Bone Marrow Aspirate Concentrate Improves the Early Osseous Integration of Fresh Osteochondral Allografts in the Knee: A Randomized Controlled Trial

Abstract

Background:

Fresh osteochondral allograft (FOCA) transplantation is an increasingly used technique for treating symptomatic cartilage defects in young and active patients. However, insufficient osseous integration of the graft remains a primary cause of failure. Bone marrow aspirate concentrate (BMAC), rich in mesenchymal stem cells, may enhance graft integration.

Purpose:

To determine whether the use of autologous BMAC in FOCA transplantation of the knee improves osseous integration on computed tomography (CT) during the first postoperative year and yields superior clinical outcomes compared to non–BMAC-treated grafts at 2-year follow-up.

Study Design:

Randomized clinical trial; Level of evidence, 1.

Methods:

We conducted a single-center, prospective, randomized controlled trial in 36 patients undergoing FOCA transplantation. Patients who met the inclusion criteria were randomly assigned to either a BMAC group or non-BMAC group. CT was performed at 3, 6, and 12 months, and imaging findings were evaluated using the semiquantitative assessment CT osteochondral allograft (ACTOCA) scoring system. Clinical outcomes (International Knee Documentation Committee, Kujala, Western Ontario Meniscal Evaluation Tool, and Tegner scores) were assessed preoperatively and at 6, 12, and 24 months.

Results:

Osseous integration at the host-graft junction on CT was superior in the BMAC group at 3 months postoperatively compared with the non-BMAC group (P < .05), with no differences between groups at 6 or 12 months. Regarding graft signal density relative to host bone, differences were observed between groups at 3 and 12 months, with better 3-month graft signaling in the BMAC group and better 12-month graft signaling in the non-BMAC group. No differences were observed at 6 months. Also, no differences were observed between groups in patient-reported outcome scores.

Conclusion:

BMAC augmentation in FOCA transplantation of the knee demonstrated improved early osseous integration at the host-graft junction at 3 months postoperatively, as assessed on CT using the ACTOCA scoring system, with no differences observed at 6 or 12 months. Regarding graft signal density relative to host bone, significant differences were observed at 3 and 12 months, with better 3-month graft signaling in the BMAC group and better 12-month graft signaling in the non-BMAC group. No differences were observed between groups in patient-reported outcome scores.

Registration:

NCT04236492 (ClinicalTrials.gov).