Radiographic and histopathologic evaluation of inhibitory effects of Tramadol and Metamizol on experimental bone defect healing in rabbit tibia

Nonsteroidal anti-inflammatories and opioids are of drugs that have been widely used to manage the pain after orthopedic surgery in human and animals. The purpose of this study was to compare the inhibitory effects of metamizol and tramadol on bone defect healing in rabbit tibia. In this study, thirty male New Zealand white rabbits were divided into two groups. A 5 mm in diameter circular defect was created on the medial surface of the tibial metaphyseal region of the right foot of each rabbit. Respectively, in metamizole and tramadol groups, metamizole, 5 mg / kg and tramadol 4 mg/ kg were subcutaneously administrated In a 5-day course of treatment every 12 hours and then every 24 hours during a three-day. Defect healing was assessed by obtaining radiographs on 0, 7, 14, 21, 28, 35, 42 days after surgery. Also, histopathologic evaluation was done at 7, 21 and 45 days using Goldner’s trichrome staining. It also represents a faster start filling defect in the histopathological study, following administration of tramadol compared with metamizole. Also, at the end of the study, tramadol achived more filling defect points compared with metamizole. The results of this study showed that the beginning of the process of callus formation in metamizol was later than tramadol, so there was a significant difference between groups, in the formation of callus so that in the radiographs taken on 14, 28 and 35 days. The results of this study showed that in comparison with Tramadol, metamizol has more effects in slowing bone repair.