Pressure changes during reaming with different parameters and reamer designs

Intramedullary pressure changes during reaming are a known concern in orthopedic surgery. Prior research has shown that reaming can elevate pressure and potentially lead to complications like fat intravasation. However, the specific effects of reaming parameters and reamer design on pressure remain unclear. This gap motivated the need to explore how driving speed, revolution rate, and reamer size influence pressure dynamics. No prior work had resolved the relative impact of these variables in a controlled setting. Understanding these factors could improve surgical protocols. The study aimed to address this uncertainty by testing multiple reamer types and conditions. The absence of a standardized approach to reaming parameters highlights the need for evidence-based guidelines. This research contributes to the broader field of surgical biomechanics by focusing on pressure dynamics.

This study aimed to evaluate how reaming parameters affect intramedullary pressure during orthopedic procedures. The researchers focused on driving speed, revolution rate, and reamer design as key variables. They sought to determine which factors most strongly influence pressure changes. The motivation came from the clinical risk of fat intravasation linked to high pressure. The study compared three reamer types: AO, Gray, and Howmedica. They tested different reamer sizes and speeds in a controlled model. The goal was to identify optimal reaming conditions that minimize pressure. This work provides a foundation for refining surgical techniques in orthopedic settings.

The researchers used silicone cylindrical shells to simulate bone structures. These shells had inner diameters of 10, 11, 16, 19, and 20 mm. The shells were filled with a 1:2 paraffin and petroleum jelly mixture. Reaming was performed using three reamer types: AO, Gray, and Howmedica. Each reamer size was matched to a specific shell size. Driving speeds tested were 15, 30, and 50 mm per second. Revolution rates tested were 150, 250, and 500 revolutions per minute. Each experiment was repeated seven times to ensure reliability. The model did not account for interactions between the reamer head and cortical shell.

Driving speed was identified as the most significant factor affecting pressure changes. The lowest pressure increases occurred at the lowest driving speed and highest revolution rate. The 9-mm reamer produced the smallest pressure increases in 10- and 11-mm shells. The 14-mm reamer showed similar trends in 16-mm shells. The 18-mm reamer was used for 19- and 20-mm shells with consistent results. Pressure values were consistently lower at 15 mm/s and 500 rpm. The AO, Gray, and Howmedica reamers all showed similar trends. The model did not include reamer-cortical interactions. These findings suggest that reaming parameters can be optimized to reduce pressure.

The study suggests that reaming should be performed at low driving speeds and high revolution rates. Using a small cored reamer head is recommended, especially during the first reaming steps. The results indicate that driving speed has the greatest impact on pressure. The model did not account for reamer-cortical interactions, which may affect real-world outcomes. The findings support the use of AO, Gray, or Howmedica reamers under these conditions. The optimal combination of speed and revolution rate minimizes pressure increases. The authors propose that these findings could improve surgical safety. They emphasize the need to consider reamer size and speed in clinical settings.