Glenoid pathoanatomy: what about the B Walch types?

In his classic paper, Morphologic study of the glenoid in primary glenohumeral osteoarthritis, Gilles Walch identified the B1 and B2 glenoids as being common of types of arthritic glenohumeral pathoanatomy in patients presenting for anatomic shoulder arthroplasty. 

An important characteristic of these glenoid types is the posterior decentering of the humeral head on the glenoid, a critical element in the evaluation and management of glenohumeral arthritis.  Note that the degree of decentering was (and remains) defined by the relationship of the humeral head to the face of the glenoid (and not the plane of the scapula), as seen from this figure from his classic article.

The decentering of the head on the glenoid can be evaluated on the standardized axillary "truth" view, as shown in the five examples below.

By the "truth" view, we mean an axillary view obtained with the arm elevated in the plane of the scapula that shows the spinoglenoid notch or "eye" (red arrow) as shown in this Steve Lippitt illustration:

The rationale for evaluating decentering with the arm elevated to a functional position is that CTs or MRIs obtained with the arm at the side may not reveal it, as shown in the two images of the same shoulder shown below. The MRI obtained with the arm at the side does not reveal decentering, whereas dramatic posterior decentering is shown when the arm is elevated to a functional position in the axillary "truth" view.

While often considered together, the B1 and B2 are not the same. The B1 has posterior decentering of the humerus on the glenoid without biconcavity of the glenoid from bony erosion. By contrast, the B2 has posterior decentering of the humeral head on the glenoid with biconcavity of the glenoid as shown in these illustrations from the classic article by Walch.

A third B was added by the authors of A modification to the Walch classification of the glenoid in primary glenohumeral osteoarthritis using three-dimensional imaging.

As can be seen from these figures, the B3 is monoconcave (i.e. no biconcavity) with substantial retroversion and without posterior decentering of the humeral head on the glenoid, i.e. the humeral head is centered with respect to the glenoid.

This point is emphasized by the authors of Quantitative measurement of bony pathology in advanced glenohumeral osteoarthritis who use the term "humeral-glenoid alignment (HGA)" to indicate centering or decentering of the humeral head on the glenoid. HGA is measured as the position of the humeral head center relative to the perpendicular line drawn from the glenoid center point (without reference to the scapular axis). This relationship is shown in a figure from their article showing the centering of the humeral head in a B3 glenoid (i.e. the humeral head is not decentered).

How does all this relate to the practice of anatomic shoulder arthroplasty? A recent article, Why do primary anatomic total shoulder arthroplasties fail today? A systematic review and meta-analysis, is relevant. The authors reviewed a total of 44 studies involving 35,168 aTSA procedures; 2744 failures were identified. The three most prevalent types of failure were: 

(1) implant loosening (26.1%), with 21.7% of failures attributed to glenoid component loosening. 

(2) Rotator cuff insufficiency (17.3%).  

(3) Instability (10.4%) 

Another recent article compared the types of failure in the Kaiser and the Australian Orthopaedic Association databases.Early revision in anatomic total shoulder arthroplasty in osteoarthritis: a cross-registry comparison.

The most common reasons for revision in the AOA experience were instability/dislocation (31.1%), rotator cuff insufficiency (24.2%), and loosening/lysis and implant breakage glenoid insert (11.0% each). The most common reasons in Kaiser experience were rotator cuff tear (32.3%), glenoid component loosening (29.0%), and dislocation and infection (12.9% each). 

While these articles did not study the relationship of glenoid type to loosening or instability, we can venture that because B1 and B2 glenoids demonstrate preoperative posterior decentering, they would be at risk for postoperative instability. The B3, being centered preoperatively would seem less at risk for instability as long as the centering was not disrupted by the arthroplasty.

There are a number of approaches for shoulders with each of the different B types, each of which has its proponents, advantages and limitations. As emphasized in Short-term outcomes of anatomic total shoulderarthroplasty with nonaugmented glenoidcomponent for Walch B2 and B3 glenoidmorphology, all B's are not the same. In fact, each patient and their shoulder is a one of a kind combination. We like to say that each patient is an N of 1.

