Introduction

The ability of activated platelets to induce cellular proliferation is well recognised. In a previous diffusion model, platelets combined with Tri-calcium phosphate (TCP) led to an osteoprogenitor mitogenic response followed by cellular differentiation. This study was designed to look at osteoprogenitor responses when cultured directly onto TCP granules combined with activated platelets.

Rotator cuff tendon healing has proven to be a substantial clinical challenge. There is significant interest in finding biologic augmentation methods to improve this healing process. Two currently available products include platelet rich plasma/platelet rich fibrin matrix and several commercially available extra cellular matrix (ECM) patches. Platelet rich plasma is a sample of an autologous blood which has been centrifuged to a concentration of platelets three to four times that of normal. Platelets contain multiple growth factors, many of which have been shown to be involved in all phases in tendon healing. An alternative is platelet rich fibrin matrix. This forms a fibrin matrix with the platelets embedded within. Growth factors are subsequently released as the fibrin is reabsorbed. There are only a few studies which look at the effectiveness of platelet rich plasma and fibrin matrix. Overall, there is no strong evidence to support its routine use in the setting of rotator cuff repair. Extra cellular matrix patches are used to reinforce the strength of the repair and offload the tendon. They also provide the potential to form a scaffold for new growth and differentiation and may at some point be a delivery vehicle for cells and growth factors. There are currently two prospective randomised studies evaluating ECM patches – one showed that the patch studied was actually harmful to repair and the second suggested there was some benefit in larger tears. While there is not a lot of strong evidence to support routine use, further research and development is necessary to maximise this strategy