Page 24 - ISAKOS 2019 Newsletter Volume 1

CURRENT CONCEPTS
Is There a Role for Primary ACL Repair and Biologics?
BMAC is clot activated with use of batroxobin enzyme to create a malleable gel and is applied arthroscopically to the repair site.
Summary
ACL reconstruction with use of either autogenous or allograft tissue is the accepted standard of care for most cases of symptomatic knee instability resulting from ACL insufficiency. ACL repair has been considered to be prone to failure, and there has been limited recent research into repair techniques, particularly with regard to certain injury patterns. There is renewed interest in treating properly indicated lesions with repair techniques that may better restore normal joint kinematics.
01 Arthroscopic images showing primary repair of an ACL injury.
As these techniques progress and appropriate injury patterns for such treatment are better delineated, it is possible that surgical options for ACL injuries will evolve.
References
1. Caplan AI, Correa D. The MSC: an injury drugstore. Cell Stem Cell, vol. 9, no. 1, pp. 11–15, 2011. 2. Steadman JR, Cameron-Donaldson ML, Briggs KK, Rodkey WG. A minimally invasive technique (“healing response”) to treat proximal ACL injuries in skeletally immature athletes. J Knee Surg. 2006;19(1):8-13. 3. Steadman JR, Matheny LM, Briggs KK, Rodkey WG, Carreira DS. Outcomes following healing response in older, active patients: a primary anterior cruciate ligament repair technique. J Knee Surg. 2012;25(3):255-260. 4. Gobbi A, Bathan L, Boldrini L. Primary repair combined with bone marrow stimulation in acute anterior cruciate ligament lesions: results in a group of athletes. Am J Sports Med. 2009;37(3):571-578. 5. Gobbi A, Karnatzikos G, Sankineani SR, Petrera M. Biological Augmentation of Acl Refixation in Partial Lesions in a Group of Athletes: Results at the 5-year Follow-up. Tech Orthop. 2013 Jun 1;28(2):180-4.
01A No. 1 PDS suture is used to reapproximate the
disrupted proximal and distal bundle tissue.
01B An awl is used to create several perforations of
the lateral intercondylar notch about the anatomic footprint of the ACL to release marrow elements.
01C Activated bone marrow aspirate concentrate
(BMAC) gel is applied to the repair site under dry arthroscopy.
01D Second-look arthroscopy at 6 months after
primary ACL repair and biologic augmentation, demonstrating a healed ACL.
Commentary
This paper on primary ACL repair with biologic augmentation is of value to look at an older concept and see if it should be revisited. The initial work on primary repair by Feagin noted a high failure rate at 5 years. John Marshall attempted to improve this and noted a positive pivot shift in almost 40% of patients. As our surgical skills and techniques have improved, there is renewed interest in ACL repair. Gobbi et al. have added biologics to the suturing technique to aid healing. While this may help in theory, there is presently no proof of the value of biologics in this environment. The addition of stem cells from the iliac crest (BMAC) may be helpful, but it remains uncertain. It would also be helpful to know the number of stem cells present. In addition, some investigators believe that the peri-vascular stem cells required to promote healing are specific for each tissue.
The technique described by Gobbi et al. in this paper appears to be for mid-substance tears. If a repair was attempted, it may be better to work with avulsions. In Gobbi’s paper in 2009, only patients with partial proximal tears were included. In this article, mid-substance tears were included.
Steadman’s work of creating a healing response with microfracture is noted, but most of his cases were older skiers with proximal avulsions, which in our experience can heal without surgery in some patients. I have treated a number of these non-operatively with rehabilitation and a follow up MRI in some has demonstrated good healing. In considering primary repair, the site of injury is important since mid-substance tears have injury throughout, while proximal avulsion may be more localized and possibly better candidates for repair in some patients. I have tried this recently with anchors and sutures in some older patients with proximal ACL tears. I have also done this suture repair for some PCL avulsions over the years. With mid-substance ACL tears, a reconstruction is more likely to be successful, as re-tensioning the injured tissue will be difficult and I believe they will tend to fail.
Overall, I have the impression that some healing after repair for partial tears or avulsions may occur and be of value. However, in my opinion, such cases are rare and reconstruction will more predictably result in a stable knee, particularly for competitive athletes with mid-substance tears.
Russell F. Warren, MD
Hospital for Special Surgery New York, UNITED STATES
22 ISAKOS NEWSLETTER 2019: VOLUME I