Cervical spondylosis—also known as cervical osteoarthritis (OA)—is the most common age-related disorder of the cervical spine, which is characterized by degeneration of the intervertebral disks and facet joints as well as spur formation off the vertebral body endplates. Studies have shown that X-rays of 95% of adults over the age of 65 will show signs of cervical OA, even in the absence of neck pain or other symptoms. Because whiplash is a process that affects the cervical spine, how might pre-existing cervical OA impact whiplash recovery?
A comprehensive literature search conducted in 2021 identified nine studies that included 894 patients. An analysis of the data from these studies revealed a statistically significant association between moderate facet joint degeneration (with or without concurrent disk degeneration) and non-recovery. Past studies involving both cadavers and medial branch nerve blocks have demonstrated that degenerative changes to the facet joints can alter biomechanics in the spine and are commonly a pain source for patients experiencing spinal pain, including neck pain. In four of the studies, researchers observed a significant correlation between cervical OA and poor prognosis following whiplash injury with a higher risk than the general population for persistent whiplash associated disorders (WAD) symptoms up to two years following their whiplash event. Interestingly, the data did not show a link between isolated disk degeneration and non-recovery.
Current research suggests that nearly 50% of WAD patients will continue to experience symptoms that include neck pain, stiffness, paresthesia, dizziness, deafness, tinnitus, depression, sleep disturbance, and posttraumatic stress disorder. The 2021 literature review mentioned above suggests that cervical spondylosis may be a risk factor for chronic WAD. This is potentially troubling as studies have shown that excessive device use may result in signs of cervical OA at younger ages.
These new findings, in addition to other risk factors for chronic WAD—central sensitization, high initial pain and disability, current low back pain at time of whiplash event, history of neck pain, new onset headaches, post-injury anxiety, and cold hyperalgesia (high sensitivity to cold)—can help doctors identify patients at elevated risk for worse WAD outcomes so a more aggressive treatment plan can be adopted. Doctors of chiropractic are well equipped to manage WAD cases with a multimodal treatment approach in conjunction with allied healthcare providers, when necessary.