Contribution of Palmar Radiocarpal and Ulnocarpal Ligaments to the Stability of the Canine Antebrachiocarpal Joint

Objective The aim of this study was to evaluate the contribution of the palmar radiocarpal ligament and the palmar ulnocarpal ligament to canine antebrachiocarpal joint stability. Materials and Methods The right carpus of four dog cadavers, free of musculoskeletal pathology, was stripped of muscle. Each specimen was placed into a custom-made joint testing machine and tested at 15° extension, and 0° and 15° flexion. A single motion tracking sensor was fixed to the metacarpal bones. All specimens were tested with all ligaments intact and after transection of the palmar radiocarpal and ulnocarpal ligaments. A range of weights between 0.2 and 2.0 kg was used to test the carpi in three directions (axial, medial/lateral and cranial/caudal) and two moments (pronation/supination and valgus/varus). Results No differences were found between the translations and rotations of the manus relative to the radius and ulna with the ligaments intact and the ligaments transected at any of the carpal angles tested, except at 15° of flexion. Increasing the angle of flexion resulted in a significant increase in cranial and caudal translation of the manus relative to the radius and ulna both in the intact and transected specimens. Clinical relevance Antebrachiocarpal joint position plays a more important role in craniocaudal antebrachiocarpal joint stability than the palmar radiocarpal and ulnocarpal ligaments.