 Okay so hi everyone my name is Vasili Shishkin and today I'm going to be talking about planning orthopedic surgery with Blender. So I must give a little warning at first that the presentation contains some graphic images that some viewers may find disturbing so if you're not feeling yourself comfortable watching a human flesh blood and bone I would advise you to refrain from a couple of words about myself I'm a Blender user since 2013 but I'm not a developer I'm not an artist I'm an orthopedic surgeon I work at the Central Clinical Hospital of the Russian Academy of Sciences in Moscow and I'm currently carrying out a research project on 3D surgery planning. Some words about orthopedic surgery it's a branch of surgery that deals with the disorders of the musculoskeletal system that is ruptures of the muscles, tensons, and the ligaments and the problems with bones such as bone fractures and bone deformities that can be congenital that means that they are inborn or the post-traumatic ones meaning that the male unit when a fracture occurs and heals in an incorrect position so today we're going to be talking about bone deformities. The preoperative planning is an initial stage in every surgery it gives the assessment of X-ray images of the deformed bone to define the stages of surgery and the needed amount of the correction to be made and also to choose the correct implant. The conventional way of planning surgery is pretty straightforward you make an X-ray and take the measurements with the stuff you have the rulers protractors and then you make a decision about the surgery. It's pretty simple and fast but it's quite inaccurate and it depends on the experience of the surgeon because when you see a male unit deformed the bone you really have to imagine how that bone looks like in a healthy way and that's quite hard and it's 2D so it doesn't give much information about it so having done some conventional surgery planning I decided that there's a need of a technology to perform preoperative planning in patients with the use of 3D reconstruction of the skeletal system for the improvement of surgery so that's when I came upon Blender with the advantages that we all know but what was more important for me there was 3D and computer graphics software it was not CAD software it didn't have all the complicated instruments for measurements engineering measurements to be made because in medicine there is no need for really high accuracy everything is quite relative well humans are not machines so we start out by making a CT scan of the specific body region and then we use the divide that's software from Netherlands the Delft Technical University to convert the CT scans into 3D surface models that we use later on in Blender the invaluable advantage of the human body is the bilateral symmetry of the organism meaning that the left part of the body looks like the right part of the body it's just that it's flipped and so by making two CT scans of the affected arm or leg and the healthy one and by mirroring the healthy one in Blender we can get a 3D model that can be an ideal template for the reconstruction and so this is the picture showing the green one is the model of a healthy bone and the red one that's the deformed bone by matching of the parts that look alike we can see that the deformity steps out over here so the red part sticking out is telling us that there's something wrong here we have to address that spot later on so after finding the level of the deformity we can define the osteotomy plane that is the bone cut so when a bone heals in an incorrect position it's obvious that if you want to make it straight again you have to cut it so we can choose the necessary level and the angle of the cut and then by using of the 3D model of the healthy bone we reposition the bone fragments upon the healthy model on the left you see the repositioning process on the right we remove the template and we can then address the model that has the new model we can assess the defect over here and choose the correct type of bone implant to fill in the void and we actually can use 3D models of implants to select which implant really suits the patient we're using 3D scan models of plates and screws of different types and this gives us an understanding of the correct positioning of the implant to avoid the conflict with the fixator and the surrounding tissues and after making these calculations in blender we somehow need to get them into surgery into the wound itself and so that's when we use 3D printing by making patient specific drill guides and osteotomy wedges for performing correction osteotomies so that's what I'm going to be talking about later so a clinical case a female 42 years old sustained an open fracture of the left tibial and femur bones that's in the leg in a rhodax in about 15 years ago and she underwent multiple surgeries in an external elizara fixator that's the thing that you see on the top picture a bulky metallic structure that sticks out of the leg and holds the bone fragments in place she was actually wearing this for two times for a year each and she was really unhappy with that and after the removal of that fixator she noted the formation of the deformity in the leg and two years before coming to us she started to experience pain in the left ankle and the knee joints so this is how her leg looked like before surgery you can see that it's pretty crooked on the photograph and on the x-ray I don't know if it's seen on the screen but there's a deformity over here and down here now those of you who think that the deformity should