Here's an approach we commonly use for effectively and durably restoring stability and mobility. Note that usually we do not attempt to "correct" preoperative glenoid version (see Does postoperative glenoid component retroversion following anatomic total shoulder arthroplasty affect clinical outcomes? A systematic review and meta-analysis) and judge the need for an anteriorly eccentric humeral head based on intraoperative testing at surgery with trial components in place (see Management of intraoperative posterior decentering in shoulder arthroplasty using anteriorly eccentric humeral head components).

We start with Anatomic total shoulder - preoperative planning and intraoperative decision making, recognizing the different characteristics among the 3 Bs

B1 - conservative reaming without attempting to alter version, preserving glenoid bone stock, excellent carpentry to assure perfect seating of the component, and use of an anteriorly eccentric humeral head to manage excessive posterior translation if that is evident on intraoperative examination with a concentric trial humeral head component in place.

B2 - conservative reaming - just sufficient to convert the biconcavity to a mono concavity without attempting to alter glenoid version, preserving glenoid bone stock, excellent carpentry to assure perfect seating of the component, and use of an anteriorly eccentric humeral head to manage excessive posterior translation if that is evident on intraoperative examination with a concentric trial humeral head component in place.

B3 - conservative reaming without attempt to alter glenoid version, preserving glenoid bone stock, excellent carpentry to assure perfect seating of the component. An anteriorly eccentric humeral head component is rarely necessary because of the absence of preoperative decentering.

For additional information on this approach see:

Anatomic Total Shoulder Arthroplasty with All-Polyethylene Glenoid Component for Primary Osteoarthritis with Glenoid Deficiencies

Does Postoperative Glenoid Retroversion Affect the 2-Year Clinical and Radiographic Outcomes for Total Shoulder Arthroplasty?

Does glenoid version and its correction affect outcomes in anatomic shoulder arthroplasty? A systematic review

Anatomic total shoulder arthroplasty for posteriorly eccentric and concentric osteoarthritis: a comparison at a minimum 5-year follow-up

Glenoid retroversion does not impact clinical outcomes or implant survivorship after total shoulder arthroplasty with minimal, noncorrective reaming

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Spring 2021

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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 ream and run procedure (see this link)
The total shoulder arthroplasty (see 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).

Anatomic or reverse total shoulder arthroplasty for B2 and B3 glenoid pathoanatomy?

Severe glenohumeral osteoarthritis (GHOA) with posterior glenoid erosion remains challenging to address for shoulder surgeons, especially for glenoid types B2 and B3.

The authors of Anatomic Total Shoulder Arthroplasty with All-Polyethylene Glenoid Component for Primary Osteoarthritis with Glenoid Deficiencies evaluated 66 shoulders with type-B2 glenoids (n = 40) or type-B3 glenoids (n = 26) undergoing total shoulder arthroplasties with a non-augmented glenoid component inserted without attempting to normalize glenoid version. The component was inserted using a standardized technique (see this link) that minimized glenoid bone removal and optimized cementing and seating.

 
The Simple Shoulder Test score improved from

3.2 preoperatively to 9.9 postoperatively at a mean followup of 2.8 years for type-B2 glenoids 

and from 

3.0 preoperatively to 9.4 postoperatively at a mean followup of 2.9 years for type-B3 glenoids.

These results were not inferior to those for shoulders with other glenoid types. 

Postoperative glenoid version was not significantly different (p > 0.05) from preoperative glenoid version. 

The mean humeral-head decentering on the glenoid face was reduced 

for type-B2 glenoids from -14% preoperatively to -1% postoperatively

and for type-B3 glenoids from -4% preoperatively to -1% postoperatively. 

The rates of bone integration into the central peg for type-B2 glenoids (83%) and type-B3 glenoids (81%) were not inferior to those for glenoid types without posterior bone deficiencies. 

None of the total shoulders performed on shoulders with type-B2 glenoids or type-B3 glenoids required revision surgery. 

In spite of this high success rate with this approach to anatomic total shoulder arthroplasty (aTSA), some surgeons prefer reverse total shoulder arthroplasty (RSA) for B2 and B3 glenoids. 

The authors of Anatomic and Reverse Shoulder Arthroplasty for Management of B2 and B3 Glenoids: A Matched Cohort Analysis compared the clinical outcomes of patients with glenohumeral arthritis and Walch B2 and B3 glenoid morphologies treated with aTSA and RSA.

