Novel crescent drill design and mechanistic force modeling for thrust force reduction in bone drilling

Area of Science:

• Biomaterials Engineering
• Orthopedic Surgery
• Mechanical Engineering

Background:

• Bone drilling can cause mechanical damage and thermal necrosis, impacting surgical quality and patient recovery.
• Controlling cutting forces and bone temperature is essential for optimizing surgical tools.

Purpose of the Study:

• To design a novel crescent drill bit with an improved positive rake angle to minimize thrust force and thermal elevation.
• To develop a mechanistic model for predicting thrust force and torque in bone drilling for different drill bit geometries.

Main Methods:

• A mechanistic model was developed in a polar coordinate system to calculate cutting forces for twist and crescent drill bits.
• Drilling experiments were conducted using both drill bit types under various cutting conditions.

Main Results:

• The proposed mechanistic model showed good agreement with experimental data.
• The novel crescent drill bit significantly reduced thrust force and bone temperature below the thermal threshold.
• The tool design enabled effective coolant-free drilling.

Conclusions:

• The crescent drill bit design is effective in reducing mechanical damage and thermal necrosis during bone drilling.
• The developed mechanistic model accurately predicts drilling forces.
• This innovation presents a viable clinical option for coolant-free orthopedic drilling procedures.