Glenoid component version in anatomic total shoulder arthroplasty- does it matter?

 

Almost 30 years ago Gilles Walch called our attention to arthritic glenoid retroversion. Morphologic study of the glenoid in primary glenohumeral osteoarthritis

From that point on, there has been great interest in the version of the arthritic glenoid: what is it?, how should it be measured?. 

And in the execution of an anatomic total shoulder (aTSA),  should the version of the glenoid component be "corrected" to some particular value?, if so what value?, how should this correction be achieved? and does changing the preoperative version affect the clinical outcome of aTSA?

It goes without saying that a lot of time and money can go into the evaluation and management of arthritic glenoid retroversion. Perhaps it's time to see how much glenoid component matters to the patient.

About 15 years ago, Patterns of loosening of polyethylene keeled glenoid components after shoulder arthroplasty for primary osteoarthritis: results of a multicenter study with more than five years of follow-up pointed out that posterior tilting of the glenoid component was associated with preoperative posterior decentering and with excessive reaming. The authors suggested that preserving subchondral bone may be important for long-term longevity of the glenoid component.

Glenoid component retroversion is associated with osteolysis found that osteolysis around the center peg of a glenoid component was correlated with component retroversion of ≥15°, the paper clearly stated that "the presence of osteolysis around the center peg was not correlated with a worse clinical outcome defined by shoulder scores or a reoperation due to glenoid loosening". 

Nevertheless, achieving component retroversion of <15° has become a goal for many surgeons and an opportunity for orthopaedic companies who have made substantial investments in three-dimensional planning platforms, patient specific instrumentation, navigation, augmented / virtual reality and robotic assisted glenoid preparation.

A recent paper,  Does postoperative glenoid component retroversion following anatomic total shoulder arthroplasty affect clinical outcomes? A systematic review and meta-analysis assessed the clinical importance of implanting the glenoid component in <15° of retroversion. After screening 2,457 articles, 15 studies comprising 1,190 shoulders met inclusion criteria. Patients were stratified by whether postoperative glenoid component retroversion was <15° or ≥15°. The principal finding was that no clinically significant differences were observed between the two groups in patient-reported outcome scores, range of motion, or complications. 

An unexpected and important finding in this meta-analysis was that shoulders with ≥15° of postoperative retroversion were actually more likely to have no radiolucency (a Lazarus grade 0 radiographic score) than those with <15° retroversion (76.9% vs. 55.6%; P = .00021). This finding argues against the presumption that retroversion promotes loosening. 

Does Postoperative Glenoid Retroversion Affect the 2-Year Clinical and Radiographic Outcomes for Total Shoulder Arthroplasty? directly addressed the question in a case-control study. At 2-year follow-up, patients with glenoid components implanted in ≥15° retroversion had similar improvement in Simple Shoulder Test (SST) scores, similar final outcome scores, and similar radiographic findings compared to those with <15° retroversion. Notably, none of the patients with retroverted glenoid components underwent revision surgery, compared to 3 of 50 patients in the non-retroverted group.

Anatomic Total Shoulder Arthroplasty with All-Polyethylene Glenoid Component for Primary Osteoarthritis with Glenoid Deficiencies reported outcomes of aTSA with conservative, noncorrective reaming in shoulders with glenoid deficiencies, including those with significant retroversion. Mean postoperative retroversion in this series was 16°, yet mean postoperative SST was 9 out of 12, consistent with the excellent results achieved in shoulders without glenoid deformity. The revision rate was zero in 143 shoulders at mean follow-up of 34 months.

Anatomic total shoulder arthroplasty for posteriorly eccentric and concentric osteoarthritis: a comparison at a minimum 5-year follow-up compared outcomes of aTSA for posteriorly eccentric (Walch B) versus concentric osteoarthritis at minimum 5-year follow-up, finding no significant difference in ASES scores, revision rates, or radiographic loosening between groups. These durable results were achieved without attempting retroversion correction.

Does glenoid version and its correction affect outcomes in anatomic shoulder arthroplasty? A systematic review analyzed 16 studies and 1,211 shoulders finding that 8 of 11 reports found no significant association between pre- or postoperative glenoid retroversion and clinical results, including patient-reported outcomes, range of motion, and revision rates.

Total shoulder arthroplasty outcomes after noncorrective, concentric reaming of B2 glenoids reported a 95% implant survivorship at a mean of 4.9 years in a series treated with noncorrective reaming with a mean postoperative retroversion of 19°.

