Preoperative digital plan and 3D rapid prototyping technique in treatment of complete fracture-dislocation of thoracic and lumbar spine fracture

Abstract

Objective To apply the preoperative digital plan and 3D rapid prototyping technique in supervising the surgical manipulation and restoring spinal stability of thoracic and lumbar spinal fracture accompanied by complete dislocation and investigate the clinical feasibility and effecacy. Methods From January 2009 to January 2014, 32 cases (19 males and 13 females) of thoracic and lumbar spinal fracture accompanied by complete dislocation were admitted. Age ranged from 17 to 56 years[(30.1±7.6)years]. Fifteen cases admitted before October 2010 received open posterior reduction, pedicle screw fixation and bone grafting (conventional group). Prior to the posterior open reduction and internal fixation, 17 cases admitted after October 2010 were aided using the new technique (computer-assisted group). 3D reconstruction of the CT scanned spine was performed so as to get the dislocation patterns and degree of pedicle rupture, 3D templates were fabricated using the rapid prototyping technique, and preoperative plan included the decompression area, fusion segments, and insertion point and angle. Operation time, blood loss, drainage, visual analogue scale (VAS), Frankel score and fusion rate were compared between the two groups. Results All cases were followed up at least 1 year[(3.6±0.5) years]. Operation time and bleeding in conventional group were (194.0±38.5)min and (502.0±114.5)ml, significantly lowered compared to(168.8±23.8)min and (420.0±94.6)ml in computer-assisted group (P 0.05], but there was significant difference at the final follow-up [(1.87±0.27) vs. (1.67±0.22)points, P 0.05). Frankel score used for assessment of nerve function did not differ significantly between the two groups (P>0.05). Conclusions Preoperative digital plan and 3D rapid prototyping technique enable the understanding of fracture patterns and pedicle integrity and then help guide decompression and screw insertion. The benefits included shorter operation time, improved reduction and decreased risks of implant failure. Key words: Spinal fractures; Thoracic vertebrae; Lumbar vertebrae; Dislocations; 3D-printing