Femoral Neck Fracture

A femoral neck fracture is a serious break in the upper part of the thigh bone, near the hip joint. While these fractures are common in older adults after simple falls, they can also occur in younger people following high-impact trauma. Most cases require surgery, and quick diagnosis and treatment are essential to prevent serious complications.

Table of contents

• What is a Femoral Neck Fracture?
• Hip and Femoral Neck Anatomy
• Causes and Risk Factors
• Who is Affected?
• Signs and Symptoms
• Diagnosis
• Treatment Options
• Complications

What is a Femoral Neck Fracture?

A femoral neck fracture is a specific type of hip fracture that occurs in the neck region of the femur, which is the upper part of your thigh bone.^[1] The femoral neck is the narrow section of bone that connects the rounded ball at the top of the thigh bone (called the femoral head) to the long shaft of the bone that runs down through your thigh.^[3]

This type of fracture is classified as an intracapsular hip fracture because it occurs within the hip joint capsule.^[1] Femoral neck fractures can be either displaced or non-displaced. In a displaced fracture, the broken bone moves out of its normal position, while in a non-displaced fracture, there is no significant movement or instability of the bone.^[3]

Hip and Femoral Neck Anatomy

Your hip is a ball-and-socket joint.^[3] The ball portion is the head of the femur, which fits into a rounded socket in your hip bone called the acetabulum.^[1] The femoral neck acts as a bridge connecting the femoral head to the main shaft of the thigh bone. This location makes the femoral neck particularly vulnerable to fractures.^[1]

An important consideration with femoral neck fractures is the blood supply to the femoral head. The main source of blood to the femoral head is the medial femoral circumflex artery, which runs along the femoral neck.^[1] When a femoral neck fracture is displaced, it can damage or tear the blood vessels that supply the bone, potentially leading to serious complications.^[1]

Causes and Risk Factors

The causes of femoral neck fractures vary significantly depending on age and overall health. In elderly people, these fractures typically result from low-energy falls, such as tripping at home or twisting the hip.^[1] In younger individuals, femoral neck fractures usually occur from high-energy trauma such as motor vehicle accidents, falls from significant heights, or injuries during extreme sports activities.^[1]

Several factors increase the risk of sustaining a femoral neck fracture:^[1]

• Female gender
• Decreased mobility
• Low bone density
• Osteoporosis (a condition that causes bones to become weak and brittle)

Young individuals who are unaccustomed to sudden strenuous activity or changes in physical activity patterns may also be at risk, particularly athletes.^[6]

Who is Affected?

Hip fractures are extremely common injuries worldwide. There are approximately 1.6 million hip fractures annually across the globe, and about 70 percent of all hip fractures occur in women.^[1] The risk of hip fracture increases exponentially with age and is more common in white females.^[1]

In the United States alone, it is estimated there will be approximately 300,000 cases of hip fractures annually by the year 2030.^[1] The economic burden is substantial, with approximately 20 billion dollars spent on the management of hip fractures in the United States, making it one of the top 20 most expensive diagnoses.^[1]

Signs and Symptoms

The symptoms of a femoral neck fracture are typically severe and immediate. Common signs and symptoms include:^[3]

• Severe hip pain
• Pain that radiates to the knee
• Inability to bear weight on the affected leg
• Inability to walk or move the leg
• Shortening or sideways rotation of the affected leg
• Increased pain in the hip during rotation of the leg
• Swelling on the side of the hip

Diagnosis

Femoral neck fractures are diagnosed based on a combination of physical examination, your symptoms, and the circumstances of the accident or injury.^[3] Your doctor will examine you and assess the position and movement of your hip and leg.

To confirm the diagnosis, your doctor will order imaging tests. An X-ray is the primary imaging tool used to diagnose a femoral neck fracture and to see exactly where the break has occurred.^[3] In some cases, additional imaging tests may be needed to obtain more detailed information. These can include:^[3]

• Magnetic resonance imaging (MRI) — uses magnets and radio waves to create detailed images of soft tissues and bones
• Computed tomography (CT) scan — creates three-dimensional images of the bone to better understand the fracture pattern

A radiographic image showing a broken Shenton’s curve, which describes the relationship of the femoral head to the acetabulum, can indicate a femoral neck fracture.^[3]

Treatment Options

Treatment for a femoral neck fracture depends on several factors, including your age, the extent of bone displacement, your overall health, and your bone density.^[3] Immediate diagnosis and management are required to prevent serious joint complications.^[1]

Conservative Treatment

Conservative therapeutic approaches without surgery are suggested only for uncomplicated, non-displaced fractures.^[3] This approach typically includes bed rest for a few days followed by a physical rehabilitation program after two or three days. Your doctor may also prescribe medications to prevent blood clots, relieve pain, and treat any infection that may be present.^[3]

However, femoral neck fractures are rarely stable enough to manage with only conservative therapy and usually require surgical repair.^[3]

Surgical Treatment

Surgery for a femoral neck fracture is performed under either general or spinal anesthesia (numbing medication given through the spine).^[3] The type of surgery depends on the severity and displacement of the fracture, as well as your age and bone quality. The main surgical options include:

Hip Pinning (Internal Fixation): This is recommended if your fracture is minimally displaced and you have sufficient bone density.^[3] Your surgeon will make a small incision on the outside of your thigh and insert several screws to stabilize the broken bones and hold them in place while they heal.^[3]

Hip Hemiarthroplasty (Partial Hip Replacement): This procedure is suggested if you have a displaced fracture.^[3] The surgeon will make an incision over the outside of the hip, remove the damaged femoral head, and replace it with a metal implant. The socket portion of the hip joint is not replaced in this procedure.^[3]

Total Hip Replacement: This is recommended if you had arthritis of the hip before the fracture occurred.^[3] Your surgeon will replace both the femoral head and the socket of the hip joint with artificial metal implants called prostheses.^[3]

Complications

Most complications associated with femoral neck fractures are related to fracture displacement or delays in diagnosis and treatment.^[12] Potential complications include:

• Delayed union — when the bone takes longer than expected to heal
• Nonunion — when the bone fails to heal properly
• Refracture — breaking the bone again
• Avascular necrosis (also called osteonecrosis) — death of bone tissue due to lack of blood supply, which is particularly concerning in displaced fractures where blood vessels may be damaged^[1]

In badly displaced femoral neck fractures, the decreased blood supply to the bone can prevent proper healing.^[3] This is why the blood supply to the femoral head is an essential consideration when planning treatment, especially in displaced fractures and in younger patients.^[1]