The Anatomy of the Iliac Crest

The iliac crest is the curved area at the top of the ilium bone, the largest of three bones that make up the pelvis. If you put your hand on your waist and press firmly, you can feel the prominent, bony surface of your iliac crest.

The iliac crest has a rich supply of bone marrow, making it an ideal source for bone marrow transplants. Playing contact sports can cause injuries to the iliac crest. These are known as "hip pointer" injuries.

Anatomy

Structure

The iliac crest forms a thick, curved bony border on the edge of the ilium. It is concave in front, rounding inward, and convex in back, rounding outward. The front tip of the iliac crest is called the anterior superior iliac spine; the back tip is known as the posterior superior iliac spine. At the widest point of the iliac crest is the iliac tubercle, an area that protrudes slightly from the crest itself.

The iliac crest receives most of its blood supply from the deep circumflex ilial artery. The interior of the iliac crest is a rich source of red bone marrow.

Location

The iliac crest is located on the outer edge of the pelvic bones and located approximately at the L4 vertebra of the lumbar spine.

Function

The iliac crest is part of the pelvis and therefore functions to stabilize the body by bearing the weight of the spine and upper body.

Many important abdominal and core muscles are attached to the iliac crest, including the hip flexors, the internal and external abdominal oblique muscles, the erector spinae muscles, the latissimus dorsi, the transversus abdominis, and the tensor fasciae latae. The iliotibial band attaches to the hip at the iliac tubercle.

Associated Conditions

Because the iliac crest is prominent and easily felt from outside the body, it is vulnerable to injuries, as well as conditions that affect the nerves and ligaments that attach to it. These include:

Hip Pointer Injuries

A hip pointer injury is caused by trauma to the hip. Athletes who play contact sports, particularly football and hockey, are prone to these injuries. They are also seen in other sports where side or hip falls are common, like volleyball, baseball, or rock climbing.

Direct impact on the iliac crest can cause tissue and bone bruising, swelling and inflammation, and even bone fracture. Hip pointer injuries cause immediate, intense pain and tenderness over the upper hip. There can also be muscular spasms and a decline in the strength and range of motion of the affected hip and leg. The pain tends to worsen with movement.

Iliac Crest Pain Syndrome

Iliac crest pain syndrome occurs when the iliolumbar ligament tears as a result of a trauma, such as a car accident or fall, or actions that involve repeated twisting or bending. Weak muscles in the back, hip, and abdomen can also cause pain along the iliac crest.

Iliac crest syndrome can also be a result of inflamed tendons and ligaments in the area. Symptoms of iliac crest pain include pain in the lower back that can spread to the hip and groin.

Post-Graft Complications

The harvesting of bone in the iliac crest to reconstruct a person's jaw or leg bone commonly causes pain in the crest. In some cases the procedure can also cause numbness, infection, fractures, and gait problems that can impact a person's ability to walk properly.

Rehabilitation

Hip pointer injuries generally improve with standard, non-surgical treatments including:

• Icing
• Anti-inflammatory medications
• Elevation and compression
• Rest and avoiding bearing weight on the affected leg (using crutches if necessary)

Range of motion and active resistance exercises can gradually be resumed as pain and swelling subside. Your doctor will tell you when it's safe to resume playing sports. Going back too soon can increase your risk of another injury.

There are a few things you can do to help reduce your chance of getting an iliac crest injury when playing sports or exercising:

• Don't play or practice without pads.
• Learn and use proper technique (stronger, more confident movements decrease your risk of injury).
• Wear properly fitted protective gear (e.g. hockey or football pants correctly sized so that pads cover hips).
• Don't play when you’re tired, as injuries are more likely to occur when fatigued.
• Know and follow the rules of your sport.

For iliac crest syndrome, the key is to strengthen and condition the muscles in the hip area. In the case of post-graft pain, some research has shown that replacing the area of bone that was removed with bone cement secured by screws can help reduce complications.