Cannulated disposable torque limiting device with plastic shaft

A method, comprising:

• providing to a workpiece a torque-limiting driver comprising:
• a body having a handle comprising a lumen;
• an upper cylindrical shank;
• a lower cylindrical shank having a square drive socket;
• a nut;
• a spring between the upper cylindrical shank and the nut, wherein the spring is configured to apply a force across the upper cylindrical shank and the lower cylindrical shank;
• a shaft having a workpiece-engaging tip and a square drive connection engaged within the square drive socket of the lower cylindrical shank, the shaft extending axially through the lower cylindrical shank, the upper cylindrical shank, the spring, and the handle with an end portion of the shaft disposed within the lumen of the handle, the shaft having a plurality of thread rests on a portion of the shaft, the thread rests cut and engaged by a threading in the nut, the shaft having a lumen extending across an axial length of the shaft, and the shaft comprising a plastic material or a composite including plastic;
• applying an applied torque to the torque-limiting driver, whereby the upper cylindrical shank and the lower cylindrical shank engage for relative rotation if the applied torque does not exceed the predetermined torque limit, and whereby the upper cylindrical shank and the lower cylindrical shank disengage if the applied torque exceeds the predetermined torque limit;
• and
• delivering a device or material to the workpiece through the lumen.

A method, comprising:

• providing to a workpiece a torque-limiting driver comprising:
• a body having a handle comprising a lumen;
• an upper cylindrical shank;
• a lower cylindrical shank having a square drive socket;
• a nut;
• a spring between the upper cylindrical shank and the nut, wherein the spring is configured to apply a force across the upper cylindrical shank and the lower cylindrical shank;
• a shaft having a workpiece-engaging tip and a square drive connection engaged within the square drive socket of the lower cylindrical shank, the shaft extending axially through the lower cylindrical shank, the upper cylindrical shank, the spring, and the handle with an end portion of the shaft disposed within the lumen of the handle, the shaft having a plurality of thread rests on a portion of the shaft, the thread rests cut and engaged by a threading in the nut, the shaft having a lumen extending across an axial length of the shaft, and the shaft comprising a plastic material or a composite including plastic;
• wherein the upper cylindrical shank and the lower cylindrical shank engage for relative rotation, and wherein the upper cylindrical shank and the lower cylindrical shank disengage when a predetermined value of torque is exceeded;
• aligning the torque-limiting driver relative to the workpiece by use of a guidewire delivered through the lumen of the shaft;
• and,
• applying an applied torque to the torque-limiting driver, whereby the upper cylindrical shank and the lower cylindrical shank engage for relative rotation if the applied torque does not exceed the predetermined torque limit, and whereby the upper cylindrical shank and the lower cylindrical shank disengage if the applied torque exceeds the predetermined torque limit.