Adjacent Segment Degeneration, Anterior Cervical DF 10 Yearr: Spine 2009 Dec 17 epub

[Slackwater]

PMID: 20023606
(C) 2009 Lippincott Williams & Wilkins, Inc.

Spine: POST AUTHOR CORRECTIONS, 17 December 2009
doi: 10.1097/BRS.0b013e3181b8a80d

Spine (Phila Pa 1976). 2009 Dec 17. [Epub ahead of print]

Anterior Cervical Decompression and Fusion Accelerates Adjacent Segment Degeneration: Comparison With Asymptomatic Volunteers in a Ten-Year Magnetic Resonance Imaging Follow-up Study.

Matsumoto M, Okada E, Ichihara D, Watanabe K, Chiba K, Toyama Y, Fujiwara H, Momoshima S, Nishiwaki Y, Iwanami A, Ikegami T, Takahata T, Hashimoto T.

*Orthopaedic Surgery, Diagnostic Radiology, and Preventive Medicine and Public Health, Keio University, Tokyo, Japan;
Department of Orthopaedic Surgery, Murayama Medical Center, Tokyo, Japan; Department of Orthopaedic Surgery, Isehara Kyodo Hospital, Isehara, Japan; and
Department of Orthopaedic Surgery, Tokyo Den-ryoku Hospital, Tokyo, Japan.

STUDY DESIGN.: 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.

SUMMARY OF BACKGROUND DATA.: 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.

CONCLUSION.: 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.


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The development of adjacent segment degeneration above or below a fusion procedure is sometimes referred to in "equivocal terms" in journal articles due to lack of controls and long term follow-up diagnostics. The suggestion above, in this reader's limited view, is the biomechanical studies done in laboratories does bear credence in real life situtations. The context is the increasing age of a person (patient) makes it challenging to determine if ASD is related to normal aging or a fusion procedure.

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