Yes,
Way back in 1928 Meyer published a fair bit on the biceps.
One of the things he published was a small bony irregularity on the lesser tubercle side of the proximal intertubercular groove.
This is hypothesised to be a point of tension and if it is irregular a cheese grater effect on the LHBT which may lead to a tear at this level.
I have never seen a LHBT fail leaving a stump which corresponds to this location so either it is very rare or many have seen me, but I have not seen them!
What I see every week is 2 types of LHBT failure.
1: Complete tear of the LHBT from the superior labral origin with preservation of the biceps vinculum. In these cases the biceps is absent in the area of the rotator cuff interval, but it is present in the intertubercular groove and there is a moderate degree of the LH biceps muscle belly atrophy.
2: Complete tear of the LHBT from the superior labral origin with failure of the biceps vinculum. In these cases the biceps is absent in the area of the rotator cuff interval and also absent in the interterbercular groove. There is a more severe degree of the LH biceps muscle belly atrophy.
Rarely I see proximal MTJ failures of the LHBT,
I have never seen the tear you describe, but as I said it doesn’t mean it hasn’t seen me !!!
Your radiologist sounds excellent and very well read.
Steve