Flexor retinaculum

The flexor retinaculum is composed by thick transverse fascial bands, from medial carpal bones to the accessory carpal bone, forming the carpal canal.

• In dogs, the flexor retinaculum is attached laterally to the medial part of the enlarged free palmar end of the accessory carpal bone, widens as it passes medially to be attached to the styloid process of the radius and on the palmar projections of the intermedioradial and first carpals. The flexor retinaculum is divided into two parts: one superficial and the other deeper between the tendons of the superficial and deep digital flexors.
• In ruminants and horses, the retinaculum is double, resulting in two carpal canals (superficial and deep (proper canal)).