Trends and Variations in Cervical Spine Surgery in the United States: Medicare Beneficiaries, 1992 to 2005
From: Spine. 2009 Apr 2. [Epub ahead of print]
Degenerative changes of the cervical spine are commonly diagnosed, and seen radiographically in over half of the population aged 55 years or greater. Previous studies have shown that rates of surgery for this condition increased 90% in the general adult US population from 1990 to 2000. Marked geographic variation has also been shown in the rates of anterior cervical discectomy and fusion procedures in all adults, with the highest rates occurring in Southern United States.
In elderly patients, degenerative changes of the cervical spine are widespread. In addition, the overall US population is aging, with the most rapid increase in people 85 years and older. Prior studies, however, have not focused on the elderly population, even though an increase in the mean age and number of comorbid conditions has been noted in patients hospitalized for cervical spine surgery. Primary diagnosis and surgical procedure also varies by age, with elderly patients more commonly diagnosed with cervical spondylosis with myelopathy and treated by posterior or combined anterior and posterior procedures.
To better define recent population-based trends and variations in cervical spine surgery in elderly patients, the authors examined surgery for degenerative changes of the cervical spine in Medicare beneficiaries from 1992 to 2005.
Cervical spine fusions for degenerative changes of the cervical spine increased 206% from 1992 to 2005, among Medicare beneficiaries in the United States after adjustment for age, sex, and race. The increase in cervical spine fusions is similar to the 220% increase from 1990 to 2001 seen in lumbar fusion surgery in adults of all ages.
Among Medicare beneficiaries undergoing surgery for degenerative changes of the cervical spine, the most common primary diagnosis and procedure were cervical spondylosis with myelopathy and cervical fusion; of these, anterior fusions were the most common. Rates of anterior cervical discectomies with or without fusion were highest in the South.
It is interesting to speculate that an increase in rates of surgery for older adults might be driven in part by patient factors such as longer life expectancy or a demand for continued or improved function with increasing age. The role of patient expectations in this context is unknown.
Patient outcome and cost-effectiveness of treatment options are not clearly defined for degenerative changes of the cervical spine. Long-term outcome is also not well known and the natural history of cervical spondylosis is not clear. Some studies suggest that surgical intervention after neurologic decline is associated with worse outcome. Surgical decision-making for degenerative changes of the cervical spine thus remains a topic of debate. For patients with progressive neurologic deficits and degenerative changes of the cervical spine, there is general consensus that surgical treatment is the best option. However, surgical indications are less clear when patients do not have a progressive course. Some evidence suggests that patients with cervical spondylosis with myelopathy may plateau and remain symptomatically stable for a long time. However, other studies also suggest that once patients develop moderate symptoms, they may be less likely to improve even after surgery.
