Enhanced histologic repair in a central wound in the anterior cruciate ligament with a collagen-platelet-rich plasma scaffold.
ABSTRACT The anterior cruciate ligament (ACL) of the knee is an intra-articular ligament that fails to heal after primary repair. The medial collateral ligament (MCL) of the knee is an extra-articular ligament that heals uneventfully in the majority of cases. Why these two ligaments have such different responses to injury remains unclear. In this article, we address two hypotheses: first, that the histologic response to injury is different in intra-articular and extra-articular ligaments, and second, that the response of the intra-articular ligaments can be altered by placing a collagen-platelet-rich plasma (collagen-PRP) hydrogel in the wound site. Wounds were created in extra-articular ligaments (MCL and/or patellar ligament) and an intra-articular ligament (ACL) in canine knees, and the histologic response to injury evaluated at 3 days (n = 3), 7 days (n = 4), 3 weeks (n = 5), and 6 weeks (n = 5). In the 3-week (n = 5) and 6-week (n = 5) animals, bilateral central wounds were made in the ACLs and the wounds in one knee of each animal treated with a collagen-PRP hydrogel while the contralateral side was untreated. Extra-articular ligament wounds had greater filling of the wound site and increased presence in the wound site of fibrinogen, fibronectin, PDGF-A, TGF-beta1, FGF-2, and von Willebrand's factor when compared to intra-articular ligament wounds. Treatment of the intra-articular wound with a collagen-PRP hydrogel resulted in increased filling of the wound site with repair tissue that had similar profiles of growth factor and protein expression to the extra-articular ligament wounds. The use of a collagen-PRP scaffold can ameliorate histologic differences noted between healing extra-articular ligamentous wounds and nonhealing intra-articular ligamentous wounds. This study supports the hypothesis that premature scaffold failure may play a key role in the normally expected failure of the ACL to heal after injury.
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ABSTRACT: Bio-enhanced ACL repair, where the suture repair is supplemented with a biological scaffold, is a promising novel technique to stimulate healing after ACL rupture. However, the histological properties of a successfully healing ACL and how they relate to the mechanical properties have not been fully described.Orthopaedic journal of sports medicine. 11/2013; 1(6).
Article: ACL injuries and stem cell therapy.[Show abstract] [Hide abstract]
ABSTRACT: Tears of the anterior cruciate ligament (ACL) are very frequent injuries, particularly in young and active people. Arthroscopic reconstruction using tendon auto- or allograft represents the gold-standard for the management of ACL tears. Interestingly, the ACL has the potential to heal upon intensive non-surgical rehabilitation procedures. Several biological factors influence this healing process as local intraligamentous cytokines and mainly cell repair mechanisms controlled by stem cells or progenitor cells. Understanding the mechanisms of this regeneration process and the cells involved may pave the way for novel, less invasive and biology-based strategies for ACL repair. This review aims to focus on the current knowledge on the mechanisms of ACL healing, the nature and potential of ligament derived stem/progenitor cells as well as on the potential and the limitations of using mesenchymal stem cells (MSCs) for treating injured ACL.Archives of Orthopaedic and Trauma Surgery 07/2014; · 1.31 Impact Factor
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ABSTRACT: Tendons are subjected to tendinopathies caused by inflammation, degeneration, and weakening of the tendon, due to overuse and trauma, which may eventually lead to tendon rupture. Recently, there has been increasing interest in biological approaches to augment tissue healing. Tendon healing occurs through a dynamic process with inflammation, cellular proliferation, and tissue remodeling. In this review article, we discuss the more frequently proposed biological therapies for tendon injuries as platelet-rich plasma, mesenchymal stem cells, extracorporeal shockwave, and scaffolds.Current Reviews in Musculoskeletal Medicine 06/2014;