INTRODUCTION — As the elderly population grows, the number of hip fractures continues to increase. The elderly have weaker bone and are more likely to fall due to poorer balance, medication side effects, and difficulty maneuvering around environmental hazards. Clinicians in many fields are involved in caring for patients with hip fractures and should be familiar with the basic assessment and management of these injuries.
This topic review will discuss the major types of hip fractures, including basic anatomy, fracture classification, and clinical and radiographic assessment. The details of surgical treatment are beyond the scope of this review. Prevention of hip fractures, preoperative assessment and the prevention and management of common medical complications associated with hip fractures are all discussed separately. (See "Medical consultation for patients with hip fracture" and "Falls in older persons: Risk factors and patient evaluation".)
EPIDEMIOLOGY — Worldwide, the total number of hip fractures is expected to surpass 6 million by the year 2050 [1]. A total of 310,000 individuals were hospitalized with hip fractures in the United States (US) alone in 2003, according to data from the US Agency for Healthcare Research and Quality, accounting for 30 percent of all hospitalized patients [2]. Approximately one-third (101,800) of fracture patients went on to receive a hip replacement. The estimated cost for treatment is approximately $10.3 to 15.2 billion a year in the US [3-6].
Hip fractures substantially increase the risk of death and major morbidity in the elderly [7,8]. One-year mortality rates have ranged from 12 to 37 percent in these patients [3,7,9,10], but may be declining [11]. Approximately one-half of patients are unable to regain their ability to live independently [12]. A meta-analysis of prospective studies found the relative hazard for mortality during the first three months following a hip fracture to be 5.75 (95% CI 4.94-6.67) in older women and 7.95 (95% CI 6.13-10.30) in older men [13]. Although it decreases over time, the increased risk of death likely persists, according to this review and other studies [9]. However, one large prospective case-control study found no increased risk of mortality after the first year following a hip fracture among women 70 years or older [10].
A large review of hip fractures in the US found that femoral neck and intertrochanteric fractures occur with approximately the same frequency in patients between the ages of 65 and 99 years [14]. Intracapsular (ie, femoral neck) fractures occur about three times more often in women. The highest rates were found among white women. Intertrochanteric extracapsular fractures also occur in a 3:1 female to male ratio. Subtrochanteric fractures show a bimodal distribution (20 to 40 years and over 60 years) [15].
Isolated trochanteric fractures occur more often in young, active adults between the ages of 14 and 25 [16]. Eighty-five percent of less severe trochanteric avulsion fractures occur in patients under 20 years of age [17]. Trochanteric fractures in elderly patients usually result from direct trauma (eg, fall), but can be associated with pathologic injury (eg, fracture through bone metastases).
Issues related to the timing of surgical repair of hip fractures and perioperative mortality and morbidity are reviewed separately. (See "Medical consultation for patients with hip fracture", section on 'Timing of surgical intervention'.)
RISK FACTORS — Major risk factors for hip fractures among elderly patients include osteoporosis and falls. It is estimated that approximately 30 to 60 percent of community-dwelling older adults fall each year [18]. Approximately 90 percent of hip fractures in the elderly occur from a simple fall from the standing position [19]. Women sustain hip fractures more often due to their higher rates of osteoporosis. The lifetime risk of hip fracture is 17.5 percent for women and 6 percent for men [20]. On average, women who sustain a femoral neck fracture are 77 years old and men are 72 years old [19]. Low socioeconomic status is associated with an increased incidence of hip fracture [21-23]. Cardiovascular disease may also be associated with an increase in the risk of hip fracture among older patients [24], as may some endocrine disorders (eg, diabetes, hyperthyroidism) and a number of medications. (See "Prevention of falls and complications of falls in community-dwelling older persons" and "Osteoporotic fracture risk assessment" and "Bone disease with hyperthyroidism and thyroid hormone therapy", section on 'Fracture risk' and "Bone disease in diabetes mellitus", section on 'Fracture' and "Drugs that affect bone metabolism", section on 'Drugs that may have adverse effects'.)
