Video-assisted thoracic corpectomy and spinal reconstruction: a biomechanical analysis of open versus endoscopic technique.

The purpose of this study is to evaluate the technique of video-assisted thoracic surgery (VATS) to perform corpectomy and spinal reconstruction with the Harrington rod and polymethylmethacrylate construct, and to compare the biomechanical stability of the constructs created with both open thoracotomy and VATS technique. Fourteen farm-raised pigs were divided into two groups. Group I underwent thoracic corpectomy using a VATS approach and group II had the same procedure performed through a traditional thoracotomy. The stiffness (newtons per millimeter) for the non-destructive tests for each loading mode are flexion-compression (open 124.4 +/- 124.9; VAT 75.8 + 29.9); extension-compression (open 165.8 + 41.8: VATS 96.5 + 31.2); pure compression (open 231.4 + 126.4; VATS 264.6 + 184.3). The difference between group I (VATS) and group II (open) in extension compression is statistically significant. Although not statistically significant, the results also show the group II (open) specimens to be stiffer in flexion-compression and the group I (VATS) specimens to be stiffer in pure compression. Although corpectomy and spinal reconstruction can be performed with the VATS technique, the constructs obtained endoscopically may not have the same strength as those constructs obtained via an open procedure.