Non-tendinous healing after repairing of retracted rotator cuff tear- An Imaging Study
These authors note that follow-up magnetic resonance imaging (MRI) after rotator cuff repair can sometimes demonstrate healing with non-tendinous tissue that extends from the footprint to the retracted tendon end, which is inferred as fibrous tissue formation. They investigated 494 cases of superior medium- to massive-sized rotator cuff repairs that had healed as assessed by ultrasound.
MRI appearances were classified as
Type I=direct ‘healing’ of the tendon to the footprint (22%)
See below. A T1-weighted image shows the direct ‘healing’ of the tendon end (Type 1), but a narrow band of increased signal persists between the reattached tendinous end and the bone(red arrow).
Type II=continuity of non-tendinous tissue from the footprint to the retracted tendinous portion (54%)
See below. A T1-weighted image shows Type II healing with the portion of ‘non-tendinous’ tissue continuity without attenuation (red arrows), with the darker/black tendinous end that seemed to have retracted medially (yellow arrow).
Type III=a similar appearance but with obvious thinning of the tissue (24%)
See below. A T1-weighted image demonstrates Type III ‘non-tendinous’ healing with attenuation of the tissues (red arrows). The darker/black tendinous end that had retracted medially is even more obvious (yellow arrow).
Comparing the preoperative tendon retraction, 34.8% and 37.2% of the Patte stages 2 and 3, respectively, resulted in Type III healing, which were significantly higher compared to that of the stage 1 (15.3%, P<0.001).
The Type III had the highest average preoperative Goutallier grades.
The average postoperative VAS and the ASES scores improved significantly for all three groups, with the ASES being 86 for Type I, 94 for Type II, and 88 for Type III.
The authors concluded that only a fifth of the rotator cuff repairs led to the direct ‘healing’ to the footprint, and the rest healed with the MRI appearances of non-tendinous tissue formation bridging between the retracted tendinous portions and the footprints. These MRI appearances did not represent the true tendinous tissue formation between the torn end of the tendon and the bone after the tendon had healed as assessed by ultrasound.
These findings are consistent with a prior report: Failure With Continuity in Rotator Cuff Repair "Healing" The American Journal of Sports Medicine (ASJM) published this most interesting study of 13 patients having arthroscopic cuff repairs. The repaired tendon defects were 1-4 cm full thickness tears of the supraspinatus and/or infraspinatus with less than 2 cm of retraction, i.e. these were tears that were relatively small and reparable.
It is worth pondering why this retraction might occur. When we look a chronic cuff defect, such as the one below, there is loss of some of the length of the torn tendon due to resorption and retraction. Thus in order to approximate the torn edge to the footprint at the tuberosity, we place the repaired tendon under greater tension than the intact tendon on either side of it. Therefore, with either static or dynamic loading the pull of the cuff muscles is preferentially applied to the repaired tendon. This would tend to accentuate the problem of suture tension overload encountered during recovery. Perhaps if the resulting creep of the tendon away from the repair site took place at a slow rate, it would allow the body to 'backfill' the resulting gap resulting in 'failure with continuity'.
On reflection of all of the above, it seems that a stress relaxation hypothesis may be consistent with the observations.
Consider this diagram of a cuff tear where the orange part of the cuff has pulled away from the blue tuberosity leaving the red portions of the cuff intact.
MENDING WALL
Robert FrostSomething there is that doesn't love a wall,
That sends the frozen-ground-swell under it,
And spills the upper boulders in the sun,
And makes gaps even two can pass abreast.
The work of hunters is another thing:
I have come after them and made repair
Where they have left not one stone on a stone,
But they would have the rabbit out of hiding,
To please the yelping dogs. The gaps I mean,
No one has seen them made or heard them made,
But at spring mending-time we find them there.
I let my neighbor know beyond the hill;
And on a day we meet to walk the line
And set the wall between us once again.
We keep the wall between us as we go.
To each the boulders that have fallen to each.
And some are loaves and some so nearly balls
We have to use a spell to make them balance:
'Stay where you are until our backs are turned!'
We wear our fingers rough with handling them.
Oh, just another kind of out-door game,
One on a side. It comes to little more:
There where it is we do not need the wall:
He is all pine and I am apple orchard.
My apple trees will never get across
And eat the cones under his pines, I tell him.
He only says, 'Good fences make good neighbors'.
Spring is the mischief in me, and I wonder
If I could put a notion in his head:
'Why do they make good neighbors? Isn't it
Where there are cows?
But here there are no cows.
Before I built a wall I'd ask to know
What I was walling in or walling out,
And to whom I was like to give offence.
Something there is that doesn't love a wall,
That wants it down.' I could say 'Elves' to him,
But it's not elves exactly, and I'd rather
He said it for himself. I see him there
Bringing a stone grasped firmly by the top
In each hand, like an old-stone savage armed.
He moves in darkness as it seems to me~
Not of woods only and the shade of trees.
He will not go behind his father's saying,
And he likes having thought of it so well
He says again, "Good fences make good neighbors."