PREVENTION — Effective means for preventing hip fractures is of great importance in elderly patients. These issues, including fall prevention and the treatment of osteoporosis, are discussed separately. (See "Prevention of falls and complications of falls in community-dwelling older persons" and "Prevention of osteoporosis" and "Osteoporotic fracture risk assessment" and "Overview of the management of osteoporosis in postmenopausal women" and "Treatment of osteoporosis in men".)
ANATOMIC CONSIDERATIONS — The hip joint is a "ball and socket" joint consisting of the acetabulum (socket) and the femoral head (ball) (figure 1). The femoral neck connects the femoral head to the proximal portion of the femoral shaft and attaches to the intertrochanteric region (figure 2). The term "hip fracture" is applied to fractures in any of these locations.
Disruption of the blood supply to the head and neck of the femur can impair fracture healing in these structures (figure 3 and figure 4). An extracapsular vascular ring encircles the base of the femoral neck. This ring gives rise to feeder vessels (ascending cervical arteries) that run parallel to the femoral neck up to the femoral head. The arteries of this ring are supplied by the medial and lateral femoral circumflex arteries, which arise from the deep femoral artery. The foveal artery (a branch of the obturator artery) provides supplementary blood flow to the femoral head. It courses through the ligamentum teres into the fovea. However, the foveal artery alone is not thought to be adequate to meet the needs of the femoral head.
The femoral head is a sphere that is slightly flattened superiorly. The arrangement of its cancellous bone is oriented along the principal lines of stress. Most important of these arrangements are the primary medial trabeculae (which resist compression) and the primary lateral trabeculae (which resist tension). These structures enable the bone to endure the strong forces exerted across the proximal femur. As an example, a force 2.6 times body weight is transmitted across the hip in a one-legged stance.
The prognosis of hip fractures varies by anatomic location. The intertrochanteric region contains a large amount of cancellous bone with a good blood supply. Therefore, intertrochanteric fractures typically heal well if reduction and fixation are properly performed. However, intertrochanteric fractures can become displaced because of the actions of the iliopsoas muscle, which pulls on the lesser trochanter, and the major external rotator and abductor muscles of the hip, which pull on the greater trochanter.
In contrast to the intertrochanteric region, the femoral neck has little cancellous bone, a thin periosteum, and a relatively poor blood supply that can be disrupted by injury. Fractures in this area have a higher incidence of complications, such as avascular necrosis and degenerative changes in the femoral head.
FRACTURE CLASSIFICATION — Hip fractures are classified by anatomic location and by fracture type. The general categories include intracapsular (femoral neck and head) (figure 1 and figure 5) and extracapsular (intertrochanteric and subtrochanteric) (figure 2) fractures. Extracapsular is defined as extending from the extracapsular femoral neck to the area just distal to the lesser trochanter.
For reasons discussed above, intracapsular fractures have a higher rate of nonunion or malunion and are more likely to lead to avascular necrosis of the femoral head. Subtrochanteric fractures have an increased need for implant devices, such as intramedullary nails (or rods) and have higher rates of implant failure due to the high stresses placed upon this part of the femur. (See 'Anatomic considerations' above.)
Distinct classification schemes for femoral neck fractures and intertrochanteric fractures are described below. (See 'Femoral neck fractures' below and 'Intertrochanteric fractures' below.)
INITIAL MANAGEMENT — Initial care of the patient with a hip fracture consists primarily of providing adequate analgesia and consulting an orthopedic surgeon. Pain is often undertreated in the elderly, which is inhumane and increases the risk of delirium [25]. Intravenous opioids provide faster relief, but intramuscular or oral medications may be used. If resources are available, regional nerve blocks are effective at reducing pain and minimizing the sedation caused by opioids [26-28].
In patients at higher risk for hemorrhage, it is prudent to obtain blood for type and screen or type and crossmatch at the time of presentation. According to retrospective studies, patients at higher risk have at least two of the following features [29,30]:
Comorbidities (eg, ischemic heart disease) must be considered when determining the need for blood transfusion or other interventions. (See "Indications for red cell transfusion in the adult".)
