This is a stage 4 decub. There is exposed bone (in this picture with a light layer a fibrinous debris)
Classification
Stage 1 - Skin intact but remains reddened after >1 hour post relief of pressure
Stage 2 - Blister or other break in dermis with or without infection
Stage 3 - Subcutaneous destruction into muscle with or without infection
Stage 4 - Involvement of bone or joint with or without infection
