funding arrangements, while others are borne directly by the individual or family.

How Much Does an ACL Injury Cost?

A 2024 Australian study published in the Medical Journal of Australia modelled the economic impact of ACL injuries in amateur football players.

The researchers estimated the average total medical and societal cost of an ACL injury to be approximately $30,665.

The same research examined the potential economic benefits of implementing a national ACL injury-prevention program for amateur footballers.

Source: Ross and colleagues, Medical Journal of Australia, 2024. These figures are derived from economic modelling using historical cost inputs. They do not represent the current out-of-pocket cost for an individual patient or savings already achieved.

The study illustrates why ACL prevention and effective rehabilitation should not be thought of only as a sporting concern.

There are potential benefits for individuals, healthcare systems, clubs and the broader community.

3. Return to Sport After ACL Reconstruction: How Successful Is It?

One of the most commonly discussed outcomes after ACL reconstruction is the rate of return to sport.

But there are several ways to define success.

Returning to recreational physical activity is not the same as returning to competitive football or netball at the same standard as before the injury.

An influential 2014 systematic review reported the following outcomes after ACL reconstruction:

Source: Ardern and colleagues, British Journal of Sports Medicine, 2014. These are pooled historical results, not predicted outcomes for an individual athlete.

Research in professional and elite athletes generally reports higher return-to-play rates.

A more recent systematic review of elite and professional athletes found approximately 86% returned to play following ACL reconstruction.

These differences may partly reflect access to rehabilitation resources, athletic demands, professional support and the motivation or financial pressures associated with elite sport.

However, a higher rate of return does not necessarily mean the rehabilitation or longer-term knee outcome was better for every athlete.

Does Returning to Sport Mean Returning to Previous Performance?

Not necessarily.

Some athletes return to competition but experience changes in:

• Strength and power.
• Sprinting or acceleration performance.
• Jumping and landing ability.
• Change-of-direction capacity.
• Minutes played.
• Sporting confidence.
• Playing position or competitive level.

Others return to similar or better performance levels following a successful rehabilitation process.

The research is mixed, partly because sporting performance is difficult to measure consistently across different sports and competition levels.

At RHP, our Return to Sport assessments can incorporate objective quadriceps and hamstring strength testing, jump testing, force plates and sport-specific physical preparation.

These measures help us assess whether an athlete has rebuilt important physical qualities, rather than simply assuming recovery because they have returned to training.

4. What Is the Risk of a Second ACL Injury?

Another important long-term consideration is the risk of reinjuring the reconstructed knee or injuring the ACL in the opposite knee.

These are sometimes described as ipsilateral and contralateral ACL injuries.

A 2026 systematic review and meta-analysis involving 16,905 football players across 34 studies reported a pooled second ACL injury incidence of approximately 21.6% following reconstruction.

In that analysis:

• Second injuries to the reconstructed knee occurred in approximately 10.4% of players.
• ACL injuries to the opposite knee occurred in approximately 10.6%.
• Higher rates were observed in younger players and groups with high return-to-play exposure.

The researchers found substantial variation between studies.

The 21.6% figure should therefore not be interpreted as an exact prediction for an individual athlete. It is also specific to the football populations studied.

Nevertheless, the findings highlight why returning to sport should not signal the end of physical preparation.

Why Is the Opposite Knee Also at Risk?

The reasons are complex.

Football continues to involve high forces, rapid deceleration, pivoting and unpredictable movement after someone returns from injury.

Some athletes may also have persistent deficits in either limb, and both legs can lose physical capacity during a long rehabilitation period.

This is one reason comparing only the injured and uninjured legs can sometimes be misleading.

A person may achieve similar strength on both sides while still being less strong than they were before injury.

Our ACL & Meniscus Physiotherapy approach considers both limb symmetry and the broader strength and performance demands of the individual’s sport.

5. Mental Health and the Psychological Effects of ACL Injury

The long-term burden of ACL injury is not purely physical.

