I haven’t dealt with a tear, but my 6 yr old has weak and sore stifles. It’s been a long haul with him and we’re still working on things.
That said, I understand surgery is sometimes indicated for meniscus tears. Otherwise, PRP and/or shockwave are good options to promote healing. The problem is the tears don’t heal well, and then with riding or any level of activity, they can reinjure it. I’d at least do a follow up ultrasound to see how it looks compared to last fall.