The Effect of Version Correction Techniques

If clinical outcomes are equivalent regardless of postoperative retroversion, the question becomes whether correction efforts add value without adding risk.  Does postoperative glenoid component retroversion following anatomic total shoulder arthroplasty affect clinical outcomes? A systematic review and meta-analysis compared three correction strategies: posteriorly augmented glenoids, eccentric (“high-side”) reaming, and conservative noncorrective reaming. Eccentric reaming was associated with a significantly higher complication rate than noncorrective reaming (9.3% vs. 3.1%; P = .043, OR 3.22) and a significantly higher revision rate (7.4% vs. 1.2%; P = .015, OR 6.18). 

Loss of the dense subchondral bone layer from corrective reaming may result in reduced glenoid component support, increased micromotion, and greater loosening risk over time. 

Implications for 3D CT Planning and Technology Transfer

CT-based three-dimensional preoperative planning, patient specific instrumentation, intraoperative navigation, augmented/virtual reality, and robotic glenoid preparation are all predicated on the same clinical logic: that achieving a glenoid component position closer to neutral version will improve patient outcomes. As reviewed above, the available evidence indicates that differences in postoperative glenoid component retroversion do not produce clinically detectable differences in pain relief, function, or implant survival at the follow-up intervals studied.

Use of Preoperative CT Scans and Patient-Specific Instrumentation May Not Improve Short-Term Adverse Events After Shoulder Arthroplasty: Results from a Large Integrated Health-Care System compared aTSA with and without preoperative CT scanning and PSI. These technologies expose patients to additional radiation from CT scanning and incur substantially greater costs of care. Use of CT scans and PSI did not reduce the rate of short-term adverse events following shoulder arthroplasty. Patients receiving PSI may be at greater risk of deep vein thrombosis or deep infection, possibly reflecting the additional operative time this technology requires. 

Three-dimensional computed tomography analysis of pathologic correction in total shoulder arthroplasty based on severity of preoperative pathology analyzed 152 shoulders with 3D CT postoperatively and found that while glenoid component shift occurred in 51% of patients, neither component shift nor central peg osteolysis was associated with worse clinical outcomes at minimum 2-year follow-up. 

What the Evidence Does Suggest About Optimizing aTSA outcomes?

The available evidence points to factors other than retroversion that drive aTSA results. 

See: Below left-poor glenoid seating with cement interposed between the glenoid component and the bone. 

Below right-posterior decentering due to poor glenoid preparation and ill-advised use of a posteriorly eccentric humeral head component.

Surgeons may wish to consider 6 aspects of aTSA that are relevant to the glenoid side of the arthroplasty.

(1) conservative reaming to retain the maximal amount of quality host bone

(2) rather than "correcting" glenoid retroversion (A, below), consider "accepting" it (B, below)

(3) component seating — good carpentry with complete backside contact of the glenoid implant against prepared bone; no cement between the component and the bone.

(4) humeral head centering on the glenoid achieved through soft tissue balancing and the possible us of an anteriorly eccentric humeral component.

(5) awareness that technologies can lead surgeons to prioritize postoperative glenoid component retroversion <15° retroversion (without acknowledging the potential risks)

(6) recognition that specialized (e.g. augmented) glenoid components may have downstream risks (see chart below from the 2025 AOANJRR)

Here is a thought provoking case in which substantial glenoid retroversion was accepted

Function at 14 years

Conclusion:

Glenoid component version may not be as critical to the outcome of aTSA as secure seating of the glenoid component on quality host bone and centering of the humeral head on the prosthetic glenoid. 

Rather than improving outcomes, there is evidence that "corrective reaming" can be associated with a significantly higher complication rate than noncorrective reaming (9.3% vs. 3.1% ) and a significantly higher revision rate (7.4% vs. 1.2%).

Seating and balance

Yellow-headed blackbird

Malheur

2024

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20 studies that have influenced my approach to shoulder arthritis.

Deconflicting use of the term "subluxation". 

Most orthopaedic surgeons use the word subluxation to refer to separation of the surfaces of a joint, as in patello-femoral subluxation

In this classic article, Morphologic Study of the Glenoid in Primary Glenohumeral Osteoarthritis,   the authors defined subluxation of the shoulder in a manner consistent with the standard use of the term:  decentering of the humeral head with respect to the perpendicular bisector of the plane of the glenoid face.

