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Hip fractures may occur in the head, neck, or area between or below the trochanters (prominences) of the femur. These fractures are most common among the elderly, particularly those with osteoporosis, and usually result from ground level falls (see Osteoporosis). Diagnosis is by x-rays or, if needed, MRI. Treatment is usually with open reduction with internal fixation or sometimes hemiarthroplasty or total hip arthroplasty.
Most hip fractures result from falls, but in the elderly, seemingly minimal force (eg, rolling over in bed, getting up from a chair, walking) can result in fracture, usually because osteoporosis has weakened the bone. Fracture locations include
Subcapital and intertrochanteric fractures are the most common types.
Complications are more common among elderly patients with a displaced femoral neck fracture.
Hip fractures most often result in groin pain and inability to ambulate. Sometimes pain is referred to the knee and is thus misinterpreted as a knee abnormality. Similarly, pubic ramus fractures can cause groin pain.
Patients with displaced fractures cannot walk and have significant pain; the affected leg may appear shortened and externally rotated. In contrast, patients with impacted fractures may be able to walk and have only mild pain and no visible deformity. However, such patients are usually unable to flex the entire lower limb against resistance with the knee extended.
Passive hip rotation with the knee flexed aggravates the pain, helping to distinguish hip fracture from extra-articular disorders such as trochanteric bursitis.
Diagnosis begins with an anteroposterior pelvis x-ray and a cross-table lateral view. If a fracture is identified, x-rays of the entire femur should be done. Subtle evidence of fracture (eg, as when fractures are minimally displaced or impacted) can include irregularities in femoral neck trabecular density or bone cortex. However, x-rays are occasionally normal, particularly in patients with subcapital fractures or severe osteoporosis.
If a fracture is not seen on x-rays but is still suspected clinically, MRI is done because it has almost 100% sensitivity and specificity for occult fractures. CT is a less sensitive alternative.
The vast majority of hip fractures are treated surgically to minimize the duration of pain and because the prolonged bed rest (see Hospitalization : Bed Rest Effects), which is required after nonsurgical treatment, increases the risk of serious complications (eg, deep venous thrombosis, pressure ulcers, deconditioning, pneumonia, death), particularly in the elderly. Rehabilitation is started as soon as possible (see Hip Surgery Rehabilitation ).
Prophylactic anticoagulation may reduce the incidence of venous thrombosis after hip fracture.
Nondisplaced and impacted femoral neck fractures in the elderly and all femoral neck fractures in younger patients are typically treated with ORIF.
Displaced femoral neck fractures in the elderly are usually treated with hip arthroplasty (replacement) to allow early unrestricted weight-bearing and to minimize the likelihood that additional surgery will be required. Elderly patients who walk very little and thus put little stress on the hip joint are usually treated with hemiarthroplasty (only the proximal femur is replaced); more active elderly patients are increasingly being treated with total hip arthroplasty (the proximal femur is replaced, and the acetabulum is resurfaced). Total hip arthroplasty surgery is more extensive and poses greater risk but results in better function.
Hip (particularly subcapital and intertrochanteric) fractures are common among older patients with osteoporosis.
Osteonecrosis of the femoral head, fracture nonunion, and osteoarthritis are common complications.
For all patients with unexplained hip or knee pain and difficulty walking due to pain, rotate their hip with their knee flexed; if this maneuver aggravates the pain, hip fracture is possible.
If a fracture is suspected based on clinical findings but is not seen on x-rays, do MRI.
Treat most fractures surgically (ORIF or hip arthroplasty) so that patients can walk as soon as possible.
* This is the Professional Version. *