Hip Fracture

Question 1

Hip Fracture Intro

Answer 1

Hip fracture occurs in approximately 341,000 persons in the United States each year. [1] The rate of hip fracture increases with age, doubling every 5-6 years after age 60 years

Question 2

Guidelines for management of hip fracture in the elderly

Answer 2

Recommendations supported by strong evidence include the following:

1. Regional analgesia can be used to improve preoperative pain control in patients with hip fracture.
2. In patients undergoing hip fracture surgery, similar outcomes can be achieved with general or spinal anesthesia.
3. Arthroplasty should be used for patients with unstable (displaced) femoral neck fractures.
4. Use of a cephalomedullary device is recommended for the treatment of patients with subtrochanteric or reverse obliquity fractures.
5. In asymptomatic postoperative hip fracture patients, a blood transfusion threshold of no higher than 8g/dl should be used.
   Intensive post-discharge physical therapy improves functional outcomes.
6. Use of an interdisciplinary care program in hip fracture patients with mild to moderate dementia improves functional outcomes.
   Multimodal pain management should be used after hip fracture surgery.

Question 3

Signs and symptoms

Answer 3

In elderly patients, hip fracture most often results from a simple fall. The patient typically complains of pain and inability to move the hip.

With stress fractures in young athletes and nondisplaced fractures, the patient may complain of pain in hip or knee and may be ambulatory.

On physical examination, the anatomical position of the extremity provides useful clues to the type of injury, as follows:

1. Femoral head fracture: Posterior dislocation is most common (eg, a dashboard injury), in which case the extremity appears adducted and internally rotated; with anterior dislocation, the extremity is abducted and externally rotated
2. Femoral neck fracture: With partial or completely displaced fractures (types 3 and 4, respectively), the patient has severe pain and lies with the extremity slightly shortened, abducted, and externally rotated; with a stress fracture or severe impaction fractures (types 1 and 2, respectively), the only physical findings may be minor pain with little or no limitation in range of motion
3. Trochanteric fracture: With a greater trochanteric fracture, the patient presents with pain, especially with abduction and extension; no deformity may be apparent, but pressure through greater trochanters will result is pain; with a lesser trochanteric fracture, pain occurs during flexion and internal rotation
4. Intertrochanteric fracture: The extremity appears shortened and significantly externally rotated, in contrast to the minimal deformities associated with femoral neck fractures; pain, hip edema and ecchymosis, and pain with any movement may also be noted
5. Subtrochanteric fracture: The proximal femur usually is held in flexion and external rotation

Question 4

On physical examination, the anatomical position of the extremity provides useful clues to the type of injury, as follows:

Answer 4

1. Femoral head fracture: Posterior dislocation is most common (eg, a dashboard injury), in which case the extremity appears adducted and internally rotated; with anterior dislocation, the extremity is abducted and externally rotated
2. Femoral neck fracture: With partial or completely displaced fractures (types 3 and 4, respectively), the patient has severe pain and lies with the extremity slightly shortened, abducted, and externally rotated; with a stress fracture or severe impaction fractures (types 1 and 2, respectively), the only physical findings may be minor pain with little or no limitation in range of motion
3. Trochanteric fracture: With a greater trochanteric fracture, the patient presents with pain, especially with abduction and extension; no deformity may be apparent, but pressure through greater trochanters will result is pain; with a lesser trochanteric fracture, pain occurs during flexion and internal rotation
4. Intertrochanteric fracture: The extremity appears shortened and significantly externally rotated, in contrast to the minimal deformities associated with femoral neck fractures; pain, hip edema and ecchymosis, and pain with any movement may also be noted
5. Subtrochanteric fracture: The proximal femur usually is held in flexion and external rotation

Question 5

Diagnosis

Answer 5

On plain radiographs, anteroposterior (AP) and lateral views demonstrate most hip fractures.

For patients in whom femoral neck fracture is strongly suspected but standard x-ray findings are negative, an AP view with internal rotation provides a better view of the femoral neck.

If standard radiograph findings are negative and hip fracture still is strongly suspected, MRI and bone scan have high sensitivity in identifying occult injuries; MRI is 100% sensitive in patients with equivocal radiographic findings.