Thus, this humeral head is not subluxated.

Neither is this one where the humeral head is centered with respect to the perpendicular bisector of the plane of the glenoid face (even though the glenoid is retroverted with respect to the plane of the scapula). Today, we would identify this as a B3 glenoid.

In the example below, however, the humeral head is posteriorly decentered (subluxated) with respect to the plane of the glenoid face. This is a classic B2 glenoid,

Consistent with Walch's classic article, the authors of Quantitative Measurement of Osseous Pathology in Advanced Glenohumeral Osteoarthritis  defined subluxation in terms of "humeroglenoid alignment" or HGA, and found that the humeral head was relatively well centered in the retroverted B3 type compared with the type B2 glenoid.

However, as pointed out in Subluxation in the Arthritic Shoulder many authors have recently confused the use of the word "subluxation" by using it to refer to alignment of the humeral head with the scapular axis, rather than with respect to the plane of the glenoid face. The relationship of the humeral head to the plane of the scapula is mostly determined by glenoid retroversion and is not a measure of glenohumeral subluxation.

Interestingly, the authors of Progression of Glenoid Morphology in Glenohumeral Osteoarthritis  found that arthritic shoulders that started out with the humeral head centered with respect to the plane of the glenoid face rarely progressed to becoming subluxated (i.e. decentered).

Does glenoid version need "correcting" 

If humeral head decentering on the glenoid face is not driven by glenoid retroversion, is it necessary to "correct" glenoid retroversion when performing a shoulder arthroplasty?

The authors of Does glenoid version and its correction affect outcomes in anatomic shoulder arthroplasty? A systematic review  found that "there is currently insufficient evidence that pre- or postoperative glenoid version influences postoperative outcomes independent of other morphologic factors such as joint line medialization. Given that noncorrective reaming demonstrated favorable postoperative outcomes, and that postoperative glenoid version was not significantly and consistently found to impact outcomes, there is inconclusive evidence that correcting glenoid retroversion is routinely required."

Anatomic total shoulder arthroplasty for posteriorly eccentric and concentric osteoarthritis: a comparison at a minimum 5-year follow-up found that the results of TSA with conservative glenoid reaming without attempt at version correction were favorable at a minimum 5- year, and mean 8-year, follow-up. There were no differences in clinical and radiographic outcomes between patients with eccentric and concentric wear patterns. Incomplete glenoid component seating was the greatest predictor of glenoid component radiolucency.

Does Postoperative Glenoid Retroversion Affect the 2-Year Clinical and Radiographic Outcomes for Total Shoulder Arthroplasty?  noted that postoperative glenoid retroversion was not associated with inferior clinical results at 2 years after surgery. 

Glenoid subchondral bone density distribution in male total shoulder arthroplasty subjects with eccentric and concentric wear  pointed out that attempts to correct glenoid version may result in loss of the dense glenoid bone that contributes to good fixation of a glenoid component.

The authors Management of intraoperative posterior decentering in shoulder arthroplasty using anteriorly eccentric humeral head components  showed that decentering of the humeral head with respect to the plane of the glenoid face could be corrected without changing glenoid version through the use of an anteriorly eccentric humeral head component

.

How do anatomic and reverse total shoulders compare in the treatment of glenohumeral arthritis with an intact cuff?

A comparative analysis of anatomic total shoulder arthroplasty versus reverse shoulder arthroplasty for posterior glenoid wear patterns noted that patients with shoulder osteoarthritis and posterior glenoid wear patterns with an intact rotator cuff who underwent TSA had similar outcomes as RSA. The TSA group had superior active external rotation and internal rotation at 2 years postoperative compared with RSA.

Treatment of B2 Type Glenoids with Anatomic versus Reverse Total Shoulder Arthroplasty: A Retrospective Review found that anatomic and reverse total shoulder arthroplasty can produce good results in patients with B2 glenoid morphology with low rates of revision with appropriate patient selection. Anatomic total shoulder arthroplasty may result in improved range of motion.

 

Survivorship of shoulder arthroplasty in young patients with osteoarthritis: an analysis of the Australian Orthopaedic Association National Joint Replacement Registry  noted that instability/dislocation were the leading causes of revision for RTSA (41.7%) For TSA, the majority of revisions were for either instability/dislocation (20.6%) or loosening (18.6%).The high early dislocation rate associated with RTSA, as well as the lack of revision options available to address this, indicates that careful selection of patients and a greater appreciation of anatomic risk factors are needed in the future.

