The anterior cruciate ligament (ACL) is one of two key stabilising ligaments in the knee, originating from the posteromedial aspect of the lateral femoral condyle and inserting into the anterior intercondylar aspect of the tibia. The ACL resists anterior translation of the tibia and rotational forces through the knee.
Full recovery following surgery requires long-term rehabilitation lasting between 9 to 12 months for return to full sport, with return to running for well-progressing patients often achievable earlier, commonly from around 12 to 16 weeks depending on individual progress and criteria-based milestones.
A large proportion of ACL ruptures in athletic populations are sports-related, particularly in activities involving change of direction, rapid deceleration, pivoting and direct contact, though the exact proportion varies depending on the population studied. Women face a two to eight times greater risk of ACL rupture during sport compared to men, due to a combination of anatomical, biomechanical and hormonal factors.
Not every ACL rupture requires surgery, though it’s generally recommended for those looking to return to sport or maintain an active lifestyle, to restore knee stability and function. Reconstruction surgery involves replacing the damaged ligament with a graft, which serves as a scaffold for new tissue to build around.
Graft Types
Autografts
These are the most commonly used grafts in ACL reconstruction and involve using tissue from the patient’s own body. Autografts have a low risk of rejection and generally heal well.
Hamstring Graft
This graft is usually taken from the semitendinosus through a small incision at the back of the knee. The tendon is folded multiple times to create one strong, multi-stranded graft, which is then secured into tunnels drilled in the knee.
Pros:
- Reduced anterior knee pain
- Smaller scar incision
- No bone plug required, making surgery less invasive
Cons:
- Slightly weaker initially, with rerupture risk elevated in the weeks following surgery due to revascularisation of the graft and cell remodelling
- Potential hamstring weakness
Patella Tendon Graft
This involves taking the middle third of the patella tendon with bone from the patella and tibia (bone plugs). These bone plugs are used to anchor the tendon in place inside the knee.
Pros:
- Bone plugs offer strong anchoring, allowing faster graft integration
- High success rate, particularly for athletes with high physical demands
Cons:
- Increased risk of anterior knee pain and recurring flare-ups
- Increased risk of developing patella tendinopathy
- Difficulty kneeling on the operated leg
- May take longer to recover
- Scar incision may be more prominent
Quadriceps Graft
This involves taking a portion of the quadriceps tendon, which connects the quadriceps to the patella. A bone plug may or may not be taken, depending on orthopaedic preference.
Pros:
- Larger, thicker, stronger and stiffer than other graft types
- Patients are less likely to develop anterior knee pain compared with patella tendon grafts
Cons:
- Increased risk of patella fracture
- Prominent incision site
- Quadriceps weakness
Allografts
Allografts use tissue from a deceased donor.
Pros:
- Less invasive for the patient, as no graft is removed from their own body
- Shorter surgery time
- Fewer graft site complications
- Can be a good option for those with multiple prior ACL injuries who don’t have enough tissue left to harvest
Cons:
- Increased risk of infection
- Increased risk of rejection
- Limited availability and increased cost
- Slower incorporation and healing time compared with autografts
Why Graft Choice Matters for Long-Term Knee Health
ACL reconstruction is a highly effective surgical procedure for restoring knee stability, and plays a role in reducing the risk of developing secondary complications such as meniscal and cartilage damage. Research shows that people who sustain an ACL rupture face an increased long-term risk of developing knee osteoarthritis, with that risk further elevated when the meniscus is also involved. This highlights the importance of timely surgical management and structured, criteria-based rehabilitation to support long-term knee health.
How BeFit Can Help
Our Sports Physiotherapy team supports patients through every stage of ACL rehabilitation, from early post-operative care through to a structured Return to Sport pathway.
If you’re preparing for ACL surgery or navigating your recovery, you may also find these guides helpful:
- What to Expect in the First Six Weeks After ACL Reconstruction
- How to Recover From ACL Surgery Without the Risk of Re-Injury
- Why Rehabilitation Should Be Outcome-Driven, Not Timeline-Based
Book an appointment at BeFit Training Physiotherapy — no referral needed.
Edgecliff: (02) 9327 7749 | Coogee: (02) 7205 2805
References
Øiestad BE, Engebretsen L, Storheim K, Risberg MA. Knee Osteoarthritis After Anterior Cruciate Ligament Injury: A Systematic Review. Am J Sports Med. 2009;37(7):1434-1443.
Ardern CL, et al. 2016 Consensus Statement on Return to Sport From the First World Congress in Sports Physical Therapy, Bern. Br J Sports Med. 2016;50(14):853-864.
Australian Physiotherapy Association. Clinical guidelines. physiotherapy.asn.au.