Question 6

Management

Answer 6

1. Femoral head fractures
   Treatment of type 1 femoral head fractures is as follows:
   -Obtain orthopedic consultation in the ED
   -Reduce dislocated femoral head and fracture fragment as soon as possible to avoid avascular necrosis
   -Small fracture fragments may need to be removed
   -If a single attempt at closed reduction fails, open reduction and internal fixation (ORIF) is the next treatment of choice

For type 2 femoral head fractures, early orthopedic consultation for admission and arthroplasty is recommended.

2. Femoral neck fractures
   Type 1: Some practitioners handle these fractures nonoperatively with initial immobilization in selected patients, while others prefer operative treatment in all patients

Types 2, 3, and 4: Management usually includes ORIF or arthroplasty; however, some impacted fractures can be treated conservatively; early orthopedic consultation is recommended

3. Trochanteric fractures
   Type 1: Management is most often conservative, and orthopedic consultation is recommended
   Type 2: These fractures usually are treated with ORIF, except in older or debilitated patients in whom conservative treatment is appropriate
4. Intertrochanteric fractures
   - Apply traction or a traction splint
   - Note the potential for significant blood loss; IV fluid resuscitation is generally recommended
   - Stable and unstable fractures usually are treated with ORIF unless the patient is not an operative candidate for other reasons
   - Early orthopedic consultation is recommended
5. Subtrochanteric fractures
   - Significant hemorrhage is common, and IV fluid resuscitation is frequently necessary
   - ED application of traction or traction splint is necessary
   - Properly evaluate the entire patient to rule out associated severe injuries
   - Consult orthopedic surgeon for admission and ORIF for most patients

Question 7

Background Summary

Answer 7

Fractures of the hip are relatively common in adults and often lead to devastating consequences. Disability frequently results from persistent pain and limited physical mobility. Hip fractures are associated with substantial morbidity and mortality; approximately 15-20% of patients die within 1 year of fracture. Interestingly, morbidity and mortality in those older than 90 years sustaining a hip fracture were not found to be statistically higher than others in the same age group without such an injury.

Most hip fractures occur in elderly individuals as a result of minimal trauma, such as a fall from standing height. In young, healthy patients, these fractures usually result from high-velocity injuries, such as motor vehicle collisions or falls from significant heights. Despite comparable fracture locations, the differences in low- and high-velocity injuries in older versus younger patients outweigh their similarities. High-velocity injuries are more difficult to treat and are associated with more complications than minor trauma injuries.

Egan et al identified several risk factors associated with the risk of a hip fracture patient sustaining a second fall. Increasing age, cognitive impairment, decreasing bone mass, decreasing depth perception, decreased mobility, dizziness, and a poor/fair self-perceived state of health were all linked to increasing likelihood of sustaining a second fall and thus a possible second hip fracture.

Several recent studies have identified additional risk factors for hip fracture. Sennerby et al identified generalized cardiovascular disease as a significant risk factor for hip fracture, while Carbone et al determined that heart failure is a specific risk for hip fracture . Specific characteristics in men were evaluated to determine the relationship to hip fracture; smoking, tall stature, stroke, and dementia were found to increase the risk of hip fracture, while non–work-related physical activity and high BMI were found to be protective. Kettunen at al studied previously elite male athletes and found that these individuals sustained hip fractures at significantly older ages than their less active counterparts.

Two medication classes have also been implicated in hip fractures. Nursing home patients on antipsychotic medications and HIV-positive patients on protease inhibitor therapy were more likely to sustain fractures than those on other agents

Question 8

Skeletal Anatomy

Answer 8

The hip joint is a large multiaxial ball-and-socket synovial joint, enclosed by a thick articular capsule. The hip joint is designed for stability and a wide range of movement. Next to the shoulder, it is the most moveable of all joints. During standing, the entire weight of the upper body is transmitted to the heads and necks of the femurs. The round head of the femur articulates with the cuplike acetabulum. The depth of the acetabulum is increased by the reinforcing fibrocartilaginous labrum, which “grasps” the femoral head, covering more than half of it. Articular cartilage covers the entire head of the femur, except for the pit (fovea) for the ligament of the femoral head.

