Tendo m. flexoris digitorum profundi
The DDFT (deep digital flexor tendon) is the distal continuation of the deep digital flexor muscle. In the foot it glides over the navicular bone within the navicular bursa before inserting on the solar (flexor) surface of the coffin bone. Its dorsal surface at the navicular level is covered with fibrocartilage to withstand the compressive and frictional forces generated during weight-bearing and break-over. The tendon is a central component of the podotrochlear (navicular) apparatus. Lesions commonly occur within the digital flexor tendon sheath (pastern and fetlock) and inside the navicular bursa. MRI frequently shows core lesions, sagittal splits, or dorsal abrasions, often concurrent with navicular bone, bursa, or impar-ligament changes. The tendon’s role in both active flexion and passive support makes it critical to soundness.
See Deep Digital Flexor entries. MRI is valuable for intra-bursal lesions, but bursoscopy is the reference standard and can reveal lesions, such as adhesions, that MRI may miss. Bursoscopy can be both diagnostic and therapeutic for selected tears and adhesions.
## 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
## Overview Sesamoiditis is chronic inflammation and remodeling of the proximal sesamoid bones from repetitive loading and suspensory ligament traction. It is common in young racehorses and sport hor
Heel or foot pain that does not resolve with standard management often needs advanced imaging to evaluate the DDFT. Protect the foot and follow rehabilitation plans carefully after any diagnosed tendon injury.
## 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
## Overview Sesamoiditis is chronic inflammation and remodeling of the proximal sesamoid bones from repetitive loading and suspensory ligament traction. It is common in young racehorses and sport horses. Signs include low-grade forelimb lameness, pain on palpation of the sesamoids, a positive flexion test, and enlarged, remodeled sesamoids on radiographs. ## Causes Repetitive strain at the suspensory insertion. ## Diagnosis Radiographs showing sesamoid changes, correlated with clinical signs. Ultrasound or scintigraphy may add information. ## Treatment Rest, anti-inflammatories, and gradual return to work. Shock wave or regenerative therapies are sometimes used. Prognosis for high-level performance is often guarded. ## Recovery and Prognosis Guarded for return to previous athletic level in many cases. ## Prevention Careful training of young horses and early management of suspensory soreness. Signs include: chronic low-grade forelimb lameness; pain on sesamoid palpation; positive flexion test; enlarged remodeled sesamoids on radiographs
See Deep Digital Flexor entries. MRI is valuable for intra-bursal lesions, but bursoscopy is the reference standard and can reveal lesions, such as adhesions, that MRI may miss. Bursoscopy can be both diagnostic and therapeutic for selected tears and adhesions.
Heel or foot pain that does not resolve with standard management often needs advanced imaging to evaluate the DDFT. Protect the foot and follow rehabilitation plans carefully after any diagnosed tendon injury.
See the Deep Digital Flexor Tendon (DDFT) on our interactive 3D horse model. Open 3D Model