Navicular ligaments stabilize the coffin joint.

• A. Seasmoidean ligaments
• B. Medial collateral ligaments
• C. Pastern joint ligaments
• D. Navicular ligaments

Answer: (D)

The stability of the coffin joint comes from the navicular apparatus, which includes the navicular bone and the ligaments that bind it to the coffin and with the deep digital flexor system. The navicular ligaments specifically anchor the navicular bone and help keep the distal interphalangeal joint in proper alignment, resisting hyperextension and abnormal movement when the foot bears weight. That direct, stabilizing role for the coffin joint makes the navicular ligaments the correct choice. The other ligaments are associated with other joints (for example, the sesamoidean ligaments with the fetlock region, and the pastern joint ligaments with the proximal interphalangeal joint), so they don’t directly stabilize the coffin joint.