Equine Joint Luxations Study Guide

Overview and Clinical Importance

Joint luxation (dislocation) in horses refers to the complete displacement of articular surfaces, while subluxation represents partial separation. These injuries are relatively uncommon in horses compared to other species due to the robust ligamentous support of equine joints. However, when they occur, they represent significant orthopedic emergencies requiring prompt diagnosis and treatment.

Joint luxations in horses most commonly affect the coxofemoral (hip) joint, fetlock (metacarpophalangeal/metatarsophalangeal) joint, proximal interphalangeal (pastern) joint, stifle (femoropatellar/femorotibial) joint, and carpus. Additionally, tendon luxations, particularly of the superficial digital flexor tendon from the calcaneus, are clinically important conditions.

Coxofemoral (Hip) Joint Luxation

Anatomy and Pathophysiology

The coxofemoral joint is a ball-and-socket joint formed by the femoral head and the acetabulum. This joint is stabilized by the ligament of the femoral head (round ligament), the accessory femoral ligament (unique to horses), and the fibrocartilaginous acetabular rim. These structures provide robust support, making complete luxation relatively rare in adult horses.