For many athletes, sport is closely tied to identity, social connection, confidence and a sense of belonging.

Someone who has trained and competed for years may suddenly find themselves unable to participate in the activities that structure their week.

They may miss competition, teammates, exercise, routine and the feeling of being physically capable.

A 2026 systematic review and qualitative evidence synthesis involving 56 studies and 806 participants identified several recurring themes following ACL injury.

These included:

• Disruption to sporting identity.
• Fear of reinjury.
• Periods of psychological distress.
• Social disconnection and isolation.
• The importance of family, teammates and clinical support.
• A desire for healthcare that considers the individual rather than only the knee injury.

Some people experience substantial distress, while others adapt relatively well or find new interests during rehabilitation.

Neither experience should be assumed.

Why Psychological Readiness Matters When Returning to Sport

An athlete may demonstrate excellent quadriceps strength, hop testing and running capacity but still feel apprehensive about returning to competition.

This is understandable when the activity involves the same movements during which the original injury occurred.

Psychological readiness has been associated with return-to-sport outcomes, and can be considered alongside physical testing.

Appropriate support may involve:

• Clear and realistic rehabilitation expectations.
• Meaningful goals throughout recovery.
• Regular feedback about physical progress.
• Gradual exposure to more demanding movements.
• Maintaining connection with teammates and coaches.
• Involving the athlete in return-to-sport decisions.
• Referral for additional mental health support when appropriate.

Confidence is not simply something we can tell a person to have.

It develops through experience, understanding, exposure and support.

6. ACL Injury and Knee Osteoarthritis: What Happens Years Later?

One of the most significant long-term considerations following ACL injury is an increased likelihood of developing knee osteoarthritis.

When osteoarthritis develops following a major joint injury, it is sometimes described as post-traumatic osteoarthritis.

An ACL tear often affects more than the ligament itself.

The original injury may also involve:

• Meniscus injury.
• Articular cartilage damage.
• Bone bruising or subchondral bone injury.
• Other ligament injuries.
• An inflammatory response within the joint.

Changes in joint biology, loading, associated tissue damage and subsequent injury may all influence longer-term knee health.

It is not simply a process of cartilage wearing away because someone continues to exercise.

How Common Is Osteoarthritis 10 Years After an ACL Tear?

A systematic review investigating knee osteoarthritis more than ten years after ACL injury found substantial variation in reported rates.

Different studies examined different populations, associated injuries, treatments and definitions of osteoarthritis.

In one well-known prospective cohort, approximately 44% of participants demonstrated radiographic knee osteoarthritis at an 11-year follow-up.

This does not mean that 44% of all ACL injuries will lead to symptomatic arthritis after eleven years.

The result describes one particular group and uses structural changes identified on imaging.

That distinction matters because radiographic osteoarthritis is not the same thing as persistent pain or disability.

Some people have osteoarthritic changes on imaging and continue to function well.

Others experience significant knee symptoms despite relatively modest structural changes.

What Happens 5, 10 or 20 Years After an ACL Injury?

There is no fixed timeline of deterioration after an ACL injury.

However, long-term research gives us a useful perspective on what may be relevant at different stages.

These are areas worth reviewing over time, not predetermined stages of joint degeneration. Many people maintain good function throughout these periods.

7. Does ACL Reconstruction Prevent Knee Osteoarthritis?

It is reasonable to wonder whether surgically reconstructing the ACL might protect the knee from arthritis later in life.

ACL reconstruction can restore mechanical stability in an unstable knee, which can be particularly important for some people returning to demanding pivoting sports.

But the evidence does not establish that reconstruction reliably prevents osteoarthritis.

A 2026 systematic review and meta-analysis involving more than 33,000 patients found no significant overall difference in radiographic knee osteoarthritis between ACL reconstruction and non-operative management.

The review also reported a lower rate of knee replacement in reconstructed patients, although that result was based on substantially fewer studies and cannot be assumed to reflect a direct protective effect of surgery.

