On my 40th birthday, I distinctly remember thinking:
“If I blew out my ACL now, I’d have to have an allograft.”
Those are the random and irrational thoughts that go through a physio’s head. I know I’m not alone… admit it, if you are a 40+ physio, you are nodding your head in agreement.
So yeah. I am 42 years old and if you follow my blog or my Twitter account, you know I tore my ACL skiing recently… well, precisely 4 days ago. My surgeon is letting me choose my graft, despite my age, because I “can make a well-informed decision”.
Or can I?
My first intuition, was to manage this conservatively and not have surgery all together. I have fallen twice, and buckled many, without my ACL. Not at all awesome when this happens vacuuming or putting on my pants. I’m waiting to see if this improves as my quads return and my effusion resolves; but ultimately, I am choosing surgery to protect my meniscus.
Typically, our surgeons use allografts (usually from an Achilles tendon) for patients older than 40. That would be me. It is assumed that graft failure is less likely in “older” patients because of reduced activity level. There are higher rates of allograft failure in athletes younger than 25 (Kaeding 2011) and we do not recommend allografts for young patients. Clearly, I am not younger than 25, but I am very active. My activity level is higher than it was in my 30’s and similar to what it was in my 20’s. Though Tegner scores return to “baseline” in “aging” athletes with allografts, intuitively, knowing that I have a “weaker” graft in my knee may make me more tentative and worse yet, discontinue or modify the things I like to do.
On the other hand, I’ve had many patients, younger than 40, including a former NFL player, thrilled with their allograft, albeit usually revisions or second and third ACL surgeries. My surgeon asked how many of his allografts I have seen fail, and honestly, I can’t think of any in the past 5 years. And who’s to say, maybe they didn’t decide to proceed with another ACL surgery or have gone somewhere else. We just don’t really know. There is just something about knowing it is weaker that will bug me.
The reasons for choosing allografts are less pain, no donor site morbidity, and “quicker” return to sports; however, allografts take longer to heal (Poehling 2005). The notion that people are ready to return to sports “quicker” with allografts is false considering it takes an allograft longer to incorporate into the tunnel. Further, after performing functional testing for ‘Return To Sports’ of all graft types, it is fairly consistent that 6 months is too early for everyone. Every. Single. Graft.
Using the semitendinosis hamstring alone or with the gracilis is another graft option. I do not like to see hamstring autografts in females. That is my very strong bias. Like most women, I would likely not have enough hamstring tendon for a decent sized graft, despite all those dead lifts at the gym. My other bias is that they creep. I feel more laxity in them. Maybe it doesn’t make a difference functionally, but I feel it. I know it is there.
The hamstrings are also an internal rotator of the tibia. From a biomechanical perspective, this loss may result in excessive tibial external rotation. There are no studies looking at the implications of this (Carofino 2005), but in my opinion, rotary stability may be altered. I will add that I have rehabilitated hundreds of patients with hamstring autografts and they do seem to get their quads back faster and subjectively do not feel unstable. They do very well.
Until recently, we choose patellar tendon autografts for athletes, especially cutting-sport athletes and skiers, unless a history of patellar tendinopathy. It is still the gold standard for graft selection. It has proven to be a strong graft, and results in less laxity than a hamstring graft (Xie 2015). There also seems to be more donor site pain initially and continued anterior knee pain longer term. My bias is that I think proper rehabilitation can mitigate any anterior knee pain. It is unfortunately all too common for physios to avoid doing isolated quad exercises on a leg extension machine during therapy. In my opinion, long term patellar tendon pain occurs when the demand on the quads is greater than the capacity. In simpler terms, quad strength has not been adequately restored prior to returning to high demand activities.
I don’t recommend patellar tendon graft for those with a history of patellar tendinitis, though this may not even be an issue unless imaging shows degenerative tendon. Imaging of potential donor tissue is not routinely performed. In my personal history, I had patellar tendinopathy last year after skiing in deep powder (damn, that was awesome). I’ve opted to not choose this graft because of it. And to confirm my feelings, my MRI showed mild patellar tendinopathy.
We have recently started doing quad tendon autografts as primary reconstructions. We’ve been using them for revisions a bit longer. It is the newest, sexiest thing in the ACL world. The graft is nice and stout. There is flexibility in choosing the size for the patient. I am certainly intrigued with the handful I have seen so far. The extensor mechanism takes it in the shorts initially, and people appear to be in much more pain, but it seems to even out between the 6-8th week. As we are all seeing more of these, I think we can figure out a way to mitigate early donor site pain. For me, having more pain post op in exchange for the strongest graft type, is an easy decision. I’ve had two babies without pain medication. I don’t think anything can be worse than that. Yep, just added that in to brag– who wouldn’t?
The curious mind of mine also wants to explore methods to improve quad activation for this graft type. This part I am looking forward to. Most of my patients are autografts, either quad tendon or patellar tendon. I want to share my experience with my patients and contribute to this very popular topic in physio. If something positive comes of my injury, it will be new ideas that may help other patients and physios.
But Laura, we don’t care what you think, what does the research say?
The current best evidence suggests that ACL reconstruction with patellar tendon autografts provides superior static knee stability and that there are fewer postoperative complications in ACLR with hamstring autografts (Schuette 2017).
