Bono, 54, who broke his arm in six places and fractured his eye socket, hand and shoulder, made the comment on the band's website.
In the letter to his fans, he said he was unable to move around physically and would have to "concentrate hard" to be fit for U2's next tour.
At the time, the hospital where Bono was being treated said he had been involved in "a high-energy bicycle accident when he attempted to avoid another rider".
The Irish rocker spoke this week about being on painkillers for weeks and said he had a "massive injury, I can't blame on anyone but myself".
"Recovery has been more difficult than I thought. As I write this, it is not clear that I will ever play guitar again. The band have reminded me that neither they nor western civilization are depending on this.
"I personally would very much miss fingering the frets of my green Irish falcon or my (red) Gretsch. Just for the pleasure, aside from writing tunes. But then does the Edge, or Jimmy Page, or any guitarist you know have a titanium elbow, as I do now? I'm all elbows, I am," he wrote.