Fractures
Proximal Sesamoid Bones
Basic Information 
Clinical Presentation
Physical Exam Findings
• All except abaxial nonarticular fractures result in metacarpophalangeal or metatarsophalangeal joint effusion and moderate to severe lameness.
• The horse may have soft tissue swelling around the sesamoid bones.
• Weight bearing on the toe is common.
• Mild to moderate pain on flexion of the fetlock joint is seen.
Etiology and Pathophysiology
• Occur as a result of excessive tension on the suspensory apparatus
• Hyperextension during maximal loading may produce tensile forces on the sesamoid bones, exceeding their internal strength.
• Sufficient exercise results in increased strength of the suspensory ligament, increasing the likelihood of sesamoid fractures versus injury to the suspensory ligament in unfit horses.
