We will consider the axisymmetric injection of a shear-thinning fluid into a confined geometry. In the absence of lubricating layers, the shear-thinning fluid spreads axisymmetrically. However, when the shear-thinning fluid is bounded by lubrication layers, fractures appear, and branches form which propagate radially. My current research, which uses both theoretical and experimental approaches, attempts to understand this fracturing behaviour. I will discuss the laboratory experiments that were undertaken to study the origin and evolution of these instabilities, as well as the mathematical modelling under development.