So You Think You Don't Plunge? An Assessment of Far Cortex Drill Tip Plunging Based on Level of Training.

Drill bit tip plunging past the far cortex places critical anatomical structures at risk. This study measured plunging past the far cortex based on level of training. The time required for screw placement when a depth gauge was used to measure bone tunnel depth was compared to the time required for screw placement when bone tunnel depth was measured in real time.Thirty orthopedic surgery staff with 1-37 years of experience applied 10-hole plates to cadaveric limbs. Procedures were performed using two different drilling systems. Time and plunge depth were recorded.Penetration past the far cortex ranged from an average of 11.9 mm in the novice group to an average of 6.1 mm in the experienced group (P <0.001). The time required to drill and place a screw decreased by an average of 14 seconds per screw when depth gauge use was eliminated.Penetration past the far cortex occurred at all levels of training, but decreased with increased levels of experience. Real time measurement of bone tunnel length decreased total drilling time. The time saved with real time measurement decreased with increased level of experience.