Knotless Anchors in Acetabular Labral Repair: A Biomechanical Comparison.

Area of Science:

• Orthopedic surgery
• Biomechanical engineering
• Materials science

Background:

• Acetabular labral tears are common in hip arthroscopy.
• Suture anchors are used to repair these tears.
• Knotless anchors offer potential advantages over traditional knotted anchors.

Purpose of the Study:

• To analyze the failure mechanisms of acetabular knotless suture anchors.
• To compare the stiffness and pullout strength of various knotless anchors.
• To evaluate the clinical relevance of anchor properties for labral healing.

Main Methods:

• Seven knotless suture anchors were tested in synthetic bone blocks.
• Anchors were subjected to pullout testing at a rate of 1 mm/s.
• Stiffness, load at displacement, and maximum load were measured.
• A knotted anchor served as a baseline for comparison.

Main Results:

• Stiffness was highest for Pushlock, SpeedLock HIP, and Knotilus anchors.
• SpeedLock HIP and Pushlock showed significantly higher loads at 1 mm and 2 mm displacement, respectively.
• Knotilus and Bioraptor knotted anchor exhibited the highest maximum load.

Conclusions:

• Most knotless anchors failed by suture pullout, except Knotilus 3.5.
• Anchors with high maximum load had lower stiffness.
• Stiffness and load at relevant displacements are critical for predicting early clinical performance.