The strong, loose fibrous capsule permits free movement of the hip joint, attaching proximally to the acetabulum and transverse acetabular ligament. The fibrous capsule attaches distally to the neck of the femur only anteriorly at the intertrochanteric line and root of the greater trochanter. Posteriorly, the fibrous capsule crosses to the neck proximal to the intertrochanteric crest without attaching to it. The fibrous capsule thickens to form 3 ligaments of the hip joint: the Y-shaped iliofemoral ligament (of Bigelow), the pubofemoral ligament, and the ischiofemoral ligament.

The hip joint is further supported by the femur and the muscles that cross the joint; this bone and these muscles are the largest and most powerful in the human body.

Question 9

Quick Summary in anatomy of fracture

Answer 9

The length, angle, and narrow circumference of the femoral neck permit substantial range of motion at the hip but also subject the femoral neck to incredible shearing forces. A fracture results when these forces exceed the strength of the bone. The intertrochanteric line is an oblique line that connects the greater and lesser trochanters, dividing the femoral neck from the shaft. Hip fractures involve fracture of any aspect of the proximal femur, from the head to the first 4-5 cm of the subtrochanteric area

Question 10

The vascular supply to the proximal femur is tenuous and provided largely by two sources.

Answer 10

Branches of the medial and lateral circumflex femoral arteries, usually branches of the deep femoral artery, ascend on the posterior aspect of the femoral neck in the retinacula (reflections of the capsule along the neck of the femur toward the head). The branches of the medial and lateral circumflex arteries perforate the bone just distal to the head of the femur where they anastomose with branches from the foveal artery and with medullary branches located within the shaft of the femur.

The ligament of the head of the femur usually contains the artery of the ligament of the head of the femur (foveal artery), a branch of the obturator artery. The foveal artery enters the head of the femur only when the center of the ossification has extended to the pit (fovea) for the ligament of the head, around age 11-13 years. This anastomosis persists even in advanced age but is never established in 20% of the population.

Femoral neck fractures often disrupt the blood supply to the head of the femur. The medial circumflex artery supplies most of the blood to the head and neck of the femur and is often torn in femoral neck fractures. In some cases, the blood supplied by the foveal artery may be the only blood received by the proximal fragment of the femoral head. If the blood vessels are ruptured, the fragment of bone may receive no blood and undergo avascular necrosis (AVN).

Question 11

Classifying Fractures

Answer 11

Hip fractures can be classified based on their relation to the hip capsule (intracapsular and extracapsular), geographic location (head, neck, trochanteric, intertrochanteric, and subtrochanteric), and degree of displacement. Higher-grade displacement implies worse prognosis. Fractures of the femoral head and neck are intracapsular, whereas those of the trochanteric, intertrochanteric, and subtrochanteric regions are extracapsular. The treatment as well as the prognosis for successful union and restoration of normal function varies considerably with fracture type.

Intracapsular hip fractures, like all other intracapsular fractures, frequently have complicated healing. The thick capsule that surrounds these fractures separates them from adjacent soft tissue and capillaries, leading to impaired callous formation. Thus, nonunion and AVN are added complications of these fractures.

Question 12

Femoral head fractures

Answer 12

Isolated femoral head fractures are rare and are usually associated with hip dislocations. Superior femoral head fractures normally are associated with anterior dislocations, while inferior femoral head fractures are associated with posterior dislocations. They are usually best appreciated on postreduction radiographs for hip dislocations. Fractures of the femoral head are more common in younger patients as a result of major trauma, which is more likely to cause femoral neck fractures in older patients.

Type 1 - Single fragment fractures

Type 2 - Comminuted fractures

Question 13

Femoral Neck Fractures

Answer 13

These are rare among younger patients but are commonly seen in older adults, most often secondary to osteoporosis or osteomalacia. These fractures usually result from minor trauma with falls accounting for 90%, or torsion. From proximal to distal, femoral neck fractures can be further delineated as subcapital, transcervical, and basicervical, all of which are intracapsular and associated with potential disruption of the vascular supply. The incidence of avascular necrosis (AVN) is up to 15% in nondisplaced fractures and increases to nearly 90% with untreated, completely displaced fractures.

Type 1 - Stress fractures or incomplete fractures
Type 2 - Impacted fractures
Type 3 - Partially displaced fractures
Type 4 - Completely displaced or comminuted fractures

Question 14

Trochanteric fractures

Answer 14

Greater trochanteric fractures usually result from avulsion injuries at the insertion of the gluteus medius. Lesser trochanteric fractures may be caused by avulsion injuries of the iliopsoas secondary to forceful contraction. These are most common in children and young athletes (eg, dancers, gymnasts).

