Short Expandable-Wing Suture Anchor for Osteoporotic and Small Bone Fixation: Validation in a 3D-Printed...

Area of Science:

• Orthopedic biomechanics
• Biomaterials engineering
• Surgical device innovation

Background:

• Suture anchors are crucial for tendon and ligament repair.
• Current anchors face challenges with fixation strength in osteoporotic bone and limited bone volumes.
• Existing designs can lead to bone penetration and inadequate cortical engagement.

Purpose of the Study:

• To develop and evaluate a novel short expandable-wing (SEW) suture anchor.
• To enhance pull-out resistance and fixation stability, particularly in compromised bone conditions.
• To compare the SEW anchor's performance against conventional anchors and existing fixation methods.

Main Methods:

• Development of a novel SEW suture anchor made from Ti6Al4V with a deployable wing mechanism.
• Finite element analysis (FEA) using CT-derived bone properties to assess intra-bone displacement and load transfer.
• Mechanical testing on artificial bone surrogates (normal and osteoporotic) to determine static and cyclic pull-out strength.
• Performance evaluation in a 3D-printed anatomical model for coracoclavicular ligament reconstruction.

Main Results:

• FEA indicated reduced intra-bone displacement and improved load transfer for the SEW anchor.
• Significantly higher static pull-out strength was observed in both normal (581 N) and osteoporotic bone (377 N) compared to controls (p < 0.05).
• SEW anchor fixation strength increased by 25-56% after cyclic loading and demonstrated nearly double the fixation strength of hook plates in a ligament reconstruction model.

Conclusions:

• The SEW suture anchor effectively enhances pull-out resistance through its deployable wing mechanism.
• It overcomes limitations of conventional anchors in osteoporotic bone and small bone volumes like the coracoid process.
• The SEW anchor shows significant potential for improved clinical translation in orthopedic repairs requiring robust fixation.