Role of Hydroxyapatite in Healing of Experimentally Induced Cutaneous Wound in Rabbits

The study was carried out to throw some light on the effect of intra_incisional application of hydroxyapatite on healing of recovered skin documented by histopathological evaluation in rabbit. Thirty adult local breed rabbits were used, divided randomly and equally into two groups: the first group (Control group), subjected to wound of the skin from their back (about 5 cm in length) then sutured with silk (No. 4-0). Similar technique was used for treated group with the exception of local application of hydroxyapatite powder inside the incision prior to closure it. The operation was performed under the effect of general anesthesia represented by a mixture of xylazine-ketamine in a dose of 20 mg/kg and 35 mg/kg B.W., respectively, which were administered intramuscularly. During a clinical- follow of all animals, we trapped two cases of stitch abscess in the control group and one in treated group, which showed a response to medical treatment. Histopathological examination was performed on (3, 5, 7, 14 and 21) days post-wounding. Results revealed infiltration of large numbers of neutrophils with the formation of granulation tissue in the first periods in both groups, while fibrous connective tissue rich in dense collagen fibers were noticed in control group covered with necrotic tissue containing dead neutrophils and complete resolution of the skin with formation of fibrous connective tissue in the treatment group at the end of experiment. In conclusion, the Hydroxyapatite, promote wound healing because it attracts the macrophages and fibroblasts rapidly to the wound site.