The certainty is limited by differences in patient populations, associated injuries and treatment selection.

Other studies investigating the timing of surgery have reported different findings, particularly when comparing early and delayed reconstruction.

These differences highlight the complexity of the question rather than providing one universal answer.

The decision about surgery should therefore consider:

• Functional instability.
• Associated meniscus or cartilage injuries.
• The individual’s sporting demands.
• Response to rehabilitation.
• Personal preferences and goals.
• The potential risks and benefits of each pathway.

The longer-term objective is to preserve function and participation, not simply to select a treatment based on the hope that it guarantees protection against arthritis.

Our ACL & Meniscus Injury page discusses both surgical and non-surgical management, while our Pre & Post Surgery Physiotherapy service supports people undergoing reconstruction or other knee procedures.

Why Does Meniscus Injury Matter So Much?

Associated meniscus injury is particularly relevant when considering long-term knee health.

The menisci contribute to load distribution, stability and shock absorption within the knee.

When meniscal tissue is damaged or removed, the forces experienced by the articular cartilage can change.

Meniscectomy has been consistently associated with increased osteoarthritis risk following ACL injury.

Where clinically appropriate, preserving and repairing meniscal tissue may therefore be important.

This is another reason ACL injuries should be assessed as injuries to the whole knee rather than simply to one ligament.

8. Will I Have Knee Pain Years After ACL Surgery?

Some people experience persistent or recurring knee pain after ACL reconstruction, while many others report excellent knee function.

Possible contributors to longer-term symptoms include:

• Patellofemoral pain.
• Meniscus-related symptoms.
• Ongoing quadriceps weakness.
• Tendon symptoms associated with the graft donor site.
• Recurrent joint swelling.
• Osteoarthritis.
• Changes in activity or training capacity.

Not every painful knee years after reconstruction is painful because of the ACL graft.

Nor does pain automatically indicate that the reconstruction has failed.

Persistent symptoms warrant an individual assessment that considers the knee itself alongside the person’s recent activity, physical capacity and goals.

For people in Brisbane dealing with ongoing knee pain, our Knee Physiotherapy service focuses on understanding the presentation and developing a practical management plan.

9. Future Healthcare Costs and the Possibility of Knee Replacement

Because ACL injury is associated with an increased risk of osteoarthritis, it is reasonable to consider the potential long-term healthcare costs.

These might include further medical appointments, imaging where appropriate, rehabilitation, medication or other interventions.

For a smaller proportion of people, severe symptomatic osteoarthritis may eventually lead to consideration of knee replacement.

However, it is important not to confuse these possibilities with inevitabilities.

An ACL injury does not mean a person will eventually need a knee replacement.

And even if osteoarthritis develops, many people can manage their symptoms and remain active without joint replacement surgery.

What Can Be Done If Knee Osteoarthritis Develops?

The Australian Osteoarthritis of the Knee Clinical Care Standard emphasises education, physical activity and appropriately tailored exercise as important components of management.

Exercise can improve pain, function and physical capacity in people with knee osteoarthritis.

Importantly, exercise should not be presented as something that inevitably damages an arthritic knee.

At RHP Physiotherapy in Kelvin Grove, our GLA:D Program provides a structured combination of education and exercise for people experiencing knee or hip osteoarthritis.

Our Exercise Physiology service can also support longer-term strength, fitness and physical activity goals.

Some people may need surgical management, but there are meaningful conservative options to consider before reaching that point.

10. Quality of Life After ACL Injury

The long-term success of ACL rehabilitation is often measured using clinical outcomes.

We measure knee movement, strength, ligament stability, jump performance and return-to-sport rates.

These are all useful.

But they do not necessarily capture the full experience of the person recovering from the injury.

Someone might return to competitive sport but still experience substantial anxiety or frustration.

