Cervical intervertebral foramen narrowing and myelographic nerve root sleeve deformities.

Intervertebral foramen narrowing on plain radiographs of the cervical spine was graded from 0 (normal) to 3 according to its severity; myelographic nerve root sleeve deformity was graded from 1 to 3 in 99 consecutive patients with cervical radiculopathy. We thus examined 1118 foramina and root sleeves. Plain radiographs of 684 foramina were normal, changes of one grade were seen in 243, of two grades in 145 and of three grades in 46. Grading of myelographic root sleeves' was normal in 789, changes of one grade in 157, of two grades in 129, and of three grades in 43. The correlations between the foraminal and root sleeve changes were: full correlation in 63.9%, a difference of one grade in 27.4%, a difference of two grades in 7.4% and a difference of three grades in 1.3%. The positive predictive value of the plain radiographs for myelographic root sleeve deformities was 55.5% and the negative value 87.1%.