Prevention of vertebral body–splitting fractures after multilevel ProDisc-L implantation

Background Prior studies of multilevel ProDisc-L (PD-L) implants (Synthes Spine, Inc., West Chester, Pennsylvania) using the standard US technique have used conventional radiography postoperatively. We found vertebral body–splitting fractures (VB-SFs) in interposed vertebral bodies after 5 sequential multilevel PD-L device implantations using the standard US technique. These were identified with postoperative computed tomography (CT) but were not visible on plain radiographs. In an additional patient, we found that a stress-relieving, pilot holes–only technique did not prevent VB-SFs. The 5 patients operated on with the standard technique composed the background series against which we compared the incidence of VB-SFs in patients operated on with a modification of the standard US technique—a combination of stress-relieving pilot holes, removal of cortex in the chisel path, and a fenestrated chisel (PH/CR/FC)—intended to reduce the incidence of VB-SFs in multilevel PD-L constructs.