The pelvis is made up of two halves, joined at the lowest point by a very heavy fibrous union. The hip joint is a socket into which the ball head of the femur fits. The ileum is a shaft of the pelvis that joins the pelvis to the spine through the sacro-iliac joint and extends forward to make up the visible bump of the tuber coxae. Given this complex anatomy, there are a variety of pelvic fractures that can take place, each of which varies greatly in terms of severity of lameness and prognosis.

The most common pelvic fracture is fracture of the tuber coxae or shaft of the ilium (knocked down hip). This injury usually occurs when a horse rushes through a doorway, catching one or the the tuber coxae on the door frame. Horses that have sustained this injury have a good prognosis for return to athletic performance but their limbs may not track straight when they travel and they may have a chronically asymmetric pelvis. They may look especially awkward at the walk.

Major hip fractures involving the hip joint often result in chronic and severe lameness. These are most often caused by a fall or slipping (usually on ice) and spreading the legs.

Radiography is a limited diagnostic tool due to the massive musculature in this area. It takes a very powerful x-ray to get through the mass, and general anesthesia may be required to visualize the fracture. Due to this, adequate x-ray equipment may only be available at universities and large equine hospitals. Ultrasound is useful for visualizing fractures, especially those of the ileum.

In most cases, the only treatments are time and rest. Many cases will benefit from box stall rest for varying periods of time. Rarely, surgery may be part of the treatment.