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). 

Technique vs technology: managing a B2 glenoid in an active 67 year old woman. 9 year followup

It is said that "technology is something we buy and technique is something we learn".

In that light, let's consider an active woman in her mid sixties from Alaska presented with activity limiting shoulder pain and stiffness as reflected by her Simple Shoulder Test

Her radiographs at the time of presentation are shown below. Her axillary "truth" view shows posterior decentering of the arthritic humeral head on a posteriorly eroded glenoid with a degenerative cyst.

After discussion of non-operative management, anatomic total shoulder, reverse total shoulder and the ream and run procedure, she elected the latter.

No preoperative CT scan, MRI, or 3D planning was carried out. The procedure was performed under general anesthesia without a nerve block; no patient specific instrumentation was used; the biceps tendon was preserved; the glenoid labrum was preserved; the glenoid was conservatively reamed - just enough to create a single concavity; no glenoid component was used; the smooth (non-ingrowth) standard length humeral component was fixed with impaction autografting; and an anteriorly eccentric humeral head component was used to provide posterior stability.

Followup radiographs showed that her humeral component was stable without evidence of stress shielding and that her anteriorly eccentric humeral head was centered in the glenoid on the axillary "truth" view.

At nine years after her ream and run at the age of 76 she reported the ability to perform all 12 of the Simple Shoulder Test Functions and added that she recently spent 30 days canoeing many miles down then Chandalar and Yukon Rivers in Alaska, going 35 miles the last day. While the photos below are not from her trip, they show a bit about these two rivers.

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). 

Do lateralization and distalization after reverse total shoulder have a clinically significant relationship with patient outcome?

There are a host of variables that may affect the clinical outcome of reverse total shoulder arthroplasty. A number of authors have attempted to relate distalization and lateralization to outcome scores. For example in Managing rotator cuff tear arthropathy: a role for cuff tear arthropathy hemiarthroplasty as well as reverse total shoulder arthroplasty, the authors found that the postoperative position of the center of rotation and greater tuberosity on anteroposterior radiographs did not correlate with the clinical outcomes for either procedure.

The authors of How To Choose The Best Lateralization And Distalization Of The Reverse Shoulder Arthroplasty To Optimize The Clinical Outcome In Cuff Tear Arthropathy investigated the effect on the 1 year ASES score of combinations of lateralization and distalization of 62 patients having reverse total shoulder arthroplasty performed for cuff tear arthropathy. They measured lateralization by the LSA as shown below





and distalization by the DSA as shown below.







They found the correlation between ASES score and LSA to be = -0.43 and the correlation between ASES score and DSA to be 0.39; both values lying in the "moderate" range.


The accepted value for minimal clinically important difference for the ASES score in total shoulder arthroplasty is 20.9


The DSA of patients with ASES scores > 76 was 48.55 while the DSA of patients with ASES scores < 76. was 37.82, a difference of 10.7.


The LSA of patients with ASES > 76 was 86.43 while the LSA of patients with ASES scores <76 was 100.09, a difference of 13.7.


Thus neither measurement exceeded the threshold for clinical significance.


The authors suggest that optimal LSA should be no more than 90.5° yet of the 24 patients with LSA > 90.5 degrees 75% had ASES scores >76. Furthermore, what should be the lower limit of the LSA?







The authors also suggest that the optimal DSA should be no less than 37.5°, yet of the 17 with DSA less than 37.5, 65% had ASES scores >76. Furthermore, what should be the upper limit of the DSA?




Comment: This is a well done study that effectively uses scatter plots to show all their data. This type of presentation lends itself to an understanding of the variability in the studied relationships.


As the authors point out in their discussion, prior authors have come to varying conclusion about the clinical (rather than statistical) significance of the relationships between distalization angles and lateralization angles.


It seems curious that distalization (a linear dimension) is being measured as an angle, rather than as a linear dimension (see yellow line) and






that laterialization (a linear dimension) is being measured as an angle, rather than as a linear dimension (see yellow line).




Both lateralization and distalization affect deltoid tension, moment arms, center of rotation, stretch on the brachial plexus, the stabilizing compressive force across the articulation, the function of the remaining cuff muscles, the ability to repair the subscapularis and more. We need to know what is the "sweet spot" when the effects of these two variables are considered together?

Finally, distalization and lateralization do not reflect other clinically important variables, such as glenoid tilt, baseplate seating, baseplate fixation, as well as baseplate-bone contact. To determine the relationship of ASES score to the geometry of the reverse total shoulder arthroplasty, a multivariable analysis would be required.

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).

Bilateral B2 glenoids in a 70+ year old man. Anatomic total shoulder or RFE? 10 year followup

 A man in his early 70's presented with painful limitation of function of both shoulders. His axillary "truth" views revealed posteriorly decentered arthritic humeral heads on biconcave "B2" glenoids.

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

The procedures were performed two years apart, the left 12 years ago and the right 10 years ago. His Simple Shoulder Tests before his left shoulder is shown below.

His Simple Shoulder Tests two years after his left, but just before his right are shown below, documenting the postoperative improvement on the left and the progression of symptoms on the right.

No preoperative CT scans or 3D planning were used. The procedures were performed under general anesthesia without a plexus block. The biceps tendons were preserved. Conservative glenoid reaming was performed - just sufficient to provide a single concavity without attempt to change glenoid version. Standard (non-augmented) all polyethylene glenoid components with a fluted central peg were used. Standard length smooth stems were fixed with impaction autografting.

