A Biomechanical Comparison of All-Inside Anterior and Posterior Cruciate Ligament Graft Preparation Techniques

• Published in: Orthopaedic journal of sports medicine 2017-07, Vol.5 (7_suppl6)
• Main Authors: Brady, Jacqueline Munch, Skoglund, Kathryn C., Wichern, Colter R., O’Sullivan, Joseph G., Burwell, Anora K., Nguyen, Joseph T., Herzka, Andrea
• Format: Article
• Language: English
• Subjects: Biomechanics; Ligaments; Orthopedics; Sports medicine
• ISSN: 2325-9671; 2325-9671
• DOI: 10.1177/2325967117S00351

Objectives: The all-inside technique for knee cruciate ligament reconstruction has gained popularity for its potential to preserve tissue and bone stock, and improve visualization during surgery in the setting of a socket vs. a tunnel approach. Various techniques of graft preparation have been described for use in all-inside reconstruction, but to our knowledge no study has compared the various techniques presently being used. This study is a biomechanical comparison of 5 graft preparation techniques used for all-inside cruciate ligament reconstruction, including 2 different methods of quadrupling the graft, and 3 alternative methods used when the available tendon is not long enough to be quadrupled. Methods: Fresh frozen porcine extensor tendons were randomized between 5 groups, including 2 quadrupled groups: Quad-A and Quad-B, and 3 alternative groups: Tripled, Folded, and Two-Doubled, (see Figure 1) with a total N=50. Within each group, 10 specimens were prepared using the designated technique, and subsequently underwent preconditioning (10 loading cycles from 20-50N at 0.1Hz), cyclic loading (500 loading cycles from 50-250N at 1.0Hz) and load-to-failure (applied at 20mm/min). Displacement (mm) and force (N) were measured throughout testing. Cyclic displacement (mm), cyclic stiffness (N/mm), pullout stiffness (N/mm), ultimate failure load (N), and ultimate failure displacement (mm) were the primary endpoints used to compare the grafts. Results: Quad-A and Quad-B demonstrated no significant difference in cyclic displacement (10.51±0.46 and 11.74±0.45, respectively; p >0.05), cyclic stiffness (1086±488.5 and 460.4±71.7, respectively; p>0.05), pullout stiffness (15.87±4.26 and 7.42±4.41, respectively; p>0.05), ultimate failure load (641.2±84.7 and 405.9±237.4, respectively; p>0.05), or ultimate failure displacement (47.35±6.72 and 55.5±0.73, respectively; p>0.05). The Tripled, Folded and Two-Doubled groups differed significantly in terms of cyclic displacement (11.34±0.37, 13.26±0.29 and 28.75±0.83, respectively; p0.05), pullout stiffness (0.95±0.77, 2.06±2.01 and 1.99±1.62, respectively; p>0.05), ultimate failure load (73.26±59.73, 143.4±140.0 and 128.6±108.3, respectively; p>0.05), or ultimate failure displacement (76.43±0.6, 69.71±0.45 and 55.35±6.06, respectively; p>0.05). Conclusion: The 2 quadrupled techniques demonstrated no sig