Precise Torque is Clinically Important
Cold welding which leads to screw breakage and stripping can make screw removal challenging.
Screw loosening requires revision surgery, which can effect outcomes.
“The mechanical stability of locked screws is significantly compromised by loose insertion, off-axis insertion, or severe distortion of the locking mechanism.”
-Dr. William Ricci
Past President Orthopaedic Trauma Association, Chief of Orthopaedic Trauma at HSS/NYP
"All screws inserted with thread-damaging torque and single cortex engaging screws inserted to high torque tightening moments showed diminished holding strength. This loss of strength amounted to 40%-50% less than screws inserted with less torque."
-Dr. James Jastifer
Clinical Professor,Department of Orthopaedic Surgery at WMU Homer Stryker
Cumulative number of reportable screw loosening
The Accuracy, Reliability, and Calibration (ARC) study found that of the reusable torque limiters in hospitals 31% were out of calibration. The majority of those out of calibration were lower than the specified tolerance band, indicating that surgeries using these torque limiters would not achieve as much torque as the surgeon expects, possibly leading to loosening screws within the patient over time.