Patients undergoing aTSA were treated with "a standard cemented all-polyethylene glenoid component", however the types of glenoid component and insertion technique were not specified. By contrast, for RSA, all patients had similar implants(AltiVate Reverse). The RSA system includes a glenosphere designed to have a center of rotation lateral to the glenoid (diameter range of 32-40 mm and lateralized center of rotation range of 2-10 mm) and a humeral stem with a 135-degree neck-shaft angle.

Patients were matched 1:1 by sex, Walch classification, and age. However the mean followup for the RSApatients was over a year shorter (mean 47 months for aTSA and 31 months for RSA).

They observed no statistically significant difference between aTSA and RSA for the preoperative change in VAS pain score, SANE score,  ASES score, forward flexion, external rotation or internal rotation.

At a mean of 47 months followup 3 of 101 shoulders with aTSA had gross glenoid loosening.

At a mean of 31 months followup 2 of 101 shoulders with RSA had gross glenoid loosening.

At a mean of 47 months followup complications had occurred in 3 of 101 TSA cases: subscapularis failure, transient postoperative neuropathy, and a revision for infected prosthesis.

At a mean of 31 months followup complications had occurred in 4 of 101 RSA cases : postoperative acromion fracture, transient postoperative neuropathy, transient cubital tunnel syndrome, and revision for glenoid component loosening. 

Comment: While in the report above, primary RSA appeared to yield in largely comparable short-term outcomes compared to TSA in patients with Walch B2 or B3 glenoid morphology, the patients were not matched for length of followup: the aTSA group was followed for over a year longer than the RSA group.

As demonstrated the figure below, complications and revisions continue to increase after shoulder arthroplasty, so in comparing two types of arthroplasty it is important that the periods of followup for the two implants are comparable.

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link.

Follow on twitter: https://twitter.com/shoulderarth
Follow on facebook: click on this link
Follow on facebook: https://www.facebook.com/frederick.matsen
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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 ream and run procedure (see this link).
The total shoulder arthroplasty (see 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).

Augmented glenoid components for B2 and B3 glenoids

An augmented glenoid component is used by some surgeons in cases of posterior bone loss and retroversion.

Its insertion requires concentric reaming of the anterior glenoid

followed by the removal of additional posterior bone to fit the back of the selected component using either an oscillating rasp

or a superior/inferior scraper

The size of posterior augment ranges from 3 to 7 mm. The amount of bone removed in a case using a 7 mm augment is shown below.

The authors of Factors Associated with Functional Improvement After Posteriorly Augmented Total Shoulder Arthroplasty sought to identify pre- and postoperative factors that impact range of motion and function after augmented TSA in patients with B2 or B3 glenoid morphology.

An individual highly experienced shoulder surgeon performed 1,044 consecutive anatomic TSAs. Of these 88% were performed using a standard (non-augmented) glenoid component. 121 (12%) were performed with posteriorly augmented, stepped glenoid components; the indications for the use of an augmented component were not specified.

50 patients (57%)(41 B2 and 9 B3 glenoids) with minimum 2 year followup were included in the analysis. Two patients having posterior dislocation were excluded.

There was strong agreement among the observers for preoperative and postoperative glenoid version as measured on plain x-rays.

There was strong agreement for plain X-ray measurements of humeral decentering preoperatively and moderate agreement for this measurement postoperatively.

Range of motion was improved over preoperative values.  

Preoperative glenoid retroversion did not significantly affect the postoperative range of motion. 

Postoperative glenoid component retroversion and residual posterior subluxation relative to the scapular body or glenoid face did not correlate with range of motion in any plane.

Preoperative shoulder SANE and VAS scores were missing from this study. The mean postoperative VAS score was 0.5 and mean SANE score was 94.5  

Posterior subluxation relative to the glenoid face was moderately associated with lower SANE scores.

While the amount of posterior decentering of the humeral head was reduced from a mean of 21 percent before surgery to 3 percent after surgery, the amount of glenoid version was only changed by 7 degrees (24 degrees to 17 degrees).  

