Femoral Neck Hip Fracture

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Introduction

Hip fractures are one of the most frequent fractures presenting to the emergency department and orthopedic trauma teams.

The terms hip fracture and femoral neck fracture both relate to the same type of injury.

Both terms describe a fracture of the proximal femur between the femoral head and 5 cm distal to the lesser trochanter.

Clinically Relevant Anatomy

A hip fracture occurs just below the head of femur (HOF), the region of the femur called the femoral neck. A femoral neck fracture disconnects the HOF from the rest of the femur. Click Hip Anatomy for more details

Etiology

Most commonly:

• Falls in the elderly: Account for the majority of hip fractures. Risk factors for falls in the elderly population are many, those strongly associated with these fractures are a previous history of falls, gait abnormalities, the use of walking aids, vertigo, Parkinson disease, and antiepileptic medications. A lot of patients have multiple risk factors, and this, combined with age-associated reduced bone quality, is the underpinning cause of most hip fractures. The majority of fragility hip fractures occurred inside the home
• Significant trauma (e.g. motor vehicle collisions) in younger patients
• About 3% of hip fractures are related to localized bone weakness at the fracture site, secondary to tumour, followed by bone cysts, or Paget’s disease.

Epidemiology

The incidence of femoral neck fractures is increasing as the proportion of the elderly population in many countries increases. Between 1990 and 2000, there was nearly a 25% increase in hip fractures worldwide.

• The peak number of hip fractures occurred at 75-79 years of age for both sexes, with most occuring in women. In white women, the lifetime risk of hip fracture is 1 in 6.
• Up to 20% of patients die in the first year following hip fractures, mostly due to pre-existing medical conditions. Less than half of those who survive the hip fracture regain their previous level of function

Classification of Hip Fractures

Hip fractures is classified into intracapsular and extracapsular fractures

Intracapsular fractures (femoral neck fractures): Occurs within the hip capsule; accounts for 45% of all acute hip fractures in the elderly; susceptible to malunion/avascular necrosis of the HOF because of the limited blood supply to the area.

Intracapsular fractures are further classified as nondisplaced or displaced based on radiographic findings

• Type 1: non-displaced and incomplete fracture
• Type 2: non-displaced complete fracture
• Type 3: complete fracture but incompletely displaced
• Type 4: complete fracture and completely displaced

Extracapsular fractures: Intertrochanteric fracture or Subtronchanteric fracture.

• Intertrochanteric fracture: occurs between the greater and the lesser trochanter; intertrochanteric region has a good blood supply, avascular necrosis or nonunion is rare.
• Subtronchanteric fracture: occurs below the lesser trochanter, approximately 2.5 inches below.

Risk factors

Risk factors for hip fracture include:

• Gender: prevalent in women; postmenopausal twice as likely as premenopausal to have hip fracture
• Reduced Bone density
• Falls
• Medications: Some medications can cause a decrease in bone density like cortisone.
• Nutrition: It is well known that calcium and vitamin D increase bone mass, so a lack of it can cause several fractures, including hip fractures.
• Age: the older you get, the higher the risk is for hip fractures. 90% of these fractures occur in persons over 70 years old.
• Alcohol and tobacco: These products can reduce bone mass, causing a higher risk to have a hip fracture
• Medical problems: Endocrine disorders can cause fragility of the bones
• Physical inactivity: Physical activity is very important for muscle mass and bone mass
• Stroke increases the risk factor for falls which can cause a hip fracture.
• Parkinson’s disease increases the risk factor for falls which can cause a hip fracture.

Characteristics/Clinical Presentation

• Dull ache in the groin and/or hip region
• Inability to put weight on the injured leg causing immobility right after the fall
• Shorter leg on the side of the injured hip
• External rotation of the injured leg
• Stiffness, bruising and swelling in and around the hip

Diagnostic Procedures

The diagnosis of a hip fracture is established based on patient history, physical examination, and radiography.

• Plain radiographs (sensitivity 93-98%) is the first-line investigation for suspected Neck of Femur(NOF) fractures.
• In patients with a suspected occult NOF fracture, MRI (sensitivity 99-100%) is recommended by many institutions as the second-line test if available within 24 hours, with CT or nuclear medicine bone scan third-line

Outcome Measures

• Functional Independence Measure
• Berg Balance Scale
• Timed Up and Go Test (TUG)
• Patient Specific Functional Scale
• Falls Risk Assessment Tool

Treatment and Prognosis

The management of hip fracture is usually a combination of surgery and rehabilitation.

• Also depends on the location of the fracture and whether it is displaced.
• In comparison to conservative management (bed rest and traction), operative management results in a reduced length of hospital stay and improved rehabilitation.
• Significant complications such as avascular necrosis and non-union are very common without surgical intervention.
• The treatment options include non-operative management, internal fixation or prosthetic replacement.
• Internal fixation can be performed with multiple pins, intramedullary hip screw (IHMS), crossed screw-nails or compression with a dynamic screw and plate.
• Replacing the femoral head is achieved with either hemiarthroplasty and total hip arthroplasty.
• A national pragmatic Randomised Control Trial: the SENSE trial will compare arthroplasties with internal fixation for undisplaced fracture neck femur in patients aged over 65

The high morbidity and mortality associated with hip and pelvic fractures after trauma has been well documented.

