Abstract
From Urist’s studies (1965) to the following observations by Sampath and Reddi (1981) on the role of BPM morphogenetic protein and, more particularly, BPMs/ Ops in the complex mechanism of bone regeneration to recent studies (Solheim, 1998) on the properties of the single elements belonging to the superfamily of AGF of platlet derivation to activate the specific receptors of stem cells, considerable progress has been made in research and clinical application. The non-specificity of the present evaluation methods of patient outcome prevent us from singling out which element has activated the osteogenetic process, and when and which one has affected the course favourably.
In order to answer all these questions, we have carried out a prospective study between autologous AGF and stem cell application in orthopaedics and the ex vivo evaluation in vitro of platelet activation of osteoblasts. From March 2002 to January 2004, we treated 21 cases of osteolysis (in mobilisations due to pros-thesis of hip and knee, necrosis of bone head femur, pseudoarthrosis of the humerus and ulna, and aneurysmal relapsing cyst). The procedure consisted in using stem cells+AGF+autologous bone graft (two cases) or bank bone graft (13 cases)-or hydroxyapatite (two cases)+autologous fibrin glue and at the same time, in vitro culture of the patient’s osteoblasts+AGF. Among the AGF, PDGF is an important mitogenous factor. Among the isoforms of PDGF, the PDGF-AA and PDGF-AB are stored in alpha –granules and released when platelets are activated. PDGF-AA is preferentially secreted by osteoblasts and fibroblasts. PDGF-AA and PDGF-AB were measured in supernatants of osteoblasts in culture media, activated platelet culture media, osteoblasts plus activated platelet culture media at day 0, day +4, after adding platelet and day +8. At the end a cytological test was performed. The study has proved that the PDGF-AA increases remarkably after adding platelet gel to the osteoblasts, more than in control cultures which are lacking in platelet gel, which might mean the platlets activate the osteoblast and activate the osteogenetic process.
The use of autologous fibrin glue enriched in AGF has demonstrated a better recovery of the tissue scar, as well as emathic save and better stop of grafts. The range of cases is not homogeneous and prevents us from drawing any statistical conclusions, but the quick bone recovery leads to great satisfaction both for patients and their physicians.
