James Cook, D.V.M., Ph.D., serves as the William and Kathryn Allen Distinguished Professor in Orthopaedic Surgery at the University of Missouri School of Medicine. Cook also is director of the Missouri Orthopaedic Institute’s Division of Research and the Mizzou BioJoint Center. Cook’s clinical interests include cartilage restoration, regenerative orthpaedics and sports medicine. His research interests include tissue engineering, as well as management, diagnosis and treatment of osteoarthritis. As senior author of the study, “Suspensory Versus Interference Screw Fixation for Arthroscopic Anterior Cruciate Ligament Reconstruction in a Translational Large-Animal Model,” his work recently was published in The Journal of Arthroscopic & Related Surgery.
A torn anterior cruciate ligament, or ACL, is one of the most common knee injuries. Each year, approximately 200,000 Americans tear their ACLs, and most elect for surgical repair. The key to success is to replace the damaged ACL with a strong graft that can grow into the knee bones just like a normal ACL. It is not possible to fully assess graft healing in a patient, so our research team developed a model to scientifically determine the best ACL grafting technique.
For a traditional ACL repair, surgeons use screws to secure a graft to the sides of tunnels created in the upper and lower bones of the knee. This repair provides stability and allows the new graft to grow to bone. However, the graft-to-bone attachment is more like a spot weld rather than a fully integrated repair. Additionally, use of the screws can cause cell and tissue damage in the new graft. Both of these issues can result in a repair that may be prone to failure.
Using our canine model, we compared this traditional method with a newer technique. The newer suspensory repair uses special sutures to pull the graft into sockets created in the bones, and secure it in-place using toggle buttons. With this method, the graft fills the entire bone socket like a potted plant. This offers the graft the best opportunity to fully grow into the bone like a normal ligament, and reduces the potential of damage to the graft.
This new technique has been reported to have excellent clinical success in patients, and our study provided scientific validation of that success. In our study, 100 percent of the dogs treated with the newer suspensory technique achieved functional and natural healing. Only 67 percent of dogs treated with the traditional method achieved full functional healing, and none of the grafts integrated into the bones in the way a normal ACL does. Our study suggests that the suspensory method provides the most reliable option for achieving natural graft-to-bone integration, and may allow patients to return to a more active lifestyle with a new ACL that is less likely to fail.