In vitro comparison of linear vs triangular screw configuration to stabilize complete uniarticular parasagittal fractures of the proximal phalanx in horses.
Authors: Labens Raphael, Khairuddin Nurul H, Murray Mark, Jermyn Kieri, Ahmad Roohi S
Journal: Veterinary surgery : VS
Summary
# Editorial Summary Proximal phalanx fractures remain a significant challenge in equine orthopaedics, and achieving stable fracture reduction under load is critical for successful healing and return to function. Labens and colleagues compared two surgical configurations for stabilising complete parasagittal P1 fractures in vitro: a two-screw linear arrangement versus a three-screw triangular pattern, using cadaver limbs subjected to computed tomography imaging under both unloaded and simulated walking loads. The triangular configuration demonstrated substantially superior fracture gap reduction regardless of loading conditions (P = 0.003 unloaded; P < 0.001 loaded), whilst linear repairs showed significant fracture gap distraction under load—a clinically concerning finding that suggests inadequate stability during weight bearing. Notably, loading conditions produced fair to excellent interobserver agreement in detecting gap widening, particularly in linear repairs (κ = 0.81), lending confidence to the measurements. For practitioners managing these challenging fractures, the triangular three-screw approach appears biomechanically advantageous during the critical postoperative weight-bearing phase, potentially improving long-term outcomes, though clinical validation and assessment of healing rates would strengthen recommendations for routine adoption of this technique.
Read the full abstract on PubMed
Practical Takeaways
- •Use triangular (3-screw) configuration instead of linear (2-screw) for proximal phalanx fracture repairs to achieve better fracture reduction and maintain stability under weight-bearing loads
- •Linear 2-screw repairs show concerning fracture gap widening when weight is applied; if 3-screw fixation is not possible, expect increased risk of complications during rehabilitation
- •This biomechanical advantage of triangular fixation supports earlier and more aggressive postoperative rehabilitation protocols in horses undergoing P1 fracture repair
Key Findings
- •Triangular 3-screw configuration provided significantly better fracture gap reduction than linear 2-screw configuration in both loaded and unloaded states (P=0.003 unloaded, P<0.001 loaded)
- •Linear repairs showed significant fracture gap distraction under simulated walking loads (P=0.008), while triangular repairs remained more stable
- •Interobserver agreement for fracture gap assessment was excellent in linear repairs (κ=0.81) and fair in triangular repairs (κ=0.53)
- •Triangular repair configuration reduced fractures better irrespective of loading condition, suggesting improved biomechanical stability during postoperative weight bearing