Total Shoulder Arthroplasty Versus Reverse Shoulder Arthroplasty in Primary Glenohumeral Osteoarthritis With Intact Rotator Cuffs: A Meta-Analyses  in the setting of primary glenohumeral osteoarthritis with an intact cuff reverse total shoulder were found to be non-inferior to the TSA.

The Influence of Rotator Cuff Disease on the Results of Shoulder Arthroplasty for Primary Osteoarthritis demonstrated that minimally retracted or nonretracted rotator cuff tears limited to the supraspinatus tendon do not appreciably affect most shoulder-specific outcome parameters in total shoulder arthroplasty performed for the treatment of primary osteoarthritis. Conversely, fatty degeneration of the infraspinatus and, less importantly, subscapularis musculature adversely affects many of these parameters.

Reverse total shoulder challenges

Development, Evolution, and Outcomes of More Anatomical Reverse Shoulder Arthroplasty  presents the evolution of RSA design, particularly the development of a lateralized center of rotation constructs, which aimed to address the disadvantages associated with the Grammont-style design and more closely reproduce the native anatomy in order to improve patient outcomes in an expanded context of pathologies. 

Glenoid morphology in reverse shoulder arthroplasty: Classification and surgical implications showed that abnormal glenoid morphology has a significant effect on anatomical and surgical factors which can necessitate adjustments in surgical technique for reverse shoulder arthroplasty including the use or the alternative spine centerline.

Implant-Positioning and Patient Factors Associated with Acromial and Scapular Spine Fractures After Reverse Shoulder Arthroplasty noted that while the original indication for a reverse total shoulder was cuff tear arthropathy with pseudoparalysis, patients with this condition have inferior outcomes in comparison to those with intact rotator cuffs. Poor bone density and rotator cuff deficiency appear to be the strongest predictors of acromial and scapular spine fractures after RSA. To a lesser degree, increased humeral lateralization appear to be associated with lower fracture rates while glenoid-sided and global lateralization are associated with higher fracture rates. However, glenoid lateralization may improve shoulder stability, range of motion and function while reducing the risk of unwanted prosthesis-bone contact with associated limitations in range of motion and scapular notching.

An alternative approach to cuff tear arthropathy.

Cuff Tear Arthropathy: Pathogenesis, Classification, and Algorithm for Treatment  showed that the use of an extended humeral head prosthesis for Types-IA, IB, and IIA cuff tear arthropathy revealed substantial improvement in pain relief, range of motion, and functional goals. 

Managing rotator cuff tear arthropathy: a role for cuff tear arthropathy hemiarthroplasty as well as reverse total shoulder arthroplasty showed that for patients having cuff tear arthropathy with retained active elevation, an extended head humeral hemiarthroplasty yielded clinically important improvement in comfort and function while avoiding the complications of dislocation and acromial/spine fracture that can be associated with a reverse total shoulder. 

New technologies

Assessing the Value to the Patient of New Technologies in Anatomic Total Shoulder Arthroplasty The analysis did not identify evidence that the results of TSA were statistically or clinically improved over the 2 decades of study or that any of the individual technologies were associated with significant improvement in patient outcomes.

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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).

A B2 glenoid in a 67 year old man - 12 year followup after a basic arthroplasty

 An active man in his mid 60s presented with pain and stiffness of his left shoulder. His radiographs at presentation showed an arthritic shoulder with the humeral head posteriorly decentered on a retroverted biconcave glenoid.

After discussion of the option of a reverse total shoulder, he elected to proceed with an anatomic total shoulder.

The procedure was performed without preoperative CT scanning or preoperative 3D planning. General anesthesia was used without a nerve block. The shoulder was exposed with a subscapularis peel preserving the long head of the biceps. The glenoid was conservatively reamed without attempting to alter version. A standard non-augmented all polyethylene glenoid with an ingrowth central peg was used. The standard length smooth humeral stem was fixed with impaction autografting. 

At the age of 80, he returned for routine followup. His 12 year x-rays (shown below) reveal no evidence of stress shielding, component loosening, or instability.

 He reported excellent comfort and function. 

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/X: https://x.com/RickMatsen

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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). 

Does postoperative glenoid version matter in anatomic total shoulder arthroplasty? The jury is in.

