I'd like to thank AOSSM as well as my co-authors for the opportunity to speak today. These are our disclosures, which can also be found on the Academy website online. Osteochondralograft transplantation has increasingly become a preferred treatment for focal articular cartilage defects in the knee. Success of an osteochondralograft transplant, however, hinges on successful graft-osteointegration that involves both bone-to-bone healing as well as repopulation with native cells from the host. Bone marrow aspirate concentrate has been of interest in this area as an adjunct treatment with encouraging early results for cellular repopulation and viability of implanted grafts. We're not the first to investigate this, and there have been other previous retrospective studies, level three studies looking at either x-ray or MRI. And just to review three of these with mixed results, the first is a follow-up x-ray study looking at the effect of angel-based bone marrow aspirate concentrate on soaked osteochondralografts prior to implantation. What they found was improvements in integration of the graft as well as sclerosis of the graft on x-ray at each time point. However, two more recent studies using an MRI-based scoring system failed to find any benefit from bone marrow aspirate concentrate or bone marrow aspirate non-concentrated respectively. The purpose of this study was to investigate this further, looking at the effect of graft pretreatment with bone marrow aspirate concentrate for osteochondralograft transplantation of the knee, looking at both osteointegration as well as patient-reported outcomes. We hypothesized that bone marrow aspirate concentrate would have a beneficial effect both for integration as well as patient-reported outcomes. Thirty-six patients were recruited in the study and were randomized to either Iliac Crest bone marrow aspirate concentrate or sham. For the sham group, there was an incision performed at the Iliac Crest harvest site, but the bone was not compromised. Patients were blinded to their allocation. After harvesting the donor plug, grafts were soaked in bone marrow aspirate concentrate after a previous lavage to remove native cells, as well as in some cases, application of carbon dioxide to further dry the implant and improve uptake of bone marrow aspirate concentrate, which is shown in this image here. We subsequently implanted grafts using a press-fit technique, which has previously been described and is commonly performed. CT scans were performed at six months and were graded by two blinded graders using a previously validated CT-based scoring system for integration of an osteochondral allograft. We also obtained patient-reported outcomes at six months and 12 months post-operatively. All patients underwent the six-month CT. We did not have any loss of follow-up in that regard, and what we found was there was no difference in graft signal density, osseous integration, the presence of a discernible cleft between graft and host, or intraarticular fragments between groups. What we did find was a difference in the distribution of cystic changes within the graft and at the graft-host interface. In particular, there was a higher percentage of small cystic changes in the bone marrow aspirate group, with a concurrent reduction in large cyst formation over three millimeters. Looking at surgical failures, which we defined as re-operation for graft abreedment, surgical failure was observed in only one bone marrow aspirate concentrate patient and five controls. We were underpowered to detect significance with this. Finally, with patient-reported outcomes, we identified no differences in any patient-reported outcome subscale at six months or one year. We also identified no differences in the change from preoperative to one-year post-operative between BMAC or standard treatment groups. So in conclusion, patients who received bone marrow aspirate concentrated treated grafts were more likely to demonstrate smaller cystic changes at the graft-host interface with a concurrent reduction in large cysts. However, there was no difference in patient-reported outcomes or the other CT-based osseointegration parameters. There may be a trend towards improved failure rates with bone marrow aspirate concentrate treated grafts. However, we did not reach statistical significance in that regard. Taken in the context of existing literature, we believe this provides some support for use of bone marrow aspirate concentrate with the trends towards improved failure rates and decreased large cyst formation, but certainly more research is needed and we hope there are additional prospective randomized trials such as ours to help clarify these results. Thank you.

bone marrow aspirate concentrate

osteochondral graft transplantation

knee

graft integration

patient-reported outcomes