Safety and Feasibility of Intradiscal Autologous Bone Marrow Aspirate Concentrate at the Time of Lumbar Microdiscectomy: A Prospective Pilot Study.

Lumbar microdiscectomy improves pain and disability in patients with lumbar disc herniation, but it does not restore disc biology, and recurrent herniation at the index level remains a clinically important limitation. Intradiscal autologous bone marrow aspirate concentrate (BMAC) has growing preclinical support as a potential biologic adjunct, but human safety data remain limited. This study evaluated the safety and feasibility of intradiscal BMAC administration at the time of lumbar microdiscectomy. Patients underwent lumbar microdiscectomy and 1 mL intradiscal autologous BMAC with 1-year follow-up. Primary outcomes were injection- or procedure-related complications, readmissions, reoperations, and same-site recurrence; secondary outcomes were Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) for leg and back pain; exploratory quantitative magnetic resonance imaging (qMRI; T1-rho, T2) screened for adverse compositional changes. 27 adults underwent lumbar microdiscectomy with concurrent intradiscal BMAC injections. No intraoperative or postoperative injection- or procedure-related complications occurred. Same-site recurrence occurred in 1/27 (3.7%) and was managed without reoperation. Patient-reported outcome measures (PROMs) were completed by 18/27 (67%), and qMRI was obtained in 16, including 6 with complete imaging through 1 year. Among patients with completed PROMs, mean ODI, NRS-leg, and NRS-back improved at 1 year, but the uncontrolled design precludes efficacyinference. No adverse changes in T1-rho or T2 were observed through 1 year. In this single-center prospective pilot, intradiscal BMAC at the time of microdiscectomy was safe and feasible, with no injection-related harm through 1 year and one same-site recurrence. Without a control group and with incomplete follow-up, findings are preliminary safety data, not evidence of efficacy or reduced recurrence risk. These results support a multicenter study with longer follow-up and a controlled comparison group.