Implantation of a synthetic meniscal scaffold improves joint contact mechanics in a partial meniscectomy cadaver model

Meniscal substitutes should ideally distribute loads across adjacent articular cartilage much in the way of the native tissue, thereby protecting the cartilage from degeneration. The objective of this study was to quantify the loads transferred to the tibial plateau after implantation of a porous polyurethane scaffold. Our hypothesis was that scaffold implantation would improve the contact mechanics of a partial meniscectomy knee. Six sheep cadaver knees were mounted in a load-controlled knee-joint simulator. A pressure-sensor sheet, secured to the tibial plateau, dynamically recorded pressure data over 10 gait cycles for the following conditions: (i) intact, (ii) partial meniscectomy, (iii) implanted scaffold, and (iv) total meniscectomy. Implantation of the scaffold increased the contact area and decreased the contact pressures compared to the meniscal defect knee. No significant difference was found between the average and peak contact pressures of the intact knees and scaffold-implanted knees; however, contact area was significantly lower for the scaffold-implanted knees compared to intact knees. Our hypothesis was accepted; replacement with a polyurethane scaffold improved knee-contact mechanics relative to a partially meniscectomized knee. On the basis of these findings, the scaffold will be evaluated for its chondro-protective capacity in an in vivo ovine model. (C) 2009 Wiley Periodicals, Inc. J Biomed Mater Res 92A: 1154-1161, 2010