Comment: The questions needing answers are 

(1) how important is version correction to a value of 15 degrees or less as proposed by some authors?

(2) while it is evident that postoperative posterior decentering can lead to eccentric loading and rocking horse loosening of the glenoid component

is "correction" of glenoid version necessary for re-centering the humeral head on the glenoid?
(3) are the results of anatomic shoulder arthroplasty with a standard glenoid component for B2 and B3 glenoids inferior to those for glenoid types A1 or A2?
(4) are the clinical results of anatomic shoulder arthroplasty for B2 and B3 glenoids using an augmented component superior to those obtained with a standard glenoid component?

Some of the answers may be found in Anatomic Total Shoulder Arthroplasty with All-Polyethylene Glenoid Component for Primary Osteoarthritis with Glenoid Deficiencies.These authors sought to evaluate the ability of shoulder arthroplasty using a standard glenoid component to improve patient self-assessed comfort and function and to correct preoperative humeral-head decentering on the face of the glenoid in patients with primary glenohumeral arthritis and type-B2 or B3 glenoids. They identified 66 shoulders with type-B2 glenoids (n = 40) or type-B3 glenoids (n = 26) undergoing total shoulder arthroplasties with a non-augmented glenoid component inserted without attempting to normalize glenoid version and with clinical and radiographic follow-up at a minimum of 2 years.

Shoulder pathoanatomy was characterized on the axillary "truth" view in terms of glenoid version (angle between lines G and S) and humeral head decentering on the face of the glenoid (distance between line P - the perpendicular bisector of line segment G - and the center of the humeral head, C). Preoperative CT scans and computer planning software were not used in this case series.

This method allowed direct comparison of glenoid version and humeral decentering before and after the arthroplasty

The Simple Shoulder Test (SST) score improved from 3.2  points preoperatively to 9.9  points postoperatively at a mean time of 2.8 years for type-B2 glenoids and from 3.0 points preoperatively to 9.4 points postoperatively at a mean time of 2.9 years for type-B3 glenoids. These patient reported outcomes were as good as those achieved with other glenoid types.

These outcomes were achieved without changing glenoid version: postoperative glenoid version was not significantly different from preoperative glenoid version.

The humeral head centering on the glenoid was restored without the use of an augmented component: the mean humeral-head decentering on the glenoid face was reduced for type-B2 glenoids from 14% preoperatively to 1% postoperatively and for type-B3 glenoids from 4% preoperatively to 1% postoperatively.

The rates of bone integration into the central peg for type-B2 glenoids (83%) and type-B3 glenoids (81%) were not inferior to those for other glenoid types (A1 67%, A2 85%, B1 74%, D 75%).

Anterior penetration of the glenoid neck by the central peg of the glenoid component was observed in 2 (11%) of 19 of the type-B1 glenoids, in 6 (15%) of 40 of the type-B2 glenoids, and in 6 (23%) of 26 of the type-B3 glenoids. Perforation of the glenoid by the central peg was not associated with inferior clinical or radiographic outcomes. Twelve of the 14 shoulders with glenoid neck penetration had ingrowth of bone between the flanges of the central peg with no radiographic evidence of component loosening. The final mean SST score for the 14 shoulders with central peg penetration was 9.4 points, a value not significantly different from that for all of the type-B2 and B3 glenoids (9.7 points).

These minimum 2-year outcomes for 40 shoulders with type-B2 glenoids and 26 shoulders with type-B3 glenoids do not appear to be inferior to the minimum 2-year results reported recently for a combined group of 71 shoulders with type-B2 or B3 glenoid anatomy treated with posteriorly augmented glenoids inserted using preoperative CT scans and 3-dimensional planning software (see this link).

This study demonstrates that good two year clinical outcomes can be achieved for B2 and B3 glenoid components using a standard (non-augmented) glenoid component inserted without changing glenoid version.

Further clinical research will be required to establish clinical practice guidelines and appropriate use criteria for augmented glenoid components. 

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link.

Follow on twitter: https://twitter.com/shoulderarth
Follow on facebook: click on this link
Follow on facebook: https://www.facebook.com/frederick.matsen
Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

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 ream and run procedure (see this link).
The total shoulder arthroplasty (see 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).

