Surgical needle design: torsion resistance

Area of Science:

• Surgical instrumentation
• Biomechanical engineering
• Materials science

Background:

• Needle-forceps stability is crucial for surgical procedures, especially with blunt-point needles.
• Quantifying rotational and twisting resistance at the needle-forceps interface assesses stability.
• MO and CT needles are commonly used for soft tissue closure requiring high closure strength.

Purpose of the Study:

• To compare the rotational and twisting stability of MO and CT surgical needles.
• To document and quantify differences in needle-forceps junction resistance.
• To evaluate the suitability of MO needles for blunt-point applications.

Main Methods:

• Assessed needle-forceps stability using a digital torque meter (Hios HP-10).
• Measured resistance to rotation and twisting for both CT and MO needles.
• Compared quantitative stability data between the two needle types.

Main Results:

• No significant difference in twisting resistance between MO and CT needles.
• MO needles demonstrated 25% greater resistance to rotation compared to CT needles.
• Observed rotational resistance difference varied by 10% from theoretical expectations.

Conclusions:

• Needle geometry significantly impacts rotational resistance but not twisting resistance.
• MO needles provide superior rotational stability over CT needles.
• Study design accounted for discrepancies between expected and observed rotational differences.