Joost Peerbooms

59 PRP in upper limb conditions The high concentration of non-activated leukocytes, present in the PRP, promotes antimicrobial activity at the wound site through destruction of bacteria and foreign materials and removal of damaged tissue. 32,33 The success rate of an OSD depends on a rapid recovery of the shoulder function. Time to recovery can be improved through good wound healing and less post-operative pain. ROTATOR CUFF TEAR The literature reveals that, despite the technical expertise of the surgeon, a significant failure rate can be expected after rotator cuff repair. The biological milieu at the rotator cuff footprint and the inherent poor healing potential of the distal rotator cuff tendon create an environment that is not optimal for healing of the tendon to bone. Augmentation of the rotator cuff repair with PRP could hypothetically optimize the biologic environment at the repair site and allow for a more robust healing response at the osseous-tendon interface. The intra-operative use of PRP augmentation of the rotator cuff repair has been gaining in popularity among shoulder surgeons. Gamradt et al. 34 have reviewed the basic science regarding the use of autogenous platelets and growth factors used to enhance the healing of the repaired rotator cuff. PRP augmentation of rotator cuff repair at the tendon-bone interface is described in this review. This same group of researchers is currently conducting a randomized clinical trial assessing the efficacy of their described technique. In addition, the use of stem cells for the augmentation of rotator cuff repair is under investigation. Stem cells can give rise to specialized cells. When unspecialized stem cells give rise to specialized cells, the process is called differentiation. Scientists are just beginning to understand the signals inside and outside cells that trigger stem cell differentiation. The internal signals are controlled by a cell’s genes, which are interspersed across long strands of DNA, and carry coded instructions for all the structures and functions of a cell. Randelli et al. 35 conducted an uncontrolled pilot study of PRP augmented arthroscopic rotator cuff repair to evaluate safety and outcome. In 14 patients, PRP was injected with thrombin (GPS II Platelet Concentrate System, Biomet Biologics, LLC) into the footprint after the repair was performed and the irrigation ceased. 35 There were no complications, and, at a mean of 2 years, all patients had statistically significant improvements in VAS, Constant, and University of California Los Angeles shoulder scores compared with pre- operative values. The authors are currently conducting a randomized controlled trial to ascertain the efficacy of PRP in arthroscopic rotator cuff repair. 4