Abstract
Current issues being debated in ACL reconstruction include injury prevention, graft choice, graft positioning, graft fixation, graft remodelling and rehabilitation. Tissue engineering, the alteration of biological mechanisms by application of novel proteins, enzymes and hormones, is rapidly changing the way we approach all aspects of surgery. Tissue engineering techniques in ACL/PCL reconstruction focus on new biosynthetic ACL material, fixation of soft tissue grafts to bony tunnels and graft remodelling
OP-1 is recombinant human Osteogenic Protein 1 (BMP-7). It is a member of the Transforming Growth Factor β (TGFβ) super family. OP-1 promotes the recruitment, attachment, proliferation and differentiation of pluripotential mesenchymal stem cells. It promotes both osteogenesis and chondrogenesis. The carrier is highly purified bovine bone type 1 collagen, which provides an osteoconductive matrix.
We have completed a study assessing the use of OP-1 as a means of enhancing early biological fixation of soft tissue grafts within bone tunnels in a sheep ACL model.
We have commenced a clinical trial using OP-1 in adult ACL reconstruction, believing that OP-1 will enhance early biological graft fixation, and hence, improve clinical results, speed up rehabilitation and prevent tunnel widening.
Other studies have shown the beneficial effects of BMP-2 on an extraarticular bone tendon fixation model, the use of TGF-B to enhance graft remodelling and the application of gene therapy to deliver BMP’s for enhanced graft fixation.
Several projects are underway looking at creating biosynthetic ACL grafts using tissue engineering techniques. As opposed to purely synthhetic grafts, bioACL grafts are made of a collagen scaffold, allowing for remodelling and revascularisation.
ACL reconstructive surgery is constantly evolving. Tissue engineering may provide us with a means of minimising morbidity, accelerating rehabilitation and improving the clinical outcome following this common surgery.
The abstracts were prepared by Professor Jegan Krishnan. Correspondence should be addressed to him at the Flinders Medical Centre, Bedford Park 5047, Australia.