Particularly in elderly patients injured during a fall, the clinician should take a careful history to determine the cause of the fall (eg, syncope) and perform a thorough physical examination looking for internal and additional orthopedic injuries (eg, intracranial hemorrhage, cervical spine fracture). Conditions associated with the fracture may include dehydration, possibly complicated by rhabdomyolysis due to prolonged down time. (See "Falls in older persons: Risk factors and patient evaluation" and "Evaluation and acute management of cervical spinal column injuries in adults".)
Prophylaxis against deep vein thrombosis and wound infection is important and discussed separately. (See "Medical consultation for patients with hip fracture", section on 'Thromboembolic prophylaxis' and "Medical consultation for patients with hip fracture", section on 'Prophylactic antibiotics'.)
A systematic review concluded that neither skin nor skeletal traction prior to surgery provides any benefit in reducing pain or improving the ease or quality of hip fracture reduction [31]. Eleven studies involving 1654 patients, primarily elderly, were included. The effectiveness of traction for specific types of hip fractures could not be determined.
TIMING OF SURGERY — The timing of surgery to repair a hip fracture has an important impact on outcomes. These issues are discussed separately. (See "Medical consultation for patients with hip fracture", section on 'Timing of surgical intervention'.)
FEMORAL NECK FRACTURES
Pertinent anatomy — Femoral neck fractures are intracapsular. The tenuous blood supply to the femoral neck increases the risk of complications, such as avascular necrosis (figure 3 and figure 4). The presence of a fracture-dislocation further increases such risks. Hip anatomy is discussed in greater detail above. (See 'Anatomic considerations' above.)
Mechanism of injury — Femoral neck fractures tend to occur in elderly patients who fall. Among the elderly, there are several possible mechanisms of injury:
In younger individuals, femoral neck fractures generally occur as a result of major trauma, such as a motor vehicle collision or a fall from a height. The femur is usually axially loaded. If the hip is abducted at the time of injury, a femoral neck fracture occurs; if adducted, the result is often a fracture-dislocation. (See "Initial evaluation and management of adult pelvic trauma".)
Symptoms and examination findings — Elderly patients usually describe the sudden onset of hip pain, either before or following a fall, and the inability to walk, although some patients with a minimally impacted fracture may continue to bear weight. A displaced hip fracture usually involves a significant amount of groin pain and the leg may appear externally rotated and shortened. Typically there is little bruising because the fracture is intracapsular. With insufficiency fractures, there may be no obvious history of trauma and the patient may complain of vague knee, buttock, groin, or thigh pain.
Particularly with elderly patients, the clinician should determine the reason for any fall (eg, syncope, stroke), assess for additional orthopedic and internal injuries, and initiate management as indicated.
Radiographic findings for hip fracture — Plain radiographs of the hip, including an anterior-posterior (AP) view with maximal internal rotation and a lateral view, should be obtained in all patients with a suspected hip fracture (picture 1). Comparison with the uninvolved hip can be helpful and therefore an AP pelvis x-ray is frequently obtained.
X-rays should be examined for alterations in the normal trabecular pattern, defects in the cortex, and shortening or angulation of the femoral neck. The normal angle between the femoral neck and the femoral shaft on an AP x-ray is 45 degrees. The angle between the medial femoral shaft and the trabecular lines running through the shaft to the femoral head is 160 to 170 degrees. Alterations in these angles suggest a fracture.
The Garden classification scheme is based upon radiographic appearance and is used specifically for femoral neck fractures [32]:
If plain radiographs are unrevealing but pain is significant and clinical suspicion is high or the patient is at high risk, a bone scan or MRI can determine the presence of a fracture. MRI has the advantages of earlier fracture detection and the absence of radiation exposure. It can take up to 72 hours following an injury before diagnostic findings appear on a bone scan.
