Mechanical analysis of resorbable plates for long-term soft-tissue molding

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Pediatric Craniofacial Surgery

Background:

• Resorbable plates are increasingly utilized in pediatric craniofacial surgery.
• Novel applications involve long-term soft-tissue molding, though plates weren't designed for this.
• The mechanical stability of these plates under prolonged out-of-plane bending remains unaddressed.

Purpose of the Study:

• To evaluate the mechanical rigidity and stability of resorbable plates during prolonged out-of-plane bending.
• To assess the suitability of current resorbable plate designs for soft-tissue molding applications.

Main Methods:

• Ten types of resorbable plates were bent to a right angle.
• Plates were subjected to an 80-g load at body temperature for 2 weeks.
• Angle height was measured to assess maintenance of out-of-plane bend, with 3 successive tests per plate.

Main Results:

• All tested resorbable plates exhibited a decrease in angle height over the 2-week period.
• Plate thickness correlated with mechanical rigidity and the ability to sustain out-of-plane bends.
• Synthes PLGA (85/15) 1.2-mm and BioGeneral PLA (poly-D,L-lactic acid) 1.0-mm plates demonstrated superior performance.

Conclusions:

• No resorbable plates tested maintained their initial out-of-plane bend over 2 weeks.
• Current resorbable plates are inadequate for long-term soft-tissue molding applications requiring sustained out-of-plane stability.
• Industry collaboration is necessary to enhance resorbable plate mechanical properties for these specialized uses.