The importance of preserving the coracoacromial ligament in reverse total shoulder.

Does Preservation of Coracoacromial Ligament Reduce the Acromial Stress Pathology Following Reverse Total Shoulder Arthroplasty?

These authors point out that acromial pathologies (AP), such as acromial stress reaction (ASR), acromial stress occult fracture (ASOF), and acromial stress fracture (ASF), are known as complications that compromise the outcome for patients having reverse total shoulder arthroplasty (RSA). 

They point out that the coracoacromial ligament (CAL) distributes the stress on the acromion.

In 265 patients, they investigated the incidence of AP according to the preservation (68) or sectioning (197) of the CAL.

ASR and ASOF were identified through symptoms and ultrasound, and ASF identified through simple radiograph or computed tomography. 

In the 197 patients with CAL sectioning 

there were 21 cases of ASR(10.7%), 28 cases of ASOF (14.2%),10 cases of ASF (5.1%), and 59 cases of total AP (29.4%). 

In the 68 cases with preservation of the CAL 

there were 2 cases of ASR (2.9%) , 6 cases of ASOF (8.8%), 1 case of ASF (1.5%), and 9 cases of total AP (13.2%). 

Comment: These clinical results are consistent with the results of a recent cadaver study:

Scapular Ring Preservation: Coracoacromial Ligament Transection Increases Scapular Spine Strains Following Reverse Total Shoulder Arthroplasty

Stating that the coracoacromial ligament (CAL) is often transacted during surgical exposure for reverse total shoulder arthroplasty (RSA), these authors hypothesized that the CAL contributes to the structural integrity of the “scapular ring” and that the transection of this ligament during RSA alters the scapular strain patterns in a way that may contribute to scapular fractures following this procedure.

They performed RSA on 8 cadaveric specimens and measured strains at the acromion and scapular spine before and after CAL section while a shoulder simulator positioned the joint in 0, 30, and 60 of glenohumeral abduction.

With the CAL intact, there was no significant difference between strain experienced by the acromion and scapular spine at 0, 30, and 60 of glenohumeral abduction. 

CAL transection generated significantly increased strain in the scapular spine at all abduction angles compared with an intact CAL. 

They concluded that the  CAL is an important structure that completes the “scapular ring” and therefore serves to help distribute strain in a more normalized fashion. 

Comment: In his 1934 book, E. A. Codman wrote prophetically, "The coracoacromial ligament has an important duty and should not be thoughtlessly divided at any operation."

We have not found it necessary to divide the CAL "at any operation." Not only is it a halyard stabilizing the scapular spine and acromion to the robust coracoid process, as suggest by this study, but it is also an essential element of the stabilizing coracoacromial arch.

which, when sacrificed, risks anterosuperior escape

which, in turn, is one of the reasons for performing a reverse total shoulder. 

So, we agree with Codman, "The coracoacromial ligament has an important duty and should not be thoughtlessly divided at any operation."

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How you can support research in shoulder surgery Click on this link.

Here are some videos that are of shoulder interest

Shoulder arthritis - what you need to know (see this link).

How to x-ray the shoulder (see this link).

The total shoulder arthroplasty (see this link).

The ream and run technique is shown in this link.

The cuff tear arthropathy arthroplasty (see this link).

The reverse total shoulder arthroplasty (see this link).

The smooth and move procedure for irreparable rotator cuff tears (see this link).

Shoulder rehabilitation exercises (see this link).

Don't cut the coracoacromial ligament! (Codman)

Scapular Ring Preservation: Coracoacromial Ligament Transection Increases Scapular Spine Strains Following Reverse Total Shoulder Arthroplasty

Stating that the coracoacromial ligament (CAL) is often transacted during surgical exposure for reverse total shoulder arthroplasty (RSA), these authors hypothesized that the CAL contributes to the structural integrity of the “scapular ring” and that the transection of this ligament during RSA alters the scapular strain patterns in a way that may contribute to scapular fractures following this procedure.

They performed RSA on 8 cadaveric specimens and measured strains at the acromion and scapular spine before and after CAL section while a shoulder simulator positioned the joint in 0, 30, and 60 of glenohumeral abduction.

With the CAL intact, there was no significant difference between strain experienced by the acromion and scapular spine at 0, 30, and 60 of glenohumeral abduction. 

