Does the Anchor Eye Alignment Affect the Performance of the Rotator Cuff Repair? A Biomechanical Study

Area of Science:

• Orthopedic biomechanics
• Surgical implant research

Background:

• Metallic screw-in suture anchors are utilized in orthopedic procedures.
• Proper anchor placement is crucial for optimal biomechanical performance.
• The influence of eyelet alignment on anchor performance requires further investigation.

Purpose of the Study:

• To evaluate the failure mode and load to failure of metallic screw-in anchors.
• To compare anchor performance with two distinct eyelet alignments: malpositioned versus manufacturer-recommended.
• To assess the biomechanical integrity of the bone-anchor-suture construct in ovine humeri.

Main Methods:

• Sixteen ovine humeri were used, with metallic anchors and polyethylene sutures inserted.
• Anchors were divided into two groups: malpositioned eyelets (Group 1) and aligned eyelets (Group 2).
• Cyclic loading followed by load-to-failure testing was performed to determine ultimate load and failure modes.

Main Results:

• No significant difference was observed in the mean ultimate failure load between the malpositioned (Group 1) and aligned (Group 2) eyelet groups (P = .472).
• Failure modes were similar between the two groups, indicating no substantial impact of eyelet alignment on structural integrity.

Conclusions:

• Eyelet alignment does not significantly alter the failure mode or load to failure for metallic screw-in suture anchors.
• The positioning of the anchor eyelet in the greater tuberosity does not directly influence the biomechanical performance of the bone-anchor-suture system.
• These findings support the robustness of this anchor model regardless of minor eyelet malpositioning.