Fooled by Ruptured Biceps Tendon

[David Smith]

Hi Stephen,
I had a recent case where I could not detect pathology, and when I did an MRI it showed rupture of the proximal tendon of LH biceps. When I reviewed my images, it seemed like I was fooled by the presence of scar tissue in the intertubercular groove. Any tips on not mistaking scar tissue for a LH biceps tendon still in the groove?
Thanks,
Dave

[Stephen Bird]

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

[Diane]

Hi Steve!

With patients with a ruptured biceps tendon but intact vinculum, do you see any muscle atrophy with these or do you only see muscle atrophy for ruptured biceps tendon and failed vinculum?

Thanks!

[Stephen Bird]

Hi Diane,

You see muscle atrophy changes in both subgroups.

It is more dramatic if the vinculum fails, but present in both groups.

Steve

[Diane]

Do you ALWAYS see muscle atrophy in these subgroups (both acute and chronic situations) or is it only in chronic cases? Or how long would it take to see muscle atrophy generally?

Thanks again!

[Stephen Bird]

I don’t think you see it immediately after the injury, but the onset is fairly rapid and after a few weeks it is present.

In the acute setting we have other clues like an effusion / haematoma.

Steve

[Diane]

Hi Steve,
Just had another patient recently – he claimed to have tendon reattachment 10 years ago, unsure if the rotator cuff or biceps tendon but presented with pain after flicking away a leaf.

There was no biceps seen in the rotator cuff interval so I thought the tendon was torn from the proximal end. When I did the image of the biceps muscle belly however, there was no atrophy. There was what seemed to be haematoma in the proximal vinculum.
What I was suspecting is that he had a past biceps tenotomy/tenodesis within an intact vinculum and haematoma associated with the patient presentation?

What are your thoughts? Also the picture I labelled, is that the typical appearance of what a biceps reattachment site is?

Thanks!

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[Stephen Bird]

This is nice,

Must have been a heavy leaf!

I think I can see suture material in the retracted biceps tendon and the suture material is no longer tight.

What I think has happened is they have had a biceps tenodesis previously and the acute injury has caused the tenodesis to fail.
I think it was a tenodesis with a bone anchor as this will explain the suture material.
there is a small fleck of bone which mat have possibly come off causing the tenodesis failure.
In the biceps sheath there is retracted tendon / suture and haematoma.

The vinculum may actually still be intact as they would have left that at the time of the tenodesis and this could explain why there is no popeye muscle and also only minor muscle belly atrophy. I do think the long head belly is a bit smaller than the short head.

I think the area you have suggested for the tenodesis does look correct.. There are different techniques used, some sub-pectoral, some in your location just on the edge of the groove and some they don’t bone anchor at all, simply leaving the vinculum for support.

Steve

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