Hip fractures
From Medical-Wiki
Hip fractures are classified as intracapsular, which includes femoral head and neck fractures, or extracapsular, which includes trochanteric, intertrochanteric, and subtrochanteric fractures.
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Anatomy of the hip
The important anatomy of the hip includes the femoral head, which is connected to the shaft by its neck. The greater and lesser trochanters are prominences on the proximal femur where the iliopsoas muscle attaches—lesser trochanter, and the abductors and short rotator muscles attach—the greater trochanter. Additional muscles attach along the intertrochanteric line.
Demographics
9 out of 10 hip fractures are in a population older than 65. 40% of hip fractures die within a year of the fracture. 50% of survivors become less independent than before the injury. Without accompanying pathology such as Gaucher disease, fibrous dysplasia, or bone cysts, fractures of the proximal femur are exceedingly uncommon in young adults. The trauma associated with such fractures is typically a high velocity auto accident. Such are the realities of hip fractures. [1]
Stress fractures
Stress fractures, occurring primarily at the femoral neck, are classified as tension, at the superior portion of the femoral neck, or compression, at its inferior portion. Identification of stress fractures is crucial in order to avoid avascular necrosis (AVN). This complication is more common in younger patients. [2]
Obviously the context of presentation determines the important features in a patient’s history. Neither an 80 year old Alzheimer’s patient from a nursing home nor a 30 year old involved in a high speed auto accident will contribute anything of historical relevance. At the opposite extreme, a patient with a stress fracture will present with a subtle history that must be teased out to reveal its secrets.
It is usually the latter category in which history plays a significant role. These patients may complain of anterior groin or thigh pain. The pain will typically worsen with activity and linger—sometimes for hours. While pain with activity is the most common presentation, night pain is not uncommon.
Acute fracture
The typical acute fracture will present with the affected leg in external rotation. It will appear shortened because the muscles acting on the hip joint depend upon the integrity of the joint for function. When continuity of the joint is disrupted, the leg appears shortened. When an injury presents with these findings, it is important to asses the leg’s vascular integrity—with Doppler if possible.
Diagnosis
Physical findings
In less obvious fractures, physical examination reveals a decrease in range of motion, particularly internal rotation. Heel percussion will produce pain as well as attempted passive motion of the hip. Patients with a stress fracture may have an antalgic gait. Acute fractures may have ecchymosis. Deep palpation of the inguinal area will produce pain.
The differential diagnosis for hip fracture is lengthy—basically identical to that for groin pain.
It is important to evaluate the possibility of femoral neck fractures whenever their possibility is even raised. Many impacted fractures have been missed because patients walked into doctors’ offices with complaints of diffuse groin pain, able to walk because of their fractures’ stability, imparted by the impaction. However, impaction does not prevent against nonunion and necrosis—diagnosis is important. [3]
Radiological findings
When hip fractures are either of the stress variety or subtle and anatomically stable, MRI is the imaging technique of choice—if plain films are unrevealing. [4]
Treatment
Rarely will a hip fracture not require surgical reduction and internal fixation. However, the choice of surgical procedure is a decision that depends upon the patient’s age, the patient’s preinjury level of activity, comorbid medical problems, and the anatomic site of fracture. Extracapsular intertrochanteric fractures are most often repaired with standard reduction and internal fixation. Intracapsular femoral neck fractures, however, may be treated with internal fixation, hemiarthroplasty or total hip replacement. A surgeon will decide on the surgical procedure based upon joint stability and those factors noted above.
Medical reduction in osteoporosis has had a significant role in reducing the incidence of hip fractures. Women experience a higher incidence of hip fractures and for a time, hormone replacement therapy (HRT) was the primary defense against osteoporosis. However, the Women’s Health Initiative cast dispersions on the use of HRT because of side effects and use has been significantly cut back.
Now, prevention consists of bisphosphonates or selective estrogen receptor modulators, smoking cessation, moderation of alcohol use, simplification of drug regimens, gait stabilization therapy, and the use of assistive devices to prevent falls. In addition, all patients should take appropriate doses of calcium (1,000 to 1,500 mg per day) and vitamin D (400 to 800 IU per day), and to engage in weight-bearing, and muscle-strengthening exercises. [5]
