Damage and degenerative changes in menisci-covered and exposed tibial osteochondral regions after simulated landing impact compression - A porcine study

Abstract

The capacity of menisci-covered and exposed tibial osteochondral regions in resisting impact-induced damage and degeneration is not fully understood. This study sought to evaluate damage and degenerative changes in these regions upon a single simulated landing impact. We hypothesized that the menisci-covered regions are more susceptible to damage and degeneration than their exposed counterparts.Meniscicovered and exposed tibial osteochondral explants were extracted from fresh porcine hind legs and placed in culture up to 14 days. Impact compression, based on a single 10-Hz haversine,was performed atDay 1. Control (non-impact) and impacted explants were randomly selected for cell viability assessment, glycoaminoglycan and collagen content assays, histology, immunohistochemistry, and micro-computed tomography.Whensubjected to 2-mmdisplacement compression, exposed explants achieveda significantly higher peakimpact stress (p < 0.05) than menisci-covered explants.No significant difference in cell viability, glycoaminoglycan and collagen content, and Mankin scores (p > 0.05) was observed between both explant groups. Both groups were observed with reduced proteoglycan and type II collagen staining at Day 14; the exposed group was noted with increased cartilage volume at Days 7-14. The inferior resistance of menisci-covered regions, against impactinduced damage and degeneration, is a potential factor thatmay contribute to themeniscectomymodel of osteoarthritis. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.