Stabilization and Gap Formation of Adjustable Versus Fixed Primary ACL Repair With Internal Brace: An in Vitro Full-Construct Biomechanical Cadaveric Study

• Published in: Orthopaedic journal of sports medicine 2023-09, Vol.11 (9), p.23259671231201462-23259671231201462
• Main Authors: Bachmaier, Samuel, Smith, Patrick A., Hammoud, Sommer, Ritter, Daniel, Hauck, Oliver, Wijdicks, Coen A.
• Format: Article
• Language: English
• Subjects: Biomechanics; Original Research; Orthopedics; Sports medicine
• ISSN: 2325-9671; 2325-9671
• DOI: 10.1177/23259671231201462

Background: A knotless, tensionable primary anterior cruciate ligament (ACL) repair system preloaded with an internal brace has been released. Currently, there is no biomechanical data on the stabilization and gap formation behavior of the adjustable system when compared with fixed repairs in human ACL tissue. Hypothesis: That knotless adjustable suture repair with an internal brace would provide overall higher construct stability and greater load share on the ACL with less gap formation compared with fixed repair. Study Design: Controlled laboratory study. Methods: Human cadaveric knees were utilized for internal braced ACL repair constructs (each group n = 16). Two fixed groups consisting of a single-cinch loop (SCL), cortical button (SCL group), and knotless suture-anchor (anchor group) were compared with an SCL-adjustable loop device (SCL-ALD) group. Testing was performed at 4 different peak loads (50, 150, 250, 350 N) over 4000 cycles at 0.75 Hz including suture repair preconditioning (10 cycles at 0.5 Hz) for SCL-ALD. Specimens were ultimately pulled to failure with a cut internal brace. The final loading situation of the construct and ACL repair with gap formation and ultimate strength were evaluated. Results: Peak elongation at various peak loads showed a significantly higher (P