Stem Cells in Spinal Fusion

Abstract

Study Design:Review of literature.Objectives:This review of literature investigates the application of mesenchymal stem cells (MSCs) in spinal fusion, highlights potential uses in the development of bone grafts, and discusses limitations based on both preclinical and clinical models.Methods:A review of literature was conducted looking at current studies using stem cells for augmentation of spinal fusion in both animal and human models.Results:Eleven preclinical studies were found that used various animal models. Average fusion rates across studies were 59.8% for autograft and 73.7% for stem cell–based grafts. Outcomes included manual palpation and stressing of the fusion, radiography, micro–computed tomography (μCT), and histological analysis. Fifteen clinical studies, 7 prospective and 8 retrospective, were found. Fusion rates ranged from 60% to 100%, averaging 87.1% in experimental groups and 87.2% in autograft control groups.Conclusions:It appears that there is minimal clinical difference between commercially available stem cells and bone marrow aspirates indicating that MSCs may be a good choice in a patient with poor marrow quality. Overcoming morbidity and limitations of autograft for spinal fusion, remains a significant problem for spinal surgeons and further studies are needed to determine the efficacy of stem cells in augmenting spinal fusion.

Allogenic Stem Cells in Spinal Fusion: A Systematic Review

“…1-8 As a result, surgeons and spine researchers are in constant search for the best biological solution or material to help achieve solid arthrodesis in spine fusion cases. While ICBG has been long accepted as the “gold standard” graft material for spine fusion as it possesses osteogenic, osteoinductive, and osteoconductive properties that are critical for spine fusions, 13-18 the use of ICBG is limited by concerns of harvest morbidity, cost, and lack of efficacy in elderly or osteoporotic patients. 14,15,19-21 A variety of bone graft substitutes are available for utilization in spine surgery by spine surgeons today with variable fusion results.…”

“…22-28 Stem cells or progenitor cells are undifferentiated cells that are uncommitted in their cellular differentiation that also possess the property of self-renewal, and they can be driven toward specific tissue or cellular differentiation with growth factors and mitogens. 16,17,29-32 For spine procedures, mesenchymal stem cells and osteogenic progenitor cells may be differentiated into osteoblasts that can help achieve fusion by providing cells that participate in bone formation and may also produce osteoinductive molecules. 16,17,29-32 They can be isolated from autologous and allogeneic sources then expanded to provide a constant and viable source of bone graft substitute alternative to ICBG.…”

“…16,17,29-32 For spine procedures, mesenchymal stem cells and osteogenic progenitor cells may be differentiated into osteoblasts that can help achieve fusion by providing cells that participate in bone formation and may also produce osteoinductive molecules. 16,17,29-32 They can be isolated from autologous and allogeneic sources then expanded to provide a constant and viable source of bone graft substitute alternative to ICBG. Unlike other bone graft substitutes available in the market today, mesenchymal stem cells and progenitor cells are believed to possess the osteogenic and osteoinductive properties of ICBG.…”

“…Unlike other bone graft substitutes available in the market today, mesenchymal stem cells and progenitor cells are believed to possess the osteogenic and osteoinductive properties of ICBG. 17,32 In addition, when mix with other bone graft extenders as carriers or fillers, they can add osteoconductivity to the final stem cell products. 17,32 While the potential of mesenchymal stem cells and osteogenic progenitor cells to provide the clinical results in spine fusion as ICBG is quite appealing, we need supportive data to confirm that assertion.…”

A Monte Carlo framework for managing biological variability in manufacture of autologous cell therapy from mesenchymal stromal cells therapies

“…In addition to acting through direct engraftment, MSCs are considered a potent therapeutic for modulating disease environments through a complex bioactive secretome with anti-inflammatory and immunomodulatory properties that interacts beneficially with endogenous repair pathways [1]. MSCs have potential in the treatment of several clinically challenging and hard-to-heal orthopedic indications [2,3]. As a result, a first generation of MSC-containing products (collectively termed "cellular bone matrices") have achieved clinical uptake despite being crudely prepared donor extracts with supply limitations (being harvested from cadavers), variable results and inconclusive clinical outcomes [4].…”