Much innovation, time, money, and technology are being spent on "correcting" glenoid version in anatomic total shoulder arthroplasty. Are these resources being well spent? Is "correcting" glenoid retroversion better than "accepting" it (see this link)?

The published evidence indicates that postoperative prosthetic glenoid retroversion is not associated with worse patient outcomes after anatomic total shoulder arthroplasty. 

Rather than the amount of retroversion, the quality of the seating of the glenoid component appears to be the primary driver of the clinical outcome. 

The importance of seating of the glenoid component is demonstrated in 

Edge displacement and deformation of glenoid components in response to eccentric loading. The effect of preparation of the glenoid bone

The use of augmented glenoid components may make it more difficult to achieve perfect seating (see this link and this link).

Let's look at some recent articles from the peer-reviewed literature

The authors of Anatomic Total Shoulder Arthroplasty with All-Polyethylene Glenoid Component for Primary Osteoarthritis with Glenoid Deficiencies used standard all polyethylene non-augmented glenoid components inserted without attempt to "correct" glenoid retroversion in managing glenohumeral arthritis in patients with types A1, A2, B1, B2, and B3 glenoid pathoanatomy. 

The average postoperative Simple Shoulder Test Scores tended to be higher for the glenoid components inserted in more retroversion.

Postoperative glenoid version was not significantly different from preoperative glenoid version. The mean humeral-head decentering on the glenoid face was reduced for type-B2 glenoids from -14% ± 7% preoperatively to -1% ± 2% postoperatively (p < 0.001) and for type-B3 glenoids from -4% ± 6% preoperatively to -1% ± 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

The authors of Anatomic total shoulder arthroplasty for posteriorly eccentric and concentric osteoarthritis: a comparison at a minimum 5-year follow-up compared the clinical and radiographic outcomes of 210 TSAs using conservative glenoid reaming with no attempt at version correction for patients with and without eccentric wear patterns.There were no differences in outcome measures between patients with postoperative retroversion of more and less than 15 degrees . On multivariable analysis, glenoid component radiolucencies were most strongly associated with incomplete component seating rather than with postoperative glenoid component version.

The authors of Does Postoperative Glenoid Retroversion Affect the 2-Year Clinical and Radiographic Outcomes for Total Shoulder Arthroplasty? reported on patients undergoing anatomic TSA in whom no specific efforts were made to change the version of the glenoid. They compared the outcomes for 21 patients in which the glenoid component was implanted in 15 degrees or greater retroversion to those for the 50 in which it was implanted in less than 15 degrees retroversion. The improvement in the Simple Shoulder Test (6.7 ) for the retroverted group was not inferior to that for the nonretroverted group (5.8)). The percent of maximal possible improvement (%MPI) for the retroverted glenoids (70%) was not inferior to that for the nonretroverted glenoids (67%). No patient in either group reported symptoms of subluxation or dislocation. The radiographic results for the retroverted glenoid group were similar to those for the nonretroverted group with respect to central peg lucency, average Lazarus radiolucency scores, and the mean percentage of posterior humeral head decentering. None of the patients with retroverted glenoids underwent revision in comparison to 3 of the 50 patients with nonretroverted glenoids who required revision. They concluded that postoperative glenoid retroversion was not associated with inferior clinical results at 2 years after surgery.

The authors of Does glenoid version and its correction affect outcomes in anatomic shoulder arthroplasty? A systematic review evaluated studies on the effect of preoperative and postoperative glenoid retroversion on clinical functional and radiologic outcomes in patients who underwent anatomic TSA. They concluded that there is currently insufficient evidence that pre- or postoperative glenoid version influences postoperative outcomes independent of other morphologic factors such as joint line medialization. Given that noncorrective reaming demonstrated favorable postoperative outcomes, and postoperative glenoid version was not significantly and consistently found to impact outcomes, these authors find that there is inconclusive evidence that correcting glenoid retroversion is routinely required.

The authors of Factors associated with functional improvement after posteriorly augmented total shoulder arthroplasty pointed out that posteriorly augmented glenoid components in anatomic total shoulder arthroplasty attempt to address posterior glenoid bone loss but have inconsistent clinical results. They performed a retrospective review of 50 patients who underwent TSA with a step-type augmentation performed by a single surgeon between 2009 and 2018. Glenoid morphology included type B2 glenoids in 41 patients and type B3 glenoids in 9. Postoperative ROM and function showed no clinically important associations with postoperative glenoid retroversion. Component loosening was frequent among shoulders with 7 mm augmentation.

