Early changes in the cervical foraminal area after anterior interbody fusion with polyetheretherketone (PEEK) cage containing synthetic bone particulate:: a prospective study of 20 cases

Objectives: Although the use of intervertebral fusion after anterior cervical microdiscectomy remains controversial, a new surgical device is proposed for use in intervertebral fusion instead of bone graft. The authors evaluate the effects of implantation of polyetheretherketone (PEEK) cage containing synthetic bone particulate on the height and cross-sectional area of the foramen, the intervertebral disk height and the degree of lordosis. Methods: Twenty consecutive patients with radiculopathy owing to cervical disk herniation were scheduled. They underwent multislice computed tomographic scanning pre-operatively and 1 day post-operatively. Results: Pre-operatively, the mean height of the right foramina was 8.807 +/- 1.120 mm, the left foramina was 9.500 +/- 1.529 mm. Post-operatively, the mean foraminal height of the right side was 11.080 +/- 1.121 mm and 10.020 +/- 1.453 mm on the left. This difference reached statistical significance on the right foraminal height (p=0.000) but not on the left side (p=0.078). The mean area of the right foramina was 46.82 +/- 14.54 mm(2) and 52.71 +/- 15.62 mm(2) on the left side pre-operatively. Post-operatively, the values were 60.87 +/- 15.91 mm(2) and 55.83 +/- 13.88 mm(2) respectively. In terms of pre-operative value, the 1 day post-operative measurement reached again statistical significance (p=0.002) on the right side. The mean value of disk height was 3.653 +/- 0.596 mm pre-operatively and 6.387 +/- 0.533 mm at 1 day post-operatively. This difference is statistically significant (p=0.000). Discussion: Implantation of a PEEK cage containing synthetic bone particulate in the treatment of cervical disk disease offers good immediate stabilization by easier implantation technique and avoids donor site morbidity. It provides an increase in height and cross-sectional area of the neural foramina. These preliminary results suggest that interbody fusion cages appear to be safe and effective.