Paper # 90: The Role of Platelet Derived Growth Factors on Graft Healing After ACL Reconstruction

Abstract

The platelet gel, applied locally, enhance early revascularization of the graft in the zone of the osteoligamentous interface in the bone tunnel, after anterior cruciate ligament reconstruction. Long rehabilitation after arthroscopic anterior cruciate ligament (ACL) reconstruction still represents big problems for patients, especially in professional sportsmen. The reason is slow graft healing in bone tunnels and a slow graft ligamentization process. Purpose: The purpose of this study was to determine if the use of platelet gel (PG) accelerates graft revascularisation after anterior cruciate ligament (ACL) reconstruction, and does it have any morphological and clinical relevance for outcome of the operation. Platelet gel was produced from the platelet rich plasma (PRP), prepared from a unit of whole blood in an Autologous Platelet Separator. PG was applied locally. Fifty patients were included, 25 in the platelet and 25 in a control group. We quantitatively evaluated the process of revascularization in the zone of the osteoligamentous interface in the bone tunnels and in the intra-articular part of the graft. Contrast enhanced magnetic resonance imaging (MRI) studies were carried out at 4-6, 10-12 and 25-27 weeks post surgery. We also evaluated extension of new sclerotic bone formation around tunnels and tunnels dilatation with MRI, knee stability with KT-2000 and functional outcomes with functional scores. At the first control (4-6 weeks), patients treated with PG demonstrated a significantly higher level of vascularization in the osteoligamentous interface (0.33±0.09), compared with the control group (0.16±0.09), p<0.001. In the intra-articular part of the graft we found no evidence of revascularization in either group. At the second control (10-12 W), the level of vascularisation decreased in the platelet group (0.20±0.13) and increased in the control group (0.17±0.10). In the intra-articular part of the graft we found minimal levels of revascularization but no differences among the groups. At third control (25-27 W) the level of vascularisation decreased in both group. The amount of new sclerotic bone formarion, was significantly higher in platelet group (68.57±14.2) in comparation with control group (54.50±16.6), p<0.0062, 6 months after surgery. The anteroposterior knee stability, was also significanty better in platelet (4.7±1.9) than in control (6.7±2.1) group, six months after sugery (p<0.003). The platelet gel, applied locally, enhance early revascularization of the graft in the zone of the osteoligamentous interface in the bone tunnel, after anterior cruciate ligament reconstruction. Enhancement of this early postoperative biological process, is demonstrated in late morphological and clinical manifestations, as extensive new bone formation around bone tunnels, smaller enlargement of bone tunnels and more stable knee joint.