@Trajectory, there are several things I find that can do in the joints of a cane (and believe meup here on the scottish boarder I know all about snow and ice as well).
Firstly, if pressure or weight is put on one specific section, the joints can indeed balloon out, particularly if you fall slip and lean your weight on the cane. To actually snap them you need some massive weight applied all at once as tom said (I once got one snapped by an oncoming lorry), but usually a small amount of weight applied in the wrong way more slowly can bend the cane, like if you lean on it, which can also result in the joints splaying outwards. The best way I found to avoid this was hold the cane more lightly, and not to try and use it for physical support, also to make sure that I turn the peaces of the cane around so that the same pressure is not being put on one section all the time with me hitting the ground with it..
Second, cane's joints always get done in when you fold the cane, especially the elastic in the centersinse the edges of the joints can be sharp and go through the elastic. The way to solve this and make your canes last a very long time is to keep them unfolded as much as possible, say by leaning them up in the corner of a room. Of course, if your out and need to sit down in class or at a cafe or whatever, the cane needs folding, but just when your at home, it's remarkable how much longer canes last if you just don't fold them up, I've had some that have lasted years doing this, indeed my current cane must be over 10 years old, though admitedly I've used it only rarely in the last five years due to having a guide dog, (it only tends to get used when I want to take Reever for an off harnice walk or sometimes when I visit my brother).
As to the joints getting full of guff, well I've occasionally had points where the cane gets stiff and hard to unfold due to the temperature, but the joints themselves don't get muck in them unless I've stuck the cane on the ground after folding it up. If this is happening a lot, perhaps look at getting something to put your cane in, like a small waterprooff bag.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)
in ages. I use one with a rolar ball on the end, and it works good for me. I hear in the states they have a cane tip that roles forward backward, left and right, I'd really like to get my hands on one of those.