EARLY BIOLOGIC BEHAVIOR OF BONE-GRAFTS - A FINE-NEEDLE ASPIRATION CYTOLOGY STUDY

OBJECTIVE: To conceptualize, with fine needle aspiration cytology (FNA C), the early cellular events occurring in and around fresh autogenous and allogenic bone grafts during the first 40 postimplantation days. STUDY DESIGN: Forty-eight cases of bone grafts were studied by FNAC at serial intervals of 10, 20, 30 and 40 postimplantation days. Twenty p atients were recipients of autogenous grafts, 16 received 0.6N HCl par tially decalcified allogenic bone implants, and 4 received combined au togenous and allogenic bone grafts (included in the allograft group). There were eight control cases of closed fracture shaft femur, which w ere managed conservatively. RESULTS: The initial cellular responses in autogenous grafts, allografts and controls appear to be a part of the nonspecific reparative process followed by a more specific phase, wit h a steady increase in relative lymphocyte count from the 20th day onw ards. Osteogenesis, as judged by osteoblasts and osteoclasts, was also comparable. CONCLUSION: Partially decalcified allografts appear to be a good substitute for autogenous bone grafts in clinical practice whe n adequate autogenous material is not available. FNAC is a good techni que for studying bone graft responses without interfering with graft u ptake. It is helpful in the early detection of subclinical infection o r any other pathology at the graft site.