Hi Jonathan,
Great to hear from you,
We do our hip joint injections in the long axis of the femoral neck aiming for the femoral neck / head junction area as you describe,
I agree the capsule is sometimes a bit tricky to pinch and some rotation of the bevel is helpful to make sure you are in the joint.
The major vessels are not a problem as they are well medial to the scan plane we use, however there is a small vessel (lateral femoral circumflex artery) that is see n in the short axis and is almost always in the area close to the needle path.
If you aim a bit more proximal on the femoral head you will be injecting on the cartilage and I am not convinced the joint capsule is any easier at this site.
I have never seen someone use the lateral approach you suggest but I think it is worth some thought.
If the patient has lateral hip adiposity (which is common in my case mix) I think it is not a great option, however if the lateral hip adiposity is less it may be a great option.
I would locate the gluteus minimus tendon on the anterior facet in the long axis and then follow it proximal until you see the glut med sitting on glut min sitting on the lateral joint capsule which is our target.
There is a superior gluteal nerve running in the fascial plane between between glut min and med which you can not see that might be an issue with this approach.
There is another alternative where you scan the femoral neck in the long axis then turn the transducer transverse. You know where the joint capsule is and pass the needle from lateral to medial under the rectus femoris tendon / MTJ area to the anterior aspect of the femoral neck into the joint.
Find the part of the femoral neck in the long axis that is adjacent to the femoral head, spin short axis and approach lateral to medial as flat as you like so you see the needle well.
This works well and you have great needle visulalisation.
The femoral artery is medial so it does not come into play.
have a go !
Steve.