Failure of suture material at suture anchor eyelets

Area of Science:

• Orthopedic Surgery
• Biomaterials Engineering
• Musculoskeletal Research

Background:

• Suture anchors are crucial for soft tissue to bone repair.
• Suture material failure at the anchor eyelet is a known complication.
• Understanding anchor eyelet biomechanics is vital for surgical success.

Purpose of the Study:

• To evaluate the load strength at which suture material fails within different metallic suture anchor eyelets.
• To identify the influence of eyelet design and loading conditions on suture failure.
• To compare the performance of various metallic suture anchor models.

Main Methods:

• A biomechanical study involving 22 metallic suture anchor models.
• Tensile load at failure and failure mode of Ethibond No. 2 suture material were recorded.
• Sutures were pulled at varying angles (straight, 45 degrees) and orientations until failure using an Instron materials testing machine.

Main Results:

• All suture failures occurred at the anchor eyelet.
• Failure loads varied significantly based on loading angle, ranging from 69 N to 226 N.
• Specific anchors like Statak, Corkscrew, and PeBA showed higher load-bearing capacities.
• Suture failure direction was influenced by the presence of sharp edges on the eyelet.

Conclusions:

• Metallic suture anchor eyelets can cut suture material, reducing its effective strength.
• Sharp edges on eyelets significantly decrease failure load, potentially to 73% below the suture's breaking strength.
• Anchor design, particularly suture-protecting channels, and suture loading orientation are critical factors affecting failure load.