Vascularized Bone Grafting for Reconstruction of Oncologic Defects in the Spine: A Systematic Review and Pooled Analysis of the Literature

Background Resection of primary spinal tumors requires reconstruction for restoration of spinal column stability. Traditionally, some combination of bone grafting and instrumentation is implemented. However, delayed healing environments are associated with pseudoarthrodesis and failure. Implementation of vascularized bone grafting (VBG) to complement hardware may present a solution. We evaluated the use of VBG in oncologic spinal reconstruction via systematic review and pooled analysis of literature. Methods We searched PubMed/MEDLINE, Embase, Cochrane, and Scopus for studies published through September 2017 according to the PRISMA guidelines and performed a pooled analysis of studies with n > 5. Additionally, we performed retrospective review of patients at the Johns Hopkins Hospital that received spinal reconstruction with VBG. Results We identified 21 eligible studies and executed a pooled analysis of 12. Analysis indicated an 89% (95% confidence interval [CI]: 0.75-1.03) rate of successful union when VBG is employed after primary tumor resection. The overall complication rate was 42% (95% CI: 0.23-0.61) and reoperation rate was 27% (95% CI: 0.12-0.41) in the pooled cohort. Wound complication rate was 18% (95% CI: 0.11-0.26). Fifteen out of 209 patients (7.2%) had instrumentation failure and mean time-to-union was 6 months. Consensus in the literature and in the patients reviewed is that introduction of VBG into irradiated or infected tissue beds proves advantageous given decreased resorption, increased load bearing, and faster consolidation. Downsides to this technique included longer operations, donor-site morbidity, and difficulty in coordinating care. Conclusions Our results demonstrate that complication rates using VBG are similar to those reported in studies using non-VBG for similar spinal reconstructions; however, fusion rates are better. Given rapid fusion and possible hardware independence, VBG may be useful in reconstructing defects in patients with longer life expectancies and/or with a history of chemoradiation and/or infection at the site of tumor resection.