ACL Preservation


A PRESERVATION FIRST approach is a great solution for anyone who has sustained a tear to his or her Anterior Cruciate Ligament (ACL). An ACL injury is one of the worst traumas an athlete can face due to its extensive downtime and labor-intensive physical therapy, but now, getting back into the game may be closer than you think. Today, with his Preservation First approach, Dr. DiFelice addresses ACL injuries with the understanding that every tear is unique, and therefore, should not be treated with a ‘one size fits all’ solution.

The standard of care for a torn ACL is to reconstruct, or replace the ligament with a graft. In essence, to trick the body into making a new ACL out of scar tissue that uses the graft as scaffolding. One issue with this approach is that it sacrifices all of the native ACL tissue and uses the biggest surgery, with the longest recovery, for every type of ACL injury. My Preservation First approach focuses on just that: preserving tissues if possible, before replacing them. My preference, if possible, is to simply repair the ones where the ligament is only detached from the bone (the small surgery). Next, I will augment the ones that are only partially repairable (the medium surgery) and finally, I will reconstruct the ones that are not repairable (the large surgery). This approach allows me to take into account the intricate nuances of each patient, including age, activity level, tear pattern, tissue quality and level of injury. In my practice, over the last 5 years or so, I have repaired close to 50% of the operative ACL injuries that came to me, I Repaired and Augmented approximately 25% of the injuries, and I Reconstructed roughly 25% of the injuries. (Please realize, that my numbers are somewhat skewed because many people come to me to have their ACL repaired and thus my percentage of repairs is much higher than the average ACL surgeon might be.) Nonetheless, the benefits of this approach are that for 75% of my patients, I am able to save all or some of the native ACL tissue (“their original parts”), which gives patients a faster recovery, fewer complications, and a reportedly more normal feeling knee. My research team and I have documented all of these findings and published them in peer reviewed journals. Please refer to our research page if you are interested in digging into the papers.


Many are worried that the risks of my “newer” procedure are worse than those of the more traditional reconstruction procedure. Taken as a whole, this is not true. The repair procedure is much less invasive than the reconstruction procedure and therefore has fewer steps that can go wrong. The main risk that is slightly higher for repair is the possibility of reinjury. Early studies on repair show that the “failure” rate of the procedure is somewhat higher than for Reconstruction.  However, this requires a bit of explanation. If you just look at the surface of the early reports on ACL Repair techniques, it appears that ACL Repair has a rough “failure” rate of 10-15% (mine is 11%) versus 5-8% for ACL Reconstruction. However, these are early reports and do not take into account the age and activity levels of the patients in each group, nor the type of ACL Reconstruction that was performed with regards to technique and graft selection. For example, with both ACL Repair and ACL Reconstruction, the failure rates are much higher in the patients under 21 years of age and lower for those over 21 years of age. As time goes on both the indications for ACL Repair, and the techniques to perform it, have improved and will continue to improve (just as they have for Reconstruction) and the “failure” rates will continue to decrease. Our research has also shown that complications such as tearing the ACL of the opposite knee, infections, stiffness, pain and persistent awareness of the knee all seem to be less with the ACL Repair procedure. In addition, we have shown that early of recovery of range of motion (ROM) and regaining of full ROM is faster with the Repair approach.

What If This Approach Fails?

Another major benefit of this approach is that if reinjury occurs and the repair does happen to fail, it can be rather easily converted to an ACL Reconstruction. Now this is not to say that I take such things lightly. My goal is to have NO failures, but that is not possible with Repair nor Reconstruction because people go back to being active which is why they tore their ACL in the first place. The Repair procedure is accomplished via a few small poke hole incision using a few sutures and a few small anchors, and thus little damage is done to the normal anatomy in accomplishing the Repair. Therefore, if the Repair happens to fail, then the subsequent ACL Reconstruction is more analogous to doing a primary surgery rather than a revision surgery. If a Reconstruction fails and the patient has to undergo a revision Reconstruction, this is a much trickier situation due to the complexity of the initial Reconstruction. This is why revision Reconstruction patients typically do not do as well as primary Reconstruction patients. Specific to this topic, we have published on a small group of 6 patients who underwent Reconstruction after reinjuring their Repair, and found that their experience was analogous to having a primary Reconstruction and not a revision.

What Are The Long-Term Outcomes?

I performed my first ACL Repair procedure in 2008 and the patient continues to be extremely active and his knee does not bother him at all. In the first 5 years of performing this procedure, I went slowly and very cautiously. It took me 5 years to collect 20 patients. We had only 1 patient out of the first 11 experience a reinjury and that was 2 months or so after surgery. Now with follow-up on this group well past 5 years, no one else has had a reinjury, and the patients continue to do well. We have also reported on the first 56 patients out past 2 year follow-up and the reinjury rate is right around 10%. Our next paper on the first 113 patients has been submitted for publication and the failure rate hasn’t changed. However, we now have enough patients that we were able to break them down by age group and we noted that the majority of our reinjuries have occurred in patients <21 years of age. With this in mind, I have adjusted the indications and techniques in this age group. It was also found that for those patients >22 years of age, the failure rate is <5% (age 22-35, 4%; age >35, 3%). Regarding long term follow-up (decades), I cannot provide that data yet.  However, we can learn from the experience of the original ACL repairs that were done via open incisions, for all types of tears, and who were placed in a cast post-op for 2 months. These were done in the 70’s and 80’s, and failure rates were unacceptably high which is why surgeons switched to ACL Reconstruction. Although the early reports showed a higher failure rate with open Repair vs Reconstruction, this was likely because they were trying to stitch together midsubstance tears (let’s keep it simple: think of a horse tail, if I cut in the middle you wouldn’t be able to stitch it together, but if I cut it off his rump then you could still, in essence, “pin the tail on the donkey”). The 30-year follow-up studies showed clearly that the repairs that did well early, continued to do well thirty years later, and in hindsight, we have shown that these were the patients who had proximal, detachment type tear patterns that were amenable to repair. In other words, even back when they did the surgery open, they were able to “fix” the ones that were “fixable.”

Take-Home Message

With modern day imaging, surgical technology, and rehabilitation, it is now possible that patients who have torn their ACL have multiple less invasive surgical options to restore the stability of their knee and get them back in the game. I have been using and improving my Preservation First approach for over a decade and well over 300 patients have undergone my ACL Repair surgery. While there is a natural tendency for people to go with the “tried and true” way of doing things, it seems clear from the research, that ACL Preservation is a safe and effective option for many patients. My goal is to do the smallest surgery to give you the easiest recovery and the best and most durable knee possible using my Preservation First approach. Please contact my office to determine if you are a candidate.

What Research is Available for Me to Learn More?

Most of my research involves ligament preservation. To date, my team and I have published over 30 peer reviewed articles and 5 book chapters, on topics related to ACL Preservation and/or Ligament Preservation in general. We have freely disseminated the concept, the techniques, and the outcomes of my patients in the hope that surgeons across the world will be inspired by my experience and hopefully improve on the techniques and indications to help future generations of people who have the unfortunate experience of tearing their ACL. A listing of my articles can be found under “Meet Dr. DiFelice.”