Use of Matrices as a Tissue Substitute in Shoulder Surgery

The use of orthobiologics in shoulder surgery is one of the largest areas of growth in the orthopaedic surgery product market. Bone products can fill voids, enhance healing, and provide support. Soft tissue products include scaffolds and products that augment the cell based and factor based healing response. This article focuses on scaffolds and biological augmentations. In the scaffold section, engineered products as well as solutions that use natural tissue will be discussed. In the biological augmentation sections, we will concentrate on products that enhance osteoinduction, angiogenesis, and the cellular response. Scaffolds can augment the mechanical properties of repaired tendons and especially so when the scaffold is constructed from poly-glycolic acid and poly-l-lactic acid. The original polymer material, poly-tetra-fluoro-ethylene, seems to be too mechanically weak for use in the shoulder; the same is true for chitin. Porcine small intestinal submucosa, while once promising, has been exposed as a poor material for scaffold development. Dermal matrix has many questions remaining before its use can be supported. As the field of polymer based molecular delivery continues to develop, we expect the synthetic polymers to continue to dominate the discussion. Many molecular therapies show promise for changing the way the shoulder heals and altering the mechanical properties of the repaired shoulder. Bone morphogenic proteins have shown an ability to affect the formation of the bone-tissue interface. Platelet-rich-plasma and fibrin clots both are promising inductors of angiogenesis, as are low intensity pulsed ultrasound and shock wave therapy. Finally, muscle and bone derived stem cells may potentially have a positive effect on the healing process.