14 The evolution of callus formation after stimulation with bone graft and bone marrow aspirate from iliac crest B. Obada 1 , Al. O. Serban 1 , Anca Teodora Obada 1 , Anca Nicolau 2 , D. Costea 3 1 Orthopaedic-Traumatology Clinic, Emergency Clinical Hospital of Constanta, Romania 2 Pathological Anatomy Department, Emergency Clinical Hospital of Constanta, Romania 3 General Surgery Clinic, Emergency Clinical Hospital of Constanta, Romania Head of Orthopaedic-Traumatology Department: Alexandru Octavian Serban Background. The experimental research studies the behavio- ur of open fracture site after stimulation with cortical-cancel- leous graft and medular aspirate from iliac crest. Methods. The animal used was home rabbit, because he has an anatomy which permit the bone study. The animals were divided in 4 study groups due to the callus stimulation method and the aspect of fracture site (simple, comminuted). For each group of study, the evaluation was made separately, due to the osteosynthesis type, resulting subgroups of reasearch. Results. The evaluation of the results was made by clinical, histological and radiological study comparing the research groups, at established periods of time. The final evaluation was made at 6 weeks, by calculating clinical, radiological and histological scores with high specificity, which permited a correct interpretation of the obtained results. Conclusions. The study confirms the role of the bone mar- row and of the cortico-cancellous bone graft in ostheogene- sis, in which the osteoprogenitors cells survive permamently and have an important role to stimulate and to accelerate con- solidation. Keywords: callus stimulation, open fracture, bone marrow, bone graft SUMMARY 3 (40) 2016: 014-023 • ORIGINAL ARTICLE © Address for correspondence: Bogdan Obada MD, Assistant Professor Orthopaedic-Traumatology Clinic Emergency Clinical Hospital “Sf. Apostol Andrei” Bdul Tomis 145, Constanta, Romania Tel. +40723209201; email bogdanobada@yahoo.com Received: 12.08.2016 Accepted: 02.09.2016 Published: 30.09.2016 Word count: 2393 Tables: 8 Figures: 22 References: 8 BACKGROUND The aim of the experimental research was to follow the evolution of open fracture site after stimulation with cancellous bone graft and bone marrow arpirate from iliac crest and to evalu- ate the capacity to stimulate and accelerate osteogenesis. MATERIAL AND METHODS The lab animal we used in our research was the domestic rabbit because of his anatomy which permited us to make a bone study. The clinical experiments were made on 19 young rabbits (30 cases - fractures), with age between 6 and 8 months, weight between 1500 and 2000g, with the support of animal laborator (“Bioba- sis”) of Faculty of Biology from “Ovidius” University of Constanta, Romania. The research on the rabbits was made accor- ding to European Community Standards and to the World Health Organization guidelines on animal experimentations. The bone graft was taken from the iliac crest of the same rabbit, in the same surgery time with osteosynthesis.[1,2] For the conception of this study and ba- sed on the informations found in the litera- ture, we started from the ipothesis that the open fracture site will heal faster after stimu- lation with bone graft and bone marrow and we evaluated: 1. the influence of stimulation method of con- solidation upon the evolution of fracture 2. the influence of osteosynthesis type upon consolidation 3. the evolution of consolidation depending of fracture type (simple/comminuted). 4. radiological evaluation of fracture site evo- lution at 2, 4, 6 weeks