Autografts are superior to allografts in terms of laxity and failure rates. If the allograft was not irradiated the outcomes were similar to autografts (Grassi 2017). Of note, our office uses irradiated allografts, and personally, I would not want to risk infection with a non-irradiated allograft. In addition to superior stability and reduced graft rupture rates, single-legged hop tests and general satisfaction is higher in autografts than allografts (Kraeutler 2013).
The Quad tendon autograft is producing similar results to the patellar tendon autograft with less donor site morbidity (Mulford 2013). Biomechanical studies demonstrate that the residual strength of the quad tendon after graft harvest is higher than that of the intact patellar tendon, which suggests that extensor mechanism strength is less compromised (Kim 2009).
Rupture rate is dependent on age and graft type. Allografts are 4x more likely to rupture and patients younger than 25 are more likely to require revisions (Kaeding 2011); however, if the allograft was not irradiated, the re rupture rate is the same between allografts and autografts in people younger than 25 (Barber 2014). The MOON group puts age and graft type in perspective (Kaeding 2011):
A 14-year-old with an allograft ACL has a 22.0% chance of retearing the ACL; the same 14-year-old with an autograft ACL has a 6.6% chance of retear.
A 40-year-old with an autograft ACL has a 0.6% chance of retear; the same 40-year-old with an allograft ACL has a 2.6% chance of retear.
Even in people over 40, allografts are not necessarily a better choice than autograft and patients should be offered both (Barrett 2005). It is important to discuss a person’s activity level and desire to continue the same activity level. I want to continue skiing, playing softball, and doing workouts that include plyometrics and sometimes cutting. I am happy to see that outcomes in people over 50 are similar to those younger than 30 years of age (Cinque 2017). I am less happy to see “aging athlete” in a google search for ACL at 40.
It is important to emphasize graft types are not the only factor that effect long term functional outcomes. Finding a surgeon that does a high volume of ACLR per year, tunnel placement, rehabilitation and patient compliance are all important. Physios can attest to the importance of the rehabilitation and even more so, proper clearance and functional testing prior to returning to sports. My graft choice may ultimately not make a dent in the big picture. It is a personal choice and unique to the person when you take into account sport and activity level, gender, and past history.
I am going with my first thought when I ruptured (pardon the F bomb, I was clearly upset):
My ACL reconstruction with quad tendon autograft is scheduled 2/6/2018…
Barber FA, Cowden CH, Sanders EJ. Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger. Arthroscopy. 2014 Apr;30(4):483-91.
Barrett G, Stokes D, White M.. Anterior cruciate ligament reconstruction in patients older than 40: allograft versus autograft patellar tendon. Am J Sports Med. 2005 Oct;33(10):1505-12.
Carofino B, Fulkerson J. Medial hamstring tendon regeneration following harvest for anterior cruciate ligament reconstruction: fact, myth and clinical implication. Arthroscopy. 2005;21(10):1257-1264.
Cinque ME, Chahla J, Moatshe G et al. Outcomes and complication rates after primary anterior cruciate ligament reconstruction are similar in younger and older patients. Orthop J Sports Med. 2017 Oct 2;5(10)
Grassi A, Nitri M, Moulton SG. Does the type of graft affect the outcome of revision anterior cruciate ligament reconstruction” A meta-anaysis of 32 studies. Bone Joint J. 2017 Jun;99-B(6):714-723
Kaeding C, Aros B, Pedroza A, Pifel E, Amendola A. Allograft Versus Autograft Anterior Cruciate Ligament Reconstruction: Predictors of Failure From a MOON Prospective Longitudinal Cohort. Sports Health. 2011 Jan;3(1):73-81.
Kim SJ, Kumar P, Oh KS. Anterior cruciate ligament reconstruction: autogenous quadriceps tendon-bone compared with bone-patellar tendon-bone grafts at 2-year follow-up. Arthroscopy. 2009 Feb; 25(2):137-44.
Kraeutler MJ, Brayman JT, McCarty EC. Bone-patellar tendon-bone autograft versus allograft in outcomes of anterior cruciate ligament reconstruction: a meta-analysis of 5182 patients. Am J Sports Med. 2013 Oct;41(10):2439-48.
Mulford JS, Hutchinson SE, Hang JR. Outcomes for primary anterior cruciate reconstruction with the quadriceps autograft: a systematic review. Knee Surg Sports Traumatol Arthosc. 2013 Aug;21(8):1882-8.
Poehling GG, Curl WW, Lee CA, et al. Analysis of outcomes of anterior cruciate ligament repair with 5-year follow-up: allograft versus autograft. Arthroscopy. 2005;21(7):774-785.
Schuette H, Krauetler M, Houck B et al. Bone patellar tendon bone versus hamstring tendon autografts for primary anterior cruciate ligament reconstruction: a systematic review of overlapping meta-analyses. Orthop J Sports Med. 2017 Nov;5(11).
Xergia S, McClelland J, Kvist J et al. The influence of graft choice on isokinetic muscle strength 4-24 months after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatology Arthrosc; 2011;19:768-780.
Xie X, Liu X, Chen Z, et al. A meta-analysis of bone-patellar tendon-bone autograft versus four-strand hamstring tendon autograft for anterior cruciate ligament reconstruction. The Knee. 2015;22:100-110.