Even small amounts of cement leakage can pose significant problems. Some patients have a toxic or allergic reaction that can be very serious. If the cement gets into the veins and blood supply, blood clots to the lungs can occur. The cardiovascular system can become compromised.
Leakage into the disc space or spinal canal where the spinal cord is can cause serious neurologic complications. Paralysis and even death are possible though these events are rare. Some studies report increased vertebral fractures when leaks occur into the disc space.
Detecting leakage isn't always easy even with standard X-rays or special X-rays called fluoroscopy. CT scans may be needed to find and monitor leaks. The long-term effects of benign leaks (the patient has no symptoms) is unknown.
Research is ongoing to find ways to prevent leakage. Studies to track long-term results may show that this complication isn't a major concern for most patients. Right now it's not even clear how often this happens or what causes it to occur.