An In Vivo Lapine Model for Impact-Induced Injury and Osteoarthritic Degeneration of Articular Cartilage.

Abstract

OBJECTIVE:

In this study, we applied a spring-loaded impactor to deliver traumatic forces to articular cartilage in vivo. Based on our recent finding that a 0.28-J impact induces maximal catabolic response in adult bovine articular cartilage in vitro using this device, we hypothesize that this impact will induce the formation of a focal osteoarthritic defect in vivo.

DESIGN:

The femoral condyle of New Zealand White rabbits was exposed and one of the following procedures performed: 0.28 J impact, anterior cruciate ligament transection, articular surface grooving, or no joint or cartilage destruction (control). After 24 hours, 4 weeks, or 12 weeks (n = 3 for each time point), wounds were localized with India ink, and tissue samples were collected and characterized histomorphometrically with Safranin O/Fast green staining and Hoechst 33342 nuclear staining for cell vitality.

RESULTS:

The spring-loaded device delivered reproducible impacts with the following characteristics: impact area of 1.39 ± 0.11 mm(2), calculated load of 326 ± 47.3 MPa, time-to-peak of 0.32 ± 0.03 ms, and an estimated maximal displacement of 25.1% ± 4.5% at the tip apex. The impact resulted in immediate cartilage fissuring and cell loss in the surface and intermediate zones, and it induced the formation of a focal lesion at 12 weeks. The degeneration was defined and appeared more slowly than after anterior cruciate ligament transection, and more pronounced and characteristic than after grooving.

CONCLUSION:

A single traumatic 0.28 J impact delivered with this spring-loaded impactor induces focal cartilage degeneration characteristic of osteoarthritis.

• Authors: Peter G Alexander, Jesse A McCarron, Matthew J Levine, Gary M Melvin, Patrick J Murray, Paul A Manner, Rocky S Tuan
• Journal: Cartilage (Cartilage) Vol. 3 Issue 4 Pg. 323-33 (Oct 2012) ISSN: 1947-6035 [Print] United States
• PMID: 26069642 (Publication Type: Journal Article)