PARS Stress Fracture

  • Are you a young adult or a parent of a young adult who has low back pain with sports? Has your Physio expressed concern about a PARS stress fracture?

  • Perhaps the back pain really hasn’t been settling despite a couple of weeks of rest?

  • Do you find it’s notably worse when leaning backwards, for example, when serving in tennis, swimming, or sprinting?

Don’t struggle on or continue trying to play sport with pain. This may be a sign of a PARS stress facture.

What is a PARS stress fracture?

A PARS stress fracture is a stress fracture in a small bony bridge at the back of the vertebrae called the pars interarticularis.

When we’re developing as young adults and our adult height is being reached, the bones are ossifying. One of the last places that this happens in the spine is in the PARS area.

If we do a lot of activity, particularly a high volume of sport or sports when our movement patterns aren’t well controlled, we can end up overloading this area.

This is more common in certain sports, that involve a lot of lumbar extension, which might be tennis, hurdling, and sprinting. We also see this happening in rowers and gymnasts.

I had a consultation with Dr Spencer-Smith regarding an ongoing pain that no one had been able to get to the bottom of. She listened so patiently to me and was able to identify possible causes and explain the likely origin of the pain. She was extremely warm, compassionate and clear and I would not hesitate to recommend her.

How do we diagnose a PARS stress fracture in the back?

When you come to clinic, I’ll ask you some questions about what you’re experiencing, where you feel the pain, and we’ll watch you move.

Generally speaking, we can get some clues from the examination process, such as a bit of tenderness or pain in a certain position. It is actually very difficult to rule out a PARS stress fracture without MRI imaging, which is often why it gets mistaken for irritation arising from the small joints in the back (in facet joints) or muscular irritability.

In the past, we would have used what’s called a nuclear bone scan, which involves radiation, and we’d have looked for a hotspot on the scan. Now, with the advent of really high-quality MRI imaging, all that we need to do is to carry out a quality MRI scan.

It’s important that the MRI scan is a powerful MRI scan, such as 3T MRI, and that the MRI scan, when it is requested specifies that we’re looking for a PARS stress fracture (sometimes these a missed on regular MRI scans where the slices aren’t finely spaced). Sometimes there is a bit of bright uptake in the PARS bone area, but it’s not actually fractured.

This is known as bone stress in the PARS, but generally speaking, we tend to treat PARS stress fractures and bone stress within the PARS area, the same way.

Just thought I'd send you a grateful patient email. You may remember you saw me back in October when I was suffering from a meniscus tear in my right knee and what turned out to be a cyst.  We decided not to operate on the tear but we aspirated the cyst and injected the knee and I've been doing more core/stability exercises.  That definitely seems to have been the right decision.  I've been training without discomfort since the beginning of November and I finally began to post some decent results last month culminating in a victory on Monday in the M55 World Masters Cross Country championships held in Poland. Many thanks to you all for your wise counsel.

What is the treatment of a PARS stress fracture?

It’s very helpful to get a swift diagnosis, to avoid a lot of time out from sport because there will need to be some time away from the activities that are provoking pain. For example, sometimes you might need to abstain from your sport for six or more weeks.

After some time and healing has happened, we can progress on with a really robust rehabilitation programme. That’s going to include some physiotherapy, osteopathy, and we’ll be looking to restore the normal movement patterns within the spine and very importantly, how the spine is loaded during sport.

Often we’ll find that there’ll be some weakness of control into lumbar extension and poor lumbar pelvic stability. Sometimes we need to correct some of the activities or skills within the sport itself.

For example, in tennis, if your ball toss technique is too overhead, you may be encouraging yourself to overly extend the lumbar spine.

We’ll also look at the number of training hours that you’ve been doing, your nutrition, and often we’ll carry out some blood tests just to make sure that there are no areas that need optimizing, such as your vitamin D levels.

Whilst it is possible to carry out bone mineral density testing (DEXA scanning), in a young age this can only give us an indication of the current status quo because a young person won’t yet have attained their peak bone mass. DEXA scanning is more useful when people are in their thirties and beyond.

Very, very occasionally spinal surgery is needed to treat a pars injury that simply won’t settle or has started to create a bit of movement in the lumbar spine called spondylolisthesis. I’ve never had to refer anybody for this in my professional career.

If you suspect that you might have a PARS stress fracture, please don’t hesitate to book a consultation.