J Korean Neurosurg Soc.  2014 Sep;56(3):200-205. 10.3340/jkns.2014.56.3.200.

Extent of Disc Degeneration after Single-Level Cervical Anterior Microforaminotomy Analyzed with Long-Term Radiological Data

• Han C
• Kim MH

• KMID: 2339957
• DOI: http://doi.org/10.3340/jkns.2014.56.3.200

Abstract

OBJECTIVE
To prove the extents and details of cervical degeneration after anterior microforaminotomy (AMF) with 6-years follow-up.
METHODS
A retrospective study of 24 patients, underwent single-level AMF, was performed. Clinical and radiologic data were analyzed with office charts, questionaires, and picture achieving and communication system images.
RESULTS
According to Odom's criteria, 91.6% achieved favorable outcome. The mean visual analog scale score was improved from 8.6 to 3, and the mean neck disability index was improved from 27.9 to 7.3 (p<0.01). Eighteen cases (75%) showed disc height (DH) decrease. The disc invasion was correlated with DH decrease (p<0.05). The disc height decrease correlated with static, dynamic changes of shell angle and spur formation (p<0.05). Any radiological parameters did not affect the clinical outcome.
CONCLUSION
AMF is an effective technique for treating unilateral cervical radiculopathy. It showed excellent surgical outcomes even in long-term follow-ups. However, a decrease in DH occurred in a considerable number of patients. Disc invasion during surgery may be the trigger of sequential degeneration.

Keyword

Microforaminotomy; Disc height; Disc invasion; Disc degeneration

MeSH Terms

Follow-Up Studies
Humans
Intervertebral Disc Degeneration*
Neck
Radiculopathy
Retrospective Studies
Visual Analog Scale

Figure

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  Fig. 1 Measurement of diameter of anterior microforaminotomy on axial CT image. AMF : anterior microforaminotomy.

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  Fig. 2 Measurement of static angles on plain cervical lateral image. A : Functional spine unit and Cobb angles. B : Measurement of disc height and shell angle on a plain radiograph in neutral lateral position.

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  Fig. 3 Illustration showing the various entry and resection sites of microforaminotomy. A : Entry point of upper transcorporeal approach. B : Resection site of transuncal approach. C : Entry point of lower transcorporeal approach.

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  Fig. 4 Box-plot graph showing preoperative and postoperative changes of visual analogue scale (VAS) and neck disability index (NDI) scores with mean, maximum, and minimum values. VASpre : preoperative VAS, VASpost : postoperative VAS, NDIpre : preoperative NDI, NDIpost : postoperative NDI.

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  Fig. 5 Box-plot graph showing changes in preoperative and postoperative disc height (DH) with mean, maximum, and minimum values.

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