Reviewed by. BM Davies
Reason for the Study
Walking impairments are a common feature of cervical myelopathy and can lead to falls. In elderly individuals such falls, even if minor, can lead to injuries, such as broken bones. Broken bones (‘fractures’) are more common as we get older, as aging affects bone strength, including conditions such as osteoporosis. Such fractures generally occur in stereotyped locations such as the wrist, shoulder, hip, and low back and therefore termed ‘fragility fractures’. These secondary injuries are associated with a significant impact on life, including in some cases death. In 2015, a group from the USA showed that 18% of patients with a hip fracture had undiagnosed myelopathy [1]. However the overall rate of fragility fractures (a fall related injury also associated with fragile bones) amongst elderly individuals with cervical myelopathy has not yet been investigated [2]
This study was conducted by searching a database of Medicare patients (meaning previously collected anonymous medical data from individuals in the United States age 65+). This study included 24,439 patients with cervical myelopathy who had undergone surgery, 35,893 patients with cervical myelopathy who had not undergone surgery, and 831,532 patients without myelopathy who had a general medical appointment during the study timeframe of 2008-2011.
For this study, the researchers excluded patients who might confuse the data (e.g. those who had a neck surgery unrelated to cervical myelopathy or history of cancer, infection, or trauma to the spine, but also those with a history of fragility fractures). The researchers then tracked the occurrence of fractures over the next 3 years and used statistical tests to account for differences in study groups which could influence the results (e.g. age, sex or diagnosis of osteoporosis).
What did they find?
There were some differences in the characteristics of the study groups:
- The cervical myelopathy surgical group was more likely to be male and younger, than the non-operative cervical myelopathy group.
- Both cervical myelopathy groups tended to have higher rates of additional diseases than controls
- The non-operative cervical myelopathy had higher rates of osteoporosis, dementia and cerebrovascular disease than the surgical cervical myelopathy group.
At 12 months follow up, both non-operative and surgical cervical myelopathy groups were more likely to sustain fragility fractures than controls. The odds ratios were 1.59 and 1.48 respectively (odds ratios indicate relative odds of a diagnosis or injury with a value closer to 1 indicating no difference). Further, the odds of fracture were higher in both groups than controls at 36 months as well, however, at 36 months the surgical group was lower than the non-operative group.
There are some limitations to this study; first, because this was a search of a Medicare database it is most applicable to patients with cervical myelopathy 65 and older, but also due to the type of data recorded, there are some possible factors related to falls the researchers were unable to account for such as BMI or physical activity.
However, this is an extremely large study which gives us confidence the results are real, and not simply a coincidence.
Hopefully these findings will help to raise the profile of myelopathy; as 1) the impact and cost of fragility fractures is significant for healthcare providers, 2) myelopathy is not routinely considered as part of managing a patient’s falls risk and 3) falls assessments are carried out by general professionals.
Whilst surgery did not eliminate the risk of fragility fractures, they were reduced in those that had surgery. It would appear from the characteristics of the study groups, that age and ill-health were more likely to lead to conservative management of cervical myelopathy and whether or not this is appropriate, given the potential significance of fragility fractures will need further investigation.
References
[1] Radcliff et al (2015). High Incidence of Undiagnosed Cervical Myelopathy in Patients with Hip Fracture Compared to Controls. Journal of Orthopaedic Trauma. http://doi.org/10.1097/BOT.0000000000000485
[2] Horowitz JA, et al (2018). Fragility Fracture Risk in Elderly Patients with Cervical Myelopathy. Spine.
(3) Can Cervical Myelopathy cause hip fractures