Arthroscopically Accessible Anatomy of the Tarsal Collateral Ligaments in the Horse

Abstract Objective To describe the arthroscopically accessible anatomy of the tarsal collateral ligaments in the horse. Study Design Descriptive study. Animals Cadaveric equine hind limbs (n = 24) obtained from horses without tarsal disease. Methods Two pairs of tarsal joints were used to obtain silicone models of the tarsocrural joint and dissect the tarsal collateral ligaments (CLs). Ten pairs of tarsocrural joints had arthroscopic exploration and the accessible parts of the tarsal CLs were marked with an arthroscopic hook knife. Subsequently, the limbs were dissected and the marked positions were allocated to the specific parts of the CLs. Results Ipsilateral arthroscope and instrument portals were used in each pouch of the tarsocrural joint. Via the plantaromedial pouch, the superficial (2/20 limbs), middle (7), deep (6) or both middle and deep (3) short medial CL and the long medial CL (14) were reached. Access via the plantarolateral pouch allowed manipulation of the deep short lateral CL (20/20 limbs) and the long lateral CL (20). Dorsally, arthroscopy via the dorsomedial pouch gave access to the deep short medial CL (20/20 limbs), while the superficial (9) or middle (10) or both superficial and middle (1) short lateral CL could be reached via the dorsolateral joint recess. Conclusions Limited parts of the tarsal CLs can be observed or manipulated arthroscopically in normal equine tarsocrural joints.