be corrected above the knee can I ask you to raise your hands just looking at the x-ray over here okay two two people and those of you who think that the problem is down here okay that's more well actually my colleagues all of my colleagues thought that the deformity was below the knee but that was not actually true so we made the 3d planning and by matching of the tibial bones below the knee we found out that the tibia seemed quite fine it was quite well aligned but at the same time by matching of the femur you can see here that the red part that's the fracture bone sticks out and we can define the level of the deformity and then zooming in we made some planes to define the correct angle the angulation it was about 13 degrees and so we decided to make a correction over here now this is a video showing so we just cut the mesh in blender and realign the deformed bone against the healthy one having removed the template you see the bone gap that needs somehow to be filled so we made a spacer a 3d model of a spacer now you can see the leg is pretty straight made a 3d spacer that were later printed in a 3d printer that's shown in orange over here and then we made a bone substitute artificial bone substitute that we put in the bone and the shape of the substitute was made according to this shape of the spacer so we made the osteotomy cut the bone put the wedge inside and then fixed it all with a plate so this is a post operative x-ray everything looks straight looks good and that's how her legs looked after that they're straight the patient was quite satisfied she started walking normally again she started to wear high heels skirts she wasn't able of doing that for the last 15 years and in fact she was so happy then in about six months she came back to have her nose correction surgery done okay another clinical case mal united distal radius there's a severe problem over here so the patient underwent two surgeries but her arm wasn't good she came to us we made the 3d planning protocol and blender we much matched the plates and we chose the bone spacer to be used and then we designed a specific patient specific drill guide that would fit on the bone so by using Boolean operations we made this strange looking model and once again printed it on a 3d printer and on the top image you see this piece of plastic on the bone it snaps just right in according to the bone anatomy down here we drill the holes that we we pre-drill the holes for the plate the next picture over here you see the things sticking out the wires sticking out they define the position of the holes and the next thing we do we just cut the bone at the place specified and put the screws in the predefined holes and the correction goes away I mean the deformity goes away itself so you just screw the plate in and you get a straight bone there's no need to calculate anything there's no need to measure the length or the angles so everything looks pretty good and in this case we put a bone transplant between the bones the her own bone and she was also happy so we have some issues that we have to address human anatomy is quite unique and when we're talking about 3d models we have to address the mesh because the mesh is really complex and we cannot really do it more simple by using decimation because we will lose the accuracy and the hard thing about it is matching of the corresponding parts of the bone and this is done manually and it's quite difficult quite tedious I was looking for a script for automatic model alignment but had no luck finding it so if you have any idea of how this can be done I would be really grateful for help so please contact me I'll have my details later but anyway we're trying to get things done manually at the moment it works out and so for conclusion the 3d preoperative planning protocol gives the surgeon a better understanding of the deformity allows to try out 3d virtual surgery before carrying out the actual one enhances precision of real surgery and reduces guesswork and reduces time of surgery and interoperative radiation is exposure and of course none of this would be possible without blender thank you for your attention any questions yeah sure is yet yep hi I make it off I can imagine that this is very it comes very in handy and you could use it for almost any surgery you bone surgery you want but how to account for nerves and tendons and such within that area because those aren't showing up in the blender model yeah that's right we're working with models of bones as orthopedic surgeons and CT scan gives us the information about the bones if you want to address the nerves and the tendons that's the MRI scan that's something different but this is not actually a big problem because they are soft tissues so if you correct the bone alignment they will well somehow have the right position I mean we didn't encounter any problems with soft tissues so no so no for example the woman with the leg no problems with the tendons there that they were too short or no no well she was a bit uncomfortable for the first three months but then again the human body has good adaptation mechanisms so she's quite fine now okay any else that's okay yeah which software do you use to do the segmentation of the images and I imagine you segment the images then to reconstruct to do the 3d reconstruction are we use the divide software that's from Delft Technical University there are numbers of the programs but this is the one that we use there's also a mirror software but there's a bunch of them and they are pretty open source and free okay anyone else okay thank you