ACL reconstruction revision rates

Do ACL Hamstring Grafts Fail More than Patellar Tendon Grafts?

This month’s issue of the American Journal of Sports Medicine included two studies comparing the revision rates of ACL reconstruction between hamstring grafts and patellar tendon grafts of over 25,000 people.  The overall number of people studied between the two groups was really compelling to me as a sample size this big is certainly worth discussing.

In recent years the graft choice for ACL reconstruction has been slowly shifting towards favoring hamstring grafts rather than patellar tendon grafts.  Recent reports have noted 84% of ACL reconstructions in Denmark and Sweden use hamstring grafts, 60% in Norway, and now are even becoming more popular in the US with 44% of ACL reconstructions using a hamstring graft compared to 42% using a patellar tendon graft.

Many research papers have been published showing that both grafts result in very good stability of the knee with excellent subjective outcome scores.  The major complaint of patellar tendon grafts is the increased risk of issues after surgery, such as patellofemoral pain and loss of motion.  Despite the reports of good stability and subjective outcomes, revision surgery is probably a more important factor to consider.

Do ACL Hamstring Grafts Fail More than Patellar Tendon Grafts?

The first study reviewed the nationwide Danish Knee Ligament Reconstruction Registry, which included 13,647 people undergoing ACL reconstruction between 2005 and 2011.

The revision rates for hamstring tendon grafts were 0.65% at 1 year after surgery, and 4.45% at 5 years after surgery.  The revision rates for patellar tendon grafts were 0.16% at 1 year after surgery, and 3.03% at 5 years after surgery.

Essentially, hamstring grafts had a 4x greater risk of revision in year one and 1.5x at 5 years following ACL reconstruction.

ACL reconstruction revision rates

The second study reviewed the nationwide Norwegian Cruciate Ligament Registry, which included 12,643 people undergoing ACL reconstruction between 2004 and 2012.

The revision rates for hamstring tendon grafts were 5.1% at 5 years after surgery, and 2.1% for patellar tendon grafts.  This study also looked at different age groups and found this increased rate to be consistent across all age group.s  However, the younger group (age 15-19) had a 9.5 revision rate at 5 years using the hamstring graft in comparison to 3.5% using a patellar tendon graft.

Together, there was a 2x greater risk of revision overall when using the hamstring graft, but closer to 3x greater risk for younger people.

ACL hamstring patellar tendon graft

Both Grafts are Great Options for ACL Reconstruction

When we really assess the numbers, it is clear that both graft options are great choices with low revision rates.  Even though we are comparing the two, realistically the revision rates after ACL reconstruction are low for both hamstring grafts and patellar tendon grafts.  There are many factors that go into deciding which graft to use.  Also realize this does not apply to skeletally immature patients.  This revision information is just a piece of the puzzle.

The patellar tendon graft has less failure rate and has been reported to heal faster in animal models due to the bone-to-tendon interface.  While this is true there are also reports of increased anterior knee pain and loss of motion.  I have discussed this in the past, but I really do believe that many of the issues with patellar tendon grafts after surgery are minimized or eliminated with proper physical therapy (in addition to excellent patient compliance).  This is especially true if these factors are the primary emphasis of the early phases of ACL rehabilitation.

SEE ALSO: 6 Keys to the Early Phases of Rehabilitation Following ACL Reconstruction Surgery

That all being said, hamstring grafts have also been shown to result in less strength of the hamstrings after surgery.  Considering the role of the hamstring to assist the ACL in control anterior tibial translation, this has to be considered when reviewing the higher ACL reconstruction revision rate when using hamstring grafts.  Perhaps it really has nothing to do with the graft itself and more to do with the hamstring strength.

Regardless, the revision rate following ACL reconstruction is higher when using a hamstring graft than when using a patellar tendon graft.

15 replies
    • Jamie
      Jamie says:

      Means happening again, I did my acl 2 years ago (hamstring) procedure 9 months into football it snapped and and went back for second one which I did last week (patella) I found my self in much less pain and walk on the second day with only one crouch, still not sure which is better will tell u in 2 years! :p

      • Alex Rodriguez
        Alex Rodriguez says:

        Hello jaime… just wondering how’s the knee? Do you have a better grasp on which procedure was better ? I have a torn acl and in my 40’s, still very active and I was undecided on which procedure to go with…

  1. Singapom
    Singapom says:

    Thanks for this post. As you say, each case is different, and it is good to have information to enable an informed decision.

