Bone Stimulators & How to Return to Running After a Stress Fracture

A stress fracture is a runner’s worst nightmare.

It can completely shut down any plans for a season of racing, and worse, the only treatment is that dreaded four-letter-word: rest.

Even one or two unplanned days off can be irritating if you’re a serious runner, but being required to take four, six, or eight weeks off to let a stress fracture heal can be truly agonizing.

Wouldn’t it be great if there was a way to speed up that recovery period?

Recently, some doctors have been prescribing a special machine called a bone growth stimulator which uses pulsed waves of ultrasound in an effort to get stress fractures to heal more rapidly.

Today we’ll take a look at whether this technology can help you get back running faster following a stress fracture. Then we will discuss new research on how to return to running as quickly as possible once your fracture has healed.

The stress fracture treatment you have been waiting for?

Ultrasound bone growth stimulators have been used to treat regular bone fractures with fairly good success. A 1994 study in the Journal of Bone and Joint Surgery randomly assigned sixty-seven patients with fractured tibias to either an ultrasound bone growth stimulator or a placebo device.¹

Both the patients and the doctors were “blinded” to which treatment they received, so there would be no potential bias in interpreting how well the bone fractures were healing.

The patients who used the placebo device had fully healed from their broken bone in 114 days, while the patients who used the ultrasound bone growth stimulator healed in only 86 days.

 Now:

Bone stimulators are also used to treat nonunion fractures, a situation where the bone on each side of a fracture does not heal back together, though the research is less clear on whether ultrasound bone stimulation is helpful in these cases.

A 2012 review study concluded that low-intensity ultrasound waves were effective at speeding up healing in “fresh” fractures, but a lack of quality studies prevented the authors from endorsing it for nonunion fractures.²

The pulses of ultrasonic waves generated by a bone growth stimulator claim to speed up bone healing by increasing the cellular uptake of calcium in bone cells and speeding up the rate at which new bone cells solidify.³

These claims are based on research in lab rats with artificially-induced fractures, so it’s unclear if these same benefits extend to stress fractures as well.

Does it really work for most fractures?

To date, only one peer-reviewed clinical trial has investigated ultrasound as a treatment for stress fractures.

Look:

A 2004 article by J.P. Rue and coworkers at Johns Hopkins University studied twenty-six US Navy recruits with tibial stress fractures.⁴ Many of the sailors had stress fractures in both legs, so the study involved a total of forty-three fractures.

Much like the 1994 study, half of the patients were assigned an ultrasound bone growth stimulator to use for twenty minutes every day, and half were assigned a placebo device that did nothing, and again, both the patients and the doctors were blinded to who received which treatment.

Unfortunately, the ultrasound treatment did not lead to any decrease in healing time—the sailors who got the fake treatment recovered just as fast as the ones who got the real thing.

It get’s worse:

Rue et al.’s study is particularly disappointing because it’s fairly well-designed. Though twenty-six subjects is on the low end of what’s acceptable for this kind of experiment, results from studies with significantly fewer participants have been trumpeted if the result is positive.

Navy recruits are also an ideal population, because recruits are all about the same age and live very similar lifestyles. Further, the training that was done which led to the stress fracture is also very similar from patient to patient.

Is it worth the price tag?

What’s the bottom line?

Because of the relative strength of this study, and the absence of any other research supporting the use of ultrasound waves for stress fractures, bone growth stimulators do not appear to be worth your time and money as a runner.

Some doctors still may prescribe them for stress fractures with a high risk of nonunion, like navicular stress fractures, but only your doctor can make that call.

Ultrasound bone growth stimulators are exorbitantly expensive, and worse, they are marketed as “single use” devices—you, or your insurance company, pays $2,000 to $4,000 for a machine programmed to render itself inoperable after only a few months’ worth of use!

Still, because of the research demonstrating the benefit of ultrasonic waves in stimulating healing in fresh fractures, more research should be conducted on using ultrasound bone stimulators to promote healing in stress fractures.

[bctt tweet=”Ever considered a bone stimulator to heal your fractures faster? @Runners_Connect had some interesting findings” via=”no”]

What can I do to help my stress fracture heal?

Rue et al. suggested that future studies could try higher power ultrasound waves, treatments longer than twenty minutes, or multiple uses per day to see if a stronger dose would have a measurable effect.

Until that research rolls in, however, we still don’t have a “magic wand” that can speed up how quickly a stress fracture heals, but we can offer you our best advice on how to promote recovery.

Conservative Treatments

• Use this time to reflect on your training. Look at what you could have done for this injury develop. Look especially at the past 3-4 weeks to see if you overdid it at any point. This helps to accept what has happened, and learn from it to prevent it occurring in the future.

• By looking at images, or once your body recovers enough to run, look at your stride. Are you over striding? We have a great post on heel striking, over striding, and cadence to help you reach the magic number of 180 steps per minute or more. This will put less stress on your joints, and reduce your risk of injury.

• Look into other health issues that may have played a part in your susceptibility to fractures.  Amenorrhea in females is a major concern, and also a major health risk even outside of running.

