1-4 techniques, depending on how you count.
tightrope repair dogs or extracapsular [there's a traditional way and a new, improved version]
TPLO [I have seen this called "TTO -- Triple Tibial Osteotomy" but I'd always heard it called Tibial PLateua Leveling Osteotomy, TPLO]
TTA Tibial Tuberosity Advancement
MMP Modified Maquet technique [updated high-tech version of TTA]
Do a lot of googling, do your homework, find the best local vets. I've heard it said: shop for a surgeon, not a technique.
After Al awoke lame on Day 6 of a backpacking trip at age 6 3 years ago, I'd feared he was lamed for life. He was never diagnosed with a CCL rupture -- never actually examined by an orthopedic specialist -- but I came within 1 phone call with a surgeon who does the MMP, even though I didn't have the money. Al recovered slowly and perhaps incompletely -- I don't dare take him on the adventures that used to be routine -- but he did fine on a 3-day backpack this year, 3 years later, at age 9, running down the trail in the dark late Monday night after 3 days and 40 miles. in the mountains, and he still plays soccer.
He's never caught the squirrel yet, though.
At the risk of sounding like I have only one string on my guitar: Always get a second opinion.