Tattooing over a surgical scar? Timing decides whether you get the design you wanted or a warped version of it. After a hip or knee replacement, the surface heals in ~2 weeks. Underneath, collagen, nerves, and blood flow keep rebuilding for 12-18 months. The scar isn't finished when it looks finished. Ink too early and you risk heavier bleeding, spreading ink, and lines that blur as the scar settles. Sharp at 3 months, warped by month 12. My rule: flat, pale, painless when you press it. Get your surgeon's clearance first, and choose an artist experienced with scar tissue. It's denser and takes ink differently. The art is permanent. Make sure the canvas is ready.