Effect of Graft-Host Interference Fit on Graft Integration after Osteochondral Allograft Transplantation: A Comparative MRI Analysis of Two Instrumentation Sets.

Precise graft-host interference fit is a potentially import factor for the successful incorporation of osteochondral allograft (OCA) transplants for the treatment of symptomatic focal cartilage defects. It was hypothesized that selection of OCA plug instrumentation set has a significant effect on graft integration and morphology after OCA transplantation.

Thirty-one patients who underwent OCA transplantation between July 2013 and July 2016 were identified for this comparative magnetic resonance imaging (MRI) analysis. Patients were stratified into two groups based on the treatment with the Arthrex Allograft OATS Instrument Set or the JRF Ortho Osteochondral Allograft Plug Instrumentation. MRI was obtained at 12 months postoperatively. All grafts were assessed for integration using the Osteochondral Allograft MRI Scoring System (OCAMRISS), host marrow edema size, graft-host interface distance, graft cartilage integrity, cyst size, graft contour and presence of effusion.

At a mean follow-up of 11.39 ± 1.98 months, 95.5% of all grafts showed osseous integration into the recipient bone with 68.2% presenting without cystic changes of the graft or host-graft junction. No differences were seen in any OCAMRISS subscale besides cartilage signal, which demonstrated minimal differences (P = 0.046).

OCAs show excellent osseous integration at the graft-host junction at 12 months postoperatively. The comparative MRI analysis of two instrumentation sets yielded no significant differences in terms of graft integration, bone marrow edema, or cystic formation. Hence, this study cannot recommend one instrumentation set over the other. Consequently, the individual preference should guide the surgeon's selection of instrumentation for OCA transplantation.