Value of magnetic resonance imaging and discography in determining the level of cervical discectomy and fusion.

STUDY DESIGN: The correlation between magnetic resonance imaging and discography of the cervical spine in degenerative disc disease was studied. In addition, the results of cervical discectomy and fusion were evaluated.

OBJECTIVES: To compare the value of cervical magnetic resonance imaging versus discography in selecting the level for discectomy and fusion and to evaluate the surgical outcome.

SUMMARY OF BACKGROUND DATA: The value of magnetic resonance imaging and discography in patients with cervical discogenic pain is less clear. Also, the status of a hypointense signal (dark) cervical disc and/or a small herniated disc on magnetic resonance imaging has not been determined.

METHODS: The magnetic resonance imaging studies and discography followed by computed tomography in 55 patients with cervical discogenic pain were evaluated. Surgical planning was based on the complete information of clinical symptoms, magnetic resonance imaging, and discography as well as computed tomography discography. Anterior cervical discectomy and keystone fusion was performed. Postoperative pain relief was assessed by the patients, and the follow-up radiographs were viewed by an independent reviewer. The overall surgical outcome was evaluated using Odom's criteria.

RESULTS: There were 161 disc levels that successfully underwent cervical discography with 79 positive levels. A positive discography result was found in 63% of dark (hypointense signal) discs and 45% of speckled discs. Fifty-nine percent of small herniated discs and 59% of torn discs had a positive discography, respectively. There were 100 abnormal cervical discs on magnetic resonance imaging. Magnetic resonance imaging had a false-positive rate of 51% and a false-negative rate of 27%. Successful cervical fusion was achieved in 95% of patients, and the overall satisfactory result was 76%.

CONCLUSIONS: Magnetic resonance imaging can identify most of the painful discs but still has relatively high false-negative and false-positive rates. There is a high chance that hypointense signal and small herniated discs are the pain generators, but they are not always symptomatic. Discography can save the levels from being unnecessarily fused. The combination of clinical symptoms, magnetic resonance imaging, and discography provides the most information for decision making and can improve the management of cervical discogenic pain.