**5. Classification of hip fractures**

**Figure 2.** Conceptual model of the fall-induced hip fracture procedure and associated effective factors [15].

• Medications (including tranquilizers, hypnotics, anticonvulsant drugs, and steroids)

• Osteomalacia from vitamin D deficiency, malabsorption, and liver or renal disease

• Underlying bone disease (e.g., Paget's disease, bone tumors, and secondary bone tumors)

In addition to the mentioned causes, high-trauma falls and accidents such as car and motorcycle accidents can lead to hip fracture [50]. But they are not studied in this dissertation. **Figure 2**

• Endocrine abnormalities: hyperthyroidism, hyperparathyroidism, or hypercortisolism

• Genetic and family history

70 Total Hip Replacement - An Overview

• Cardiovascular disease and cardiac arrhythmias

shows how different factors contribute to the hip fracture [6, 38].

• Sedentary lifestyle • Impaired nutrition

• Smoking

• Excess alcohol

In general, there are three types of hip fractures, depending on what region of the proximal femur is involved [67]:

**1.** Femoral neck fractures occur in the narrow section of the proximal femur that lies between the femoral head and the intertrochanteric cross section. Most femoral neck fractures occur within the capsule surrounding the hip joint and are, therefore, termed intracapsular fracture. The blood supply to the femoral head is carried by a number of arteries that pass through the femoral neck region. Therefore, femoral neck fractures may disrupt the blood supply to the femoral head, causing death of the femoral head bone tissues, called osteonecrosis or avascular necrosis. Femoral neck fractures are further grouped into nondisplaced and displaced fractures by the alignment of the fractured segments in relation to the original anatomic position of the femur [68].

**6. Demographic feature of hip fractures**

A variety of studies have examined hip fracture rates in different regions of the world [10, 51, 52, 70]. Greater than tenfold differences have been found on the basis of studies undertaken at a regional or national level for different calendar years. The studies show that the main demographic risk factors for hip fractures include increased age and female gender [10, 25]. The geographic distribution by fracture risk is shown for men and women combined in **Figure 4**. Heterogeneity in hip fracture risk in countries can be seen in this figure. Based on statistical results [10], for women, the lowest annual incidences are found in Nigeria (2/100,000), South Africa (20), Tunisia (58), and Ecuador (73). The highest rates were observed in Denmark (574/100,000), Norway (563), Sweden (539), and Austria (501). The incidence of hip fracture in men is approximately half of that noted in women. The highest annual incidence in men has

Hip Fracture: Anatomy, Causes, and Consequences http://dx.doi.org/10.5772/intechopen.75946 73

As it is shown in **Figure 4**, the high-risk countries are Iceland, the United Kingdom, Ireland, Denmark, Sweden, and Norway in Northwestern Europe; Belgium, Germany, Austria, Switzerland, and Italy in Central Europe; Greece, Hungary, Czech Republic, Slovakia, and Slovenia in southwestern Europe; Lebanon, Oman, Iran, Hong Kong, Singapore, Malta, and Taiwan in Asia; and Argentina in South America. Regions of moderate risk include North America, Oceania, the Russian Federation, and southern countries of Latin America. Lowrisk regions include the northern regions of Latin America, Africa, Jordan, Saudi Arabia,

**Figure 4.** Hip fracture rates (men and women combined) in different countries of the world categorized by risk. Where estimates are available, countries are color-coded red (annual incidence >250/100,000), orange (150–250/100,000), or

green (<150/100,000) [10] (reproduced with permission).

been found in Denmark (290/100,000) and the lowest in Ecuador (35/100,000) [10].


In more complicated cases, the fracture of the bone can involve more than one of these zones. **Figure 3** shows different types of proximal femur fracture.

**Figure 3.** Three main types of hip fractures: femoral neck fracture (subcapital and transcervical fractures), intertrochanteric fracture, and subtrochanteric fracture [69].
