If you’re preparing for ACL reconstruction, you may need to decide which type of graft to use. There is no single ACL graft that is best for every patient, so the right choice depends on factors such as your age, activity level, sport and individual knee.
In this guide, Dr Sime explains the main graft options and what patients should consider before surgery.
What Are ACL Grafts?
An ACL graft is a piece of tendon used to replace your torn ligament. Graft choice is one of the first decisions in ACL reconstruction surgery. Most grafts are autografts, or tendons taken from your own knee. The alternative is an allograft, which comes from a donor.
The Four Most Common ACL Graft Types
Patellar Tendon
The middle third of the tendon below your kneecap is taken with a small block of bone at each end. Bone heals to bone, which gives a firm early fixation. The trade-off is discomfort at the front of the knee, especially when kneeling.
Hamstring
One or two tendons from the back of your thigh are folded into a thick four-strand graft. A hamstring graft ACL reconstruction uses a smaller incision and causes less kneeling pain. Graft diameter can vary from person to person, and some patients might notice mild hamstring discomfort or weakness.
Quadriceps
A strip of the tendon above your kneecap is used, with or without a small piece of bone. It is a thick, strong graft that has become more popular in recent years because there’s less discomfort from where the tissue was taken.
Allograft
An ACL allograft uses a donor tendon, so nothing is taken from your knee. This is an excellent alternative as early recovery can feel much faster and easier. Patient suitability is important here as failure rates can be higher in young active patients.
ACL Graft Types Side by Side
Here's how the main ACL graft types compare. Re-rupture figures come from a 2026 meta-analysis of patients aged 25 and under, and strength figures come from this 2016 laboratory testing.
| Graft | Lab strength | Re-rupture (age 25 and under) | Recovery | Donor site problems | Often suits |
|---|---|---|---|---|---|
| Patellar tendon | About 2,977 N (10 mm) | 5.1% | Quadriceps strength slower to return | Kneeling pain, front of knee pain | Young athletes in pivoting sport. Revision ACL reconstruction. |
| Hamstring | About 4,090 N (four-strand) | 11.1% | Quadriceps strength returns sooner | Hamstring weakness, small scar | Adults over 25 and people who kneel for work |
| Quadriceps | About 2,353 N (10 mm with bone) | 2.5% (small sample) | Some early quadriceps weakness | Less kneeling pain than patellar tendon | Young athletes wanting less kneeling pain |
| Allograft | Varies with processing | Not studied in this group | No harvest site to recover from | None from your knee | Older, lower demand patients and revisions |
For comparison, a healthy native ACL fails at about 2,160 N in the same testing. Every autograft here starts at least as strong as the ligament it replaces.
Possible Kneeling Pain and Long-Term Donor Site Issues
For many patients, this is the deciding factor. In the New Zealand ACL Registry, 21.3% of patellar tendon patients reported severe kneeling difficulty at two years, compared with 9.4% after hamstring grafts.
A 10-year Sydney trial by Pinczewski and colleagues found that kneeling pain was more common after patellar tendon grafts. However, the difference may lessen over time.
In a separate 15-year Melbourne trial, Webster and Feller found similar rates of kneeling pain between patellar tendon and hamstring graft patients at the final follow-up.
Quadriceps grafts sit in the middle. A 2024 meta-analysis found far less donor site pain with quadriceps than with patellar tendon grafts. If you kneel for work or for your faith, mention it at your consultation.
Re-Rupture Rates by Graft and Age
Age changes the numbers more than anything else. In this study of more than 2,400 reconstructions, 4.4% of grafts re-tore overall. The odds of a re-tear were 5.2 times higher with an allograft than a patellar tendon autograft. The odds also dropped with every extra year of age.
Across all ages, a 2021 systematic review of 152,548 patients found yearly failure rates between 0.72% and 1.76%, with no significant difference between graft types. The differences show up mainly in younger, high-demand patients. These are published study figures, not a prediction for any one knee.
Choosing by Age and Sport
Age and activity level can influence which graft is most suitable. Younger patients returning to sports such as football or netball generally have a higher risk of re-injury, so graft choice becomes especially important.
For adults between 25 and 40, several graft options may be suitable depending on your sport, work and lifestyle. For older patients or those with lower activity demands, an allograft may also be considered.
Your graft choice can also affect your ACL recovery time, particularly how quickly strength returns after surgery.
How the Decision Is Made in Consultation
Choosing among ACL graft options comes after the bigger question of surgery versus rehab, which is covered in ACL injury treatment options.
Once surgery is agreed, a surgeon works through your age and sport first. Your job and any previous knee surgery come next. They may also check the size of your tendons on MRI.
Your priorities count as much as the data. Some patients will accept kneeling pain for a lower re-rupture risk, and others won't. Go with an orthopaedic surgeon who lays out the trade-offs plainly so you can agree on the plan together.
Book a consultation to find the graft that fits your knee and your goals.
FAQs
What are ACL grafts?
They're tendons used to rebuild a torn ACL. Autografts come from your own knee, and allografts come from a donor.
How many years does an ACL graft last?
A healed graft is meant to last for life. In the Pinczewski trial, 7 of 90 patellar tendon grafts and 12 of 90 hamstring grafts ruptured by 10 years.
Which ACL graft is strongest?
Based on laboratory testing, a four-strand hamstring graft has the highest load to failure. Lab strength doesn't predict re-rupture on the field, though. In young athletes, hamstring grafts failed more often than patellar tendon grafts.
How common is ACL graft failure?
There’s a low rate of graft tear after at least two years of follow-up. Rates were higher in younger, more active patients, reaching 11.1% for hamstring grafts in those aged 25 and under.