Overview
Its four heads converge on the patella: rectus femoris, vastus lateralis, vastus medialis and vastus intermedius. The model shows the first three; the vastus intermedius lies deep, on the cranial surface of the femur.
As in the horse, cattle have three patellar ligaments (lateral, intermediate and medial), joining the patella to the tibial tuberosity. The medial patellar ligament rests on the medial ridge of the femoral trochlea, which is thicker than the lateral one.
Origin
- Rectus femoris (m. rectus femoris): body of the ilium, cranial to the acetabulum. The only head that crosses the hip.
- Vasti (m. vastus lateralis, medialis, intermedius): proximal femur.
Insertion
Patella and, through the patellar ligaments, the tibial tuberosity.
Action
Extends the stifle. The rectus femoris also flexes the hip.
Innervation
Femoral nerve (n. femoralis).
Clinical relevance
- Femoral nerve paralysis occurs in large calves after forced extraction at calving, from hyperextension of the hip and stifle. The calf cannot bear weight on the limb, the patellar reflex is absent and the quadriceps atrophies.
- In upward fixation of the patella the medial patellar ligament hooks over the medial trochlear ridge and the limb is locked in extension. It is treated by medial patellar desmotomy.
- It is part of the round cuts of the hindquarter, where injections should not be given.