3D-Printed Double-Helical Biodegradable Iron Suture Anchor: A Rabbit Rotator Cuff Tear Model

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Materials Engineering

Background:

• Suture anchors are crucial for rotator cuff tear surgery.
• Advancements in 3D printing enable the development of biodegradable metals for orthopedic use.
• Biodegradable Fe suture anchors offer a potential alternative to traditional titanium anchors.

Purpose of the Study:

• To compare the performance of 3D-printed biodegradable Fe suture anchors against commercial Ti suture anchors.
• To evaluate the in vitro and in vivo biomechanical properties and bone integration of Fe suture anchors.

Main Methods:

• Three-dimensional-printed biodegradable Fe suture anchors and commercial Ti suture anchors were used.
• In vitro testing involved polyurethane foam blocks and rabbit bone to assess ultimate failure load.
• Static immersion tests measured the corrosion rate of Fe anchors.
• In vivo studies on rabbits involved reattaching supraspinatus tendons and analyzing bone integration via micro-computed tomography and histology.

Main Results:

• In vitro studies showed similar ultimate failure loads for both Fe and Ti anchors.
• The corrosion rate of Fe anchors was measured at 0.049 ± 0.002 mm/year.
• In vivo, Fe anchors demonstrated superior ultimate failure load at 6 weeks post-surgery.
• Micro-computed tomography and histology revealed enhanced bone volume and density around Fe anchors.

Conclusions:

• 3D-printed biodegradable Fe suture anchors exhibit comparable in vitro performance to Ti anchors.
• Fe suture anchors show superior in vivo biomechanical strength and promote better bone integration compared to Ti anchors.
• These findings suggest that 3D-printed Fe suture anchors outperform current Ti anchors for rotator cuff repair.