Hi David,
for sure I have some tips.
When the long head of biceps tendon ruptures it comes off at the proximal Cabral origin in nearly all cases.
Once the injury occurs 2 patterns may develop.
In the inter tubercular groove there is a collagen structure called the vinculum which connects the long head of biceps tendon to the bone in the groove. This structure is quite strong and often supports the tendon in the groove.
You will see in the shoulder material that I do a short axis image in the groove and another on top of the humeral head at the level of the rotator cuff interval.
When the biceps is ruptured and the vinculum is intact the groove image may look remarkably normal, however the rotator cuff interval image will show the biceps tendon being absent.
The next image i do is the “butterfly” image which is lower at the level of the muscle bellies just distal to the sternal head of pectorals major insertion to the humerus. In this image the long head muscle will be smaller and more echogenic when compared to the short head of biceps muscle belly. The long head muscle is on the lateral aspect, short head on the medial aspect and the muscle deep to them is coracobrachialis with the musculocutaneous nerve also seen.
This “butterfly” image and muscle atrophy helps to make the diagnosis.
It emphasises the need to look at the full length of the tendon and the muscle belly as well. I use this principle everywhere.
The other option is that the trauma was more dramatic and in these cases the vinculum also fails. In these cases you will not see a tendon in the groove OR at the rotator cuff interval and the butterfly image will show marked muscle atrophy of the long head muscle.
The clinical picture is interesting. If the vinculum remains intact the clinical picture can be remarkable normal. If the vinculum fails the patient will have the classic “popeye” deformity.
Some surgeons use the vinculum when they perform a biceps tenodesis and they don’t bother with an anchor, simply using the vinculum to maintain biceps support.
I think many cases of biceps rupture with intact vinculum go undiagnosed on ultrasound. If you use the methods I have described you will get the diagnosis right every time.
Steve