Spondylolysis (Stress Fractures) in the low back in young athletes, incidental finding or truly the cause of the back pain?
Australia’s cricket team, and more specifically their fast bowlers are currently under the microscope due to a spate of low back injuries.
“In recent years, no other team has been afflicted by injuries to leading pacemen as chronically as Australia (O’Connell, Australian cricket’s pace injury plague continues, March 2016)’
Fast bowler James Pattinson has not played due to a back injury he sustained in NZ in February 2016. He was diagnosed with a lower back stress fracture.
Australia are also missing several other fast bowlers like the young and talented Pat Cummins, who has been injury riddled and unable to get himself right to play. Again, a back problem that appears to be stress related is being blamed.
What is a low back stress fracture, and is preventing these the solution??
Spondylolysis is defined as a bony defect in the pars interarticular of the vertebral arch. Essentially this is a weakness or stress fracture in a part of the vertebra in the back that connects one bone to the next one.
These stress fractures in the spine occur for the same reason they do any part of the body.
Too much load, too fast with not enough time to adapt to the load.
Training errors such as too much load too soon is known to be a common contributing factor to bone stress injury. Athletes training regimen of sport related activity should not increase by more than 10% from one week to the next (Kishner et al, 2015).
Other factors that can predispose an athlete to stress fracture include (Patel et al, 2011):
- Consuming >10 alcoholic drinks per week
- Excessive physical activity with limited rest periods
- Female athlete triad, which leads to a relative energy insufficiency (eating disorders, amenorrhea etc which decrease bone strength),
- Female sex
- Low levels of 25-hydroxyvitamin D
- Sudden increase in physical activity
- Certain sport types (eg like bowling or tennis that involve rapid and repeated hyperextension)
- Bowling action in cricket (side-on versus front-on versus mixed approach)
Is it possible or even likely that these back injuries are due to something other than these stress fractures?
One of the big errors that can be made by physiotherapists, or other allied health professionals is incorrect diagnosis/classification. And this can lead to a pathway of management that is incorrect.
This is not a comment specifically about the Australian fast bowlers. I have no knowledge of their specific clinical findings or injury details, and so it would be unfair of me to comment about them specifically.
What I can say is that in back pain in young athletes, my clinical experience is that other health professionals can misdiagnose these problems.
What is the clinical presentation of someone whose pain is coming from a stress fracture in the back?
- Pain localised to a specific spot in the back
- Pain is worsened with physical activity and relieved by sitting or lying
- Pain is worsened with extension (backward bending) activities like walking, running
- Pain with the stork test (single leg extension in standing on the painful side)
The difficulty is that the diagnosis is often made on a combination of the above signs, and accompanying radiological findings of stress fracture or stress reaction in the spine.
Can we accurately make our diagnosis based on the above clinical findings and some imaging results?
The answer is not every time, and not even nearly every time.
Sometimes the pattern above will indeed be a stress reaction, but others it will not.
And the difficulty with diagnosis is multi-faceted, and in no part limited by bias. Almost every physiotherapy/orthopaedic textbook on the topic of low back pain in athletes like fast bowlers in cricket will caution to have a strong index of suspicious for fracture.
Imaging such as x-ray, bone scan and MRI is often heavily relied upon to support a clinical suspicion of stress fracture.
The problem with this, is that things show up on the scan that may suggest ‘bone stress’ or ‘bone reaction’, and these may not be related to pain. Is this bone stress seen on imaging just the normal reaction to the loading of repetitive bowling?
A 2007 study by Alas et al looked at 33 elite tennis players, who have a similar pattern of hyper-extension and rotation with serving as bowlers in cricket. These tennis players underwent a lower back MRI, and they were all asymptomatic (that is they did NOT have any back pain).
- 85% had abnormal imaging findings (and the mean age of these players was 17, so they are less likely to shown age related changes than older athletes)
- 9 players out of 33 (27%) showed pars lesions, with 10 lesions in total as one player had 2 levels with pars lesions
- 3/10 of these pars lesions were complete fractures!
How can we increase our likelihood of correctly classifying a back problem given imaging cannot be relied upon?
The McKenzie Method, also known as Mechanical Diagnosis & Therapy (MDT) uses repeated movements to aid in classifying patients, and it is a heavily researched approach (May and Aina, 2012).
How pain and clinical signs change in response to repeated movements can be very powerful in assisting diagnosis and narrowing down between competing diagnoses with very different treatment pathways.
