Does Age Influence the Efficacy of Demineralized Bone Matrix Enriched with Concentrated Bone Marrow Aspirate in Lumbar Fusions?

Study Design: Retrospective study. Objective: Evaluate the effect of age on the efficacy of allograft/demineralized bone matrix (DBM) enriched with concentrated bone marrow aspirate (BMA) in posterolateral lumbar fusions (PLFs). Summary of Background Data: Cell-based therapies such as concentrated BMA have been developed as a potential alternative to iliac crest bone graft (ICBG). BMA contains mesenchymal stem cells (MSCs) and growth factors that can confer osteogenic and osteoinductive potential to osteoconductive scaffolds such as DBM/allograft. To date, no studies have examined the role of age on fusion outcomes when BMA is utilized despite the well-established deleterious effects of advanced age on bone marrow and MSC potential. Materials and Methods: Fifty-one patients that underwent PLF were divided into 3 groups. Group A (n = 14) composed of patients age 65 years and older who received BMA with DBM. Group B (n = 17) consisted of patients younger than 65 years of age who received BMA with DBM. Group C (n = 20) composed of patients age 65 years and older who received ICBG. Fusion rates and clinical outcomes were assessed. Results: Fusion was significantly lower in group A (35.7%) compared with both groups B (76.4%) and C (80%) (A vs. B, P = 0.03; A vs. C, P = 0.01). There were no differences in clinical outcomes among all groups except for pseudarthrosis which occurred in 28.6% of patients in group A compared with none and 5% of patients in groups B and C, respectively (A vs. B, P = 0.03; A vs. C, P = 0.13). Conclusions: Elderly patients undergoing PLF using DBM enriched with BMA achieved lower radiographic fusion success compared with their nonelderly counterparts and compared with elderly patients that had fusion with ICBG. This may be partly due to the effect of advanced age on MSC potential.