Biological internal bracing with remnant repair allows the “best of both worlds” for subacute ACL femoral avulsions

We thank the authors of the letter ‘Anterior cruciate ligament primary repair is a valid treatment option for proximal tears with good to excellent tissue quality in the acute, sub-acute and delayed setting.’ for their interest in our video article and for giving us an opportunity to further discuss this contentious topic. The authors have offered constructive recommendations based on their experience with ACL preservation, and have discussed their reasons for propagating repair in all proximal anterior cruciate ligament (ACL) tears with good tissue quality irrespective of duration of injury. Our video article which focuses on surgical technique [1Pardiwala D.N. Lee D. Arthroscopic biological internal bracing with remnant repair for subacute ACL femoral avulsions.J ISAKOS. 2023; 8: 54-56Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar] with a limit of 1000 words and 10 references could not acknowledge previous publications that advocate a “preservation first approach”. Authors have previously described combined repair with augmentation for ACL proximal tears, however, these techniques focus on synthetic augmentation with sutures and tapes [2MacKay G. Anthony I.C. Jenkins P.J. Blyth M. Anterior cruciate ligament repair revisited. Prelimnary results of primary repair with internal brace ligament augmentation: A case series.Orthop Muscular Syst. 2015; 4: 188Google Scholar,3Smith J.O. Yasen S.K. Palmer H.C. Lord B.R. Britton E.M. Wilson A.J. Paediatric ACL repair reinforced with temporary internal bracing.Knee Surg Sports Traumatol Arthrosc. 2016; 24: 1845-1851Crossref PubMed Scopus (73) Google Scholar,4Gipsman A.M. Trasolini N. Hatch 3rd, G.F.R. Primary anterior cruciate ligament single-bundle repair with augmentation for a partial anterior cruciate ligament tear.Arthrosc Tech. 2018; 7: e367-e372Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar], bundle specific reconstructions for partial ACL tears [5van der List J.P. DiFelice G.S. Preservation of the anterior cruciate ligament: surgical techniques.Am J Orthop (Belle Mead NJ). 2016; 45: E406-E414PubMed Google Scholar], or remnant sparing ACL reconstruction techniques [6Sonnery-Cottet B. Freychet B. Murphy C.G. Pupim B.H. Thaunat M. Anterior Cruciate Ligament Reconstruction and Preservation: The Single-Anteromedial Bundle Biological Augmentation (SAMBBA) Technique.Arthrosc Tech. 2014 Nov 24; 3 (PMID: 25685675; PMCID: PMC4314548): e689-e693https://doi.org/10.1016/j.eats.2014.08.007Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar,7Takazawa Y. Ikeda H. Kawasaki T. et al.ACL reconstruction preserving the ACL remnant achieves good clinical outcomes and can reduce subsequent graft reruptures.Orthop J Sports Med. 2013; 12325967113505076https://doi.org/10.1177/2325967113505076Crossref Scopus (49) Google Scholar,8Jung Y.B. Jung H.J. Siti H.T. et al.Comparison of anterior cruciate ligament reconstruction with preservation only versus remnant tensioning technique.Arthroscopy. 2011; 27: 1252-1258Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar]. The technique described in our video article is a modification of previously described techniques in that the augmentation is biological and it is indicated for complete ACL avulsions (Sherman Type 1 and 2 tears). The graft for biological internal bracing should be large enough to ‘reconstruct’ the ACL; but not so large that it disrupts the anterior tibial insertion, or occupies the entire femoral footprint in Type I avulsions (where remnant healing to femoral footprint is desired), or causes notch impingement. The different methods we use to repair the ACL depend on the type of ACL avulsion and stability of the remnant ACL stump, and are discussed in detail in our article. In each technique, the focus is to preserve the unique fan shaped tibial insertion of ACL which is not possible to recreate using present reconstruction techniques. The optimal timing for surgery following an acute ACL tear is a topic of controversy. Following Shelbourne’s landmark studies that reported an increased risk of arthrofibrosis in acutely reconstructed ACL tears [9Shelbourne K.D. Wilckens J.H. Mollabashy A. DeCarlo M. Arthrofibrosis in acute anterior cruciate ligament reconstruction: the effect of timing of reconstruction and rehabilitation.Am J Sports Med. 1991; 19: 332-336Crossref PubMed Google Scholar,10Shelbourne K.D. Patel D.V. Timing of surgery in anterior cruciate ligament-injured knees.Knee Surg Sports Traumatol Arthrosc. 1995; 3: 148-156Crossref PubMed Scopus (0) Google Scholar], numerous authors concluded that the risk of developing a stiff knee after surgery can be significantly reduced if the surgery is delayed until the acute inflammatory phase has passed, the swelling has subsided, and a normal or near normal range of motion (especially extension) has been obtained [11Duncan K.J. Chopp-Hurley J.N. Maly M.R. A systematic review to evaluate exercise for anterior cruciate ligament injuries: does this approach reduce the incidence of knee osteoarthritis?.Open Access Rheumatol. 2016 Jan 8; 8: 1-16PubMed Google Scholar]. On the other hand, recent studies with modern rehabilitation protocols suggest that acute ACL surgery is not associated with an increased risk of postoperative stiffness [12Andernord D. Karlsson J. Musahl V. Bhandari M. Fu F.H. Samuelsson K. Timing of surgery of the anterior cruciate ligament.Arthroscopy. 