The collateral sesamoidean ligaments are a pair of ligaments that originate from the middle phalanx and insert on the sides of the navicular bone. They help suspend and stabilize the navicular bone within the foot and limit excessive movement of the navicular bone relative to the middle phalanx. These ligaments are important stabilizers of the podotrochlear apparatus. Desmitis or degeneration of the collateral sesamoidean ligaments is frequently identified on MRI in horses with navicular syndrome and can contribute to instability and pain in the heel region. They work together with the distal sesamoidean impar ligament to maintain proper navicular position. This information is for educational purposes only. Always consult with a licensed veterinarian for diagnosis and treatment of your horse.
## Description Coffin joint disease, also known as distal interphalangeal joint osteoarthritis or DIP joint disease, refers to degenerative changes within the coffin joint located inside the hoof cap
## Description DDFT tendinopathy refers to degenerative or traumatic injury to the deep digital flexor tendon, most commonly occurring in the region where the tendon glides over the navicular bone wi
## Description Coffin joint disease, also known as distal interphalangeal joint osteoarthritis or DIP joint disease, refers to degenerative changes within the coffin joint located inside the hoof capsule. This joint experiences significant load and motion during every stride and is closely connected to the navicular apparatus through shared joint fluid communication in many horses and through biomechanical forces. Osteoarthritis here involves cartilage degradation, subchondral bone changes, and synovial inflammation that can cause chronic pain and lameness. The condition often develops secondary to conformational abnormalities, repetitive high-impact work, or concurrent navicular pathology. It can also occur as a primary disease process. Because the joint is deep within the hoof, diagnosis and treatment require careful use of diagnostic analgesia and advanced imaging. ## Causes / Risk Factors Repetitive concussive forces from performance work; poor hoof conformation (long toes, upright pasterns); concurrent navicular syndrome; previous joint trauma or infection; age-related degenerative changes; high body weight relative to foot size. ## Diagnosis Clinical lameness examination with diagnostic analgesia (coffin joint block and palmar digital nerve block); radiographs showing joint space narrowing, subchondral sclerosis, osteophytes, or cysts; ultrasound for synovial effusion and capsule thickening; MRI for early cartilage and bone changes not visible on radiographs. ## Treatment Corrective farriery to improve breakover and reduce joint stress; intra-articular injections (corticosteroids, hyaluronic acid, or regenerative biologics); systemic anti-inflammatories; controlled exercise programs; shockwave therapy; in severe refractory cases, surgical options such as arthrodesis are rarely considered. ## Prognosis Guarded to fair for return to previous athletic levels. Many horses can be managed comfortably for light to moderate work with ongoing farriery and periodic joint injections. Prognosis is better when the disease is diagnosed early and when concurrent navicular pathology is also addressed. ## Prevention Maintain balanced hoof conformation through regular professional farriery; gradual conditioning programs; avoid excessive work on hard surfaces; address conformational issues early; maintain appropriate body weight. This information is for educational purposes only. Always consult with a licensed veterinarian for diagnosis and treatment of your horse. Signs include: Chronic or intermittent forelimb lameness that may worsen on hard ground or circles; positive response to coffin joint block or palmar digital nerve block; shortened stride; reluctance to land heel-first; joint effusion sometimes detectable on ultrasound; worsening with distal limb flexion
## Description DDFT tendinopathy refers to degenerative or traumatic injury to the deep digital flexor tendon, most commonly occurring in the region where the tendon glides over the navicular bone within the podotrochlear apparatus. Lesions can include core lesions, dorsal surface fibrillation or tears, and adhesions to the navicular bursa or bone. This is one of the most significant soft tissue contributors to caudal heel pain in horses. The condition often develops from repetitive overload, particularly in horses with conformational predispositions or those engaged in high-impact disciplines. It frequently coexists with navicular bone changes and bursal pathology, making it part of the broader podotrochlosis complex. ## Causes / Risk Factors Repetitive high-impact loading; conformational faults that increase DDFT tension (long toes, low heels); poor hoof balance; previous navicular pathology; inadequate conditioning; genetic predisposition in some breeds and lines. ## Diagnosis Clinical examination and diagnostic analgesia; ultrasound of the pastern and fetlock regions; MRI is the gold standard for identifying core lesions, dorsal tears, and adhesions within the foot; radiographs to assess concurrent navicular bone changes. ## Treatment Initial rest and controlled rehabilitation; corrective farriery to reduce DDFT tension (rolled toes, heel support); systemic anti-inflammatories; intralesional or bursal injections of biologics (PRP, stem cells); shockwave therapy; navicular bursoscopy for debridement of dorsal tears and adhesions in selected cases; palmar digital neurectomy as a last resort in chronic cases with confirmed limited tendon damage. ## Prognosis Variable and dependent on lesion severity and location. Mild core lesions or dorsal fibrillation often respond well to conservative management and farriery. Extensive tears or chronic adhesions carry a more guarded prognosis for return to high-level performance. Many horses can be maintained comfortably for lower-level work with ongoing management. ## Prevention Proper hoof balance and regular farriery; gradual conditioning with attention to surface; maintaining appropriate body condition; early intervention when subtle gait changes are noticed. This information is for educational purposes only. Always consult with a licensed veterinarian for diagnosis and treatment of your horse. Signs include: Chronic or intermittent forelimb lameness; positive response to palmar digital nerve block; shortened stride with toe-first landing; pointing at rest; worsening on hard surfaces and circles; pain on deep palpation of the heel region in some cases; effusion of the digital flexor tendon sheath in pastern-level injuries
See the Collateral Sesamoidean Ligament on our interactive 3D horse model. Open 3D Model