B2 and B3 glenohumeral pathoanatomy - the stepped glenoid component

 Stepped Augmented Glenoid Component in Anatomic Total Shoulder Arthroplasty for B2 and B3 Glenoid Pathology A Study of Early Outcomes

These authors studied the use of a stepped augmented glenoid component for management of Walch B2 (n=29) and B3 (n=21) glenoids and compared the radiographic and clinical outcomes at short-term follow-up with those achieved with a non-augmented component of the same design in Walch A1 glenoids (n=42).

Sequential 3-dimensional (3D) computed tomography (CT) imaging was performed preoperatively, within 3 months postoperatively with metal artifact reduction (MAR) to define implant position, and at a minimum of 2 years postoperatively with MAR. 

Preoperatively, these images showed that the alignment of the humeral head to the glenoid (HGA - represented by the circles in the graph below) was independent of glenoid version. Type B3 (yellow circle) showed centering of the humeral head on the glenoid that was comparable to type A1 (blue circle). On the other hand, the alignment of the humeral head to the scapular body (HSA - represented by the triangles) was strongly related to glenoid version (black line).

Similarly at two years after surgery the humeroscapular alignment (but not the humeroglenoid alignment) was closely related to glenoid version.

Clearly the humeroscapular alignment is essentially a reflection of the amount of retroversion and is not a measure of the degree of subluxation or decentering of the humeral head on the face of the glenoid (see this link).

The implant placement desired by the authors was achieved in all (100%) of the 42 A1 glenoids, 27 (93%) of the 29 B2 glenoids, and 15 (71%) of the 21 B3 glenoids.

Radiographic followup at two years showed:

A1 glenoids: Central peg osteolysis (CPO) was present in 5% of the A1 glenoids. 40% had glenoid component shift.

B2 glenoids:  CPO was present in 10% of the B2 glenoids with the augmented component. 55% had glenoid component shift.

B3 glenoids: Central peg osteolysis (CPO) was present in 29% of B3 glenoids treated with the augmented glenoid component (29%). 62% had glenoid component shift.

The two year clinical outcome scores were not different for the three glenoid types.

Comment: This authors have continued their careful and thoughtful analysis of arthritic glenohumeral anatomy. Their observations on glenoid component shift and central peg osteolysis obtained with metal subtraction imaging provide knowledge that informs our understanding and management of shoulder arthritis.

Using their careful analytical approach, high percentages of the glenoid components were noted to shift in position for all three glenoid types (A1:40%, B2: 55%, B3: 62%).

They point out both the severity and the shape of glenoid bone loss are important when considering the type of glenoid component to use and its location in aTSA. Use of the stepped augmented glenoid component requires more anterior glenoid reaming to correct pathologic glenoid retroversion in moderate-to-severe B3 glenoids, resulting in implant medialization. These B3 glenoids had a higher rate of central peg osteolysis and persistent postoperative joint-line medialization relative to the premorbid joint line. They do  not recommend use of the stepped augmented glenoid component for correction of severe B3 glenoid retroversion that requires excessive anterior glenoid reaming.

Recognizing that high degrees of retroversion, bone loss and humeral head decentering on the glenoid are indicators of worse pathoanatomy and that each of these - separately or in combination - can negatively affect the durability of the arthroplasty, several questions arise:

(1) How important is it to re-establish a "normal" joint line; how much medialization of the the joint line be compensated for by modification of the prosthetic head curvature and thickness?

(2) How important is it to re-establish "normal" version in the B2 glenoid at the expense of removing sclerotic glenoid bone; how much abnormal glenoid retroversion can be compensated for by using soft tissue balancing and anteriorly eccentric humeral components to center the humeral head on the face of the glenoid?

(3) How important is it to re-establish "normal" version in the B3 glenoid at the expense of removing sclerotic glenoid bone; since the humeral head is centered in the glenoid is it necessary to change the version?

(4) How important is it to avoid peg perforation; might perforation of the glenoid neck by the central peg actually enhance fixation as it appears to do with many designs of reverse total shoulder?

(5) What is the best way to achieve centering of the humeral head on the glenoid while optimizing bone preservation?

Follow on twitter: https://twitter.com/shoulderarth

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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)

The smooth and move for irreparable cuff tears (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).

