Vascular supply of the tendon of the equine deep digital flexor muscle within the digital sheath.

The research article discusses the study of vascular and microvascular anatomy of the equine deep digital flexor tendon within the digital sheath. The study applies various methods to understand the architecture and source of blood supply to this tendon in horses.

Methodology

• The research team investigated the tendon’s vascular structure by injecting it with colored latex or barium sulphate. These substances improve the visibility of the blood vessels under various imaging techniques.
• They used radiographic, microangiographic, histologic, and computed tomographic (CT) evaluation to scrutinize the vasculature. Two-dimensional CT slice data was transformed into 3-dimensional volumetric images for a better spatial understanding.

Vascular Sources

• Three major blood supply sources were identified through gross dissection and angiographic studies. Two were present above the fetlock joint, either a branch of the medial palmar artery or a branch of the medial palmar digital artery.
• Below the fetlock joint, the tendon was nourished by branches from the lateral and medial palmar branches to the proximal phalanx.
• The most distal part of the tendon received small branches from the medial and lateral palmar digital arteries.

Microvascular Network

• The histology and microangiography studies revealed an extensive and well-distributed vascular network above and below the fetlock joint.
• A significant finding was a relatively avascular or poorly vascularized region of the tendon palmar to the fetlock.
• In the tendon’s most distal 2.0 to 2.5 cm within the sheath, heavy fibrocartilage infiltration was observed along the dorsal aspect.

The research provides valuable insights into the intricate vascular network of the equine deep digital flexor tendon, which can contribute towards understanding tendon health, injury and repair in equine medicine.