Background and aim
The lumbar spine motion segment has multiple components that interact during normal and pathological function. Bony stress in the lumbar spine is recognised as a factor in the process of pars defects and stress fractures in the lumbar spine, but its prevalence and relationship with intervertebral disc degeneration and other pathology is not well understood. The aim of this case-control study is to report on the prevalence of bony stress in patients under 25-years-old and its association with pathology and pain in the lumbar spine.
Methods
All patients (n=493) under the age of 25 who had a lumbar MRI conducted at three radiology centres between March 2015 and March 2018 had their images screened for bony stress. A control group of patients without bony stress (n=75) was also collected. Images were retrospectively examined for disc degeneration, lumbar anatomical parameters and other pathology. Radiology reports were read for the indication for MRI. The two groups were analysed using Pearson’s Chi Square and Odds ratio.
Results
Bony stress was visible on MRI in 11% (55/493) (95% CI [8.4% - 14.5%]) patients. Bony stress was missed on routine assessment by radiologists in 36% (20/55) (95%CI [22.2% - 54.7%]) of cases.
The odds of disc degeneration being present among patients with bony stress was 2.3x higher than among patients without bony stress (OR 2.3 (95% CI [1.1 - 4.8]). The odds of pain being an indication for MRI among patients with bony stress was 5.3x higher than among patients without bony stress (OR 5.3 95% CI [2.11 – 13.3]). Facet osteoarthritis’ association with bony stress showed an insignificant result (p=0.07).
Conclusion
These findings suggest there is an associative relationship between bony stress in the lumbar spine and intervertebral disc degeneration and pain as an indication for MRI. Bony stress is going undiagnosed in many cases and it may have clinical consequences and may be a cause of cryptogenic lower back pain. Further temporal studies need to be conducted to clarify the cause and effect of bony stress on lumbar pathology.