Hi. Im so sorry to hear that! Here are a couple:
1. get a metal pizza pan and use the magnetic marbles and sticks set to play with. My kids will sit for hours with that.
2. Put some cheapie shaving cream on top of your kitchen table and let your child swirl his fingers around in it and draw pictures in it. afterwards, the shaving cream is great to clena your table, just wipe off with a paper towel and you have a very clean table afterwards. (you can also put some food coloring in it...but then u would need to use a metal baking pan and not put the shaving cream on the table.
3. Get a shallow metal baking pan and fill it with salt...have your child draw pictures in it.
4. Make some home made play doh or home made slime. you can find the recipes on line
5. Give him a pair of kid scissors and some old magazines and have him cut up all he wants. then he can glue them on a piece of construction paper.
6. puzzles are great
7. legos or bulding blocks
8. coloring, markers, etc.
9. cut out some pieces of old fabric and have him glue them on paper to make a collage
10. Google preschool activities for disabled children...I know he isnt disabled, but they will have a ton of things on there until the cast is off.