Biomechanical Assessment of the Collateral Ligament of the Distal Interphalangeal Joint of the Horse Following Alterations to the Palmar Angle—A Cadaveric Study

Therapeutic shoeing for horses is used to affect the palmar angle (PA) of the distal phalanx. These changes may influence the strain on the distal interphalangeal joint collateral ligaments (DIJCLs). This cadaveric study aimed to assess DIJCL strain under varying loads and PA adjustments. Using 26 cadaver forelimbs, eight optical markers were placed on one DIJCL for strain measurement under five different loads (1000-5000 newtons) at a neutral PA, followed by PA increases of 2°, 4°, and 6° and decreases of -2° and -4°. The results indicate that increases in PA corresponded to significantly higher strain in the distal and mid distal portions, while 2° and 4° decreases in PA significantly reduced the strain in the proximal regions of the DIJCLs. Limitations include potential discrepancies between a cadaver and live biomechanics. This study concludes that increased PA increases distal DIJCL strain, while decreased PA decreases proximal strain. Further research is recommended to evaluate the practical implications of these findings in DIJCL injuries in horses.