An in vivo analysis of the dimensional changes of the neuroforamen after anterior cervical diskectomy and fusion: a radiologic investigation.

Eighteen patients (11 men, 7 women; average age, 45.5 years) who underwent anterior cervical diskectomy and fusion (ACDF) for the treatment of radiculopathy had preoperative and immediate postoperative computed tomography (CT) scans to measure pre- and postoperative foraminal heights and foraminal areas, preoperative disk space height, and postoperative graft height. The mean foraminal height preoperatively was 0.851 cm; postoperatively, it was 1.01 cm, with a mean percentage increase of 20% (-8.8 to 56.8%). Mean preoperative foraminal area was 37.53 mm2, increasing to a mean of 49.04 mm2 postoperatively with a mean percentage increase of 33% (range, -1.5 to 76.9%). No significant correlations between graft height and change in maximal foraminal height or foraminal area or between changes in foraminal height or area and postoperative symptom relief were found. Although significant increases in foraminal dimensions were seen radiographically after ACDF, these increases were variable and not strongly related to graft height. In addition, the increases in foraminal dimensions were not related to the short-term clinical results of ACDF. This study fails to support the hypothesis that the reliable results of ACDF can be ascribed primarily to indirect decompression of the uncovertebral foramen by disk-space distraction.