Freaking the F(em) Out: Importance of Quick Diagnosis of Femoral Stress Fractures

The two words “stress fracture” can be some of the scariest words a runner can hear. Unfortunately, stress fractures are common running injuries. I personally had 3 stress fractures just in high school: one in each fibula and one in my right tibia. Of the many stress fracture locations in runners, femoral stress fractures are some of the more serious ones. While femoral stress fractures are uncommon in general athletic populations, they are frequently seen in runners.¹ The two locations for femoral stress fractures are the femoral neck and shaft. Femoral shaft stress fractures account for up to 22.5% of stress fractures among military recruits and collegiate athletes,¹ while femoral stress fractures as a whole make up 5-7% of all stress fractures among runners.² Femoral neck stress fractures are among the most serious injuries in sport due to a high likelihood of complications.

Often Misdiagnosed

Proper diagnosis of femoral stress fractures is vital for a quick and full recovery. These are unfortunately often missed by healthcare providers. People with femoral neck stress fractures typically feel nonspecific, sharp, and deep groin pain that can wrap around the hip and down towards the knee.³ Runners with femoral shaft stress fractures typically feel vague, sharp, and deep pain on the front of their thigh and into their knee.³ In both cases, this pain is aggravated by weight bearing activities like walking, standing from sitting, navigating stairs, and running.³ While these are common symptoms, experiencing them does not automatically mean that you have a stress fracture. However, it does mean that you should see a medical professional, especially someone with experience diagnosing and treating running related injuries, as femoral bone stress injuries are very commonly missed, resulting in a significant increase in severity of injury and decrease in likelihood of ever returning to full running participation. As running specialists, our typical examination process includes reviewing your recent training, recovery factors, pain characteristics, and conducting objective tests to properly screen for bone injuries. 

Imaging Implications

With most soft tissue injuries we don’t usually encourage MRIs since they often do not change the plan of care. However, if we suspect a femoral bone stress injury, we recommend getting an MRI as soon as possible. MRI is the gold standard for diagnosing femoral stress fractures because X-rays only detect these fractures 10% of the time! It is extremely important to get an MRI quickly because it helps determine if surgery is required. Femoral neck stress fractures on the top aspect of the bone typically require immediate surgery, while fractures on the bottom part of the femoral neck may not need surgery. MRIs can also determine if a fracture is displaced or not. A displaced fracture typically requires surgery, especially displaced femoral neck stress fractures due to the high risk of further complications such as avascular necrosis of the femoral head. This condition occurs when there is inadequate blood supply to the femoral head, causing the bone to start to die. If this happens, a total hip joint replacement is typically required.

Rehab & Returning to Run

The return to run timeline changes depending on whether surgery is performed or if we can treat it conservatively. 

Surgical Management 

Following surgery, return to full sport can take up to a year, but is usually initiated between 3 to 6 months following surgery.³ Immediately after surgery, there is a period of non-weight bearing, usually lasting between 4 to 6 weeks. This is a critically important time to allow the bone to fully heal. After this period, there is another 4 to 6 weeks of progressively increasing the amount of weight bearing. Most people will be able to fully bear weight roughly 8 to 12 weeks following surgery.³ During this time, you can still perform non-weight bearing exercises to gain and maintain as much leg strength as possible. Keeping your surgical side as strong as possible is beneficial to better tolerate increased weight bearing and, eventually, return to running sooner. Light jogging can often be initiated soon after full weight bearing is achieved, building up through a slow & progressive return to running program. As running specialists, we blend our knowledge and expertise of rehabilitation and run coaching to create a comprehensive return to running performance program so you can continue to reach your goals despite this set back.

Conservative Management

Conservative treatment also starts with a period of non-weight bearing. Again, this period is vital to allow the bone to heal properly without delaying the recovery process. The length of this non-weight bearing period depends on the fracture site and your symptoms. Typically, femoral neck stress fractures require a longer period of full offloading than femoral shaft fractures. For femoral neck sites, this can be roughly 6 to 8 weeks to transition from full offloading to partial weight bearing and then full weight bearing. However, this process can take up to 14 weeks.³ For femoral shaft sites, full offloading is typically 3 weeks, followed by another 3 weeks of progressive weight bearing. More targeted strengthening and eventually light, short jogs can be started when full weight bearing & walking are tolerated without pain. A full return to run process typically starts around 12 weeks after injury, or when completely pain free with walking for multiple weeks & passing bone specific tests.⁵ 

If offloading is not started as soon as a femoral stress fracture is suspected, the return to run timeline is delayed and the risk of complications and necessity of surgery both increase, further extending the return to run timeline. Unlike most running related injuries where pushing through pain can be totally fine, the most important consideration with stress fracture rehab progression post-surgery and with conservative treatment is having a zero pain tolerance during all activities! 

The return to run process following a femoral stress fracture can be lengthy and filled with uncertainty. It can be hugely beneficial to have a running specialist physical therapist on your team, both to help with the strength & plyometric progression but also for the eventual run progression. 

References

1. Mullins KM, Fredericson M. Lower extremity injuries. In: Tenforde AS, Fredericson M. Bone Stress Injuries: Diagnosis, Treatment, and Prevention. Springer; 2022: 47-55.
2. Hadjispyrou S, Hadjimichael AC, Kspiris A, Leptos P, Georgoulis JD. Treatment and rehabilitation approaches for stress fractures in long-distance runners: a literature review. Cureus. 2023;15(11). doi. 10.7759/cureus.49397
3. Robertson GA, Wood AM. Femoral neck stress fractures in sport: a current concepts review. Sports Med Int Open. 2017;1(2): E58-68. doi. 10.1055/s-0043-103946
4. Temme K, Kapur R. Pelvis and hip injuries. In: Tenforde AS, Fredericson M. Bone Stress Injuries: Diagnosis, Treatment, and Prevention. Springer; 2022: 47-55.
5. Ivkovic A, Bojanic I, Pecina M. Stress fractures of the femoral shaft in athletes: a new treatment algorithm. Br J Sports Med. 2006;40(6): 518-520. doi. 10.1136/bjsm.2005.023655