  2. Eric
    Eric says:

    Hi all,

    I am only a recipient of a PTG, so probably don’t have the medical terminology, but only my personal observations. Dr Stephan Tarlow did my PTG in 1990 after a football injury. At that time he seem to be ahead of the game in surgery of this type and due to my age (17) and activity level my parents helped me to choose his technique.

    I am now 40ish and have never been limited in any activities. I run, ski, play soccer with my children and use the gym regularly. I do agree with the ‘patient compliance’, as I believe my success was partly due to my obsessive rehab program.

    My only complaint comes from not being able to kneel on hard floors, but small price to pay, and at my age I shouldn’t be grubbing around on the floor anyway! Best of luck with anybody who has an ACL reconstruction, my parting words would be to be vigilant with your rehab!


  3. Neil
    Neil says:

    I had an autologous hamstring ACL reconstruction in my left knee back in 2003 and 11 years later I still have NOT regained the lost muscle and strength in my left leg. Unfortunately, I don’t think there is the perfect scenario as different grafts result in higher revision rates or effect physical performance. Here are my current problems as of today, June 4th, 2014:
    – lost hamstring strength due to half of semitendinosis and gracilis muscles removed.
    – range of motion is great however; I am unable to fully flex my knee/leg to allow my heal to almost touch my glut.
    – decreased hip flexibility/leg addiction due to tightening of my semitendinosis muscle.
    – PT and massage is an absolute must over the years to help combat some of the above.

    • Neil
      Neil says:

      Correction to above:
      Decreased hip flexibility/leg adduction (NOT addiction, auto correct gets me again! Ha!)

  4. Obi
    Obi says:

    Hello Ben, I’m in the process of deciding which type of reconstructive surgery to have as I’ve been offered a date very soon for the hamstring graft but I am strongly considering changing to b the patella tendon. After your hamstring graft surgery did you try and build back up the muscles in your hamstrings by going to the gym regularly ect and it still failed to return to anywhere near it’s original functioning self? Also how long ago have you had the surgery now?

  5. Ben
    Ben says:

    I had a hamstring graft done using two of my tendons (ST-G) in November of 2011 and it is one of the biggest mistakes I’ve made in life.
    So much of my tendon is missing that I’ve lost nearly 50% of the strength in my hamstrings. Functionally, I am simply unable to properly flex my knee past 90 degrees.
    Yes my ACL has been fine but at what cost? Fix one problem and cause another? I haven’t been able to return to any of the sports that I love, let alone have confidence in running. I still have imbalances in my gait and often find myself falling over to the opposing side of my body.
    The hamstring tendons should NOT be ignored in their biomechanical and functional importance. I’ve even started to develop pain in my opposing healthy knee as a result of all the compensation.
    I don’t blame my surgeon because he was quite adept. I blame myself for choosing the wrong graft type and not being aware of the consequences….do your research people and only choose a hamstring graft if you must, using minimal amounts of the tendon.

  6. Kristal Nelson PT, SCS
    Kristal Nelson PT, SCS says:

    Could not agree more Mike with your statement ” I really do believe that many of the issues with patellar tendon grafts after surgery are minimized or eliminated with proper physical therapy (in addition to excellent patient compliance). ”

    I rarely see these complications following BTB grafts. I find BTB do have more pain acutely but rarely after the first few weeks.

  7. Diane
    Diane says:

    What is your feeling on autograft vs allograft. I feel a lot of surgeons in my area use allograft but at the Cincinnati Sports Medicine course I went to in 2012 seemed to suggest allograft having a higher failure rate for the more active population.

    • Mike Reinold
      Mike Reinold says:

      I definitely would not use allograft myself. They do have higher failure rates. i want my own tissue any day. There are reasons to go for allograft, everyone is different, but i’ll take autograft any day!.

    • Mike Reinold
      Mike Reinold says:

      Hi Dillon, the revision rate means the percentage of people that go on and need to have the ACL reconstruction again. The original surgery failed and needed to be revised.

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