Patella Bone of Animals: Ox, Horse, Sheep, Goat, Pig, Dog, Rabbit, and Fowl

The patella bone, also known as the kneecap, is a prominent sesamoid bone that develops within the tendon of the quadriceps femoris muscle.

It is located in front of the stifle or knee joint and articulates with the femur at a specific groove called the trochlea.

Patella Bone of Ox

The patella bone of the ox is a large sesamoid bone placed on and articulating with the trochlea of the femur.

It appears triangular in shape in the dorsal/anterior view. It provides increased leverage to the extensors of the leg.

It is irregularly triangular and presents two surfaces, two borders, a base, and an apex.

The anterior surface is convex and rough. The posterior or articular surface is divided by a vertical ridge into two concave areas, of which the medial is larger.

The two borders converge to the apex below. The lateral border is convex. The medial border is concave, forms an angle at the base, and gives attachment to the fibrocartilage of the patella.

The base faces upward and is irregular and narrow.

Comparative Anatomy of Patella Bone in Animals

The patella bone exhibits notable anatomical variations among domestic animals, reflecting their different locomotor patterns, body weight distribution, and limb structure. While its fundamental role—facilitating extension of the stifle joint and protecting the tendon—is consistent, its shape, size, and orientation vary significantly across species.

Sheep and Goat

The patella of sheep and goats is relatively longer and narrower than that of the ox.

Horse

The base of the horse’s patella is wide and large. It appears quadrilateral in shape in the dorsal/anterior view.

Pig

The patella of the pig is highly compressed transversely and presents three surfaces.

Dog

The patella of the dog is long and narrow.

Rabbit

The patella of the rabbit lies in the patellar groove.

Fowl

The patella of the fowl is wide and thin.