A study by Hefford et al (2008) looked at the use of repeated movements and classification of patients using the MDT approach in close to 200 low back patients:
- 75% of lower back problems improved rapidly with a specific direction of movement (classified as derangement with a specific Direction Preference of treatment)
- Of those who responded rapidly to a specific direction of exercises (called the Direction Preference)
- 70 % improved with extension exercises
- 6 % improved with flexion exercises
- 24% improved with lateral exercises
If we relate this back to our fast bowlers, who usually have one sided back pain the numbers change to (based on one sided back pain that is not referred below the knee):
- 57% extension
- 6% flexion
- 37% lateral exercises
And specifically, in our fast bowlers this profile may be quite different, with more expected to respond to flexion exercises given the repetitive extension action they perform.
Given the volume of repeated movements our bowlers perform in one direction, repeatedly, it is logical they may develop a problem that needs movement in the opposite direction for relief.
And those who do respond to lateral exercises often have (McKenzie and May, 2003):
- One sided back pain
- Symptoms worsen with extension activities like walking
- They may also worsen with flexion activities like sitting
That sounds a lot like our profile of a stress fracture from earlier, minus the last point (but this is not always present).
The key difference with MDT is that testing repeated movements of the spine may uncover a specific direction based movement that rapidly alters symptoms. This can then change our clinical tests like the positive Stork test (bending backwards and twisting on one leg to compress the painful side of the back).
The MDT testing itself to confirm this classification takes minutes (in as little as 10-20 repetitions pain and clinically signs can rapidly change), or at worst usually 24-48 hours of testing a specific direction will uncover any underlying direction preference if present.
Given this testing process can greatly improve the likelihood of correctly classifying these athletes, the only limitation is training in MDT, as research shows it is reliable and valid but only in those who are sufficiently trained (May and Aina, 2012).
Getting rid of back pain in our athletes
Pars stress fractures are common in young athletes involving sports with repetitive loading like fast bowlers in cricket, or tennis players.
Pars fractures are commonly misdiagnosed (Syrmou et al., 2010).
Multiple competing diagnoses are often possible, even with our profile that typically means a stress fracture may be suspected.
Using repeated movements to classify and subgroup athletes using the MDT system avoids many of the pitfalls of relying on imaging, where stress fractures are commonly seen in asymptomatic young athletes.
Some of these athletes will indeed need relative rest, decreased loading and a gradual introduction to loading again once the bone reaction settles down with optimal conditions.
And yet others can rapidly respond to direction specific exercises, and find rapid relief and get back on the field faster! They just need to regularly perform their direction preference exercises to counter the repeated bowling action!
Come and see our McKenzie Method specialist physiotherapist Joel Laing in Melbourne’s CBD for an assessment of your back problem.
Patel, D., Roth, M. and Kapil, N. (2011). Stress Fractures: Diagnosis, Treatment, and Prevention. American Family Physician, 83(1), pp.39-46.
Kishner, S. (2017). Physical Medicine and Rehabilitation for Stress Fractures Treatment & Management: Rehabilitation Program, Medical Issues/Complications, Surgical Intervention. [online] Emedicine.medscape.com. Available at: http://emedicine.medscape.com/article/309106-treatment [Accessed 6 Jan. 2017].
www.foxsports.com.au. (2017). James Pattinson, Peter Siddle injury news, Victoria Bushrangers Matador Cup squad. [online] Available at: http://www.foxsports.com.au/cricket/victoria-gives-latest-news-on-recovery-of-james-pattinson-peter-siddle/news-story/5a214c9489f9bb3fa7180d69ced2fa75 [Oct. 2016].
O’Connell, R. (2017). Australian cricket’s pace injury plague continues. [online] The Roar. Available at: http://www.theroar.com.au/2016/03/04/australian-crickets-pace-injury-plague-continues/ [Accessed 6 Jan. 2017].
Alyas, F., Turner, M. and Connell, D. (2007). MRI findings in the lumbar spines of asymptomatic, adolescent, elite tennis players. British Journal of Sports Medicine, 41(11), pp.836-841.
Syrmou, E., Tsistopoulos, P., Marinopoulos, D., Tsonidis, C., Anagnostopoulos, I. and Tsistopoulos, T. (2010). Spondylolysis: A review and reappraisal. Hippokratia, 14(1), pp.17-21.
Hefford, C. (2008). McKenzie classification of mechanical spinal pain: Profile of syndromes and directions of preference. Manual Therapy, 13(1), pp.75-81.
May, S. and Aina, A. (2012). Centralization and directional preference: A systematic review. Manual Therapy, 17(6), pp.497-506.
McKenzie, R. and May, S. (2003). Mechanical Diagnosis & Therapy. 2nd ed. Waikanae, N.Z.: Spinal Publications.