**3. Hip fracture causes**

anatomy is first reviewed, and hip fractures are classified by anatomic location. Then, prevalence of hip fracture is presented, followed by a description of the significance of accurately

Hip fracture is a medical condition in which there is a break in the continuity of the femoral bone. Hip fracture is generally affected by hip anatomy [31], the applied forces to the hip [32], and bone mechanical properties [33]. In this section, hip anatomy is explained to show why

The hip joint is one of the most important joints in the human body. It is also one of the most flexible joints allowing a great range of motions. To better understand hip fracture, it helps to know the anatomy of the hip joint. The hip is a joint formed by the ball-shaped head of the femur and the socket of the pelvis. The femurs are the longest and the strongest bones in the human body, extending from the hip to the knee. Important geometric features of femur bones include the head, neck, and greater and lesser trochanters, as shown in **Figure 1(a)**. A femur is composed of two types of bones, cortical and cancellous. The cortical bone forms the outer layer of the femur and withstands most of the forces and moments. Cancellous bone is mostly enclosed by the cortical bone and mainly absorbs the shock energy produced in walking and running [34]. The hip joint is a stable ball-and-socket joint, much more stable than the shoulder joint. The stability in the hip mainly attributes to the deep socket, i.e., the acetabulum. Additional stability is provided by the strong joint capsule and its surrounding muscles and ligaments. The high level of stability of the hip joint is required to support the upper body [34].

**Figure 1.** (a) Anatomic structure of the hip [35]. (b) Concentration of applied forces on the proximal femur in a lateral fall

assessing hip fracture risk.

68 Total Hip Replacement - An Overview

**2. Hip fracture anatomy**

which increases the risk of fracture.

the hip is likely to experience fracture in a fall.

Hip fracture is usually caused by an applied force that exceeds the strength of the femur bone [39]. Therefore, any situation that either induces a high level of force on the femur bone or decreases the bone strength should be considered as a hip fracture cause.

The main cause of hip fracture is falling (90–92%) [36, 40–42], in particular falling in sideways direction (63–69% in fall-related fractures) [8, 43], as it induces a high level of force on the femur. Parameters that increase the risk of fall and apply a high level of force on the femur, especially in the elderly, are:


In the elderly, most fractures occur after a low-trauma fall, which would not cause any severe injury to a healthy individual. Therefore, low bone strength is another main cause of hip fracture. Osteoporosis as a progressive bone disease, which is characterized by decreases in bone mass and density, has been identified as one of the main contributors of hip fracture [46, 47]. Osteoporosis advances when bone resorption exceeds bone formation, and therefore it is more common among the elderly [48]. Approximately three to four out of ten women over the age of 50, and one in eight men, suffer osteoporotic fracture in their lifetime [49].

Apart from osteoporosis, several other causes may reduce the strength of the bone such as bone cancer and medical side effects [38]. Other factors associated with reduction in bone strength include [38]:


**4. Hip fracture consequences**

2 years [60].

community healthcare system [2, 66].

**5. Classification of hip fractures**

femur is involved [67]:

Hip fractures are associated with significant morbidity, mortality, loss of independence, and financial burden [3, 9, 25, 42, 51–53]. It has been reported that approximately 20% of hip fracture patients died within 1 year of the fracture [54]. Generally, the first year after hip fracture appears to be the most critical time. A recent meta-analysis revealed that women sustaining a hip fracture had a fivefold increase and men almost an eightfold increase in relative likelihood of death within the first 3 months compared with age- and sex-matched controls [29]. The relative death risk decreases substantially over the second year but still much higher than that of the controls [55]. Many lose their ability to walk mainly due to the pain caused by the hip fracture. In fact, only 40–79% of patients regain their previous ambulatory function a year after the fracture, and less than half return to their pre-fracture status of daily activities [56]. In addition to functional impairments, hip fracture can have a negative impact on self-esteem, body image, and mood [57], which may lead to psychological problems [58]. Individuals who suffer fractures may be immobilized by a fear of falling again and suffering more fractures. They may feel isolated and helpless. The National Osteoporosis Foundation conducted a survey [59] among 1000 women with osteoporotic fracture in the United States to investigate the psychological effects of the fracture on the patients. Eighty-nine percent of said they feared breaking another bone; 80% were afraid that they would be less able to perform their daily activities and lose their independence; 73% worried that they would have to reduce activities with family and friends; and 68% were concerned that another fracture would result in their having to enter a nursing home [59]. If not addressed, fear about the future and a sense of helplessness can produce significant anxiety and depression. These problems may be compounded by an inability

Hip Fracture: Anatomy, Causes, and Consequences http://dx.doi.org/10.5772/intechopen.75946 71

to fulfill occupational, domestic, or social duties, thus leading to further social isolation.

The disability, reduced functional status, and poor mental health caused by hip fracture can have a profound impact on the quality of the individual's life. Survivors of hip fracture reported a 52% reduction in the quality of life in the first 12 months and a 21% reduction after

Also, hip fracture is a major cause of the need for long-term nursing home care and a major contributor to healthcare costs [30, 61, 62]. There are approximately 23,000 cases of hip fracture every year in Canada with associated treatment costs of about \$1 billion [63]. In the United States, 310,000 hip fractures occurred in 2003, and the total Medicare cost was estimated between \$10.3 and \$15.2 billion, including acute medical care and nursing home services [53, 64, 65]. As the population of the elderly is still continuously increasing, the number of hip fractures is expected to rise dramatically, and it will put more burdens on the

In general, there are three types of hip fractures, depending on what region of the proximal


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

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