What happened to his nose?
Noses and ears continue to grow for as long as someone lives.
With aging in adulthood, the nose undergoes many structural or anatomical changes, such as:
Thinning of and loss of elasticity of the nasal skin
Drooping of the nasal tip
A weakening and excessive softening of the nasal cartilage
Nasal cartilage ossification, which makes it brittle (some instances)
Separation of the attachments between the upper and lower cartilage pieces on the sides of the nose
Ultimately, these changes can result in the overall lengthening of the nose.
In Stalone's case, it appears someone (Dolf Lundgren) rearranged it.