Comparison of polymethylmethacrylate versus expandable cage in anterior vertebral column reconstruction after posterior extracavitary corpectomy in lumbar and thoraco-lumbar metastatic spine tumors.

Single-stage posterior corpectomy for the management of spinal tumors has been well described. Anterior column reconstruction has been accomplished using polymethylmethacrylate (PMMA) or expandable cages (EC). The aim of this retrospective study was to compare PMMA versus ECs in anterior vertebral column reconstruction after posterior corpectomy for tumors in the lumbar and thoracolumbar spine. Between 2006 and 2009 we identified 32 patients that underwent a single-stage posterior extracavitary tumor resection and anterior reconstruction, 16 with PMMA and 16 with EC. There were no baseline differences in regards to age (mean: 58.2 years) or performance status. Differences between groups in terms of survival, estimated blood loss (EBL), kyphosis reduction (decrease in Cobb's angle), pain, functional outcomes, and performance status were evaluated. Mean overall survival and EBL were 17 months and 1165 ml, respectively. No differences were noted between the study groups in regards to survival (p = 0.5) or EBL (p = 0.8). There was a trend for better Kyphosis reduction in favor of the EC group (10.04 vs. 5.45, p = 0.16). No difference in performance status or VAS improvements was observed (p > 0.05). Seven patients had complications that led to reoperation (5 infections). PMMA or ECs are viable options for reconstruction of the anterior vertebral column following tumor resection and corpectomy. Both approaches allow for correction of the kyphotic deformity, and stabilization of the anterior vertebral column with similar functional and performance status outcomes in the lumbar and thoracolumbar area.