Radioisotopic evaluation of bone repair after experimental surgical trauma.

BACKGROUND Scientific approach of the bone reaction after surgical procedures provides valuable information on methods and techniques. The purpose of this study was to follow this process using a radioisotope marker of bone remodelling. MATERIAL AND METHODS Two bone cavities were created (one for every tibia) in adult Wistar male rats using a 0.5 mm spherical burr; left tibial cavities were filled with bovine freeze-dried bone; the right ones were left unfilled for control. Scintigrams were done with sodium methylene diphosphonate (MDP) labelled with radioactive pertechnetate (99mTcO4-) to evaluate the inflammatory response and the local osteoblastic activity. The evolution of bone repair was additionally evaluated by light microscopy. RESULTS Our results have shown that the highest bone activity was recorded between the 7th and the 14th day after surgery. The morphological analysis confirmed the results obtained with radioisotope analysis and did not reveal significant differences regarding the evolution of bone repair between the filled and the unfilled defects. CONCLUSION We confirmed that 99mTc -MDP is a valuable tool to study bone repair, as it was able to show subtle alterations of bone activity even in lesions as small as those created herein (0.5 mm wide, 0.5 mm deep).