Causes

How do fractures of the hip commonly happen?

Hip fractures are most often caused by a fall. The fracture may be caused by the impact of the upper end of the thigh bone against the floor or by a twisting mechanism. In younger people with stronger bones these fractures may be caused by higher energy trauma such as motor vehicle accidents or falls from a height.

Many hip fractures occur in bone which has osteoporosis. Osteoporosis weakens the bone by thinning the dense bone that gives it strength. As people grow older the bones get more and more fragile. Hip fractures are one of a group of so-called fragility fractures that are more common in people with osteoporosis. Common fragility fractures involve the hip, wrist and vertebrae. Osteoporosis does not prevent bones from healing in the normal fashion and at the normal speed.

Related Document: A Patient's Guide to Osteoporosis

Strictly speaking, many hip fractures are pathological fractures because they occur through abnormal (osteoporotic) bone. However, the term pathological fracture is usually reserved for fractures through abnormal deposits in bone. The most common causes are cancer deposits spread from breast cancer, prostate or lung cancer. If there is a known primary cancer, the hip region was painful before the fracture or the hip collapsed without any real accident, the doctors will be on the lookout for this. It is usually obvious on X-ray. The fracture still needs to be treated, but this may need to be combined with treatment for the tumor as well.

Because hip fracture is so common in the elderly, many health care providers have begun to stress preventing hip fractures. A falls prevention program is a very important aspect of treating hip fracture. These programs try to look at ways to reduce the risk of hip fracture including:

• eliminating hazards in the home that could trip people up
• reducing medications that may make older people drowsy or dizzy
• exercising to improve strength, balance and coordination

There is some controversy about the value of hip protectors. These are padded high impact plastic shields positioned over the hips. Some studies have shown that they protect older people against hip fractures; others have shown that they are not worn enough to be worth it.