Mesenchymal Stem Cell Allograft In One And Two Level ACDF's: A Matched Cohort Analysis

Presented at SMISS Annual Forum 2014
By Kern Singh MD
With Branko Skovrlj MD, Sheeraz Qureshi MD, MBA, Alejandro Marquez-Lara MD, Islam Elboghdady , Abbas Naqvi BS, Khaled Aboushaala MD, Steven McAnany MD, Nomaan Ashraf MD, Samuel Overley MD,

Disclosures: Kern Singh MD A; CSRS Resident Grant. B; DePuy, Zimmer, Stryker, CSRS, ISASS, AAOS, SRS, Vertebral Column - ISASS. D; Avaz Surgical, LLC, Vital 5, LLC. F; Zimmer, Stryker, Pioneer, Lippincott Williams & Wilkins, Th Branko Skovrlj MD None, Sheeraz Qureshi MD, MBA A; Cervical Spine Research Society. B; Zimmer-Biomet, Stryker Spiner, Globus Medical, Inc. D; Avaz Surgical. F; RTI, Zimmer-Biomet, Stryker Spine, Alejandro Marquez-Lara MD None, Islam Elboghdady None, Abbas Naqvi BS None, Khaled Aboushaala MD None, Steven McAnany MD None, Nomaan Ashraf MD None, Samuel Overley MD None,

Live mesenchymal stem cell (MSC)-containing allogenic bone grafts have recently gained popularity and currently account for 17% of all bone grafts and bone graft substitutes utilized in spinal surgery. Potential advantages include long-term cell proliferation, self-renewal capabilities, and multi-potent differentiation. Currently, little is known about their clinical success when used in anterior cervical discectomy and fusion (ACDF).

To assess the fusion rate in ACDF using MSC allograft.

A consecutive series of 57 patients (85 cervical levels) who underwent a one- or two- level ACDF procedure between 2010 and 2012 were retrospectively analyzed. All fusion constructs comprised of an interbody allograft, an anterior plate. and Osteocel® (NuVasive, San Diego, CA, USA). These patients were matched with regards to diagnosis, number of fusion levels, smoking status, and comorbidity burden to a control group of 57 patients (85 cervical levels). The fusion construct in the control group included a structural interbody bone allograft (Vertigraft (DePuy, Raynham, MA, USA)) and anterior plating without other graft enhancers. The six-month arthrodesis rates were assessed with thin-slice computerized tomography (CT) scan. Patients with pseudarthrosis at six-months were reassessed at 1 year with flexion-extension x-rays and CT scan. Statistical analysis was performed with independent sample T tests for continuous variables and Chi-square analysis for categorical data. Clinical and radiographic evidence of arthrodesis were compared between cohorts with <0.05 denoting statistical significance.

Of the 57 cases in both cohorts, 29 (50.9%) were single-level and 28 (49.1%) were two-level ACDFs. There were no significant differences in patient age (47.3±10.2 vs 46.6±9.0 years, p=0.71), gender, comorbidity burden (CCI: 1.95±1.48 vs 2.42±1.31, p=0.71) or body mass index (28.0±7.5 vs 28.4±5.4 Kg/m2, p=0.79) . At the one-year follow up, 50/57 (87.7%) patients in the Osteocel® cohort demonstrated a solid fusion compared to 54/57 (94.7%) in the control group (p=0.19). Seven (12.3%) patients in the Osteocel® cohort were reported as having a failed fusion at one-year. Four (7.0%) of these patients were symptomatic and underwent revision surgery with a posterior cervical fusion, while three patients (5.3%) were asymptomatic and did not require a secondary intervention. The three patients (5.3%) in the control cohort all required revision surgery.

This is the firststudy to analyze a matched cohort assessing the one-year arthrodesis rates associated with a non-structural MSC allograft in ACDF procedures. Although not statistically significant, patients treated with MSC allografts demonstrated lower fusion rates compared to a matched non-MSC cohort.