• Prolonged bed rest can increase the risk of pressure sores, atelectasis, pneumonia, deconditioning, and thromboembolic complications. Weight-bearing immediately after hip fracture surgery is safe in most patients. Complications following hip surgery involve blood clots, pneumonia, wound infections, and more, all of which can be reduced with activity
• Prognosis is varied but is complicated by advanced age, as hip fractures increase the risk of death and major morbidity in the elderly.
• Surgery <48 hours after admission may be associated with lower morbidity and may decrease hospital stay..
• The risk of avascular necrosis (AVN) depends on the type of fracture:

1. Transphyseal: ~90% risk of AVN
2. Subcapital: ~50% risk of AVN
3. Basicervical/transcervical: ~25% risk of AVN
4. Intertrochanteric: ~10% risk of AVN

Physical Examination

On physical examination, findings on the patient with a hip fracture may include the following:

• limited and painful hip range of motion, especially in internal rotation.
• the injured leg is shortened, externally rotated, and abducted in the supine position
• Pain is noted upon attempted passive hip motion.
• Ecchymosis may or may not be present.
• An antalgic gait pattern may be present.
• Tenderness to palpation around the inguinal area, over the femoral neck. This area may also be swollen.
• Increased pain on the extremes of hip rotation, an abduction lurch, and an inability to stand on the involved leg

For more on details, Click Hip Examination

Physical Therapy Management

Rehabilitation begins promptly.

Two to three days postoperative

• Instruct patient in deep breathing and cough. Goal: Prevent postoperative pneumonia and atelectasis.
• Initiate isometrics and ankle pumps with involved extremity. Goal: Prepare patient for active exercise program.
• Initiate bedside sitting once physician has cleared patient for this activity. Goal: Prepare patient to begin transfer and progressive gait training processes.

Three to five days postoperative

• Gait train patient, observing weight-bearing precautions. Progress to walker or crutches. Goal: Establish independent gait with assistive device, using proper gait pattern on all surfaces and stairs.
• Initiate training in activities of daily living, including bed mobility and transfers to and from bed and toilet. Goal: Achieve independence with all transfers.
• Initiate active range of motion/strengthening program. Individualize exercise programs according to each patient's needs, but generally include the following. Goals: Increase strength of involved extremity; increase independence with exercise program.
  • Supine: hip abduction and adduction, gluteal sets, quadriceps sets, straight leg raise, hip and knee flexion, short arc quadriceps, internal and external rotation.
  • Sitting: Long arc quadriceps, hip flexion, ankle pumps.

• When internal fixation is performed, partial weight-bearing is recommended for a period of 8–10 weeks (according to the radiological evaluation of fracture healing), and after 3 months full weight-bearing should be allowed.
• The patient can also begin strengthening exercises based on the surgeon's orders (typically six weeks post-op).

Patients should also undergo balance and proprioceptive rehab and these abilities are quickly lost with inactivity. Rehabilitation classes for balance and falls prevention are recommended.

Weight-bearing exercises are very important for mobility, balance, activities of daily living and quality of life, examples: stepping in different directions, standing up and sitting down, tapping the foot and stepping onto and off a block.

For patients who underwent a prosthetic replacement have to avoid the following for approximately 12 weeks:

• Hip flexion greater than 70–90°
• External rotation of the leg
• Adduction of the leg past midline
• Should not bend forward from the waist more than 90°

Rehabilitation program components:

• Hip extension (theraband and manual exercise)
• Heel raises onto toes (theraband and manual exercise)
• Resisted rowing (double arm lifting) (theraband and manual exercise)
• Standing diagonal reach (theraband and manual exercise)
• Modified get up and go (theraband and manual exercise)
• Overhead arm extensions (theraband and manual exercise)
• Repeated chair stands (vest and manual exercise)
• Lunges - forward and back (vest and manual exercise)
• Stepping up and down step (vest, manual exercise and plyometric step)
• Calf raises - both legs and one leg (manual exercise)

Importance of rehabilitation/home exercise program:

• Moderate to large improvements in physical performance and quality of life was found in patients who had a 10- week home-based progressive resistance exercise program
• A meta-analysis, showed that balance training within 6 months improves a person with hip fracture's physical functioning, gait, lower limb strength, performance task, and activity of daily living.
• Among patients who had completed standard rehabilitation after hip fracture, the use of a home-based functionally oriented exercise program resulted in modest improvement in physical function at 6 months after randomization.

Education and prevention are also important issues to address.

Clinical Bottom Line

• 
  The number of hip fractures worldwide will increase to 7-21 million incidences each year in 2050.
• Mortality associated with a hip fracture is about 5-10% after one month. One year after fracture, about a third of patients will have died, compared with an expected annual mortality of about 10% in this age group.
• Only a third of the deaths are directly attributable to the hip fracture itself.
• More than 10% of survivors will be unable to return to their previous residence. Most of the remainder will have some residual pain or disability. Most people who sustain the injury require surgery followed by a period of rehabilitation.
• Treatment is generally surgical to replace or repair the broken bone.
• Some loss of function is to be expected in most patients.
• Rehabilitation plays a key role in treatment.