A Long-term Look at the Cervical Spine

By: Peter Pollack

Disk degeneration noted even among healthy participants

Eijiro Okada, MD, PhD, explained that “few studies have investigated and clarified the association between sagittal alignment of the cervical spine and progression of degenerative changes of intervertebral disks. Furthermore, none have carried the research over a 20-year period. We sought to evaluate that association and the development of clinical symptoms among healthy participants.”

Dr. Okada presented findings from Paper Presentation 413, “Does the Sagittal Alignment of the Cervical Spine have an Impact on Disc Degeneration? Twenty-Year Follow Up of Asymptomatic Volunteers,” on Wednesday. The study is a continuation of 10-year data published in the European Spine Journal (November 2009).

Ongoing study

The researchers recruited 90 volunteers (30 men and 60 women) who had undergone magnetic resonance imaging (MRI) and radiography of the cervical spine between 1994 and 1996, and who had originally been asymptomatic. Follow-up MRIs were obtained at mean 21.6 years after the initial study. The mean participant age at the time of the initial study was 35.5 years (range: 11 to 65 years).

Dr. Okada and his colleagues used MRI to assess the following factors:

  • decrease in signal intensity of the intervertebral disks
  • posterior disk protrusion
  • disk space narrowing from C2-3 to C7-T1

They divided participants into cohorts according to age and sagittal alignment of the spine at baseline, (ie, under or over the age of 40 years, and lordosis or non-lordosis sagittal alignment of the cervical spine).

Over the 20-year study period, members of the research team noted an overall progression of decrease in signal intensity of the disk, posterior disk protrusion, and disk space narrowing among 84.4 percent, 86.7 percent, and 17.8 percent of participants, respectively. However, they found no significant association between sagittal alignment and progression of decrease in signal intensity, posterior disk protrusion, or progression of disk space narrowing.

Disk degeneration

The researchers also noted that the progression of degenerative change at C7-T1 was significantly more frequent in the non-lordosis, over 40 years of age cohort (90.9 percent) than those in older the lordosis group (54.2 percent). They observed no significant difference between sagittal alignment and the onset of clinical symptoms at follow-up.

“The long-term follow up study shows that disk degeneration was significant even among healthy volunteers,” noted Dr. Okada. “The data suggest that non-lordotic cervical alignment may be related to progression of disk degeneration. However, sagittal alignment of the cervical spine is not significantly associated with future onset of clinical symptoms.

“We hope that data from this study can help to clarify underlying mechanisms of various degenerative disorders of the cervical spine,” he continued. “Understanding the natural history and natural aging disk degeneration of the cervical spine can help us assess progress for patients who have experienced trauma or undergone surgical treatment.”

Dr. Okada’s coauthors are Kenshi Daimon, MD; Hirokazu Fujiwara, MD; Yuji Nishiwaki; Kenya Nojiri, PhD; Masahiko Watanabe, MD; Hiroyuki Katoh, MD, PhD; Kentaro Shimizu; Hiroko Ishihama; Nobuyuki Fujita; Takashi Tsuji, MD, PhD; Masaya Nakamura, MD; Morio Matsumoto; and Kota Watanabe, MD, PhD.

Peter Pollack is the electronic content specialist for AAOS Now. He can be reached at ppollack@aaos.org.


Okada, E., Matsumoto, M., Ichihara, D. et al. Eur Spine J (2009) 18: 1644. https://doi.org/10.1007/s00586-009-1095-5