I'd bet your sternum is as strong as ever now. I've been leaning on, bumping, smacking and being hit in mine since about 7 months post surgery with no apparent effect. I do find that the if something hits me hard sometimes it hurts more over the bumps I think are the wires. The hardest smack I gave it was when I was foolishly riding a beach cruiser down a potholed street in Mexico (is there another kind of street in Mexico?) no-handed while drinking a coffee. My foot slipped and I came off the pedals hard. My sternum came into direct contact with the bicycle stem (the bit which holds the handlebar). No problem, and no damage to anything but my pride. That was 1.5 years post.
Happy New Year, have fun on the slopes, and wear a helmet!