Several studies highlight the importance of obtaining additional imaging when indicated [33-35]. In one retrospective study of 764 patients with hip pain evaluated in the emergency department for a possible fracture, 24 fractures were identified using MRI among the 545 patients whose initial x-rays were negative [33]. In another observational study, a femoral neck or intertrochanteric fracture was identified by MRI in 46 of 100 consecutive patients being evaluated for hip fracture whose initial plain radiographs were unrevealing [34].
Indications for orthopedic consultation — Femoral neck fractures should be referred to an orthopedic surgeon, as most will require surgical fixation. Knowledgeable primary care physicians may opt to manage a patient with an old, nondisplaced fracture who is walking with minimal pain or one who is nonambulatory or a poor surgical candidate. Co-management with an orthopedic surgeon may be appropriate in such circumstances.
Treatment of femoral neck fractures — The primary care clinician often plays an important role in assessing the patient's preinjury level of function and comorbidities to help determine appropriate goals for treatment. Ambulatory patients should be treated aggressively, typically with surgical intervention, with the goal of restoring their preinjury level of activity as quickly as possible.
Debate continues among surgeons as to whether open reduction with internal fixation (ORIF) or arthroplasty is the best treatment for appropriate surgical candidates. In a systematic review of this subject that included 19 trials (3044 participants), internal fixation was found to result in lower morbidity in several categories, including blood loss and risk of deep wound infection [36]. However, patients treated with arthroplasty had significantly lower reoperation rates. No differences were identified in mortality or regaining previous residential status. Treatment with a total or partial hip arthroplasty allows for earlier recovery and may reduce the risk of avascular necrosis and nonunion.
Nonoperative management is generally reserved for debilitated patients but may be reasonable in patients with stable, impacted fractures [37]. One randomized trial of 23 patients reported that 10 of 16 patients treated conservatively developed a nonunion while none of those treated surgically did so [38]. However, a prospective study of nonoperative treatment for patients with impacted femoral neck fractures (n = 170) found that 86 percent healed [39]. The authors concluded that such management is reasonable, but should be restricted to patients over 70 years and in poor health. Mortality in the study population was 16 percent.
Complications — Infection and thromboembolism are potentially life-threatening complications associated with hip fractures for which prophylaxis should be given. The prevention and management of these complications is discussed separately. (See "Medical consultation for patients with hip fracture".)
Femoral neck fractures have a relatively high rate of complications compared with extracapsular hip fractures. Potential complications following surgical repair include infection, chronic pain, dislocation, nonunion, avascular necrosis (AVN), and posttraumatic arthritic changes. (See "Postoperative fever" and "Osteonecrosis (avascular necrosis of bone)".)
Reported nonunion rates range from 0 to 4 percent to over 30 percent. Selection bias may play a role in this wide range [19]. A number of factors determine the risk of nonunion, including patient age, bone density, fracture displacement, fracture comminution, reduction quality, and the prosthetic device and its position. Nonunion or loss of reduction can present with groin, hip, or thigh pain that never fully resolves following surgery, or increases after a period of improvement.
X-rays should be obtained periodically for a minimum of three years following surgery to screen for the development of AVN. Patients with displaced fractures are at greatest risk [40]. AVN may be painless initially but causes pain and limits motion over time. Typically, the pain is localized to the groin or ipsilateral buttock region, but may manifest as referred knee pain, and increases with weightbearing. Radiographic assessment using an MRI or bone scan is necessary when AVN is suspected. Changes on plain x-rays do not reliably appear until six months after AVN first develops. MRI is used to assess patients with titanium hardware; a bone scan is used in those whose fracture fixation hardware is ferromagnetic. (See "Osteonecrosis (avascular necrosis of bone)".)
INTERTROCHANTERIC FRACTURES
Pertinent anatomy — Intertrochanteric fractures are extracapsular, and thus at lower risk for complications related to interruption of the blood supply, but are at risk for displacement [41]. Hip anatomy is discussed in greater detail above. (See 'Anatomic considerations' above.)