The authors of Do glenoid retroversion and humeral subluxation affect outcomes following total shoulder arthroplasty? investigated in 113 patients whether glenoid retroversion and humeral head subluxation were associated with inferior outcomes after TSA and whether change of retroversion influences outcomes after TSA. They found no correlation between postoperative glenoid version or humeral head subluxation and ASES scores. For patients with preoperative retroversion of >15 degrees , there was no difference in outcome scores based on postoperative retroversion. There were no differences in preoperative or postoperative version for patients with or without glenoid lucencies. They observed no significant relationship between postoperative glenoid retroversion or humeral head subluxation and clinical outcomes in patients following TSA. 

The authors of Glenoid component retroversion is associated with osteolysis found that postoperative glenoid component retroversion was correlated with osteolysis around the glenoid center peg but that the presence of osteolysis around the center peg was not correlated with a worse clinical outcome defined by shoulder scores or a reoperation due to glenoid loosening.

The authors of Total shoulder arthroplasty in patients with a B2 glenoid addressed with corrective reaming: mean 8-year follow-up reviewed 59 patients finding that glenoid component failure was associated with worse initial glenoid component seating but that there was no association between glenoid component failure and preoperative retroversion, inclination, or humeral head subluxation.

The authors of Total shoulder arthroplasty outcomes after noncorrective, concentric reaming of B2 glenoids reviewed their outcomes for 51 patients with B2 glenoids having a mean retroversion of 19.1 degrees (range 5.4 degrees -38 degrees ) who were treated with non-corrective reaming. These patients had significant improvement in clinical outcome scores, high patient satisfaction, and high survivorship ( implant survivorship rate was 95% at a mean follow-up of 4.9 years).

Glenoid retroversion does not impact clinical outcomes or implant survivorship after total shoulder arthroplasty with minimal, noncorrective reaming in 151 anatomic total shoulder arthroplasties the mean preoperative retroversion was 15.6 degrees. Total shoulder arthroplasty was performed without corrective reaming. Higher values of retroversion were not associated with early deterioration of clinical outcomes, revisions, or failures.

As we see from the above measurements of glenoid version are important to understanding and managing glenohumeral pathoanatomy. A recent article reviewed glenoid version measurements before and after shoulder arthroplasty:Inconsistencies in Measuring Glenoid Version in Shoulder Arthroplasty: A Systematic Review. They considered 61 studies encompassing 17,070 shoulder arthroplasties. Less than half (44%) of these described explicitly how glenoid version was measured. Often different methods were used to measure version before and after arthroplasty: preoperartive glenoid version was assessed using computed tomography in 75% of the cases; by contrast, over 50% of the studies that measured postoperative version used axillary radiographs. If we are to understand the preoperative to postoperative changes in glenoid version, we need for the measurements to be made using the same imaging modality.

As shown in Accuracy and reliability of postoperative radiographic measurements of glenoid anatomy and relationships in patients with total shoulder arthroplasty the positions of the humerus and scapula are quite different for axillary and CT images.

Comment: It seems that the "most important thing" in anatomic total shoulder arthroplasty is excellent seating of the glenoid component, rather than whether the glenoid component is inserted in more or less than fifteen degrees. 

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/X: https://x.com/RickMatsen
Follow on facebook: https://www.facebook.com/shoulder.arthritis
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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). 

The B2 glenoid in a 76 year old active surgeon - 7 year followup after ream and run

 A 76 year old physically active surgeon presented with pain and stiffness in the left shoulder and these x-rays showing a type B2 glenoid with retroversion, biconcavity, and posterior decentering of the humeral head on the glenoid.

Because of his active lifestyle and his glenoid deformity he elected a ream and run procedure (https://www.reamandrun.com/). At the time of surgery the glenoid was conservatively reamed to a single concavity preserving glenoid bone stock without attempting to change the glenoid version. An anteriorly eccentric humeral head was used to center the humerus on the glenoid. A thin stemmed, smooth, standard length stem was fixed with impaction autografting.

He presented 7 years after surgery at the age of 87 for evaluation of his opposite shoulder. He reported and demonstrated full function of his left shoulder. His x-rays at 7 years after his ream and run are shown below. There is no evidence of stress shielding. The glenoid has remodeled to a smooth stable joint surface.

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/X: https://x.com/RickMatsen
Follow on facebook: https://www.facebook.com/shoulder.arthritis
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).