A Canine Arthroscopic Anterior Cruciate Ligament Reconstruction Model for Study of Synthetic Augmentation of Tendon Allografts

Abstract

Novel graft types, fixation methods, and means for augmenting anterior cruciate ligament (ACL) reconstructions require preclinical validation prior to safe and effective clinical application. The objective of this study was to describe and validate a translational canine model for all-inside arthroscopic complete ACL reconstruction using a quadriceps tendon allograft with internal brace (QTIB). With institutional approval, adult research hounds underwent complete transection of the native ACL followed by all-inside ACL reconstruction using the novel QTIB construct with suspensory fixation ( = 10). Contralateral knees were used as nonoperated controls ( = 10). Dogs were assessed over a 6-month period using functional, diagnostic imaging, gross, biomechanical, and histologic outcome measures required for preclinical animal models. Study results suggest that the novel QTIB construct used for complete ACL reconstruction can provide sustained knee stability and function without the development of premature osteoarthritis in a rigorous and valid preclinical model. The unique configuration of the QTIB construct-the combination of a tendon allograft with a synthetic suture tape internal brace-allowed for an effective biologic-synthetic load-sharing ACL construct. It prevented early failure, allowed for direct, four-zone graft-to-bone healing, and functional graft remodeling while avoiding problems noted with use of all-synthetic grafts.

Anterior cruciate ligament reconstruction is associated with greater tibial tunnel widening when using a bioabsorbable screw compared to an all-inside technique with suspensory fixation

“…Suspensory fixation may offer other biological advantages over interference screw fixation. Several authors have reported that interference screws provide a limited tendon-bone contact area because much of the tunnel circumference is occupied by the screw itself, while adjustable loop systems provide a greater contact zone [15,29], and allow "four-zone direct graft healing" which has been associated in animal study with the absence of tunnel widening on radiographic and histologic assessments [29].…”

Internal Suture Augmentation Technique to Protect the Anterior Cruciate Ligament Reconstruction Graft

“…The idea of augmenting ligamentous repair as well as reconstruction has recently been proposed by many authors and in different anatomic sites. 10 , 11 , 12 Augmentation may be indicated with variable degrees of chronicity with different techniques, particularly with the use of allografts to protect them until complete healing and ligamentization take place. Early promising results in ACL reconstruction in canine models have been reported.…”

“…Early promising results in ACL reconstruction in canine models have been reported. 10 , 11 , 12 , 13 However, there is no published technique that describes augmenting an ACL hamstring autograft fixed with a femoral cortical button and Bio-Interference Screw on the tibial side.…”

The Crossing Internal Suture Augmentation Technique to Protect the All-Inside Anterior Cruciate Ligament Reconstruction Graft

“…Similar techniques for preparation of the ACL graft tendon have been described using allograft tissue, 9 , 14 in which a FiberTape is used to secure the construct until the healing process is finished, which usually takes a longer time when using an allograft. However, in such a technique, the FiberTape is suspended over the suture loop of the femoral TightRope, which we think may be a weak point and may be subject to earlier loosening or even failure of the loop of the femoral TightRope because of the higher stresses.…”

“… 8 Preliminary results in a canine model showed good results with the use of a quadriceps tendon allograft with suture augmentation (i.e., a quadriceps tendon allograft with an internal brace) without the occurrence of synovitis or premature arthritis. 9 …”