Are all Thierry's spatulas the same? A simulation study comparing various available models.

Area of Science:

• Obstetrics and Gynecology
• Biomechanics
• Medical Device Engineering

Background:

• Thierry's spatulas are key instruments for assisted vaginal births, designed to minimize fetal head traction.
• Variations in Thierry's spatula models exist, but their biomechanical implications are not well understood.
• Understanding these biomechanical differences is crucial for optimizing assisted delivery outcomes.

Purpose of the Study:

• To compare the biomechanical performance of different Thierry's spatula models.
• To evaluate the impact of spatula design variations on force applied to the fetal head.
• To assess the influence of obstetrician experience on instrument effectiveness.

Main Methods:

• A simulation-based, prospective, randomized study involving six obstetricians and 108 simulated assisted births.
• Evaluation of three distinct Thierry's spatula models.
• Measurement of traction force, perineal pressure, operative time, and subjective difficulty.

Main Results:

• Significant biomechanical differences were found among spatula models, with the original model applying the least force (15 N).
• More experienced obstetricians (>15 years) applied significantly less traction force than less experienced ones (<5 years).
• Both spatula model and obstetrician experience were independently associated with the force applied to the fetal head.

Conclusions:

• Thierry's spatula models demonstrate distinct biomechanical properties, with the original design being the least forceful.
• Obstetrician experience is a significant factor in the performance of Thierry's spatulas.
• Awareness of model-specific differences and adequate training are essential for safe and effective use in operative births.