Articulatio interphalangea distalis
The coffin joint (distal interphalangeal or DIP joint) is the articulation between the middle phalanx (P2) and the distal phalanx (P3), with the navicular bone contributing to the palmar/plantar aspect. It is a high-motion hinge joint that allows flexion and extension of the foot and absorbs significant forces at break-over. The joint capsule extends proximally; direct communication with the navicular bursa is uncommon. Osteoarthritis, synovitis, and collateral-ligament injuries of the coffin joint are frequent causes of foot lameness. Because the joint is intimately related to the podotrochlear (navicular) apparatus, problems often occur together. Diagnostic anesthesia of the coffin joint is a standard step in the work-up of heel or foot pain; the block can also desensitize adjacent structures.
Low ringbone is osteoarthritis of the DIP joint. Diagnosis uses radiography, ultrasound, and often MRI. Intra-articular medication (corticosteroids, hyaluronic acid, biologics) is common. Collateral ligament desmitis and impar-ligament injuries are best seen on MRI. Response to a coffin-joint block must be interpreted carefully because local anesthetic can diffuse.
## Overview Coffin joint disease refers to osteoarthritis or other pathology of the distal interphalangeal joint. It is a common cause of foot lameness in performance horses. Signs range from mild sh
## Overview Deep digital flexor tendon (DDFT) tendinopathy encompasses degenerative or traumatic injury to the tendon, most commonly where it courses over the navicular bone or in the pastern. It pro
Chronic foot soreness, a shortened stride, or positive response to hoof testers over the sole or frog may involve the coffin joint. Have a veterinarian perform a full lameness exam rather than assuming it is “just the navicular.” Shoeing changes that improve break-over can help some horses.
## Overview Coffin joint disease refers to osteoarthritis or other pathology of the distal interphalangeal joint. It is a common cause of foot lameness in performance horses. Signs range from mild shortened stride and poor performance to marked lameness. Forelimbs are more often affected than hindlimbs. ## Causes Repetitive concussion, conformational faults, prior trauma, or developmental joint disease. Navicular bone changes frequently coexist. ## Diagnosis Lameness examination, distal limb flexion, and diagnostic analgesia. Radiographs show osteophytes, joint-space narrowing, or enthesophytes. Advanced imaging further characterizes cartilage and subchondral bone. ## Treatment Intra-articular corticosteroids, biologics, or viscosupplements; systemic anti-inflammatories; corrective shoeing; and workload modification. Prognosis is guarded to fair depending on severity. ## Recovery and Prognosis Many horses remain useful with management. Advanced disease limits athletic longevity. ## Prevention Balanced shoeing, appropriate footing, and early treatment of foot imbalances. Signs include: foot lameness; shortened stride; positive distal limb flexion; occasional coffin joint effusion; poor performance
## Overview Deep digital flexor tendon (DDFT) tendinopathy encompasses degenerative or traumatic injury to the tendon, most commonly where it courses over the navicular bone or in the pastern. It produces chronic or intermittent forelimb lameness and is a major component of podotrochlear syndrome. ## Causes Repetitive strain, navicular bone interaction, and age-related degeneration. Acute overload can initiate or worsen lesions. ## Diagnosis Lameness examination, nerve blocks, and imaging. Ultrasound evaluates the pastern region; MRI is useful for assessing lesions within the hoof; CT can also identify some DDFT lesions. ## Treatment Rest, controlled rehabilitation, shoeing changes, anti-inflammatories, and regenerative or surgical therapies in selected cases. ## Recovery and Prognosis Variable. Mild lesions often improve; severe or chronic tendinopathy limits long-term athletic use. ## Prevention Appropriate conditioning and early attention to foot pain. Signs include: chronic or intermittent forelimb lameness; positive palmar digital nerve block; shortened stride; pointing; worse on hard surfaces or circles
Low ringbone is osteoarthritis of the DIP joint. Diagnosis uses radiography, ultrasound, and often MRI. Intra-articular medication (corticosteroids, hyaluronic acid, biologics) is common. Collateral ligament desmitis and impar-ligament injuries are best seen on MRI. Response to a coffin-joint block must be interpreted carefully because local anesthetic can diffuse.
Chronic foot soreness, a shortened stride, or positive response to hoof testers over the sole or frog may involve the coffin joint. Have a veterinarian perform a full lameness exam rather than assuming it is “just the navicular.” Shoeing changes that improve break-over can help some horses.
See the Coffin Joint (Distal Interphalangeal Joint / DIP Joint) on our interactive 3D horse model. Open 3D Model