Primary Proximal ACL Repair: A Biomechanical Evaluation of Different Arthroscopic Suture Configurations

Steffen B Rosslenbroich; Andrea Achtnich; Cathrin Brodkorb; Clemens Kösters; Carolin Kreis; Sebastian Metzlaff; Benedikt Schliemann; Wolf Petersen

doi:10.3390/jcm12062340

Primary Proximal ACL Repair: A Biomechanical Evaluation of Different Arthroscopic Suture Configurations

J Clin Med. 2023 Mar 17;12(6):2340. doi: 10.3390/jcm12062340.

Authors

Steffen B Rosslenbroich¹, Andrea Achtnich², Cathrin Brodkorb¹, Clemens Kösters³, Carolin Kreis¹, Sebastian Metzlaff⁴, Benedikt Schliemann⁵, Wolf Petersen⁶

Affiliations

¹ Department of Trauma, Hand and Reconstructive Surgery, University Hospital Muenster, Westfalian Wilhelm's University, Waldeyerstrasse 1, 48149 Muenster, Germany.
² Department of Orthopedic Sports Medicine, Klinikum Rechts der Isar, TU Technische Universität Munich, 81675 Munich, Germany.
³ Department of Trauma Surgery and Orthopedics, Maria and Joseph Hospital Greven, 48268 Greven, Germany.
⁴ Department of Orthopedics and Trauma Surgery, St. Joseph Hospital, 12101 Berlin, Germany.
⁵ Department of Trauma, Hand and Reconstructive Surgery, Herz-Jesu Hospital, 48165 Münster, Germany.
⁶ Department of Orthopedics and Trauma Surgery, Martin Luther Hospital, 14193 Berlin, Germany.

Abstract

Purpose: Several suture techniques have been described in the past for direct ACL repair with poor healing capacity and a high re-rupture rate. Therefore, we investigated a refixation technique for acute primary proximal ACL repair. The purpose of this study is to compare the biomechanical properties of different suture configurations using a knotless anchor. Methods: In this study, 35 fresh-frozen porcine knees underwent proximal ACL refixation. First, in 10 porcine femora, the biomechanical properties of the knotless anchor, without the ligament attached, were tested. Then, three different suture configurations were evaluated to reattach the remaining ACL. Using a material testing machine, the structural properties were evaluated for cyclic loading followed by loading to failure. Results: The ultimate failure load of the knotless anchor was 198, 76 N ± 23, 4 N significantly higher than all of the tested ACL suture configurations. Comparing the different configurations, the modified Kessler-Bunnell suture showed significant superior ultimate failure load, with 81, 2 N ± 15, 6 N compared to the twofold and single sutures (50, 5 N ± 14 N and 37, 5 ± 3, 8 N). In cyclic loading, there was no significant difference noted for the different configurations in terms of stiffness and elongation. Conclusions: The results of this in vitro study show that when performing ACL suture using a knotless anchor, a modified Kessler-Bunnell suture provides superior biomechanical properties than a single and a twofold suture. Within this construct, no failure at the bone-anchor interface was seen. Clinical relevance: Since primary suture repair techniques of ACL tears have been abandoned because of inconsistent results, ACL reconstruction remains the gold standard of treating ACL tears. However, with the latest improvements in surgical techniques, instrumentation, hardware and imaging, primary ACL suture repair might be a treatment option for a select group of patients. By establishing an arthroscopic technique in which proximal ACL avulsion can be reattached, the original ACL can be preserved by using a knotless anchor and a threefold suture configuration. Nevertheless, this technique provides an inferior ultimate failure load compared to graft techniques, so a careful rehabilitation program must be followed if using this technique in vivo.

Keywords: ACL repair; ACL rupture; Kessler–Bunnell suture; knotless anchor.

Grants and funding

This research received no external funding. APC funding by Open Access Program of TU Muenchen and Open Access Publication Fund of the University of Muenster.