Most people tend to under-rotate, rather than over-rotate due to limited mobility, lack of flexibility, not enough hip rotation, etc. You can also keep in mind (using your x-ray vision) that the knee is a hinge joint, so if you can visualize the hip, knee and ankle bending at one point-the knee, all three joints should be in the same plane - look for elevation of the knee compared to hip and ankle and try to make them parallel to the table. I hope this helps!
No problem... they can still be tricky because patient size can alter the appearance of the knee. If you bend down to look at the knee (once in a lateral position), you should see a small space between the patella and the table-top, so it's good that you're using the sponge to prevent over-rotation. To prevent under-rotation, I recommend using a sponge underneath the foot of the affected side. See additional comment...
Thanks for the comment k24boy123... the superimposition I'm speaking of was referring to the posterior borders of the femoral condyles. In context, it's absolutely possible to acquire better superimposition, and we all know that the side up will be slightly larger as every radiograph will display some evidence of magnification. If any of my students are reading this, DON'T use the "eyeball" method. I'll grade you off for that! Also, no need to superimpose hips to get a good lateral knee.
amazing! in my year of clinical training, no one could explain how and why to correct things(well, hardly ever) Do u have more corrections i can watch like this? This is what you should write a book on. I'm about to start my first xray job:)
What if there is too much tube angle? I am in the latter park of my clinical externship and have my hands on every patient at this moment. However I work with many different techs that have their own strategies and techniques. There was a large gal, and I thought to put 10 degrees cephalid and it still showed the magnified medial condyle distally as shown in your insufficient tube angle pics. The tech thought it was TOO much angle and i repeated closer to 5 degrees. It was still about the same but maybe "slightly better" according to her. Can you help me with images or possiblities of too much tube angle? Thanks.
Hi Jeremy! Can you do a video on 30 60 90 patella views? We know to flex the knee at those different angles. It is necessary to angle the tube as well for the tangential projection, correct?
Can you clarify what you mean by "30 60 90 patella views"? Are you just talking about the amount of knee flexion, rotation, or something else? There are numerous ways to perform the tangential projection, but you must always angle the tube related to how much the knee is flexed.
Yes. The doctor wants the knee flexed in these different angles. The doctor just replied, "flex the knee OR angle the tube" when we asked what he wanted. Is there a way to keep the knee in a fixed position and angle the tube or the detector?
We have been acquiring 3 different images with the knee in 30 60 & 90° flexion. We're angling the tube as needed. Someone suggested angling the detector at those degrees.Do you think we could just angle the detector at 30 60 & 90° and achieve the same result?
@@Afrancis2774 Regardless of how much flexion the knee is in, you'll need to have the x-ray tube near the foot to where the beam skims the proximal tibia and the CR is centered at the space between the tibia and patella.
X-rays are not the most ideal way to see ligaments and tendons. There are ways to perform soft tissue x-rays, but MRI would be the modality of choice to look at those.
Very helpful!! Thanks for that tutorial. Yeah 2 fingers underneath patella and 4degrees cephalic angle usually works for me. In horizontal ray lateral knee, x-ray beam enters from lateral end to medial end of the knee therefore slight angle downtilt is commonly used. However I still struggle with getting a good one, what I usually do is to slide a small sponge underneath the knee and use a straight tube perpendicular to the knee joint. Any tips??
Sorry to tell you, but your phantom has been put together incorrectly. The lateral knee should have the head of the fibula showing clear of the tibia and part of this articulation showing. This becomes my only guide to correcting a failed lateral. Always an uptilt of about 5 degrees. Flex the knee and it will be easier to get the anatomy correctly orientated.
In the lateral view, flexing/extending would not allow you to visualize between the femur and patella any more. Only rotating the knee would accomplish that if you are not in a true lateral position. Flexing/extending would only glide it inferior/superior.
I just wanna share this....Everytime I jump,ran and walk something is just happening on my knee.It feels like something just slides down and go back up....So can you tell me how to solve this problem of mine,or you can just tell me some tips on making my knee firm and strong
Unfortunately, I'm not a medical doctor... I can tell you how to position and evaluate x-rays all year long, but it's beyond my scope to provide you with medical advice.
This was so incredibly helpful! I was still having such a hard time grasping this in my second year, and this totally cleared it up. Thank you!!
Glad it was helpful!
I can not thank you enough! Very informative! You answered every pressing question I had!
Most people tend to under-rotate, rather than over-rotate due to limited mobility, lack of flexibility, not enough hip rotation, etc. You can also keep in mind (using your x-ray vision) that the knee is a hinge joint, so if you can visualize the hip, knee and ankle bending at one point-the knee, all three joints should be in the same plane - look for elevation of the knee compared to hip and ankle and try to make them parallel to the table. I hope this helps!
Knee is more like Temporomandibular joint - it is a bicondylar joint. Whereas Elbow is more of "hinge" joint
No problem... they can still be tricky because patient size can alter the appearance of the knee. If you bend down to look at the knee (once in a lateral position), you should see a small space between the patella and the table-top, so it's good that you're using the sponge to prevent over-rotation. To prevent under-rotation, I recommend using a sponge underneath the foot of the affected side. See additional comment...
