This preclinical ex vivo study was conducted to evaluate the effects of submersion in saline or the Missouri Osteochondral Preservation System (MOPS®) solution during reaming on viable chondrocyte density (VCD) of osteochondral allografts (OCAs). Distal femoral OCAs preserved with MOPS were reamed to create cylindrical “plug” grafts using one of three techniques: Submersion in MOPS (SG–MOPS), submersion in saline (SG–Saline), or reamer saturated with MOPS without OCA submersion (SR–MOPS). All plug reaming was performed using standardized instrumentation and technique to harvest 18-mm-diameter plugs. Pre-reaming cartilage samples were collected to confirm baseline VCD. Post-reaming plugs were bisected and stained for live/dead analysis using fluorescent microscopy. VCD was quantified via image analysis, and %Day-0 VCD was calculated. Group comparisons were made using one-way analysis of variance (ANOVA; α = 0.05). A total of 21 plugs from 9 donors were analyzed: SG–MOPS (n = 8), SG–Saline (n = 6), SR–MOPS (n = 7). Mean %Day-0 VCD was highest in SG–MOPS (92.6 ± 7.8%), followed by SG–Saline (83.3 ± 10.2%), and SR–MOPS (80.2 ± 9.1%), though differences were not statistically significant (p = 0.68). A higher proportion of SG–MOPS plugs (7/8, 88%) exceeded the minimum essential VCD threshold (70%) compared with SG–Saline (4/6, 67%) and SR–MOPS (3/7, 43%). Submerging distal femur OCAs in MOPS during 18-mm-diameter femoral condyle plug reaming had clinically meaningful beneficial effects on viable donor chondrocyte density when compared with saline-submerged or non-submerged grafts. Based on the use of this submerged reaming technique that is standardized, repeatable, readily available, cost-effective, and safe, this methodology can be considered “best practice” for OCA plug reaming protocols, motivating implementation of this evidence-based shift in practice at our institution.

The University of Missouri's Institutional Review Board (IRB #1208392) approved this study.

Received: 26 August 2025

Accepted: 03 September 2025

Accepted Manuscript online:
04 September 2025

Article published online:
25 September 2025

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