In vivo telemetric determination of shear and axial loads on a regenerative cartilage scaffold following ligament disruption.

Abstract

Recent interest in repair of chondral and osteochondral cartilage defects to prevent osteoarthritis caused by ligament disruption has led to the research and development of biomimetic scaffolds combined with cell-based regeneration techniques. Current clinical focal defect repair strategies have had limited success. New scaffold-based approaches may provide solutions that can repair extensive damage and prevent osteoarthritis. This study utilized a novel scaffold design that accommodated strain gauges for shear and axial load monitoring in the canine stifle joint through implantable telemetry technology. Loading changes induced by ligament disruption are widely implicated in the development of injury-related osteoarthritis. Seeding the scaffold end with progenitor cells resulted in higher shear stress than without cell seeding and histology showed significantly more bone and cartilage formation. Biomechanically, the effect of transecting the anterior cruciate ligament was a significant reduction in braking load in shear, but no change axially, and conversely a significant reduction in push-off load axially, but no change in shear. This is the first study to report shear loads measured directly in knee joint tissue. Further, advances of these measurement techniques are critical to developing improved regeneration strategies and personalizing reliable rehabilitation protocols.