Mechanism of injury — In the elderly population, intertrochanteric fractures occur as the result of a fall. These fractures are rare in younger individuals, but may occur with major trauma, such as a fall from a height or a motor vehicle collision. In the younger population, there is a high incidence of associated internal and orthopedic injury [42,43].
Symptoms and examination findings — Elderly patients usually describe hip pain, swelling, and ecchymosis. The injured leg may be shortened and externally rotated if the fracture is displaced. As opposed to femoral neck fractures, intertrochanteric fractures are extracapsular and significant ecchymosis may be present, depending upon the time elapsed since the injury. A large amount of blood can be lost into the thigh and hemodynamic status should be closely monitored.
The patient will have local tenderness over the trochanteric area, but should not have tenderness over the distal femoral shaft or pelvis. Such findings suggest additional injuries.
A thorough examination, including all other extremities and the spine, should be performed due to the high association of intertrochanteric fractures with concomitant injury. The contralateral hip should be palpated and taken through its full range of motion.
Particularly with elderly patients, the clinician should determine the reason for any fall (eg, syncope, stroke), assess for internal injuries, and initiate management as indicated.
Radiographic findings — Plain radiographs of the hip, including an anterior-posterior (AP) view with maximal internal rotation and a lateral view, should be obtained in all patients with a suspected hip fracture (picture 5 and picture 6 and picture 7 and picture 8). Comparison with the uninvolved hip can be helpful and therefore an AP pelvis x-ray is frequently ordered (picture 9).
If plain x-rays are unrevealing but a fracture is suspected clinically, an MRI can be obtained. Alternatively, a bone scan may be performed 48 to 72 hours after the injury. The limitations of plain radiographs for hip fracture are described above. (See 'Radiographic findings for hip fracture' above.)
Intertrochanteric fractures can be classified as stable, for which a near anatomic reduction is achievable, or unstable [44]. In stable fractures, the lesser trochanter is not displaced, there is no comminution, and the medial cortices of the proximal and distal fragments are in alignment. In unstable fractures, displacement occurs, comminution is present, or multiple fracture lines exist.
Indications for orthopedic consultation — The large majority of intertrochanteric fractures are treated surgically and orthopedic consultation should be obtained in all cases. Early studies showed a higher mortality rate for fractures treated by closed means compared with operative repair [45,46]. Therefore, most injuries, including all displaced fractures, are treated with open reduction and internal fixation.
Treatment of intertrochanteric fractures — In consultation with the orthopedic surgeon, the primary care physician should assess the patient's ambulation, overall functional status, and medical comorbidities and then determine the appropriate definitive management. Ambulatory patients should be treated aggressively, typically with surgical intervention, with the goal of restoring their preinjury level of activity as quickly as possible. Nonoperative management with good pain control may be the best approach for the nonambulatory patient.
A systematic review evaluated arthroplasty versus internal fixation for operative repair of extracapsular hip fractures and found insufficient evidence for recommending one treatment over another [47]. A subpopulation of patients with incomplete intertrochanteric fractures had good functional outcomes, with no increase in hospital stay, when managed conservatively [48].
Nonoperative management is often appropriate in the following circumstances:
Surgery may be delayed in patients with conditions that increase the risk of postoperative complications, but are amenable to treatment. Such conditions might include sepsis or skin breakdown over the surgical site.
Complications — Complications for intertrochanteric fractures are similar to those for femoral neck fractures and include infection, thromboembolism, pressure sores, and nonunion. Infection and thromboembolism are potentially life-threatening complications for which prophylaxis should be given. The prevention and management of these complications is discussed separately. (See "Medical consultation for patients with hip fracture".)
Nonunion is reported in only 1 to 2 percent of intertrochanteric fractures [41]. This is likely because the fracture occurs primarily in cancellous bone. Nonunion is typically diagnosed by a persistent radiolucent defect at the fracture site four to seven months after fracture fixation. However, in patients with abundant callous formation, loss of alignment may be the sole radiographic finding.
