Orthopedic specialists at NYU Langone identify the location and extent of fractures that affect the thigh bone, called the femur, or the pelvis, which is the large, butterfly-shaped group of bones where the legs connect to the trunk of the body.
Hip and pelvic fractures occur most commonly in people older than age 60 as a result of falls. Postmenopausal women who have osteoporosis, a condition that weakens bones, are most vulnerable.
Hip and pelvic fractures are also frequently caused by traumatic injuries from a car accident or a fall from a significant height. In New York, injuries often occur when cars hit pedestrians as they cross the street.
X-rays and other diagnostic tests can confirm whether a fracture is displaced or nondisplaced. A fracture is displaced when separated into two or more pieces that don’t remain in place. A nondisplaced fracture occurs when the pieces of broken bone don’t separate. A fracture may also be limited to a tiny crack or cracks in the bone, called stress or insufficiency fractures.
Depending on the cause of a fracture, it may occur in addition to injuries to surrounding muscles, tendons, ligaments, blood vessels, and nerves. Some of these soft tissues pass through openings in the pelvic bones and are especially vulnerable to injury if the pelvis is fractured.
Hip and pelvic fractures require immediate treatment to prevent permanent damage to the bone or surrounding soft tissues. If you’ve been injured, go to the nearest emergency room.
A hip fracture occurs when the upper part of the femur is broken. The hip is a ball-and-socket joint: the rounded top of the femur, called the femoral head, fits snugly into a cup-shaped area of the pelvis, called the acetabulum.
Below the femoral head, the femur narrows slightly to form the femoral neck, which connects to the main part of the femur. From there, it extends into a bony ridge called the trochanter that provides an attachment point for muscles supporting the hip joint.
Symptoms of a hip fracture vary depending on the severity of the injury and the location of the break. Most people experience significant sharp pain in the hip or groin and may not be able to put any weight on the affected hip. They may also notice swelling, redness, or bruising in the skin above the injury.
Rarely, a fall may cause an open fracture in the hip, in which part of a bone sticks through the skin.
A common site of hip fractures is the femoral neck. Women are much more likely than men to fracture this part of the hip, and the injury usually occurs as the result of a fall. In women older than age 60, low bone density increases the chance that even a minor fall results in a fracture.
Many fractures of the femoral head are associated with a dislocated hip, in which the femur is pulled out of the acetabular socket. In some instances, the femoral head is displaced with such force that the femoral head cracks or breaks. This type of fracture is usually the result of a high-impact injury such as a car crash.
In people with osteoporosis, a type of stress fracture called an insufficiency fracture may develop in the femoral head. An insufficiency fracture occurs when weakened bones crack under the stress of everyday movements, such as walking or climbing stairs.
A fracture that occurs between the femoral neck and the trochanter is called an intertrochanteric fracture. A fracture that occurs below the trochanter is called a subtrochanteric fracture. Either type of fracture is usually caused by a direct blow to this part of the hip due to a fall.
The pelvis is composed of three bones that fuse together during adolescence: the ilium, ischium, and pubis. Ligaments attach this ring of bones to the sacrum at the lower part of the spine. On each side of the pelvis, the cup-shaped socket called the acetabulum connects with the femoral head to form the hip joint.
The pelvis anchors the upper body and helps it remain balanced. It also protects several digestive and reproductive organs, and provides attachment points for many of the body’s muscles, blood vessels, and nerves.
The two largest pelvic bones are round, flat bones called ilia. These bones resemble a butterfly’s wings and are located on either side of the body above the legs.
Symptoms of a fractured ilium vary, depending on the extent of the injury. These usually include sharp pain in the hip or groin, swelling and bruising on the skin, and a limited ability to put weight on the affected hip.
Below each ilium is a ring-shaped structure composed of the ischium and pubic bones. Major blood vessels and nerves travel through this ring from the upper body to the legs and feet.
Most fractures of the ischium and pubis result from falls or other accidents, but in some young athletes, a fracture may occur as the result of sudden strong contractions of the muscles that attach to the pelvis. When these muscles—for example, the hamstring muscles that run along the back of the thigh—contract, the force of the contraction may pull a small piece of the ischium away from the pelvis.
Symptoms of this type of fracture depend on the extent of the injury. A young athlete with a minor fracture resulting from muscle contractions may feel soreness and discomfort, especially when in motion. A more serious fracture caused by a fall or other accident produces significant hip pain, swelling, and bruising. This type of fracture may prevent you from putting any weight on the affected hip.
A break in the acetabulum—the socket located on each side of the pelvis—is less common than other types of pelvic or hip fractures. It usually occurs as the result of a car accident or fall from a significant height, with damage to other bones and soft structures in and around the hip and pelvis.
Stress fractures in a pelvic bone usually develop as a result of repetitive, high-impact activity that puts stress on the pelvis, such as long-distance running or ballet. It often affects people who quickly increase the duration and intensity of a physical activity without gradually building up endurance.
In people with osteoporosis, insufficiency fractures in the pelvis may develop as the result of everyday movements.
Symptoms include an aching pain in the hip or groin that usually gets worse during movement or exercise, but tends to persist even during periods of rest. Some people may also experience swelling or tenderness in the skin surrounding the affected bone.
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