Thanks for the comment k24boy123... the superimposition I'm speaking of was referring to the posterior borders of the femoral condyles. In context, it's absolutely possible to acquire better superimposition, and we all know that the side up will be slightly larger as every radiograph will display some evidence of magnification. If any of my students are reading this, DON'T use the "eyeball" method. I'll grade you off for that! Also, no need to superimpose hips to get a good lateral knee.
Excellent explanation and very practical advice!
That's a great tip... I wish I could get all the tips I have heard and make some videos just on those - plenty of material there.
amazing! in my year of clinical training, no one could explain how and why to correct things(well, hardly ever) Do u have more corrections i can watch like this? This is what you should write a book on. I'm about to start my first xray job:)
Knee x-ray! Thanka for sharing. I am a doctor andI love to watch and upload medical videos.
Good sir
Plz contact with me sir i am from pakistan watsapp no ....03129891395
@@abdulazizkhano..official5369 Yes? What help do you need?
This was extremely helpful, thank you!
glad it was helpful... did this one almost 10 years ago! horrible audio/video quality, LOL
Wonderful video!! I would love to see one of rotation analysis for the oblique knee projections as well.
This video really helped me out a lot btw. Thank you!
What if there is too much tube angle? I am in the latter park of my clinical externship and have my hands on every patient at this moment. However I work with many different techs that have their own strategies and techniques. There was a large gal, and I thought to put 10 degrees cephalid and it still showed the magnified medial condyle distally as shown in your insufficient tube angle pics. The tech thought it was TOO much angle and i repeated closer to 5 degrees. It was still about the same but maybe "slightly better" according to her. Can you help me with images or possiblities of too much tube angle? Thanks.
Hi Jeremy! Can you do a video on 30 60 90 patella views? We know to flex the knee at those different angles. It is necessary to angle the tube as well for the tangential projection, correct?
Can you clarify what you mean by "30 60 90 patella views"? Are you just talking about the amount of knee flexion, rotation, or something else? There are numerous ways to perform the tangential projection, but you must always angle the tube related to how much the knee is flexed.
Yes. The doctor wants the knee flexed in these different angles. The doctor just replied, "flex the knee OR angle the tube" when we asked what he wanted. Is there a way to keep the knee in a fixed position and angle the tube or the detector?
We have been acquiring 3 different images with the knee in 30 60 & 90° flexion. We're angling the tube as needed. Someone suggested angling the detector at those degrees.Do you think we could just angle the detector at 30 60 & 90° and achieve the same result?
@@Afrancis2774 Regardless of how much flexion the knee is in, you'll need to have the x-ray tube near the foot to where the beam skims the proximal tibia and the CR is centered at the space between the tibia and patella.
@@Afrancis2774 Angling the detector won't affect how much the joint space is open. You can always do that, but it will result in elongation.
If we want to see the ligament and tendons in the knee what to do ?
X-rays are not the most ideal way to see ligaments and tendons. There are ways to perform soft tissue x-rays, but MRI would be the modality of choice to look at those.
thank you, it may be more helpful if the angle between femur and leg 135 degree?
Brian Ramirez Yes... this was an exposure of a phantom, so I did not have the ability to flex the knee. It would help with rotation though!
good video
Very helpful!! Thanks for that tutorial. Yeah 2 fingers underneath patella and 4degrees cephalic angle usually works for me. In horizontal ray lateral knee, x-ray beam enters from lateral end to medial end of the knee therefore slight angle downtilt is commonly used. However I still struggle with getting a good one, what I usually do is to slide a small sponge underneath the knee and use a straight tube perpendicular to the knee joint. Any tips??
hello, somebody can tell me what is meaning of: OID . Thanks.
Object to Image Distance
Good stuff!!!
Sorry to tell you, but your phantom has been put together incorrectly. The lateral knee should have the head of the fibula showing clear of the tibia and part of this articulation showing. This becomes my only guide to correcting a failed lateral. Always an uptilt of about 5 degrees. Flex the knee and it will be easier to get the anatomy correctly orientated.
That's incorrect. The fibular head should be slightly superimposed by the tibia. Showing a clear head means you're too externally rotated.
@@osos231 this is correct
@@johnblunk2012 What is??
Need more image evaluation
At the moment, I am without access to my x-ray lab. I'm happy to critique any images that anyone would like to send me.
Would flexing the knee or extending it open the patella more?
In the lateral view, flexing/extending would not allow you to visualize between the femur and patella any more. Only rotating the knee would accomplish that if you are not in a true lateral position. Flexing/extending would only glide it inferior/superior.
@poncekid56 great tip!
I just wanna share this....Everytime I jump,ran and walk something is just happening on my knee.It feels like something just slides down and go back up....So can you tell me how to solve this problem of mine,or you can just tell me some tips on making my knee firm and strong
Unfortunately, I'm not a medical doctor... I can tell you how to position and evaluate x-rays all year long, but it's beyond my scope to provide you with medical advice.