July 18, 2016 - Dr. David Chao
Monday Morning MD: Aaron Rodgers and the truth about ACLs
The Packers superstar made news with his comments about his 2004 anterior cruciate ligament (ACL) surgery. One of the NFL’s best and most athletic quarterbacks attributed some of his success to his cadaver donor being a “fast SOB” as he shaved almost 3/10ths of a second off his 40-yard dash time after surgery. Known to have a unique sense of humor that even fools teammates, Rodgers comments were surely made tongue-in-cheek. It wouldn’t be the first time a player was kidding the media as Danny Trevathan joked about having someone else’s kneecap last year. In any case, Rodger’s quotes give us a good chance to separate the realities from the myths of ACL surgery. Was Rodgers’ cadaver donor a “fast SOB”? There would be no clear way for Rodgers to know whom the donor was. The only cadaver information typically available to the surgeon is the age, sex, cause of death and dimensions of the graft. Upon expiration, donors are screened for diseases before being deemed viable for tissue harvesting. There is no direct tissue typing or matching to the recipient. Details of the donor’s life, ethnicity, occupation or athleticism are not considered or available. In fact, Rodgers ACL graft donor could have been female. Could someone else’s ACL make you faster post surgery? No way the graft itself makes anyone faster. First, the actual ACL from a cadaver is never directly harvested for use due to size and geometry limitations. Commonly, the patellar tendon (with two attached bone blocks), Achilles tendon (with bone on one side) or all soft tissue grafts (like posterior tibialis tendon) are used. Second, the ACL functionally can’t make one faster. It serves to stabilize the femur to the tibia and thus actually could be said to “slow’ the knee down to prevent shifting. Is it feasible to decrease one’s 40-yard dash time after ACL surgery? Rodgers said he was a 4.95 (40-yard dash) guy and then ran 4.66 after ACL surgery. Yes, ACL rehab can make someone faster/quicker if the athlete was not performing maximally prior to injury. A fully trained athlete can’t be made faster; however, a sub-optimally functioning player can be helped. In fact it is possible for an uninjured player to go thru ACL rehab style training and have performance improve. I personally witnessed Philip Rivers become a better athlete after ACL surgery in 2008. I wish I could take credit for his increased speed/mobility but it was a result of his hard work with top Chargers athletic trainers. Rodgers is downplaying his own dedication to rehab post-surgery here. How is it possible to play football for multiple years without an ACL? Playing through an ACL tear is possible in certain circumstances. Rodgers played high school, junior college and into his time at Cal with a torn ACL. Rivers played in the 2008 AFC Championship Game six days after arthroscopic surgery with a torn ACL. The ACL is like an internal seat belt for the knee. Just like it is possible to drive a car with the seat belt broken, one can function without the ACL. However, when racing NASCAR, your seat belt better be working, just like your ACL is needed for the aggressive running/jumping/cutting of football. Without an ACL it is playing “Russian roulette” with your knee as there can be permanent cartilage damage if the knee gives out.. Rodgers was able to play through with a brace at lower levels of competition. Rightfully, his ACL surgery was done before exiting college and advancing to the NFL. Is cadaver the best ACL graft like Rodgers recommends? Certainly, the cadaver ACL worked for Rodgers. However, that would not be my (or most NFL physicians’) first recommendation. Fortunately, disease transmission risk with cadaver grafts is small. Even so, autograft (own tissue) patellar tendon with bone on each end is the most popular graft choice in the NFL. Bone-tendon-bone (BTB) graft is the strongest and most likely to succeed. Cadaver can work but has the higher re-tear rate over hamstring and BTB autografts. Using cadaver leads to less post-operative soreness and makes for a quicker recovery but may not be worth the significant (up to 30% per the ACL Study Group) re-tear rate. The cadaver failure rates are highest for younger and more active patients. Remember, missing a second consecutive season likely means the end of an athlete’s career. Why is cadaver a potentially weaker graft choice? All ACL grafts are scaffolds for one’s own tissue to grow into. Logic would tell you that your own tissue grows best into your own tissue versus someone else’s. A graft that does not incorporate and ligamentize is doomed to failure. There is no true rejection, as that is an immunologic response and cadaver patients don’t need to take special medications like organ transplant patients. Perhaps when technology arrives to tissue type and match to donor to recipient, cadaver failure rates will improve. Can the ACL be stronger after surgery? After one year of recovery, my patients are twice as likely to tear the other knee ACL versus re-tearing the reconstructed ACL. This is why I recommend bracing during the first year with early return to sport. The new ACL is not truly stronger, just lower re-tear risk. No, I would not recommend prophylactic ACL surgery. Has ACL recovery gotten faster? It sure seems that way. Rehab techniques have improved but there is no way to speed up biology. The media with Adrian Peterson’s nine-month return to rush for 2000 yards makes it seem like early return is something new but ACL recovery has been getting faster for over a decade. Shannon McMillian returned to play international soccer 102 days after her ACL surgery and at four months played in the 2003 Women’s World Cup for USA. What is best thing to do for an ACL tear? Pick a surgeon you trust and not the specific technique or graft choice. There are many ACL techniques (open, double incision, single incision, medial portal technique, all-inside) and many autograft (BTB, hamstring, quad tendon, contralateral) or allograft (BTB, Achilles, posterior tib) options. Let the chef tell you what he cooks well and the best meal to order. Let the surgeon tell you the procedure he is most comfortable with and what is best for you. Don’t make a surgeon who recommends cadaver harvest a hamstring graft. In other words, when you go to Morton’s get the steak. If you want fish, go to Oceanaire. Trust the recommendation or choose a different restaurant or surgeon. Overall the joke is on us to take Rodgers comments so literally. It is very nice of Rodgers to thank and credit his ACL donor. At least this gave us a chance to discuss some of the fact and fiction about ACL surgery and recovery.