Type 1 - Nondisplaced fractures
Type 2 - Displaced fractures; >1 mm displacement for fractures of the greater trochanter and >2 mm displacement for fractures of the lesser trochanter

Question 15

Subtrochanteric fractures

Answer 15

These fractures have a bimodal age distribution and are seen most often in those aged 20-40 years in association with high-energy trauma and in patients older than 60 years secondary to falls on osteoporotic bones.

Stable: Bony contact of medial and posterior femoral cortices

Unstable

Question 16

Frequency

Answer 16

United States

In the United States, hip fracture occurs in approximately 341,000 persons each year. [1] The rate of hip fracture increases with age, doubling every 5-6 years after age 60 years. [1] The fracture rate does decrease slightly after age 85 years. [1] Nearly half of all hip fractures occur in adults older than 80 years. Hip fracture at a young age is rare and is usually the result of a high-velocity injury or, rarely, secondary to bone pathology.

International
The US frequency of hip fracture, when age and sex are adjusted, ranks the highest in the world. Western Europe and New Zealand also have reported high rates, with the lowest rates occurring in the South African Bantu people and in East Asian countries, where the incidence of osteoporosis is low.

Question 17

Mortality/Morbidity

Answer 17

Reported overall mortality rate of hip fractures is 15-20%, yet in older persons this can increase to 36% over the year following hip fracture. Rate of mortality is greatest in the first few months following injury but remains high for up to 1 year. It then returns to the same rate for age- and sex-matched people without hip fracture. Surgical delay independently affects mortality.

Patients for whom surgery is delayed for 2 days or more, have a 17% higher mortality rate at 1 month. A subsequent study showed increased mortality but decreased readmission rate in those repaired more than 4 days from the time of injury.

Morbidity associated with hip fracture is staggering, especially in older persons. Morbidity from immobilization includes development of deep vein thrombosis, pulmonary embolism, pneumonia, and muscular deconditioning. Morbidity from surgical procedures includes complications of anesthesia, postoperative infection, loss of fixation, malunion or nonunion, as well as the complications associated with immobilization as outlined above. As many as 20% of patients return to the emergency department in the year following a hip fracture with concerns relating to the morbidity of the initial fracture.

Surgical delay of greater than 48 hours has also been shown to increase morbidity and mortality.

Question 18

History

Answer 18

In elderly patients, hip fracture most often results from a simple fall; in a small percentage, it occurs spontaneously, in the absence of any trauma.

Patient complains of pain and inability to move the hip.

With stress fractures in young athletes and nondisplaced fractures, patient may complain of pain in hip or knee and may be ambulatory.

Patient may have a history of other osteoporotic fractures, such as Colles or vertebral compression fractures.

Question 19

Causes

Answer 19

In young persons, hip fractures generally result from trauma associated with significant force. For example, 75% of all femoral head fractures, more common among young patients, occur as a result of motor vehicle collisions.

In older persons, more than 90% of hip fractures result from trauma or torsion associated with a minor fall or, occasionally, in the absence of any obvious traumatic event.

Osteoporosis is the leading cause of hip fracture. Bone mineral density equivalent, calculated from DXR, was significantly lower in the 122 patients who later suffered a hip fracture than in the patients who did not experience a hip fracture. The age-adjusted hazard ratio per standard deviation change in DXR Tscore for hip fracture in the study was 2.52 and 2.08 for women and men, respectively.

Other risk factors for hip fracture include the following:
Neurological impairment
Caucasian race
Cigarette smoking
Institutional living
Maternal history of hip fracture
Previous hip fracture
Physical inactivity
Tall stature
Alcohol abuse
Previous Colles or vertebral fracture attributed to osteoporosis
Low body weight
Impaired vision
Prolonged corticosteroid use
Use of medications that decrease bone mass, including furosemide, thyroid hormone, phenobarbital, and phenytoin

Question 20

Medications Used

Answer 20

Parenteral analgesia is strongly recommended. A muscle relaxant also may be necessary. Administer antibiotics to cover skin flora (ie, cefazolin sodium) and tetanus immunization, as necessary, in open fractures.