 Okay. So in our department, we do about 60% of spinal procedures and 40% of cranial procedures. And we are by far not belonging to the departments with a lot of, with the most surgeries per year in Germany. But the most cases belong to the 10 departments having the most cases in cervical spine procedures. I don't know why, but it is like this. We are ranking about seven to eight depending on the year. So we have talked about the indication for anterior cervical discectomy and the fusion and which grafts we use. The patient in Germany, if they're coming to our outpatients, they are very good informed and they have several papers taken from the internet and they say, I don't want a bone graft. I heard about that it will hurt and I want a PKage or something like that. So they're well informed and they tell us which graft they want. And so for years, we are using this PKage and we are very convinced with this. And then after the question, which interbody graft we use, we have the question, shall we use an anterior blade in all of the anterior cervical spine fusions? Or is it not necessary to put this graft? So this is a regular follow-up after monosegmental anterior fusion. You see this is a standalone PKage and these PKages primarily they are designed as a standalone cage. Primarily it's not necessary to put an anterior blade. And you see a normal follow-up, six-week post-operative and two years after surgery and you see the fusion and everything is fine. But on the other hand, you sometimes see these follow-ups. So this is the post-operative X-ray, you see the cage and you see six weeks later a subsidence and the X-ray, two years later you see these irregularities, you see the subsidence and there is a psoid atrosis and the patient has pain. And you also can see this on the MRI scans, you see there is edema in the vertebral bodies and the patient is suffering of pain because of these psoid atrosis and the subsidence of a cage. And so what is the biomechanics concerning this problem? And why worry about the subsidence? On one hand if you have this non-fusion and you have the subsidence, the patient has a pain, a local pain. And on the other hand if you have this subsidence you see after surgery the foramen is widened and if you have this subsidence the foramen is narrow again the patient may have a radiculopathy and third point is if you are putting this craft you can re-establish a lordosis and if you have this subsidence you will lose this lordosis again. So the biomechanics are changed due to this situation. And these in vitro studies show that you have a significantly higher range of motion if you have put this standalone cage then the healthy spine. So this results in a significant risk of subsidence and so the in vitro studies suggest the use of plate but there are no prospective clinical studies available concerning this problem. And so one of our colleagues designed this study, we changed our product. So we had first about a little bit less than 100 consecutive patients with an anterior cervical spine fusion but only in soft disc herniations no other micro-degenerative changes. So only selected cases and the next period of time almost the same number of patients the same diagnosis only soft cervical disc herniations and we put these the same cage but with an anterior plate. And so these are the results you see these the reddish are the standalone cages and the blue one are the peak cage with an anterior plate and you see kind of subsidence in about 60%. We had to do a redo surgery and 11% of these standalone cages and you see the fusion rate with the peak cage and the anterior plate is significantly higher than with the standalone cage. And why is that? You see if we have the standalone cage the cage will protect the motion in this range and the joints there are intact so you have no motion in this range but because of the anterior longitudinal ligament is resected you have a motion in this range. And this is more motion than the healthy spine has. And this motion can in our understanding cause the subsidence of the cage and if you put now the anterior plate this plate stops the motion also in this range. So this is the fixation that is missed by the anterior longitudinal ligament and there were no complications related with the putting of the plate. And so for us we concluded that the cage prevents case dislocation that it reduces the rate of painful subsidence enhances the rate of fusion. We do not use a cervical collar so the patients can immediately went around without something as we heard it is not that sufficient as we all thought some years ago and this anterior plate has no significant artifacts on CT or MRI scan. Of course it's a prolonged time of surgery but about 10 minutes not more and the costs are even higher of course. So we are using the anterior plate in all our anterior cervical fusions. If there are spondylitic cases or herniations we use it in all of our fusions. And so some technical recommends. We have heard about the significance of the midline and so what I do is if I see the longest collar on both sides I first put these screws to determine the midline because if you mobilize the longest collar you cannot do it symmetrically. So the first step is to put these screws to place the screws in the midline and so you have the midline for the rest of the surgery. That's the first thing. And the second I always try to use the drill and the round drill and you see if you angle it I drill up till I do not see this half of the drill. And so both plates and you have this result without you have touched the end plates so they keep strength you do not weaken them and this is also important for the stability of the cage. And you can go very far lateral so that you see both nerve roots and so you also can determine the midline at the posterior part. You see one nerve root you see on the other side the other nerve root and so you cannot miss of course it was a complicated case but if you see both nerve roots you can also determine the midline in the posterior part. And now while you have seen these screws in the midline you can place the cage that it is midline and you also can place the blade. You see this is one straight line and so the plate is proper fixed. And we have talked about to remove the ventral spondylofacts because if the plate is too anteriorly it will not fix. Yes you have to put it really immediately at the vertebral body not at the spondylofites. And then we ask is it necessary or is it good to fill the cage and this was a case we operated on this two level in C4, C5, C5, C6 and we fill the cage with all the bone we harvest by removing the spondylofacts. It's not much but it's enough to fill the cage so we do not have to go to the iliac rest or something else. We use the bone we harvest so we have enough bone to fill it and this patient she got cervical discarnation three months after the first surgery and we did surgery in the next level and you see after three months there was an ossification of the cages so we go on to fill the cage with the bone. And we have spoken about the resection of the anterior spondylofatic prominences use the shortest plate that fits so you can prevent an adjacent segment disease. The x-ray during screw fixation may be helpful but we do not use it. If I do the incision before the incision I do an x-ray to not only have the point of the vertebral disc but also the direction yes and I put a needle like this parallel to the vertebral disc and so I choose my incision here and so I have a straight access to the disc and so as a rule the inferior screw mostly from straight down and the superior screw a little bit up and so you have these divergent screw direction in the saccital plane and in the axial plane they should also be divergent. There are probably no advantages of b-cortical screws but as said monocortical screws have to enter up at least 80% of the vertebral body depth and in case of unsatisfied fixation of the screws in vitro studies show that maybe the segment augmentation is more helpful than using these bigger screws, the so-called rescue screws.