ACL Preservation

Q:Dr. DiFelice, with your recent release of the technique manual, ACL Primary Repair, it seems that you are challenging the current treatment standard of reconstruction for ACL rupture.  Do you think that arthroscopic ACL preservation will become the new standard of treatment?
 
A:Not at all. The procedure that I have described is an arthroscopic method of reattaching the ACL back to its native origin or insertion using suture anchors. It is really only applicable to avulsion or "peel off" type tears and will never become the standard of care for ACL tears, in general, since the majority of them are mid-substance tears that is not effective for this technique. However, it is a nice tool to have in your surgical toolbox.
 
Q:Isn’t there a lot of historic experience regarding ACL repair that led us to migrate our treatment towards reconstruction? Aren't you just repeating history here?
 
A: I would certainly like to think not. The historic treatment of ACL repair was done as an open procedure and the studies looking at outcomes were significantly limited by the techniques, and knowledge base of the time. Looking back, the studies had significant bias that limited the conclusions that could be drawn. The paper considered to be the landmark paper on ACL repair at the time, by Mark Sherman et al (1), was the only one to analyze subgroups, and suggested that proximal tears with excellent tissue quality had a much better chance of positive outcomes. This is the group that I have focused on.
 
Q:How do you perform the procedure?
 
A: I liken the procedure to performing a rotator cuff repair in the knee. In fact, this is how I came up with it. I do a lot of shoulder work and thus, I simply migrated the shoulder instrumentation to use in the knee.  I use a Scorpion FastPass to pass a locking Bunnell type stitch of #2 FiberWire into each bundle of the ACL. Then, I retension the bundles to their respective origins using 4.75 BioComposite Vented SwiveLock.
 
Q:You recently reported your early results at the International ACL Study Group meeting in South Africa. Can you share a little about your experiences, thus far?
 
A: To date, I have performed this procedure on 32 patients. Follow-up is from one week to six years. In South Africa, I presented on my first 15 patients with an average of 24 months follow-up. To my knowledge, this is the first ever report of arthroscopic ACL preservation for complete ACL tears performed on human beings. I had one early failure in a noncompliant patient, and one patient who was stable at three months, but lost to follow-up, thereafter. Everyone else is stable and functioning well with outcome scores in the 90s. There have been no other failures in the larger group to date, although follow-up is shorter.
 
Q: Your experiences would suggest this is a promising technique. What are your thoughts looking forward?
 
A: Caution must be used in interpreting the data thus far. This is a small, retrospective series with short-term follow-up. However, the data is promising. The technique, although limited by injury pattern, makes sense from a biologic standpoint and opens the door to a new way of thinking about the ligament remnant. Hopefully, it will provide a spark to ignite a new body of research with a more biologic focus to our treatment of ACL injuries.  

1. Sherman MF, Lieber L, Bonamo JR, Podesta L, Reiter I. The long-term followup of primary anterior cruciate ligament repair. Defining a rationale for augmentation. Am J Sports Med. 1991; 19(3): 243-255.