Nonunion of ulna after 5 surgeries

[Tandddoyle]

I had a compound fracture of the ulna along with a distal ulna fracture and fractured radius in march of 2015. Three plates and screws were installed and after a year and a half it was discovered that the ulna had not completely healed. I had an additional surgery that included a cadaver bone graft and new ulnar plate. Two weeks later the bone was infected so they removed the graft and both ulnar plates and put me in a cast and then a brace for a total of 12 weeks. Then I got a second opinion and two additional surgeries were performed. One to place antibiotic beads to rule out any lingering infection and the second one to do a new bone graft (this time from my hip) and put in a new plate. Long arm cast for 7 weeks and now a short arm cast for an additional 6 weeks. After my last X-ray (7 weeks post op) there is still no sign of incorporation of the graft with my ulna. I'm starting to get nervous because surgery number 6 will be bone from my femur. Has anyone experienced anything similar where the bone refuses to heat after multiple attempts?