Efficacy of Percutaneous Vertebroplasty in the Treatment of Intravertebral Pseudarthrosis Associated With Noninfected Avascular Necrosis of the Vertebral Body

Study Design. A retrospective clinical study on the effect of percutaneous vertebroplasty (PVP) in the treatment of intravertebral pseudarthrosis caused by avascular necrosis of a vertebral body. Objectives. To evaluate the efficacy of PVP in the treatment of spinal instability associated with avascular necrosis. Summary of Background Data. Two radiologic features of avascular necrosis of a vertebral body are intravertebral vacuum phenomenon and fluid collection, combined with a collapsed vertebra. These can sometimes result in dynamic instability due to intravertebral pseudarthrosis. A treatment for this instability, associated with avascular necrosis, has not been established. Method. Sixteen patients with instability, associated with avascular necrosis of a vertebral body, were treated by PVP. The indicators of the condition included spinal instability associated with avascular necrosis, which was diagnosed by a vacuum phenomenon or by fluid collection in the vertebral body as found from imaging studies. The instability of the vertebral body was confirmed from the dynamic lateral view in both flexion and extension. The anterior body height and kyphotic angle changes between pre- and post-treatment were measured on a lateral radiograph. Plain radiography was used during the follow-up period (8–14 months; mean, 11 months) to assess the vertebral column stability. The pain level of each patient was assessed, both before and after the procedure, using a visual analog scale (VAS), ranging from 0 to 10. Marked or complete pain relief was achieved in eight (50%) patients, and moderate pain relief in six (38%), with the immediate postoperative average pain score reduced from 9.0 to 4.3. The mean corrected angle and vertebral height between pre- and post-treatment were 8.5° and 7.0 mm (P =0.001), respectively. There was no significant change in the kyphotic angle of the treated level during the follow-up period (P =0.711). Conclusions. Percutaneous vertebroplasty is a reasonable procedure for the treatment of spinal instability associated with avascular necrosis, but not that caused by an infection. PVP was found to be a minimally invasive and effective procedure that provides pain relief and stabilization of spinal instability associated with noninfected avascular necrosis of the vertebral body.