Another person might stop playing football but develop a satisfying and active lifestyle involving running, cycling, gym training and family activities.

Both situations challenge the assumption that return to a particular sport is the only meaningful measure of recovery.

Quality of life may include:

• Being able to work comfortably.
• Playing with children.
• Maintaining friendships and social activities.
• Participating in recreational exercise.
• Feeling confident and physically capable.
• Managing any ongoing knee symptoms.
• Having confidence in future activity choices.

For some people, a successful outcome means returning to elite sport.

For others, it means being able to hike, run recreationally or simply remain physically independent later in life.

The definition of success should reflect what matters to the individual.

What Can Improve Long-Term Outcomes After an ACL Injury?

We cannot guarantee that an ACL injury will have no lasting effects.

However, several approaches are valuable when considering the longer-term recovery and management of the knee.

These strategies are sensible parts of care, but none should be interpreted as a guarantee that reinjury or osteoarthritis will be prevented.

Why ACL Injury Prevention Matters Beyond a Single Sporting Season

Many ACL injury-prevention discussions focus on keeping athletes available for the coming season.

That matters, but the potential benefits of reducing ACL injuries extend much further.

Avoiding an injury may also prevent:

• Months of rehabilitation.
• Substantial medical and indirect costs.
• Disruption to work and family life.
• Psychological and social consequences.
• Exposure to a second ACL injury.
• Some of the longer-term consequences associated with major knee trauma.

For players in football, netball and other sports, appropriate physical preparation therefore has value beyond immediate performance.

Our Sports Physiotherapy service supports athletes with strength development, sports injury rehabilitation and return-to-sport preparation.

Frequently Asked Questions About Long-Term ACL Injury Outcomes

It’s Not All Doom and Gloom

After discussing reinjury, osteoarthritis, financial burden and the possibility of reduced sporting participation, it would be easy to develop a pessimistic view of ACL injury.

That is not the intention.

Many people return to high levels of sport and maintain excellent function for years after an ACL injury.

Others choose different sporting or recreational activities and continue to enjoy very active lives.

Even when osteoarthritis develops, people can often improve symptoms and physical function through appropriate exercise and management.

The value of understanding long-term ACL outcomes is not to suggest that negative consequences are inevitable.

It is to encourage a broader conversation about recovery.

Can we help someone return to the activities they value?

Can we rebuild strength and physical confidence?

Can we support ongoing activity and good health long after formal rehabilitation finishes?

These are important questions because an ACL injury affects a person, not simply a ligament.

ACL Injury Rehabilitation and Long-Term Knee Health in Brisbane

At RHP Physiotherapy in Kelvin Grove, Brisbane, our sports physiotherapists work with people recovering from ACL injuries through both surgical and non-surgical pathways.

Our approach considers the early injury, strength rehabilitation, physical testing and return-to-sport process, but also the person’s longer-term sporting and lifestyle goals.

Depending on your presentation, the following services may be relevant:

• ACL & Meniscus Physiotherapy for assessment, treatment decisions and structured rehabilitation.
• Pre & Post Surgery Physiotherapy for those preparing for or recovering from knee surgery.
• Return to Sport for objective strength testing, jumping, running and sport-specific preparation.
• Knee Physiotherapy for persistent or recurring knee symptoms.
• GLA:D for structured education and exercise when knee osteoarthritis develops.

Whether you have recently sustained an ACL injury, are still working towards sport or are experiencing knee symptoms years after reconstruction, the starting point is understanding your current situation and what you want to achieve.

Author in the know

Sam Donaldson

Director, APA titled Sports and Exercise Physiotherapist. Sam loves to treat athletes with lower limb injuries and has a special interest in knees of all ages; adolescent knee pain, athlete with knee pain, ACL injuries, ACL rehabilitation, Knee Osteoarthritis and Knee Replacement recovery. He is a Dad, Football enthusiast and loves to move. BAppSci (HMS), MPhtyStudies, MPHTY (Sports)