Length of time to fuse depends on (among other things) age, fitness & state of health. A 40 year old regular cyclist known to me (OK, me) in good health was once told by an A&E doctor that it'd probably be knitted together in two weeks. On expressing surprise, I was told that she'd knocked several years off my age because of my exercise levels.
Two weeks later, I went back for a checkup & found she was right. All closed up. The orthopaedic doctor who checked it wasn't surprised. Another three weeks to let it harden a bit & I was off to Normandy for a week of cycling.
Similar age & poor health, or older, & they'd expect it to take longer.
Y'know, Bobb's painfully acquired expertise in left-handed wanking now looks wasted. A pity, eh?