CAL transection generated significantly increased strain in the scapular spine at all abduction angles compared with an intact CAL. 

They concluded that the  CAL is an important structure that completes the “scapular ring” and therefore serves to help distribute strain in a more normalized fashion. 

Comment: In his 1934 book, E. A. Codman wrote prophetically, "The coracoacromial ligament has an important duty and should not be thoughtlessly divided at any operation."

We have not found it necessary to divide the CAL "at any operation." Not only is it a halyard stabilizing the scapular spine and acromion to the robust coracoid process, as suggest by this study, but it is also an essential element of the stabilizing coracoacromial arch.

which, when sacrificed, risks anterosuperior escape

which, in turn, is one of the reasons for performing a reverse total shoulder. 

So, we agree with Codman, "The coracoacromial ligament has an important duty and should not be thoughtlessly divided at any operation."

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To see a YouTube of our technique for a reverse total shoulder arthroplasty, click on this link.
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How you can support research in shoulder surgery Click on this link.

We have a new set of shoulder youtubes about the shoulder, check them out at this link.

Be sure to visit "Ream and Run - the state of the art" regarding this radically conservative approach to shoulder arthritis at this link and this link

Use the "Search" box to the right to find other topics of interest to you.

You may be interested in some of our most visited web pages  arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'

Association of bursal sided cuff degeneration with degenerative changes of the coracoacromial ligament

Grade of coracoacromial ligament degeneration as a predictive factor for impingement syndrome and type of partial rotator cuff tear.

These authors assessed 96 patients (mean age, 50.1 years [17-76]; 34 men, 62 women) diagnosed with bursal-side and articular-side rotator cuff tears with a history of failed conservative treatment and persistent shoulder pain who underwent arthroscopic surgery.

Normal appearance of the coracoacromial ligament (CAL) was  grade 0, minor fraying as grade 1, major fraying as grade 2, and visualization of the bare bone under the CAL as grade 3.

Most of the patients with articular-side tears demonstrated grade 0 and grade 1 coracoacromial ligament degeneration, whereas patients with bursal-side tears had grade 1 and grade 2. 

There was a significant positive correlation between the grade of coracoacromial ligament degeneration and bursal-side partial rotator cuff tears, whereas no correlation was observed with articular-side tears. 

There was no significant difference between bursal-side and articular-side partial cuff tears regarding acromioglenoid angle, supraspinatus glenoid angle, and subacromial distance.

The authors state that , "Although the factors that are purely related to articular side partial tears are poorly understood, its inconsistency with CAL degeneration in the current study suggests that ... subacromial impingement is not an etiologic cause of articular-side tears."
Comment: While this research shows the association of CAL degeneration with bursal sided cuff deterioration, it does not necessarily clarify the cause of either.

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Consultation for those who live a distance away from Seattle.

Use the "Search" box to the right to find other topics of interest to you.

You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'

See from which cities our patients come.

See the countries from which our readers come on this post.

The stabilizing effect of the coracohumeral ligament - the science behind the rotator interval plication

The anatomy of the coracohumeral ligament and its relation to the subscapularis muscle.

One of the keys to achieving a balance between mobility and stability in shoulder arthroplasty is understanding the role of the coracohumeral ligament and the rotator interval.

On the basis of their anatomical studies, these authors concluded that the coracohumeral ligament (CHL) originated from the horizontal limb and base of the coracoid process (C) and enveloped the cranial part of the subscapularis muscle (SSC) as well as the anterior aspect of the supraspinatus (SSP). As such it "seems to function as a kind of holder for the subscapularis and supraspinatus muscles".

Comment: This article further reinforces the role of the superior aspect of the shoulder capsule, the coracoacromial ligament and rotator interval in shoulder stability. By holding the inseritional tendons to this anchoring point, translation of the humeral head (HH) with elevation of the arm is controlled. When this mechanism is deficient, a rotator interval plication can restore this function. We have found that rotator interval plication is a powerful tool for managing excessive posterior translation in shoulder arthroplasty.

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Consultation for those who live a distance away from Seattle.

Check out the new Shoulder Arthritis Book - click here.

Click here to see the new Rotator Cuff Book

To see the topics covered in this Blog, click here

Use the "Search" box to the right to find other topics of interest to you.

You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'

See from which cities our patients come.

See the countries from which our readers come on this post.

To see other similar posts, click on the label of interest below.