Critical diaphyseal bone defect healing in hens by autologous free transplant of adipose tissue

Treatment of large bone defects and incurable fractures is a challenging clinical problem. A novel approaches in bone engineering is the use of adipose-derived stem cells and adipose tissue. This study aimed to analyse the impact of adipose autograft on the process of bone regeneration in a surgically created critical size defect (CSD) in the hen ulna. In this study, 30 laying hens at the age of 14 months were randomly divided into three groups: control (C, n=10), subcutaneous adipose tissue graft (SC, n=10) and abdominal adipose tissue graft (ABD, n=10). In all 30 hens, a CSD was made in the ulna. Hens from the SC and ABD groups underwent surgery to explant subcutaneous and adipose tissue graft, respectively, and those grafts were then implanted in the ulnar CSD. The first radiographic and histological analysis wer performed 3.5 weeks after surgery on four hens from the C group and five hens from the SC and ABD groups. The second analysis on the remaining 15 hens was performed after 7 weeks. Data were analysed using the Freeman-Halton extension of Fischer’s exact test at the level of statistical significance P<0.05. Statistically significant differences regarding the presence of bridging at 3.5 and 7 weeks after surgery were observed between the C and SC groups, and between the C and ABD groups. Formation of a callus, regardless of the time of analysis, was not observed in the C group, while it was present in the SC and ABD groups (P<0.05). More hens from the ABD group (3) than the SC group (1) developed a bony callus 7 weeks after surgery, though these differences were not significant. Autologous adipose tissue graft positively affected healing of the hens’ ulna at 3.5 and 7 weeks postoperatively. Abdominal adipose tissue appears to have better healing properties than subcutaneous adipose tissue.