Shoulder rehabilitation exercises (see this link).

This is a non-commercial site, the purpose of which is education, consistent with "Fair Use" as defined in Title 17 of the U.S. Code.          

Note that author has no financial relationships with any orthopaedic companies.

Standard total shoulder arthroplasty for arthritis with glenoid bone deficiency

Anatomic Total Shoulder Arthroplasty with All-Polyethylene Glenoid Component for Primary Osteoarthritis with Glenoid Deficiencies

Currently many surgeons are using augmented glenoid components or reverse total shoulder arthroplasty to manage arthritic shoulders with type B2 and B3 glenoid pathoanatomy.

These authors sought to evaluate the ability of shoulder arthroplasty using a standard glenoid component to improve patient self-assessed comfort and function and to correct preoperative humeral-head decentering on the face of the glenoid in patients with primary glenohumeral arthritis and type-B2 or B3 glenoids. They identified 66 shoulders with type-B2 glenoids (n = 40) or type-B3 glenoids (n = 26) undergoing total shoulder arthroplasties with a non-augmented glenoid component inserted without attempting to normalize glenoid version and with clinical and radiographic follow-up at a minimum of 2 years. 

Shoulder pathoanatomy was characterized on the axillary "truth" view in terms of glenoid version (angle between lines G and S) and humeral head decentering on the face of the glenoid (distance between line  P - the perpendicular bisector of line segment G - and the center of the humeral head, C). Preoperative CT scans and computer planning software were not used in this case series.

This method allowed direct comparison of glenoid version and humeral decentering before and after the arthroplasty

The Simple Shoulder Test (SST) score improved from 3.2 ± 2.1 points preoperatively to 9.9 ± 2.4 points postoperatively (p < 0.001) at a mean time of 2.8 ± 1.2 years for type-B2 glenoids and from 3.0 ± 2.5 points preoperatively to 9.4 ± 2.1 points postoperatively (p < 0.001) at a mean time of 2.9 ± 1.5 years for type-B3 glenoids. These patient reported outcomes were as good as those achieved with other glenoid types.

These outcomes were achieved without changing glenoid version: postoperative glenoid version was not significantly different from preoperative glenoid version. 

The humeral head centering on the glenoid was restored: the mean humeral-head decentering on the glenoid face was reduced for type-B2 glenoids from 214% ± 7% preoperatively to 21% ± 2% postoperatively (p < 0.001) and for type-B3 glenoids from 24% ± 6% preoperatively to 21% ± 3% postoperatively (p = 0.027). 

The rates of bone integration into the central peg for type-B2 glenoids (83%) and type-B3 glenoids (81%) were not inferior to those for other glenoid types (A1 67%, A2 85%, B1 74%, D 75%).

Anterior penetration of the glenoid neck by the central peg of the glenoid component was observed in 2 (11%) of 19 of the type-B1 glenoids, in 6 (15%) of 40 of the type-B2 glenoids, and in 6 (23%) of 26 of the type-B3 glenoids. Perforation of the glenoid by the central peg was not associated with inferior clinical or radiographic outcomes. Twelve of the 14 shoulders with glenoid neck penetration had ingrowth of bone between the flanges of the central peg with no radiographic evidence of component loosening. The final mean SST score for the 14 shoulders with central peg penetration was 9.4 ± 2.3 points, a value not significantly different (p = 0.649) from that for all of the type-B2 and B3 glenoids (9.7 ± 2.2 points).

Comment: These minimum 2-year outcomes for 40 shoulders with type-B2 glenoids and 26 shoulders with type-B3 glenoids do not appear to be inferior to the minimum 2-year results reported recently for a combined group of 71 shoulders with type-B2 or B3 glenoid anatomy treated with posteriorly augmented glenoids inserted using preoperative CT scans and 3-dimensional planning  software (see this link). 

This study demonstrates that good two year clinical outcomes can be achieved for B2 and B3 glenoid components using a standard (non-augmented) glenoid component inserted without changing glenoid version. Further glenoid research with longer followup will be required to compare these outcomes to those achieved using other techniques.  

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 ream and run procedure (see this link).

The total shoulder arthroplasty (see 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).