Background: Knee joint trauma may result in damage of the intra-articular ligaments, with
rupture of the anterior cruciate ligament (ACL) a common and troublesome injury due to poor capabilities
for spontaneous regeneration. Autograft and allograft surgical reconstructions are the mainstay of
treatment, but have associated risks of failure, therefore tissue-engineering techniques aiming to regenerate
the native ACL are being researched as a potential alternative treatment.
Objectives: This article aims to review the current evidence produced by ex vivo and in vivo studies
investigating biomaterial scaffolding and mesenchymal stem cell (MSC) techniques in orthopaedic
tissue engineering of ACL injuries.
Methods: Databases searched were Ovid MEDLINE, Cochrane Library, Embase, Elsevier Scopus,
Web of Science and NCBI PubMed, with search terms ‘ligament’, ‘scaffold’, ‘mesenchymal stem cell’
and ‘tissue engineering’.
Results: 1132 articles were identified, with 19 articles suitable for review inclusion. Of the eligible
studies, 10 used biologic scaffold material, 6 used synthetic constructs, and hybrid scaffolds were employed
in the remaining 3 studies.
Conclusions: A large amount of preclinical evidence for viability of MSC seeded biomaterial scaffolds
in ACL regeneration exists. Studies show that with stimulation, MSCs adhere and proliferate well on
various scaffold materials ranging from silk to engineered polymers. Hybrid scaffolds are particularly
promising, and with further research, the best features from strong natural substances such as silk, and
biologically inert synthetic materials could be combined. Currently, there are few plans to begin human
clinical trials, but preclinical studies are moving into larger animal models.