[The effect of repeated bonding of octyl-a-cyanoacrylate adhesive on human tibia cortical bone]

During clinical operation, the repeated bonding of octyl-a-cyanoacrylate adhesive is necessary for satisfactory reduction and fixation. This is because the repeated bonding will change the morphologic characteristics of the bone surface in biomechanical study. The influence of repeated bonding of octyl-a-cyanoacrylate on fresh human tibia cortical bone was assessed in this experiment. First, we made the transverse fracture model on the anterior part of cortical bone of fresh human tibia shaft. After 24 hours of bonding, the tensile strength, shear strength and angular strength were tested; then we made the bonding for the second time and third time, tested the tensile strength, shear strength and angular strength respectively, and observed the change of tensile strength, shear strength and angular strength. We found the shear strength of the primary bonding being greater than that of the second bonding and the third bonding (P<0.05). The shear strength of the second bonding and the third bonding showed no statistically significant difference. The tensile strength, elastic modulus, rigidity coefficient and moment of area inertia exhibited no statistically difference between the first, second and third bonding. The repeated bonding of octyl-a-cyanoacrylate adhesive will change the morphologic characteristics of the bone surface, this will decrease the shear strength during the experiment. When the shear strength test is to be repeated, the residue of the adhesive on the surface of the bone bonded area should be removed. During clinical application, bonding should be performed only once in the area for resisting the shear strength.