Now at the age of 84, 10 and 12 years after his procedures, he reports the ability to perform 12 out of 12 functions of the Simple Shoulder Test with each shoulder.

Current AP (Grashey) views (but not axillary truth views) were available from his local hospital showing secure fixation of his humeral and 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/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). 

Managing the B2 glenoid in a 73 year old pistol instructor: RnR vs RFE?. Six year followup.

This man presented with a three year history of progressive pain in his right "shooting" shoulder that prevented him from carrying out his work as a professional firearms instructor.

His examination revealed a painful stiff shoulder. His x-rays at presentation revealed glenohumeral arthritis with posterior decentering of the humeral head on a biconcave glenoid.

Because of the large, repeated impacts sustained by the shoulder in his occupation, he elected to have a ream and run procedure, rather than an anatomic or reverse total shoulder arthroplasty.

This was performed without preoperative CT scans, 3D planning, brachial plexus block, or sacrifice of the biceps tendon. The glenoid was conservatively reamed to preserve bone stock; no attempt was made to alter glenoid version. An anteriorly eccentric humeral head component was used to center the humeral head on the glenoid. The stem was smooth and fixed with impaction autografting.

Six years after his ream and run on the right, dominant, side, he returned to have a similar procedure on his left side (scheduled for when he'll be 79 years old).

He reported excellent function of his right shoulder and full return to his work as a pistol instructor.  His range of arm elevation 6 years after surgery is shown below.

His six year followup x-rays show secure fixation of his humeral component, with no stress shielding, and with the prosthetic head centered in the glenoid. There is no evidence of medial erosion or wear of his glenoid in spite of the heavy use to which this shoulder has been subjected.

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). 

Managing the shoulder of a 68 year old active man with a B2 glenoid? RFE?

A 68 year old man presented with pain and stiffness of his right shoulder that had not responded to non-operative management.

His Simple Shoulder Test indicated that he could perform only 2 of the 12 functions.

His x-rays showed glenohumeral arthritis with posterior decentering of the humeral head on a biconcave glenoid.

After discussion of the options of reverse total shoulder, anatomic total shoulder, and the ream and run procedure, he elected the latter. His ream and run was performed without preoperative CT scan, 3D planning, or brachial plexus block. His biceps tendon was intact and preserved. His glenoid was reamed to a single concavity.

He carefully followed the rehab program with care to protect the subscapularis.

At 10 weeks after surgery he was back in the swimming pool and generously gave permission to show this video.

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). 

 

What information can be gathered from a synovial fluid aspirate?

Synovial fluid aspiration is often used to gather information about a possible periprosthetic infection. 

When a sufficient volume is recovered, laboratory tests may help surgeons evaluate the likelihood of a periprosthetic infection; however the aspiration attempt may not yield fluid even if it is image guided. To be clinically useful, the aspiration needs to be carried out several weeks in advance of a potential surgical revision to allow sufficient time for laboratory tests and culture results to be finalized.

The authors of Synovial Fluid Cutibacterium acnes Antigen Is Detected Among Shoulder Samples with High Inflammation and Early Culture Growth presented a three pronged analysis of 1,365 de-identified synovial fluid samples, of which 1,150 were culture-negative and 215 were culture-positive.  94 of the culture positive samples were positive for Cutibacterium and 121 for other organisms.

The samples were analyzed by (1) time to culture positivity (known to be a reflection of the load of bacteria in the sample), (2) a validated  C. acnes antigen immunoassay test, and (3) a synovial fluid inflammation score calculated from 4 tests on synovial fluid: C reactive protein,  alpha-defensin, WBC count and percent polymorphonuclear cells.  

They found that 

(1) The samples tended to cluster into high inflammation and low inflammation groups for both all specimens

and for those in specimens that were culture positive for Cutibacterium

(2) C. acnes antigen levels demonstrated moderate-strong positive correlation with inflammation, with 166-fold higher levels of C. acnes antigen in high-inflammation samples compared with low-inflammation samples. 

(3) The days to C. acnes culture positivity demonstrated weak- inverse correlation with inflammation, with 1.5-fold earlier growth among the 67 high- inflammation samples compared to the low inflammation samples. Because a positive culture depends on discernible colonies on the culture plate and because the threshold for discernability relates to the number of bacteria present, low loads of bacteria in the sample are expected to have longer time to culture positivity. 

The relationship between C acnes antigen levels (left) and days to culture positivity (right) for samples with low inflammation and high inflammation is shown below.

(4) 19.0% of high-inflammation, culture-negative fluid samples demonstrated elevated C. acnes antigen.  Elevated C. acnes antigen was observed in only 0.38% of the low-inflammation culture-negative fluid samples and in only 4.9% of the high-inflammation non-C. acnes-positive cultures. 

Here it is of note that synovial fluid cultures are not uncommonly culture negative when tissue and explant cultures are positive. This may be because there may be Cutibacterium in biofilm form in tissue but not in planktonic (free floating) form in fluid. Thus these shoulders may not have been culture negative if tissue and explant cultures had been available. Absence of evidence is not evidence of absence.

Comment: One way to put these findings together is that low loads of Cutibacterium (as indicated by longer times before cultures become positive and by low antigen levels) may be insufficient to cause a tissue damaging inflammatory response on the part of the host. If one uses the definition of infection as "bacteria doing harm", these shoulders may not meet that definition, even though there are bacteria present. On the other hand, high loads of bacteria are likely to have shorter time to culture positivity, higher antigen levels and more inflammation.

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).