Thank you very much. Our next speaker will be Bernhard Meyer. Is that right? Bernhard? Bernhard will be speaking to us about the risk of cement leakage and pulmonary embolism in bone cement augmented pedicle screws. Thanks, Michael. Thanks, Mattrey. Okay. So, good morning, everybody. My topic is maybe somewhat strange for some of you, but quite obviously, if you – these are my disclosures, none is relevant to the talk. If you live in Central Europe or German-speaking countries, the usage of cement augmented pedicle screws is pretty liberal these days. I don't know. This is an international symposium. Probably there are countries where you don't have them or don't use them, and there might be countries where you use them. What we found out when we started is that it's useful. Biomechanic studies have shown they're superior with respect to pull-out strength. So, it has become for us the default procedure if we instrument osteoporotic fractures or if you have a patient with severe osteoporosis and a degenerative spine disease, especially adult deformity, and spinal meds. These are the three major indications. As you see, most of them are usually done percutaneous, and then we augment it with cement. This is a typical case, multiple metastases of a renal cell carcinoma. One is symptomatic, the one you see on the thoracocervical junction, and is metastasized throughout the spine. So, this is what we usually then do. You can see on the upper right hand that in the end there was some cement extravasation. Obviously, it's a function of how many screws you have, but sooner or later you usually do see cement leakage. Despite the fact that we use cement that is especially made for this purpose, it has a very fast polymerization time and is highly viscous. So, complications that were acknowledged prior were usually epidural cement leakage and not so much the ones into the veins that then go into the lung. People who do that for a longer time know that there are also anaphylactic reactions related to the cement. There was one case, this one here, which triggered us to do that retrospective series, which I will show you. This is another tumor case, symptomatic metastasis, as you can see in the thoracic spine. The patient had multiple comorbidities, COPD, arterial hypertension, and also some form of cardiac problems. This is how we treated him, and you could see already in the post-op CT that there was a cement leakage in the prevertebral veins. Usually we use 1.5 cc per screw, and we're trying to look at it in the fluoro, so we have a live appearance of filling the cement in. Then you can see on these CT thorax afterwards that there are multiple pulmonary embolisms of the cement. The patient died ultimately from heart failure about two days later. We were looking into the literature, and we were talking to people using this type of device. There are only a very few case studies with regard to telling us the incidence of pulmonary cement embolism. Actually, asking other people, he's not yet here. For example, Claudius Tomei is using it in a large quantity of patients who claims that he doesn't have the problem that we have. Obviously, we just checked if we were doing something wrong. The aim of this study was just to assess the rate of CABSI-associated complications that we saw. That is retrospective. In a three-and-a-half-year period, all patients who received this type of instrumentation were looked at. Obviously, this is a retrospective, so it's not fully complete, and probably all the complications are on the lower end. 165 patients with over 1,300 pedicle screws, most of them in the thoracic and lumbar areas, some were sacral. Indications, as I said before, osteoporotic fractures, meds. Then some traumatic fractures with a patient who had an osteoporosis, but a true traumatic fracture. Then degenerative spine, mostly adult deformities. Then some infections, but we usually did not go right to the infections, but at the lower and the upper end of the instrumentation only. In 31 cases, we saw that already intraoperatively, there was a suspicion that some leakage was present. We usually checked it afterwards, then, and saw that in 29 of these cases, that was true. And eight patients had already intraoperative suspicion of pulmonary cement embolism and were checked afterwards, and three cases were then confirmed. 29, you could see in postoperative images, these are the checks for the routine checks for the instrumentation, that there was a suspicion of venous cement leakage, and that was confirmed by a CT, as I said, in 29 patients. Three patients, as I said, were confirmed to have pulmonary cement embolism. Usually, when we consulted our cardiologists, they say put them on heparin and oral anticoagulants, and they get a cardiac exam, but usually they are not symptomatic. However, there were four cases with relevant intraoperative hemodynamic reactions, two were due to an anaphylactic shock. One of those patients died, and two due to cement embolism, pulmonary cement embolism. Both patients died within two days or 48 hours of surgery. Three patients that had some form of dyspnea after surgery were checked, and all of them had cement embolism. So, we have seen, I can skip that because it's summarized later on, and go to epidural. Epidural cement leakages were seen in 10 cases, two of which were symptomatic, and one required a revision surgery for that. In the other eight cases, there were no symptoms. So, to summarize, two-thirds of patients do have some form of asymptomatic cement leakage. Asymptomatic pulmonary cement embolism was seen in 5%, symptomatic in 3%, anaphylactic reactions in two patients, epidural leakages, as I just said. So, all of it was a symptomatic complication rate of 5%, which is, according to me, quite high. 30-day mortality, almost 2%. And as I said before, this is probably at the lower end. So, there's pretty high risk of asymptomatic cement leakage in that type of procedure. It's just probably like vertebroplasty, but vertebroplasty you usually do in one or two segments. You do then on six, seven, eight, or whatever segments, or a vertebral body, the risk for severe complications, that means symptomatic complications up to mortality, is rather high and depends on the patient's features, as we found out, and where you do it. So, a patient with multiple metastases, a thoracic instrumentation, and a problem with his heart prior to that type of surgery will probably be at highest risk of having a symptomatic complication. So, we do have now a stricter indication, especially if you have that configuration of patients, and are very careful when we do that. You can read that because it's published in the Spine Journal, and has been the foundation of a multi-center trial prospective, 12 centers, 700 patients need to be included. And we have now 48 patients in, and already found out that the symptomatic and asymptomatic complication rate is probably even higher, and not only in our center, but in other centers too. Thank you very much.

cement leakage

pulmonary embolism

bone cement augmented pedicle screws

osteoporotic fractures

degenerative spine diseases