What You Need to Know About Insufficiency Fractures

An insufficiency fracture is a type of hairline fracture that occurs when a normal amount of body weight is applied to a weakened bone. This type of injury can happen anywhere in the skeleton, but it most often affects the spine and pelvic bones.

The leading cause of insufficiency fractures is osteoporosis—a common condition in people over the age of 50 that causes bone loss and frailty. In fact, some studies show that as many as 32% to 72% of people with insufficiency fractures have osteoporosis.

This article discusses the causes and symptoms of insufficiency fractures and includes information about who is most at-risk. It also details the link between insufficiency fractures and osteoporosis along with steps you can take to protect yourself.

A man winces with pelvic pain

 lijubaphoto / E+ / Getty Images

People with osteoporosis have the highest risk of insufficiency fractures. In the United States, at least 10.2 million people over the age of 50 have osteoporosis. Whereas about 5% of people with osteoporosis are men, about 20% are women.

Types of Insufficiency Fractures

Insufficiency fractures are most likely to happen in parts of your body that carry a lot of your body weight, particularly your pelvis, spine, and hips.

These bones can become especially weak, thin, and frail due to osteoporosis, vitamin D deficiency, or aging. As a result, a person can develop an insufficiency fracture from something as simple as a minor fall from standing position.

It's also not uncommon for a person to present lower back or pelvic pain to their doctor without knowing the exact cause. In many cases, they learn they have an insufficiency fracture even though they cannot recall any specific fall or accident in which it happened.

The following types of insufficiency fractures are most common:

Pubic Ramus Fracture

The most common type of pelvic fracture is an injury to one or both of the pubic ramus bones—two ring-shaped bones located on each side of the lower pelvis.

In at least 80% of cases, the pubic ramus fractures in two places at once; much like you can't break a pretzel in one place, this bone tends to break on the top and the bottom of the ring.

In people with osteoporosis, the pubic ramus bones often fracture during a low-impact fall. As many as two-thirds of pelvic ring insufficiency fractures in people with osteoporosis happen without any known traumatic event.

Sacral Fracture

The sacrum is a triangle-shaped bone made of five vertebrae that is located at the bottom of the lumbar spine. The sacrum connects to the tailbone and forms the back wall of the pelvis, helping to support and stabilize the pelvis.

Although sacral insufficiency fractures are common injuries, they often go undiagnosed, as the sacral bones are difficult to see on regular x-rays. Typically, a CT scan or MRI is needed to diagnose this type of hairline fracture.

The sacrum bears much of your upper body weight when you walk and is therefore vital to helping you get around. When the diagnosis is missed, the untreated injury can make it difficult to get around.

Due to the lack of mobility this causes, people with osteoporosis and untreated sacrum fractures have an 27% risk of death within five years of their fracture, due to falls, pulmonary embolism, pneumonia, and other complications.

Femoral Neck Fracture

Your femur, also known as your thighbone, stretches from your hip to your knee. At the top of your femur is the femoral head—a part of your hip joint that rotates like a ball in a socket, allowing you to move your leg around.

Supporting the femoral head is the femoral neck—the site where approximately 45% to 53% of hip fractures take place. This part of your hip bears much of your upper body weight, particularly when you walk.

A femoral neck fracture can cut off blood supply to the femoral head, resulting in avascular necrosis—a potentially life-threatening condition in which the femoral head bone tissues die due to lack of blood supply. Eventually, this can cause the femoral head to collapse.

Acetabular Fracture

The acetabulum is the socket of the hip joint, which connects to the femoral head. Acetabular fractures usually happen alongside other pelvic fractures, which can have a severe impact on your ability to walk.

Due to the acetabular's close proximity to the sciatic nerve and major blood vessels in the thigh, fracturing the acetabular is associated with a high risk of nerve damage and internal bleeding.

Like other insufficiency fractures, acetabular fractures commonly occur in people with osteoporosis who have a low-impact fall.

Recap

Most insufficiency fractures take place in the pelvis, specifically the pubic ramus and sacral bones. The femoral neck bones and the acetabular bones are the sites of most hip fractures. In people with osteoporosis, each of these can easily fracture due to minor accidents and falls.

Insufficiency Fracture Symptoms

Hairline pelvic fracture symptoms often mimic hip fractures.

That said, there is one major difference between the two types of insufficiency fractures: gentle leg motions are significantly more painful in someone with a hip fracture compared to someone with a pelvic fracture.

A fracture in your pubic ramus bones, sacral bone, or elsewhere in your pelvis can cause the following symptoms:

Pelvic fractures can result in life-threatening complications, especially when there are multiple fractures involved. This type of fracture can injure nearby organs within the pelvic ring, such as the intestines, kidneys, bladder, or genitals.

