Stress Fractures

How long does it take to heal a stress fracture? How should my training look when trying to get back into it?

Member Question

I got diagnosed with a stress fracture in my fibula in the beginning of October and walked on crutches and in an air cast until the middle of November. How long does it take to get back to running? What about cycling?

I'm asking because I'm still getting sore after I ride on the trainer and my first run (last week), lasted 1/2 mile before the pain was too much. Even if I walk/stand a lot during the day, I can feel a bit sore.

I'm getting frustrated, but at the same time, I don't want to start pushing too soon.

Answer by Bryan Petti, MS IV and Andrew Getzin, MD
Member AMSSM

Stress fractures are microscopic fractures in bone that can coalesce into a true fracture with progressive load.  They are common injuries, occurring in up to 15% of runners at some point in their lives.  We have known since the work of Julius Wolff in the 19th century that bones adapt to gradual increases in loads applied by increasing in density. However, if the cumulative forces are too great, either from an increase in volume or intensity, bone can maladapt with a resultant stress fracture.

In order to make a diagnosis of a stress fracture, your doctor should take a good training and symptom history and perform a physical exam.  Stress fractures typically present in a fairly consistent pattern that can look similar to other overuse injuries of the muscles and tendon. In the early stages of a stress fracture, pain will be present during activity but abates as activity continues.  With continued load, the pain can start to linger throughout the entire activity and into the recovery period.
On physical exam, there may be a tender location directly on the affected bone when pressure is applied.  Additional diagnostic testing such as an x-ray or an MRI may be used as an adjunct to help solidify the diagnosis.

Once diagnosed, initial treatment involves a period of relative rest.  This can include immobilizing the affected joint in a protective boot or aircast, as well as non-weight bearing status on crutches. After this period, a gradual return to activity is begun, with the next phase beginning when the last phase can be completed without recurring pain.  The key to allowing proper healing is to stay pain free.

A fibular stress fracture is a low-risk type of injury, meaning with proper rest it usually heals very well.  It sounds like you were in an aircast and crutches for an appropriate amount of time. As long as you were diligent about resting your leg during that time, we would think that you should be healed enough to bike pain free by now.  Biking is usually tolerated much sooner than running.  How was your stress fracture diagnosed? What were your symptoms at time of diagnosis? Your symptoms currently of pain before, during, and after activity could be a non-healed stress fracture or other soft tissue injuries, such as tendonopathy or injury to the cartilage of the ankle.   Lateral lower leg compartment syndrome can also present with a similar clinical picture.  If you have not obtained an x-ray or an MRI yet, it would be reasonable to discuss ordering one with your physician.

Once you've investigated these possibilities with your doctor and confirmed the diagnosis, it is time to focus on your training loads. A good principle to follow is increase your load by no more than 10% per week. This means if you ran three 1-mile loops this week, next week you'd run three 1.1-mile loops next week. The same principle also applies to your pace on training runs and rides. Also be sure that you provide a body part 2-3 days rest in between loads by cross-training on these days.

Hope this helps. Remember, training errors account for the majority of overuse injuries in endurance athletes. Start low, go slow, and have fun!

Bryan Petti, MS IV

Andrew Getzin, MD
Clinical Director Sports Medicine and Athletic Performance
Cayuga Medical Center
Ithaca, NY
www.cayugamed.org/sportsmedicine