VERTEBRAL BODY REPLACEMENT SYSTEMS WITH EXPANDABLE CAGES IN THE TREATMENT OF VARIOUS SPINAL PATHOLOGIES

Abstract

Vertebral body reconstruction after corpectomy has become a common surgical procedure. The authors describe a prospectively followed case series of patients treated with expandable cages for various indications. Sixty patients underwent single or multilevel corpectomy for degenerative stenosis (13 patients), herniated disc (7 patients), deformity (14 patients), traumatic fracture (3 patients), infection (1 patient), or tumor (22 patients). Six different expandable vertebral body systems were used in the cervical spine (41 patients), thoracic spine (15 patients), and lumbar spine (4 patients). All patients were evaluated clinically and radiographically. Thirty-nine patients underwent single-level corpectomy, 18 patients underwent two-level corpectomy, and 3 patients underwent three-level corpectomy. Anterior reconstruction alone was performed in 30 patients; circumferential reconstruction was performed in 30 patients, 9 of whom underwent reconstruction through a posterior approach only. At the time of the final follow-up examination (mean, 9 mo), the Nurick grade improved significantly. Ninety-five percent of the patients maintained or improved their Frankel score and 67% had good clinical results. The regional angulation was corrected significantly (4.0 +/- 9.0 degrees, P = 0.002), and the segment height increased significantly (3.5 +/- 8.0 mm, P = 0.002). Bony fusion was achieved in 93% of the cases. Subsidence was documented in nearly half of the patients (1.4 +/- 2.0 mm) and was reduced after circumferential fusion (0.9 +/- 1.9 mm, P = 0.08). Eighteen patients (30%) had complications and 12 patients (20%) underwent revision surgery. Expandable vertebral body replacement systems can provide solid anterior column constructs with restoration of height and sagittal alignment. Favorable clinical outcome was shown in most patients, although the complication and reoperation rates are rather high.