Visualisation of collagen fibrils in joint cartilage using STIM

The scanning transmission ion microscopy (STIM) method was used to investig ate the collagen network structure of the articular cartilage from a pig's knee in comparison with high resolution nuclear magnetic resonance imaging (microscopic NMR-tomography) and polarised light microscopy (PLM). Single c ollagen fibrils down to 200 nm in diameter were visualised. It was proved t hat the cartilage collagen network consists partly of zones of oriented fib rils as suggested by NMR measurements. Radially oriented fibrils were found in the zone near the calcified zone (hypertrophic zone) of both tibia and femur, and in the tibial radial zone. Tangentially oriented fibrils were fo und in the femoral and tibial superficial zone and in a second zone of the femoral cartilage. Polarisation light microscopy reveals broader zones of o rientation than it was found with STIM. (C) 2001 Elsevier Science B.-V. All rights reserved.