• Once you have recovered, incorporate more lower-body strength training into your regimen. Muscle size and strength are linked to bone size and strength; additionally, there is some evidence that stronger muscles will absorb more shock, leaving the bone less vulnerable to high impact loading.

• Consider your lifestyle. Are you trying to do too much? Maybe you are on the verge of overtraining. If your body is worn down, it becomes more susceptible to injuries.

Aggressive Treatment

• If you have a history of tibial or metatarsal stress fractures, you could look into a custom orthotic. Some doctors have proposed that custom orthotics can alter how forces are transmitted up your leg, theoretically leading to lower peak stresses on the bone. Be aware that this theory currently has no experimental evidence to back it up! We have some differing thoughts on custom orthotics.

• If you have a history of tibial fractures, consider running in thin, low-profile “minimalist” shoes. Wearing a thin shoe will force you to maintain a high stride frequency, and will also encourage a midfoot or forefoot strike, which should reduce impact loads on your leg.

• If you have a history of metatarsal fractures, move towards the more cushioned shoes. Minimalist shoes put increased stress on your foot and metatarsals; some doctors have warned that wearing minimalist shoes can even increase your risk for a metatarsal stress fracture.

• Take a calcium and vitamin D supplement that provides 200% of your RDV of both. This carries a small risk of kidney stones if your dietary calcium intake is already high, however.

• Change the surface you typically run on. Try to run on soft, natural surfaces like dirt trails and grass fields. However, there’s no experimental evidence that runners that train on any particular surface are more or less at risk for injury. In fact, there’s some suggestion that soft surfaces may increase the loading on your bones somewhat, as they demand your body maintain a higher overall leg stiffness. You’ll have to experiment with running surfaces to see what type you feel is more beneficial for you.

[bctt tweet=”I wish there was a magic wand to heal stress fractures, but this guide from @Runners_Connect is the the next best thing” via=”no”]

How to return to running safely

We already know stress fractures are some of the most frustrating running injuries you can get. We have already discussed that the time off is non-negotiable, but worse, if you try to return to running too quickly, you could reinjure the stress fracture and have to take even more time off!

Until recently, there hasn’t been much in the way of guidance from the scientific literature.

However, a review article on stress fractures published last October in the Journal of Orthopaedic & Sports Physical Therapy by Stuart Warden, Irene Davis, and Michael Fredericson, three of the top running injury experts in the country, outlines an easy-to-follow program to safely return to 30 minutes of running after a stress fracture.¹

We’ll take a look at the program and discuss how to follow it.

Is this program for me?

Here’s the deal:

If you’re very new to running and 30 minutes is about as far as you’ve ever run, this program might be too aggressive for you.

Additionally, this program is only for low-risk stress fractures. Most stress fractures are low-risk, meaning that they tend to heal up quite nicely during your time away from running.

But a small subset of stress fractures are designated high-risk stress fractures, meaning they are known to be prone to delayed or incomplete healing, or can easily progress to a full-blown bone fracture.²

Fortunately, the vast majority of the stress fractures that runners get are low-risk. These include fibular stress fractures and most tibial and metatarsal stress fractures as well.

High-risk stress fractures include femoral neck stress fractures, navicular stress fractures, and talar stress fractures, among others.

High-risk stress fractures require more time off and a more gradual return-to-running program. If you’re not sure if this program is right for you, talk to your doctor.

Walking completely pain free?

This is important:

To begin the program, you must first be totally pain-free during and after walking unassisted (i.e. without crutches or a walking boot) and doing all of your usual daily activities for five full days.

Every run session consists of 30 minutes of activity with progressively more jogging and progressively less walking, and each session is separated by a rest day.

When doing your run sessions, it’s probably best to stick to a flat, even surface to minimize stress on your body.

How to return to running

The initial stage of the program involves progressing from a 30 minute walk to a 30 minute jog over two weeks.

During this stage, all running is done at an easy jog—defined as 50% of your usual pace.

If you typically ran at 9-minute-mile pace before your injury, your jogging during the first three weeks should be done at 13:30 mile pace (9:00 x 1.5).

Once you’ve progressed to 30min of easy jogging, the next two weeks are spent progressing from 30min at 50% of your usual running pace to 30min at your usual speed.

Finally, the last week is spent progressing towards running daily.

You must remember:

There is a caveat to all of this: as you progress through the schedule, you must remain pain-free both during and after your run sessions.

If you feel any pain, you must take a rest day and move back to the last session you were able to complete without pain, progressing again once you’re able to do it pain-free (during and after).

 Conclusion

By following these guidelines, you can safely transition back to 30min of daily running at your usual pace in as little as five weeks.

This might seem like a long time to be away from training, but don’t forget, you can do as much cross-training (check out our podcast with Physical Therapist Jeremy Stoker) as you like as long as it doesn’t irritate your stress fracture.

Hopping in the pool for an intense aqua-jogging session on the “rest” days in this schedule is a great way to maintain your fitness while you transition back into running.