Mechanical comparison of 3 anchoring techniques in the muscular process for laryngoplasty in the equine larynx.
Authors: Lechartier Antoine, Rossignol Fabrice, Brandenberger Olivier, Vitte Amelie, Mespoulhès-Rivière Céline, Rossignol Anthony, Boening Karl Joseph
Journal: Veterinary surgery : VS
Summary
Recurrent laryngeal neuropathy (RLN) is a significant performance-limiting condition in horses, and laryngoplasty—which anchors the muscular process of the arytenoid cartilage to restore airway patency—remains the most common surgical intervention, yet the optimal fixation method remains debated. Researchers subjected 60 equine larynges to mechanical testing of three anchoring techniques: a single suture loop (SL), a surgical screw (SC), and a double suture loop (DL), evaluating their behaviour under both simulated physiological loading (3000 cycles of 5–50 N oscillation) and ultimate failure loads. The screw technique demonstrated superior stability under cyclic loading with minimal slippage (1.54 mm distraction), whilst the double loop construct withstood the highest single load to failure at 240 N—substantially stronger than the screw (189.59 N) or single loop (150.93 N)—though it failed through cartilage tearing rather than anchor displacement. These findings suggest that whilst screw fixation offers biomechanical advantages for resisting the repetitive respiratory forces encountered in athletic horses, the double loop technique may provide better margins of safety if immediate intraoperative complications or unexpected loading occurs, making technique selection dependent on individual case assessment and surgeon familiarity.
Read the full abstract on PubMed
Practical Takeaways
- •Screw anchoring may be preferred clinically because it maintains superior stability during the repetitive loading cycles that occur during swallowing and exercise, despite lower ultimate failure strength
- •Double loop technique offers highest load-to-failure capacity but experiences greater movement during cyclic loading, which may compromise long-term construct stability
- •Choice of anchoring technique should balance static strength (favour double loop) against dynamic stability during function (favour screw)
Key Findings
- •Double loop technique had greatest ultimate failure load (240±44.56 N) compared to screw (189.59±46.16 N) and single loop (150.93±44.43 N)
- •Screw technique showed greatest stability during cyclic loading (distraction 1.539±0.9 mm) with no significant difference from single loop
- •Screw technique failed by pull-out (n=13) or knot slippage (n=4) while double and single loop techniques failed by cartilage tearing
- •Double loop technique is strongest in single cycle failure testing but screw technique provides superior stability during repetitive cyclic loading