The rates of avascular necrosis (AVN) and nonunion are lower with intertrochanteric fractures than with femoral neck fractures [44]. However, overall mortality and functional outcome is generally worse with intertrochanteric fractures. One case series reported a 15 percent mortality rate after intertrochanteric hip fractures [50]. This relatively high rate was attributed to the number of major perioperative medical problems and postoperative complications.
Fixation failure occurs in up to 20 percent with some fracture patterns, typically within four months of fixation. AVN occurs at higher rates in patients with more complex or displaced fractures and in women. The typical appearance is varus collapse of the proximal fragment and cutout of the compression screw.
TROCHANTERIC FRACTURES — Isolated trochanteric fractures usually result from forceful muscular contraction of a fixed limb and occur most often in young, active adults.
Pertinent anatomy — The greater trochanter is a bony prominence on the lateral aspect of the proximal femur. It serves as the site for multiple muscle insertions including the hip abductors (gluteus medius and minimus) and external rotators (piriformis, gemelli, obturators).
The lesser trochanter lies on the posteromedial aspect of the proximal femur, inferior to the femoral neck. The iliopsoas, which is primarily responsible for hip flexion, inserts on the lesser trochanter.
Mechanism of injury — Isolated fractures of the greater and lesser trochanters, particularly in young patients, are typically avulsion fractures caused by forceful muscle contraction. Resisted hip flexion leads to a strong contraction of the iliopsoas that can avulse the lesser trochanter. A forceful contraction of the hip abductors or a fall onto the lateral hip may cause a greater trochanteric fracture.
In the elderly, such injuries can occur from direct trauma (eg, fall) but have also been associated with pathologic fractures.
Symptoms and examination findings — Lesser trochanteric fractures generally cause pain in the groin, but may also present with knee or posterior thigh pain that is worse with hip flexion and rotation. Greater trochanteric fractures cause hip pain that increases with abduction and tenderness over the greater trochanter.
Radiographic findings — Anterior-posterior (AP) and lateral radiographs are used for diagnosis. For evaluation of the lesser trochanter, an AP view with the leg in supported external rotation is obtained. The greater trochanter is typically well visualized on standard AP views (picture 10). The limitations of plain radiographs for hip fracture are described above. (See 'Radiographic findings for hip fracture' above.)
It is often prudent to obtain an MRI in patients at high risk of extension of a trochanteric fracture, such as the elderly and patients with diminished bone density. In a retrospective observational study of 13 patients with radiographic findings of a greater trochanteric fracture, extension of the fracture line into the intertrochanteric or femoral neck region was found in 10 patients on subsequent MRI studies [51]. Similar findings were described in another study of elderly patients [52].
Treatment and indications for orthopedic consultation — Most trochanteric fractures heal well with nonoperative management, unless significant displacement (>1 cm) is present. The patient generally must remain nonweightbearing for three to four weeks. Many patients are able to return to full activity as soon as two to three months following the injury. Displaced fractures should be referred to an orthopedic surgeon for possible open reduction and internal fixation.
In older individuals, isolated lesser trochanteric fractures have been associated with pathologic fractures. In the absence of trauma, therefore, it is prudent to evaluate for metastases [44-46].
Complications — Direct complications from isolated greater or lesser trochanteric fractures are rare. There may be a slight loss of abduction power in the case of greater trochanteric fracture or in hip flexion with lesser trochanteric fractures. Inappropriate prolonged immobilization can cause joint contracture. This can be avoided with early implementation of a progressive range of motion exercise program.
PRE AND POSTOPERATIVE CARE — The risk of major perioperative complications, including infection, thromboembolism, and delirium, can be substantially reduced with proper management. Another important question is the timing of surgery. Such management issues are discussed separately. (See "Medical consultation for patients with hip fracture".)
CLINICAL GUIDELINES — Evidence-based clinical guidelines on the treatment of hip fractures in the adult and elderly population have been published by several groups and are listed separately. (See "Medical consultation for patients with hip fracture", section on 'Guidelines'.)
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