Healing by first intention always accompanies a near 20-30% reduction in tensile strength of the wound, and never improves beyond 80% of normal. This is canon. His knee will not be structurally stronger, because the structure of the tissue is the connective tissue, which is now weaker than prior to the injury. The ligament, when reattached, will be weaker than prior with a fibrous scar. The scar tissue will be tough, but neither the attachment point or the wound, after healing, will ever regain 100% strength. A graft is never as strong as prior to the injury. Ever.
According to the surgeons that I have assisted, the structure is stronger. After 20 years in the surgical field, I will side with their knowledge.
Then you should question their meaning. A fence post reinforced with steel is indeed stronger, but if the entire fence is more likely to fall over than a fence that never needed reinforcement, it is not structurally stronger. If you worked in in the medical field for 20 years, you know docs speak in specifics. Your orthopod likely meant that the new ligament was stronger, due to shortening or addition, than a biologically created ligament. This is true. A piece of wood reinforced with steel is stronger than just wood. But the knee is not actually overall "stronger" in that it would be less prone to injury than the non-affected knee. This is why prevention of a ACL tear is more important than just reconstruction, because the knee is at risk for re-injury, post-op chronic pain and osteoarthritis. I get what you are saying, a reinforced ligament is stronger as a solitary component than a non-reinforced ligament. But taking everything as a whole, the affected knee is at risk for re-injury more so than if the knee was never injured, which is what I am referring to.
As far as the ACL goes, the ligament is stronger. Some studies have tested patellar tendon graft strength vs an uninjured ACL. The patellar graft tested out at over 4300 Newtons vs 1750 Newtons for an uninjured ACL. Now, there is a higher risk of reinjuring the knee until a proper healing time has been allowed especially with autograft(patient's own bone/graft) from a patellar graft harvesting. There is slightly increased morbidity(pain) at the donor site. This pain is why surgeons went away from harvesting iliac crest bone graft for anterior cervical spine fusions even though your own bone is considered the "gold standard" of all grafts. Good discussion.
Newtons? What the hell does a snack cake/cookie have to do with a torn ACL? Heard the little bastards were good bait for moles, though.
Again, the graft is going to test out a higher tensile strength just by nature of the addition and the tissue grafted. Just for analogy, if you super-glue an area of metal around or on top of a splintered wood post, the area reinforced is now stronger and more capable of withstanding force than bare wood alone. But, the reinforced area is only as strong as the super-glue, not the metal. Further, the risk of re-injury decreases with healing time, but the lifetime risk is still higher. The ligament itself, depending on the type of correction used, might even develop cross-striations of connective tissue, rather than vertical, and it may also be weaker with an increased risk of re-injury. If he was grafted, which type? Ligament, or tendon? Was he stapled, sutured or screwed? At the cellular level, the knee is weaker with an increased risk of injury. Medicine is good, but nature is better. That injured knee will always be his bad knee. If reconstruction was better than nature, it would just be a recommended cosmetic surgery for all athletes prior to play. Is this the case? Think about why it isn't.
The most obvious reason is that there is not an endless supply of grafts. Why risk the potential to have some kind of post operative complication? Would you change your car's engine just because there was potentially better one out there? Of course not. The same would apply here. Within 2-3 months, the bone will have grown into the harvested bone from a patellar graft. The screws are placed to provide support until the graft has fully ingrown. This is the most common technique used in athletes. In some cases, the screws are bioresorbable.
There is a rather endless supply of grafts. You run the risk of a graft vs host response, but allograft from cadeaver donations have been previously used. If you are autografting, there are numerous tendons and other ligaments used. You have a very minimal post operative complications, and a high percentage rate of success. You already risk the potential for complication when undergoing the surgery, but you believe it will have benefit, so you do it anyway. If it was a true and absolute benefit, it would be common and not solely post-injury. And, as to your car engine idea: Yea, if I was a NASCAR driver, I absolutely would. And this is what we are talking about, finely tuned athletes with a multi-million dollar future and a lot on the line. If my car was used in races, and had the same on the line, you bet your ass I would upgrade my engine, and so would you. That is an equal comparison, not yours. So, you have a surgery with high success, very few complications, very little risk for complication, lessened by use of auto not allograft tissue, that, supposedly, allows for a stronger knee... with millions of dollars on the line. So, why isn't it more often preventive rather than not?
Justin Hunter is flattered by all the attention his knee is getting. Quick, someone please start a JustinHunter'sKnee twitter handle to answer life's most burning question. Where is Jimmy Hoffa buried? Whatever happened to Chris O'Donnell's career? Will black jersey's and vapors make one run faster? Seriously though, I am learning something here. Carry on medical dudes.
I would disagree on the endless supply of allografts. You'd be amazed at how many get rejected based upon disqualifying conditions. Sure, hospitals can get them, but there definitely isn't an endless supply. With allograft(donor) tissues, there is a risk of the person's immune system attacking that graft and treating as a foreign material. Sure, there are other autograft(patient's own) sites that can be taken, but are slightly more unpredictable as far as results go. Plus, a multi-million dollar athlete will not miss a year or possibly two for the procedure that does have a risk of complication(all surgeries do, no matter how routine) that could prevent them from ever playing again. Sure, in Nascar, where money seems to grow on trees, switch the engine. The car doesn't have to worry about an infection.
