In Part 1 of this Blog we discussed the potential causes of back pain in the sporting adolescent. Although there are some sinister causes of Low back pain in this age group, it is important to recognise that in most cases it is self limiting and completely benign. However, should your son or daughter play cricket, compete in wrestling or do gymnastics, there may be other areas of the spine compromised. Namely, the Pars (Also known as the Pedicle). This is a condition known as Spondylolysis. (Quite a mouth full right?).
When looking at the diagnosis of spondylolysis, both ionising and non-ionising modalities are available. That means things that will expose you to radiation and things that won't (Ultimately CT Scans, X-Rays that do or MRI that don't). It is important to distinguish acute and active lesions from chronic inactive non-union and imaging is the most useful way of assessing bony healing in follow-up of acute lesions. Plain film radiography or x-ray is often the first choice imaging modality, this however may differ in the adolescent age group due to the radiation exposures. Early studies by Libson and Bloom et al. (1983) stated routine x-ray imaging series would consist of antereoposterior, lateral, oblique and angled antereoposterior. Plain film images are able to successfully demonstrate chronic non-union, this can be seen in the image to the left. The arrow highlighting the defect present.
However Papanicolaou, Wilkinson, Emans, Treves, Micheli (1985) state that x-ray investigations are unreliable for detection of early and acute spondylolysis. That basically means, when the pain is developing and often at its early stages x-rays are pretty much useless. For these more acute lesions, MRI, Computed Tomography (CT) and Single Proton Emission Computed Tomography (SPECT) may be more appropriate. For a number of years, reduction of radiation dosage has been a topic of discussion, particularly in the juvenile and adolescent population.
Early studies from the 1980’s (Langstan and Gavant, 1985) stated that CT was probably the best method for demonstrating spondylolytic defects. Langston and Gavant (1985) stated that reverse- angle axial oblique CT could identify spondylolysis. Campbell et al. (2005) stated that CT scans are limited in recognising other pathological processes; they went on to state that it cannot reliably distinguish between active and inactive lesions. Alongside this, the secondary downfall of CT is that there is also a ionising radiation associated. Another imaging process that utilises radiation is SPECT scans. Collier, Johnson, Carrera, et al. (1985) identified SPECT scans as having high sensitivity for early diagnosis of acute lysis and may be predictive of the ability for lysis to heal. Pennell, Maurer, Bonakdarpour (1985) reiterated these findings. SPECT scans, however, lacks specificity. Pennell, Maurer, Bonakdarpour (1985) found that SPECT scans were only able to detect roughly 17% of chronic lesions and that it cannot distinguish between stress reaction and overt fractures. Campbell et al. (2005) reiterated this and stated that a high proportion of developed spondylolysis in the first decade are often asymptomatic and usually negative on isotope studies. It is because of this lack of specificity alongside the radiation doses MRI should be considered as an appropriate imaging modality going forward.
Ranson et al. (2005) utilised MRI in their study and revealed that MRI investigations accurately revealed evidence that 81% of fast paced bowlers had multilevel chronic stress reactions on the non-dominant pars interarticulars. This was compared to a control group where 36% were found to have similar findings. Ranson et al (2010) carried out a second study utilising MRI investigations looking at low back pain elite cricketers ranging from 16- 24 years old. Of the selected cohort (N=28) 42.9% had evidence of a stress fracture of the lumbar spine. Of greater significance however, 53.6% of all players had MRI scans showing the presence of acute bone stress. Of these 73.3% had a partial or complete stress fracture within a mean of ten weeks. Suggesting MRI is useful in identifying early changes in the pars articularis that may lead to complete or partial fractures of the pars articularis and confirming the hypothesis of Sairyo, Katoh, Takata et al (2006) and Amari, Sakai, Katoh et al (2009).
Initial studies Udeshi and Reeves (1999) found MRI was an appropriate imaging modality for identifying normal anatomy of the pars interarticularis. Campbell and Grainger (1999) were able to support these findings. Campbell et al. (2005) specifically looked at the reliability of MRI in a juvenile population comparing the images to CT and SPECT. They were looking to develop early studies of MRI in spondylolysis and spondylolisthesis. These early studies by Johnson et al (1989) and Saiffudin and Burnell (1997) described a morphological grading system of pars defects. Ulmer et al (1995) also described modic type signal changes of vertebral endplates. However, Campbell et al (2005) criticised the early work stating they did not utilise fat-suppressed T2 weighted sequences. Hollenburg et al (2002) developed a new MRI classification system (Tabe 2), which
Campbell and colleagues (2005) felt the new classification helped distinguish between stress reaction, active and inactive spondylolysis.
From this it is fair to say that diagnostic imaging can be extremely useful when it comes to the diagnosis of Spondylolysis. However, key things to look out for are there to see within the history of the patient. The imaging is useful for identifying whether or not the lesion is Acute or Chronic, Active or Otherwise. These all dictate management of the complaint.
I hope you've found this 2 part blog interesting. As always, if you have any questions please do not hesitate to get in touch.
Catch you all soon,
Daniel