Anterior cervical decompression and fusion accelerates adjacent segment degeneration: comparison with asymptomatic volunteers in a ten-year magnetic resonance imaging follow-up study.
METHODS
Prospective 10-year follow-up magnetic resonance imaging (MRI) study of patients who underwent anterior cervical decompression and fusion (ACDF) and healthy control subjects.


OBJECTIVE
To clarify the incidence of adjacent segment degeneration during 10 years after ACDF.


BACKGROUND
There have been few studies which investigated incidence of progression of degenerative changes at adjacent segments in patients treated by ACDF comparing with healthy subjects.


METHODS
Sixty-four patients who underwent ACDF (48 males, 16 females, mean age 47.3 years, mean follow-up 12.1 year) and 201 asymptomatic volunteers who underwent MRI in our previous study (113 males, 88 females, mean age; 41.1 year, mean follow-up; 11.7 years) were included in this study. The patients and control subjects underwent follow-up MRI in this study. Following MR findings were evaluated using a numerical grading system from C2-C3-C7-T1: (1) Decrease in signal intensity of disc (DSI), (2) Posterior disc protrusion (PDP), (3) Disc space narrowing, and (4) Foraminal stenosis. When an increase in at least one grade in any of the radiographic parameters was detected between the 2 time points, progression of disc degeneration was judged as present at the level of interest.


RESULTS
Progression of DSI was significantly more frequent in ACDF group than in control group at C4-C5, while progression of PDP was significantly more frequent in ACDF group than in control group at all levels except for C5-C6. Progression of disc space narrowing and foraminal stenosis was significantly more frequent in ACDF group at C3-C4 and at C6-C7, respectively.


CONCLUSIONS
Although both ACDF patients and control subjects demonstrated progression of disc degeneration during 10 years, ACDF patients had significantly higher incidence of progression of disc degeneration at adjacent segments than control subjects, while progression of disc degeneration at adjacent segments was not always related to development of clinical symptoms.
Matsumoto
Morio
M
Departments of Orthopaedic Surgery, Keio University, Tokyo, Japan.
Okada
Eijiro
E
Ichihara
Daisuke
D
Watanabe
Kota
K
Chiba
Kazuhiro
K
Toyama
Yoshiaki
Y
Fujiwara
Hirokazu
H
Momoshima
Suketaka
S
Nishiwaki
Yuji
Y
Iwanami
Akio
A
Ikegami
Takeshi
T
Takahata
Takeshi
T
Hashimoto
Takeshi
T
D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000473:pathology / Q000601:surgery*; D016009:Chi-Square Distribution; D019299:Decompression, Surgical / Q000009:adverse effects*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000209:etiology* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012044:Regression Analysis