2013; 29: 1863-1871Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar,13Kwok C.S. Harrison T. Servant C. The optimal timing for anterior cruciate ligament reconstruction with respect to the risk of postoperative stiffness.Arthroscopy. 2013; 29: 556-565Abstract Full Text Full Text PDF PubMed Scopus (53) Google Scholar]. It is important to appreciate that most of these studies are either controlled trials with supervised rehabilitation which may be difficult to consistently replicate in “real world orthopaedics”, or retrospective studies with a potential selection bias [14Vermeijden H.D. van der List J.P. DiFelice G.S. Acute and delayed anterior cruciate ligament repair results in similar short to mid-term outcomes.Knee. 2021; 29: 142-149Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar]. We appreciate that some ACL tears with minimal knee inflammation may be appropriate for surgery in the acute phase, but would caution against performing acute ACL surgery when the knee is swollen, painful, and has a limited range of motion. ‘Early repair leads to more predictable healing’ is an intuitive dictum in orthopaedics and is seen not just in bones, muscles-tendons, and menisci, but also in ligaments [15Chamberlain C.S. Crowley E. Vanderby R. The spatio-temporal dynamics of ligament healing.Wound Repair Regen. 2009 Mar-Apr; 17: 206-215https://doi.org/10.1111/j.1524-475X.2009.00465.xCrossref PubMed Scopus (51) Google Scholar]. The ACL is not likely to be an exception. Although the mechanisms behind the functional loss of healing with delay of repair remain unknown [16Magarian E.M. Fleming B.C. Harrison S.L. Mastrangelo A.N. Badger G.J. Murray M.M. Delay of 2 or 6 weeks adversely affects the functional outcome of augmented primary repair of the porcine anterior cruciate ligament.Am J Sports Med. 2010; 38: 2528-2534https://doi.org/10.1177/0363546510377416Crossref PubMed Scopus (47) Google Scholar], several studies have advocated for early repair to optimise healing rates and clinical outcomes [16Magarian E.M. Fleming B.C. Harrison S.L. Mastrangelo A.N. Badger G.J. Murray M.M. Delay of 2 or 6 weeks adversely affects the functional outcome of augmented primary repair of the porcine anterior cruciate ligament.Am J Sports Med. 2010; 38: 2528-2534https://doi.org/10.1177/0363546510377416Crossref PubMed Scopus (47) Google Scholar,17Aho A.J. Lehto M.U.K. Kujala U.M. Repair of the anterior cruciate ligament : Augmentation versus conventional suture of fresh rupture.Acta Orthop. 1986; 57: 354-357Crossref Scopus (0) Google Scholar,18van der List J.P. Jonkergouw A. van Noort A. et al.Identifying candidates for arthroscopic primary repair of the anterior cruciate ligament : a case-control study.Knee. 2019; 23: 619-627Abstract Full Text Full Text PDF Scopus (0) Google Scholar,19Ferretti A. Monaco E. Annibaldi A. et al.The healing potential of an acutely repaired ACL: a sequential MRI study.J Orthop Traumatol. 2020; 21https://doi.org/10.1186/s10195-020-00553-9Crossref Scopus (12) Google Scholar]. We respect the authors preference to repair chronic ACL avulsions in patients with good quality tissue based on the results of the quoted study [14Vermeijden H.D. van der List J.P. DiFelice G.S. Acute and delayed anterior cruciate ligament repair results in similar short to mid-term outcomes.Knee. 2021; 29: 142-149Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar]. However, since this is a retrospective study with limitations (the study was underpowered to determine the secondary outcome measure of treatment failure, and 21% of the patients operated in the acute group were lost to follow-up) we would not advocate the same for general use as of now. With the evidence available today, most surgeons would be apprehensive of offering repair to sub-acute and chronic ACL avulsions despite good macroscopic tissue quality during arthroscopy. In conclusion, prospective studies with sufficient follow-up comparing the outcomes and failure rates of ACL repair versus reconstruction are needed prior to widespread implementation of ACL repair [20van der List J.P. Vermeijden H.D. Sierevelt I.N. DiFelice G.S. van Noort A. Kerkhoffs G.M.M.J. Arthroscopic primary repair of proximal anterior cruciate ligament tears seems safe but higher level of evidence is needed: a systematic review and meta-analysis of recent literature.Knee Surg Sports Traumatol Arthrosc. 2020 Jun; 28: 1946-1957https://doi.org/10.1007/s00167-019-05697-8Crossref PubMed Scopus (52) Google Scholar]. In the absence of this higher level of evidence, the ‘ongoing reluctance toward ACL primary repair within today’s orthopaedic sports medicine and trauma community’ [21Rilk S. Saithna A. Ferretti A. Sonnery-Cottet B. Kosters C. Bottoni C.R. et al.The modern-day ACL surgeon's armamentarium should include multiple surgical approaches including primary repair, augmentation, and reconstruction: A letter to the Editor.J ISAKOS. 2023; https://doi.org/10.1016/j.jisako.2023.03.434Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar] is likely to persist. Under these circumstances, there is a need for a “best of both worlds” approach that allows gold-standard ACL reconstruction to be performed along with all the potential advantages of ACL repair. In our opinion, arthroscopic biological internal bracing with remnant repair for subacute ACL femoral avulsions [1Pardiwala D.N. Lee D. Arthroscopic biological internal bracing with remnant repair for subacute ACL femoral avulsions.J ISAKOS. 2023; 8: 54-56Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar] fulfils this need. None None The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.