This letter is in response to the commentary entitled, “Advances in anterior cruciate ligament reconstruction techniques” recently published in the Annals of Translational Medicine. The authors of this editorial comment on our article published in the March 2016 issue of The Journal of Bone and Joint Surgery which examined how the diameter of soft-tissue hamstring ACL grafts significantly changes after applying circumferential compression to the grafts. We thank the authors for highlighting our article as an important contribution in the field of ACL reconstruction. The use of hamstring grafts for ACL reconstruction has been increasing worldwide and while there is ample literature supporting the use of these grafts (1-3), we sought to highlight further the nuances associated with this surgical technique.
In the study, we showed that the diameter of hamstring grafts can be decreased by almost 1 mm by applying a simple method of circumferential compression during graft preparation (4). We believe that this has several clinical implications. Because it has been shown that the size of soft-tissue grafts is associated with re-rupture rates (5,6)—with smaller grafts more prone to re-rupture—one of the goals of surgery is to implant as large a graft as possible, even augmenting autografts with allograft if needed (7,8). We posit that graft diameter is merely an indicator of total collagen content and that the measured graft size is not necessarily as important as the fact that more collagen is being implanted to reconstruct the ACL.
We believe that our technique of circumferentially compressing ACL grafts allows the surgeon to drill/ream smaller diameter tunnels despite still implanting the same amount of collagen. This may have important clinical implications since it has been observed that bone tunnel enlargement can occur after the use of soft-tissue only grafts for ACL reconstruction (9,10). Because of this, bone preservation during primary or revision ACL reconstruction is important.
Finally, just as pre-tensioning soft-tissue grafts prior to implantation is an accepted practice during ACL reconstruction, we believe that circumferentially compressing grafts should also be considered as a method of “pre-conditioning.” While further study is needed to investigate whether this method of ACL graft preparation improves clinical outcomes, we believe that preparing grafts in this manner eases graft passage, allows the use of smaller diameter grafts without sacrificing inherent graft strength, and allows for the preservation of more bone during ACL reconstruction.
Respectfully,
Aristides I. Cruz, Jr. MD
Peter D. Fabricant, MD, MPH
Acknowledgements
None.
Provenance: This is a Guest Correspondence commissioned by Section Editor Pengfei Lei, MD (Clinical research fellow at Department of Orthopedic Surgery Brigham and Women’s Hospital, Harvard University, Boston, MA, 02115, United States; Surgeon of Department of Orthopaedic Surgery, Central South University Xiangya Hospital, Changsha, China).
Conflicts of Interest: The authors have no conflicts of interest to declare.
References
- 1.Hamner DL, Brown CH, Jr, Steiner ME, et al. Hamstring tendon grafts for reconstruction of the anterior cruciate ligament: biomechanical evaluation of the use of multiple strands and tensioning techniques. J Bone Joint Surg Am 1999;81:549-57. 10.2106/00004623-199904000-00013 [DOI] [PubMed] [Google Scholar]
- 2.Pailhé R, Cavaignac E, Murgier J, et al. Biomechanical study of ACL reconstruction grafts. J Orthop Res 2015;33:1188-96. 10.1002/jor.22889 [DOI] [PubMed] [Google Scholar]
- 3.Scheffler SU, Südkamp NP, Göckenjan A, et al. Biomechanical comparison of hamstring and patellar tendon graft anterior cruciate ligament reconstruction techniques: The impact of fixation level and fixation method under cyclic loading. Arthroscopy 2002;18:304-15. 10.1053/jars.2002.30609 [DOI] [PubMed] [Google Scholar]
- 4.Cruz AI, Jr, Fabricant PD, Seeley MA, et al. Change in Size of Hamstring Grafts During Preparation for ACL Reconstruction: Effect of Tension and Circumferential Compression on Graft Diameter. J Bone Joint Surg Am 2016;98:484-9. 10.2106/JBJS.15.00802 [DOI] [PubMed] [Google Scholar]
- 5.Conte EJ, Hyatt AE, Gatt CJ, Jr, et al. Hamstring autograft size can be predicted and is a potential risk factor for anterior cruciate ligament reconstruction failure. Arthroscopy 2014;30:882-90. 10.1016/j.arthro.2014.03.028 [DOI] [PubMed] [Google Scholar]
- 6.Magnussen RA, Lawrence JT, West RL, et al. Graft size and patient age are predictors of early revision after anterior cruciate ligament reconstruction with hamstring autograft. Arthroscopy 2012;28:526-31. 10.1016/j.arthro.2011.11.024 [DOI] [PubMed] [Google Scholar]
- 7.Darnley JE, Léger-St-Jean B, Pedroza AD, et al. Anterior Cruciate Ligament Reconstruction Using a Combination of Autograft and Allograft Tendon: A MOON Cohort Study. Orthop J Sports Med 2016;4:2325967116662249. 10.1177/2325967116662249 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Leo BM, Krill M, Barksdale L, et al. Failure Rate and Clinical Outcomes of Anterior Cruciate Ligament Reconstruction Using Autograft Hamstring Versus a Hybrid Graft. Arthroscopy 2016;32:2357-63. 10.1016/j.arthro.2016.04.016 [DOI] [PubMed] [Google Scholar]
- 9.Lind M, Feller J, Webster KE. Bone tunnel widening after anterior cruciate ligament reconstruction using EndoButton or EndoButton continuous loop. Arthroscopy 2009;25:1275-80. 10.1016/j.arthro.2009.06.003 [DOI] [PubMed] [Google Scholar]
- 10.Webster KE, Feller JA, Hameister KA. Bone tunnel enlargement following anterior cruciate ligament reconstruction: a randomised comparison of hamstring and patellar tendon grafts with 2-year follow-up. Knee Surg Sports Traumatol Arthrosc 2001;9:86-91. 10.1007/s001670100191 [DOI] [PubMed] [Google Scholar]