A side-effect induced by the combination of a demineralized freeze-dried bone allograft and leucocyte and platelet-rich plasma during treatment for large bone cysts: a 4-year follow-up clinical study.

During platelet activation over 30 growth factors are released from their alpha granules. By concentrating platelets, higher levels of growth factors are obtained and can be used to stimulate the healing processes. Moreover, during blood centrifugation, huge numbers of leukocytes and thrombocytes can be obtained to form leukocyte and platelet-rich plasma (L-PRP). After platelet degranulation the active gelatinous matrix called leukocyte and platelet-rich gel (L-PRG) is formed. In the present clinical study, we report the influence of PLRG and freeze-dried allografts on healing of large femoral bone cysts. Each of 6 participants was followed on a regular basis with clinical examinations, roentgenograms and dual-energy X-ray absorptiometry (DXA) examinations. Our four-year follow up clinical study using allografts and PLRG in the treatment of large cystic lesions of the proximal femur showed that mixing these substances is not efficient and it might induce unknown local reactions between them causing complete bone graft destruction. Further studies are necessary to fully understand the mechanisms of the local activity of L-PRP gel.