PE after knee surgery and complications

[Buzzword]

Hi - my OH experienced a PE 3 days after his knee surgery and is now on apixiban for 3 months. The problem is, he keeps experiencing internal bleeding which pools around the knee which isn't dispersing and consequently allowing him to move forwards with knee recovery.

Has anyone experienced this complication before? He has to stay on apixiban for another 5 weeks and has already had one arthroscopy to remove the blood, but 10 days later it looks as though it's filling up again.