STUDY DESIGN

A retrospective study of 15 cases of pure foraminal type cervical disc herniation (CDH) was performed.

OBJECTIVES

The objectives were to describe the clinical characteristics and to assess the radiologic findings.

SUMMARY OF BACKGROUND DATA

Although foraminal lumbar disc herniation has been reported, pure foraminal-type CDH has not been fully elucidated. It is not only a rare condition but also a difficult one to diagnose.

METHODS

All patients underwent MRI, CT myelography (CTM), and CT discography (CTD). Herniated discs were removed by the posterior approach. Clinical symptoms were evaluated at preoperative and postoperative period.

RESULTS

On MRI, 2 cases were positive, 6 cases were suspected, and 7 cases were negative. On CTM, 7 cases were positive and 8 cases were negative; and on CTD, all cases were positive. As to the association between the herniated disc and posterior longitudinal ligament, 12 cases were intraligamentous. The association between the herniated disc and nerve root revealed that 10 discs were at the axillary portion of the nerve root.

CONCLUSIONS

Pure foraminal-type CDH may be overlooked with conventional MRI or CTM, so CTD should be performed. It provides valuable and additional information in difficult or ambiguous cases such as pure foraminal type.