Cyclic testing reliability analysis on a novel light-curable bone fixation technique.

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Mechanical Engineering

Background:

• Current metal fixation for bone fractures lacks patient specificity and can cause soft tissue adhesions.
• A novel light-curable bone fixation, AdhFix, offers in situ customizability and reduced soft tissue adhesion.
• Previous AdhFix studies focused on monotonic failure in dry conditions, necessitating evaluation in physiological environments.

Purpose of the Study:

• To cyclically test the AdhFix osteosynthesis technique in a near-physiological environment at relevant force levels.
• To assess the clinical efficacy and mechanical stability of AdhFix under simulated rehabilitation loading conditions.

Main Methods:

• Ovine proximal phalanges underwent midshaft osteotomies and fixation with the AdhFix technique.
• Constructs were subjected to cyclic four-point bending (12,600 cycles) in Ringer solution at 37°C.
• Samples were divided into four groups, tested at peak forces corresponding to 100x, 150x, 175x, and 250x physiological bending moments.

Main Results:

• All samples in the 100x group survived, while all in the 250x group failed.
• Kaplan-Meier survival analysis showed significantly different survival curves between groups (p < 0.001).
• Final cycle displacement amplitude was statistically significant (p < 0.001), indicating mechanical performance differences.

Conclusions:

• The AdhFix osteosynthesis method demonstrated survival under clinically relevant cyclic loading (100x bending loads).
• This novel fixation technique shows potential as a durable alternative to traditional metal implants for bone fracture repair.
• Further research is required to confirm AdhFix safety and efficacy across various fracture conditions and physiological stresses.