Overview
The femur is one of the most robust bones of the bovine skeleton. It forms the skeleton of the thigh and articulates at the hip with the acetabulum and at the stifle (articulatio genus) with the tibia and patella. It is wrapped in large muscle masses, so it can hardly be palpated except at its ends. Unlike the horse, cattle have no third trochanter.
Proximal end
- Head (caput ossis femoris): hemispherical, sits in the acetabulum. The fovea of the head receives the ligament of the femoral head.
- Neck (collum ossis femoris): short, joins the head to the shaft.
- Greater trochanter (trochanter major): lateral, insertion of the gluteal muscles; palpable.
- Trochanteric fossa (fossa trochanterica): caudal, between the greater trochanter and the neck.
- Lesser trochanter (trochanter minor): medial, insertion of the iliopsoas.
Shaft and distal end
- Shaft: cylindrical. Distally, on the caudal surface, the supracondylar fossa (fossa supracondylaris) gives origin to the superficial digital flexor.
- Trochlea (trochlea ossis femoris): broad, with the medial ridge thicker and higher than the lateral; the patella glides over it and can become hooked on it.
- Medial and lateral condyles: caudal articular surfaces in contact with the menisci and tibia. Between them, the intercondylar fossa houses the cruciate ligaments.
- Extensor fossa (fossa extensoria): between the lateral condyle and the trochlea; origin of the long digital extensor and the peroneus tertius.
Clinical relevance
- Femoral fractures in newborn calves: often from forced extraction at calving, especially when the calf's hips lock in the maternal pelvis. They involve the shaft or the distal physis and cannot be immobilised with a cast.
- Capital physeal fracture: separation of the femoral head in young cattle after falls, mounting or rough handling.
- Coxofemoral luxation: in cows that slip or become recumbent; craniodorsal luxation is the most common, although ventral luxations also occur, sometimes with the head lodged in the obturator foramen.