The hip is a ball-and-socket joint. The femur (thigh bone) has a round head, which fits into the socket of the hipbone (pelvis). This arrangement gives the hip a great deal of mobility and stability. A great deal of force is required to cause a hip dislocation or fracture in a young healthy person, but motor vehicle accidents and falls from a roof or ladder can generate this amount of force.
In older people, less force is required because of the higher prevalence of osteoporosis in older people and the natural weakening of bones with age. However, a program of exercise and weight training can greatly reduce the risk of hip fracture in older people, and will help younger people live longer, healthier lives.
Hip dislocations and fractures are medical emergencies, requiring immediate and expert medical care. A person with a hip fracture or dislocation will not be able to stand or walk. The muscles hip will twist the leg one direction or the other, depending on the type of injury. Nerve damage may cause the person to lose feeling in the foot or ankle. Blood vessel damage may cause the death of the upper part of the femur.
Some hip dislocations can be treated without surgery. The physician can administer pain medication and manually place the hip back in its socket. For other dislocations and most fractures, surgery is required, and pins may be used to hold broken bones together.