My Labrador was diagnosed with it at 6 months. It was explained to me if I didn't due surgery he would be in a great deal of pain & unable to run & fetch by the time he hit 6 yrs. Worse pain in the senior years. I did the TPO surgery.... I think... Vaguely remember TPLO also... I got to do a surgery available to those who's growth plates had not closed yet. WORTH EVERY PENNY! Had it done at UC Davis.
My labrdork did agility, & ran & fetched his little heart out right up until the day we had to send him over the rainbow bridge (likely heart related) just shy of his 14th birthday. Without signs of pain or stiffness.
Depends on how bad it is. He also had it in the other hip, but very minor. Kept his weight down, swimming, walking & joint pills like a cult post surgery.
People commented right up until the end how good he looked. I have seen stiffer moving dogs half his age.
Best of luck.