Articulatio interphalangea proximalis
The proximal phalanx (long pastern, P1) and middle phalanx (short pastern, P2) form the pastern region. P1 extends from the fetlock joint to the pastern joint; P2 extends from the pastern joint to the coffin joint. The pastern joint (proximal interphalangeal or PIP joint) between P1 and P2 is a lower-motion joint that contributes to shock absorption and allows limited flexion and extension. The superficial digital flexor tendon inserts near this joint, and the deep digital flexor tendon passes behind it. P1 is one of the most commonly fractured bones in racehorses, particularly sagittal fractures. The angle of the pastern affects concussion absorption; a more upright pastern transmits more force upward.
Ringbone (osteoarthritis of the pastern joint) is a common condition that can cause progressive lameness. P1 fractures are significant injuries in racehorses. Disease of the pastern joint can alter limb biomechanics and indirectly affect loading of the foot and navicular region. Diagnosis uses clinical examination, nerve blocks, and radiographs; advanced imaging is sometimes needed.
Shortened stride, heat or swelling over the pastern, or reluctance to work on hard ground should be evaluated. Correct hoof balance and appropriate shoeing help manage many pastern issues.
Ringbone (osteoarthritis of the pastern joint) is a common condition that can cause progressive lameness. P1 fractures are significant injuries in racehorses. Disease of the pastern joint can alter limb biomechanics and indirectly affect loading of the foot and navicular region. Diagnosis uses clinical examination, nerve blocks, and radiographs; advanced imaging is sometimes needed.
Shortened stride, heat or swelling over the pastern, or reluctance to work on hard ground should be evaluated. Correct hoof balance and appropriate shoeing help manage many pastern issues.
See the Pastern Joint (Proximal Interphalangeal Joint / PIP Joint) on our interactive 3D horse model. Open 3D Model