Not necessarily. Some patients have more than one fracture that needs repair. Some patients develop new fractures after the first one is repaired. Other complications such as infection, abscess, or cement leak can also cause problems.
It's best to have a doctor re-evaluate your uncle. He may just need more time to heal. He may need an exercise program to strengthen the muscles around his spine to help improve his posture. Or he may need a second vertebroplasty.
Early diagnosis and treatment is the key to preventing further problems. Don't delay in calling the doctor's office and letting them know what's going on.