Pressure changes during reaming with different parameters and reamer designs

Reaming increases intramedullary pressure and can cause fat intravasation. This study investigated the influence of reaming parameters on pressure changes using the AO, Gray, and Howmedica reamers. Silicone cylindrical shells with 10-, 11-, 16-, 19-, and 20-mm inner diameters were filled with a 1:2 ratio of paraffin and petroleum jelly. The 10- and 11-mm shells were reamed using a 9-mm reamer, the 16-mm shells with a 14-mm reamer, and the 19- and 20-mm shells with an 18-mm reamer. Each experiment was performed seven times while singularly varying driving speeds of 15, 30, and 50 mm per second, with a revolution rate of 150, 250, and 500 revolutions per minute. Using stepwise linear regression analysis, driving speed was the most significant parameter. The lowest pressure increases occurred at the lowest driving speed and the highest revolution rate in all cylinders. The model used for this study did not take into consideration the interaction between the cortical shell and reamer head. The results of this study suggest that reaming should be done at a low driving speed and a high revolution rate using a small cored reamer head, especially during the first reaming steps.