Autologous Stem Cells in Cervical Spine Fusion

STUDY DESIGN: Systematic review. OBJECTIVES: To systematically review, critically appraise and synthesize evidence on use of stem cells from autologous stem cells from bone marrow aspirate, adipose, or any other autologous sources for fusion in the cervical spine compared with other graft materials. METHODS: A systematic search of PubMed/MEDLINE was conducted for literature published through October 31, 2018 and through February 20, 2020 for EMBASE and ClinicalTrials.gov comparing autologous cell sources for cervical spine fusion to other graft options. RESULTS: From 36 potentially relevant citations identified, 10 studies on cervical fusion met the inclusion criteria set a priori. Two retrospective cohort studies, one comparing cancellous bone marrow (CBM) versus hydroxyapatite (HA) and the other bone marrow aspirate (BMA) combined with autograft and HA versus autograft and HA alone, were identified. No statistical differences were seen between groups in either study for improvement in function, symptoms, or fusion; however, in the study evaluating BMA, the authors reported a statistically greater fusion rate and probability of fusion over time in the BMA versus the non-BMA group. Across case series evaluating BMA, authors reported improved function and pain and fusion ranged from 84% to 100% across the studies. In general, complications were poorly reported. CONCLUSIONS: The overall quality (strength) of evidence of effectiveness and safety of autologous BMA for cervical arthrodesis in the current available literature was very low. Based on currently available data, firm conclusions regarding the effectiveness or safety of BMA in cervical fusions cannot be made.