Is there really no way you'd be able to knit again even after recovery? :( I don't know about tendonitis in the wrists but I had it in my ankle. It has took a while to recover but cortisone injections helped. Once it was recovered I occasionally get a twinge when I just make sure I rest it etc.
It would be a shame to see you have to stop knitting forever :(
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My First Finished Project in 20 years!: Sirdar Foxy Scarf!