If you have a fracture in your acetabular bone, sacral bone, femoral neck, or elsewhere in your hip, you may experience the following:

  • Hip pain that can radiate to your knee
  • Low back pain
  • Pain or unsteadiness when standing or walking
  • Bruising and swelling in your hip

Similarly, hip fractures can also result in life-threatening complications due to how close the hip is to major blood vessels. The injury may cause a blood clot in your leg to break away and travel to your lung. This event is known as a pulmonary embolism, and it can be fatal unless treated immediately.

Diagnosis

Because insufficiency fractures can result in serious complications, it's important to see your doctor if you are having pain in your pelvis, hip, or lower back—even if you don't recall injuring yourself.

If you can recall a time when you fell, bumped into something, or landed too hard on yourself, no matter how insignificant the event was, let your doctor know.

Your doctor will likely begin by asking you about your pain. They will want to know where your pain is located, whether your pain is dull or stabbing, and what sorts of movements make it worse.

From here, your doctor may ask you to walk across the room to assess your gait. They may also have you lie on your back while they move your leg in various angles. Doctors use these maneuvers to check how your hip moves and whether or not there is swelling.

At this point, your doctor may have a few ideas of what's going on, and will likely order imaging tests to take a closer look at a specific body part. Tests to diagnose insufficiency fractures include x-rays, CT scans, and MRIs

While x-rays can generally help your doctor eliminate some types of bones fractures and breaks, your doctor may need to order a CT scan or MRI to see hairline fractures with more detail.

Insufficiency fractures can sometimes be misdiagnosed or under diagnosed. Don't hesitate to speak up or get a second opinion if you suspect your doctor missed something.

Treatment Options

Most often patients will recover with a short course of rest, followed by physical therapy and a progressive increase in walking.

With certain types of fractures, your doctor or physical therapist may require you to limit how much weight you place on your injury. Some doctors may encourage their patients to place as much weight as they can tolerate on the injured body part, taking rests as needed. 

In some circumstances, you may need inpatient hospitalization or nursing care to assist with your daily activities. This will likely depend on how severe your injury was, how well you are able to move, and whether or not there were complications.

Beyond this, treatment should focus on identifying what caused the fracture. Treating osteoporosis is difficult, but it's important to try, as it may prevent future insufficiency fractures

Vitamin D deficiency is also a common culprit of insufficiency fractures. If your doctor suspects a vitamin D deficiency has something to do with your fracture, they may recommend calcium and vitamin D supplementation to help strengthen your bones.

Treating sacral and pelvic insufficiency fractures can be frustrating and inconvenient, but it is not as invasive as the treatment of a hip fracture, which almost always requires surgery. Therefore, every effort should be made to prevent injuries from happening.

Prevention

As you get older, your bones naturally lose bone mass and become weaker, which is why the majority of people who get insufficiency fractures are over the age of 60.

Although any person of any age can get an insufficiency fracture, they are most prevalent in people with thin, weakened bones—especially people with osteoporosis or a vitamin D deficiency.

Women have a higher risk of developing osteoporosis compared to men, and the progressive disease also runs in families. But whether you have osteoporosis or not, it's never too late to start strengthening and protecting your bones with these steps:

  • Eating a healthy, colorful diet with ample vitamin D and calcium
  • Doing weight-bearing exercises regularly, like yoga and weightlifting, to strengthen the muscles that support your joints and bones
  • Avoiding tobacco and limiting how much alcohol you consume

If you have osteoporosis or osteomalacia already, you can also take the following steps to prevent falls and protect yourself from insufficiency fractures:

  • Improve your leg strength and balance with low-impact exercises like yoga, tai chi, and swimming⁠—just be sure to get your doctor's approval before starting a new exercise routine
  • Get your eyes checked at least once a year
  • Make your home safer by clearing pathways, removing clutter that you could trip over, placing a rubber bathmat or nonslip seat in the shower, and moving more slowly through your home

Summary

Insufficiency fractures are a type of hairline stress fracture that are most common in people with osteoporosis. This type of fracture can occur in any bone that bears body weight, but they are most common in the pelvis, hips, and sacrum.

Fractures in each of these areas can cause similar symptoms, and they can also result in potentially life-threatening complications. If you feel pain in any of these body parts, it's important to visit your doctor—even if you don't recall injuring yourself.

A Word From Verywell

Living with a fear of falling and injuring yourself is not uncommon in people with osteoporosis. For some, this can have a negative impact on their physical and psychological health, lead to social isolation, or create a significant financial burden.

Understanding osteoporosis, learning how to prevent injury, and joining a support group may help you cope. In addition, many people find that wearing a medical alert bracelet or necklace provides them and their loved ones peace of mind.

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