You aren't having to HLA match for an infinite amount of people. There are a finite number of multi-million dollar athletes, and athletes with multi-million dollar potential that run the risk of a torn ACL. All surgeries have complications, and yet there are still preventative and cosmetic surgeries done on a quite regular basis, as you no doubt know. This is risk vs reward. When the reward (a non-career ending injury costing you in excess of tens of millions of dollars) outweighs the risk (what, about 8% for unsuccessful?), I'd say if it made a stronger more durable knee, it would be done with rather increasing frequency. In medicine, it is easy to worry about the future of the patient, the problem is that patients don't, and yet nobody is banging down the door to get their ACL reinforced. You aren't running a risk of serious sequela for the procedure, and you know it. How many ACL surgeries are not done because you are worried about risking a staph infection? None. If I had a nickel for every surgeon that was worried that we might cause a shift in VRSA, I'd have as many nickels in my pocket as I do right now. Zero. If you have all the risk factors for breast cancer, you might be recommended a mastectomy. If you have FAP, a colectomy. If you have a lot of recurrent sinus infections, you get your adenoids removed. Yet, all the risk factors for an ACL tear that will give you the benefit of "super knees," no preventative surgery. Adding to is more difficult than taking away, for sure, but with an 92% success rate... not really that much more difficult.
Even if the knee is stronger, it can be re-injured, super or not. It is also true that many elective surgeries are done with the risk vs reward, I would bet 99% are not high performance athletes. You are correct that surgeons treat VRSA and MRSA as an afterthought, they still think about it to a degree, just not to the level of cancelling the procedure. Just because the surgery has a very high success rate, doesn't mean that a complication can't happen. Take me for example, I had a surgery with 97% success rate(and eventually it did heal) however, I was one of the unlucky ones that had a post op infection and IV antibiotics twice a day for 6 weeks. Even if you have a superknee, it could be blown out again.
There will always be complications, but like everyone else, you chose to have your procedure because the risk of complication is low compared to the events that might occur from not having the procedure. All are done with the intent to improve the future. There will always be complications, but again, patients generally do not worry with them, and beyond ensuring that the patient makes an informed decision, the provider typically does not worry, either. Typically; there are exceptions, of course. But if the procedure is deemed necessary, possible complications rarely affect the decision to proceed. My question, or rather disagreement, was not that the knee would be re-injured, super or otherwise. My question/disagreement was whether it would be more likely to be re-injured at a higher rate than a knee that was never injured. If studies have shown that there is no increased risk of injury compared to the natural, then sure, we conclude that the knee is stronger, or at least equal in strength, due to the procedure. Otherwise, I see no way to claim the knee is structurally stronger. Any studies on such a question that you are aware of? I imagine there are plenty comparing various techniques, but are you are aware of any that measure outcome (injury) directly based on never injured knee vs knee with technique x?
I think I maybe get what y'all are talking about, but I'm going to ask you to explain this to me like I'm a 7 year old. I'll start by answering my own questions, and these will lead into questions for you: (1) What is the ACL? The ACL is a tissue band that connects the thighbone to the shinbone. (2) Okay, so it sounds like there are two possible ways that an ACL could be injured. The tissue band could either snap in half. Or the tissue band could remain intact but become unattached to one of the bones. Which one of these usually happens? The former. The tissue band tears in half. (3) How is this injury fixed? Does the tissue band that was torn grow back together? You know, like what happens when you break a bone? Actually not. This used to be the way they would fix it, but it didn't work very well. What works much better is to basically take that torn ACL, throw it in the trash, take a tissue from a different part of the body, and then attach that tissue band to the shinbone and thighbone as the ACL was previously attached. (4) So when these guys keep arguing about whether the knee is structurally stronger, couldn't they be referring to two different things? Yes, two questions come into play: (1) is the replacement tissue band as good a tissue band as the original ACL?, and (2) when they attach this tissue band to the bones, is that attachment as strongly attached as was the original ACL? Now, I need y'all's help. I that when Volguy says the knee is stronger, he is referring to the tissue itself. More than likely the replacement tissue band is the patellar tendon, which is -- from what I understand -- actually a stronger tissue band than the original ACL. Do we agree on this? I think that when fL0at_ says that the knee will never be stronger, he is referring to the connection to the thighbone and the shinbone. I think he is saying that even if the replacement tissue band is strong, the knee is still not as good structurally because the connections to the bone will never ever be as good as they were originally. Did I get that right? If I did get that right, then only one question remains: which of the following two events has a greater chance of occurring: (a) the original tissue band snapping in half (like with Justin Hunter), or (b) the replacement tissue band becoming disconnected from either the thighbone or the shinbone. If the answer is (a), then for all practical purposes Volguy is correct. If the answer is (b) then float is correct. You see why it is important to frame the question this way? The important question isn't whether the knee is more structurally sound as a whole. If the tissue band rarely, if ever, becomes disconnected from the bone, then it isn't a huge deal if it that connection is 10% weaker. The important question is: are the things that normally go wrong with knees more or less likely to go wrong after the operation and rehabilitation. Gentlemen, you have the floor. I simply ask that you stay within my simplistic framework, so that more people can follow along in the conversation. Including me.
This is from one of the studies that has been done on post-op follow up after ACL repair. This study used the patellar tendon autograft technique. The injury rate to the ACL-reconstructed knee within five years after surgery for patients younger than 18 was 8.7%, but the re-injury rate dropped significantly to 2.6% for patients 18-25 years of age and to 1.1% for patients above the age of 25. Of note is that the ACL injury rate to the opposite knee was 8.7% for patients younger than 18, 4.0% for patients 18-25 years old, and 2.8% for patients older than 25. Overall, the incidence of subsequent injuries was lower for the ACL-reconstructed knee (4.3%) compared to the opposite knee (5.3%). *published in the American Journal of Sports Medicine in 2009. This supports my previous statement that structurally, the knee should be stronger. 25% of the patients in this study participated in intercollegiate athletics. All of the patients were participants in high school athletics at a competitive level.
