Lower back pain in Adolescents – Pars Stress Fractures

I recently went to a lecture for Physiotherapists discussing lower back pain in adolescents, with the focus being on pars stress fractures. I was surprised at some of the statistics for the prevalence of stress fractures, and decided that I would like to discuss it in this month’s blog. So if you are OR have a teenager with back pain, keep reading.

In athletic adolescents with back pain, up to 47% have spondylolysis (a pars stress fracture). This statistic is only 5% in athletic adults with back pain.

This means that HALF the teenagers who walk into our practice with lower back pain and whom are participating in an elite or ‘at risk’ sport, have a pars stress fracture. Huge statistics, that even I was surprised by. 

In fact the most common causes of adolescent back pain are pars fractures, and/or poor control/loading/hypermobility disorders. Less common, but not to be missed, are disc injuries, scoliosis factors, Scheuermann’s disease and rheumatoid conditions.

What is a pars stress fracture?

A small stress fracture of the lumbar vertebrae, at a site called the pars interarticularis (see image). This is also known as a spondylolysis. The most common level for this is L5. 

Who is most at risk?

Spondylolysis cricket.jpg

This injury often occurs in a young sportsperson whose sport involves repetitive or excessive extension and/or rotation of the lumbar spine. Such sports include gymnastics, ballet, cricket (fast bowlers), tennis, rowing, diving, track and field throwing, pole vault and high jump. Other risk factors include: a growing/maturing skeleton, heavy training loads, poor lumbo-pelvic control and posture. These are teenagers who usually have poor awareness, can’t dissociate their pelvis/lumbar from hip movements, have weak glutes and tight/weak hamstrings, an increased lordosis and can’t eccentrically contract their hip flexors.

What are the signs and symptoms?

  • Unilateral lower back pain - in a focal area. This can sometimes refer into the buttock/thigh of the same side. 
  • Tenderness over the site of fracture. 
  • Pain with lumbar extension (bending backwards/arching lower back) and rotation or side-bending to this side. 
  • Pain during their sport. 

Do they need a scan?

Yes. Diagnosis is confirmed by imaging, and MRI is the preferred choice here (this will show any bone marrow oedema). Often if we suspect a Pars Fracture, we refer to a Sports Physician who will then refer on for appropriate imaging. They may also consider a SPECT or a CT scan. X-rays will only pick up the late stages of a fracture (when it has been there for several months), and may miss it during the bone oedema/early stages – where the chance of healing is at it’s best.

A scan is often repeated throughout rehab to ensure that the client is on the right track and if further rest is needed. In an elite sporting setting it is not uncommon to have 3+ MRIs. However, amongst the general population price and convenience must be factored in. As a minimum, one MRI is recommended for diagnosis and another at the 2-3 month mark (to track progress). You do not want to leave the second MRI too long in the case that it is too late to make changes to rehab if the fracture has progressed. Some companies will offer bulk billing options for this.

What is the management/treatment?

  • First and foremost – activity modification. This usually means rest from their sport. This is an extended rest, and most Sports Doctors and Physio’s will recommend 3-4 months off (as a minimum). This is CRUCIAL for healing, there are no quick fixes. A pars fracture picked up early has a good chance of healing. However, if diagnosis is delayed or the client does not adhere to this rest, then the chances of healing (or fracture ‘union’) are less likely and this opens the risk of lower back pain and problems into adulthood.
  • During this rest period, rehabilitation should be done. This should be done with a Physio or Exercise Physiologist (and usually involves the team coach or strength and conditioning staff at their sporting club). The goals of rehab are individual, but usually involve:
    • Core control and strengthening – particularly transversus abdominus and multifidus.
    • Gluteal strengthening.
    • Lengthening hamstrings (which are usually in spasm).
    • Postural corrections and awareness – especially if excessive lordosis.
      • Anti-lordotic bracing is currently still debated. It is generally not standard practice to prescribe one of these. However, if the client is unable to correct or control their excessive lumbar arch then this may be warranted in the initial month of rehab.
    • By around week 12 we get the client to recommence running/sprinting sessions.
    • At later stages (usually around week 16-20) – sport specific drills. This may involve technique correction if this is an issue. Sport specific training should be done for 4-6 weeks before competing.
  • Hands on treatment will sometimes be recommended if there are tight muscles that need manual release or if there are stiff thoracic segments (usually lumbar spine is hypermobile and doesn’t need mobilising).

Should Exercise Rehabilitation be supervised?

 Dead Bugs! - An example of a common core stabilisation exercise we give to challenge clients. 

Dead Bugs! - An example of a common core stabilisation exercise we give to challenge clients. 

Yes! As much as possible. Initially we are trying to correct poor postures and movement patterns. If the client is doing an exercise with poor technique then it might not have the benefits it should OR could even worsen things. Our adolescent clients tend not to be the best with remembering/adhering to their exercises either, so supervised sessions ensure they are getting their rehab done with the best form possible.

How can I prevent a pars stress fracture?

  • Increase sporting load gradually. For a growing adolescent, it may be appropriate to choose one sport at a given time. Teenagers more at risk are those participating in multiple sports at the same time, particularly if heavier load (involving lots of running and jumping).
  • Take at least one or two days off from sport each week.
  • Maintain good hip mobility (including hamstring and glute length), good core and gluteal strength.
  • If your child is very active and complains of lower back pain, then seek the attention of a Physio or Sports Physician. Remember, early diagnosis has a far better shot of healing!

Written by Courtney Kranz, Physiotherapist and Pilates Practitioner at Embody Physiotherapy + Pilates.

References:

1. Brukner P & Khan K, CLINICAL SPORTS MEDICINE, 4th Edn, McGraw-Hill Australia. North Ryde, NSW.

2. Cavalier R et al. (2006). Spondylolysis and Spondylolisthesis in Children and Adolescents: I. Diagnosis, Natural History, and Non-surgical Managament. J Am Acad Orthop Surg, 14:417-424

3. Perth Radiological Clinic,  Sports Imaging Series; Speakers: Sandra Mejak, Nick Jones & Peter Counsel. 4th May 2017.