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

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).

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

**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 origi-

**2.** Intertrochanteric fractures occur at a lower location than femoral neck fractures, in the area between the greater and lesser trochanters. The trochanters are bony projections where major hip muscles are attached. Intertrochanteric hip fractures occur outside of the joint capsule and are therefore also called extracapsular fracture in the literature. Intertrochanteric fractures are complicated by the pull of the hip muscles on the bony muscle attachments, which can exert competing forces against fractured bone segments and pull them out of alignment. Thus, healing of the fracture in a misaligned position is considered as a complication for intertrochanteric fractures. Intertrochanteric fractures may be further grouped into stable and unstable fractures, depending on the location, number, and size of

**3.** Subtrochanteric fractures occur in the zone about 5 *cm* below the lesser trochanter of the proximal femur. The blood supply to the bone of the subtrochanteric region is not as good as the blood supply to the bone of the intertrochanteric region, and thus subtrochanteric fracture heals more slowly [68]. Similar to the intertrochanteric fractures, subtrochanteric

In more complicated cases, the fracture of the bone can involve more than one of these zones.

fracture, and subtrochanteric fracture [69].

nal anatomic position of the femur [68].

72 Total Hip Replacement - An Overview

the fractured bony segments [68].

fractures are likely to cause femur misalignment [68].

**Figure 3** shows different types of proximal femur fracture.

Patients diagnosed with high fracture risk may consider the following prevention measurements:

Hip Fracture: Anatomy, Causes, and Consequences http://dx.doi.org/10.5772/intechopen.75946 75

• Examination of basic neurological function, including mental status, muscle strength,

Protection measurements must be provided to patients with high fracture risk, for example:

• Remembering that sideways falling is more likely to result in a hip fracture than falling in

• Taking steps to reduce the potential energy and subsequently decrease the risk of fracture

○ Consuming a calcium-rich diet that provides about 1000 mg (milligrams) daily for men and women up to age 50 [88]. Women over age 50 and men over age 70 should increase

○ Obtaining 600 **IU** (international units = 0.025 μg) of vitamin D daily up to age 70 [88].

From biomechanics point of view, assessment of hip fracture under stance loading or lateral impact force has been performed using three criteria: factor of safety (FOS) [90], risk factor

their intake to 1200 mg daily from a combination of foods and supplements.

Men and women over age 70 should increase their uptake to 800 **IU** daily.

**8. Bone fracture criterion and hip fracture risk measurement**

○ 5–15 min' exposure to sunlight 4–6 times per week [89].

• Landing with the aid of hands or rea`chable objects around to break the fall [81]

• Individualized exercise programs:

○ Muscle-strengthening exercises [76]

○ Increasing the lower extremity joint function [32]

lower extremity peripheral nerves, and reflexes [79]

• Implementing surveillance and observation strategies

○ Trying to fall forward or backward not from sides

• Environmental modification (e.g., flooring) [31]

• Medication and nutritional improvement:

• Using mobility assisting devices (e.g., walking stick, frames)

○ Obtaining maximum vision correction [6, 78]

○ Practicing balance exercises [77]

• Management of visual impairment:

other directions [8]:

• Using hip protectors [82–87]

[80]

**Figure 5.** Estimated number of hip fractures by sex in the year 1990 and the number expected in 2025 and 2050 by region assuming no increase in age- and sex-specific rates, a 1% annual increase worldwide, or no increase in North America and northern Europe but an increase in age- and sex-specific incidence elsewhere of 2, 3, or 4%. (ROW is rest of world) [25] (reproduced with permission).

India, China, Indonesia, and the Philippines. It is notable that in Europe, the majority of countries are categorized as high or moderate risk. Low risk is identified only in Croatia and Romania [10].

Hip fracture incidence rates are known to increase exponentially with age in both men and women for the most regions of the world [71–74]. The increasing rate of hip fracture in the elderly is mainly associated with their slower reflex response and the inability to effectively use their arms to reduce the energy of the fall and low bone density of the proximal femur [44, 45].

Epidemiological studies show that the number of hip fractures will rise from 1.66 million in 1990 to 4.5–21.3 million by 2050 (**Figure 5**) depending on the underlying assumptions about age- and gender-specific incidence trends [9, 25, 51, 75].
