Thursday, December 3, 2020

Reverse total shoulder: avoiding notching

 Clinical and radiological outcomes of eccentric glenosphere versus concentric glenosphere in reverse shoulder arthroplasty

Scapular notching is an important complication of reverse total shoulder arthroplasty



It results from unwanted contact between the humeral polyethylene and the neck of the scapula





These authors conducted a retrospective analysis of 49 reverse total shoulders with an inferiorly eccentric glenoid (EG) and 49 RSAs with a concentric glenoid (CG) at a minimum 60 months. Notching was observed 2.7 times more often in the CG group (p=0.040). However the notching severity was not statistically relevant between the groups.

 Compared to a CG, an EG did not increase the percentage of radiolucent lines around the screws,


As pointed out be the authors, the eccentric glenosphere reduces the risk of notching by moving the humerus further distally away from the scapular neck.




Moving the humerus distally can result in a relatively un-anatomic reconstruction with increase tension on the deltoid, acromion and brachial plexus.

   

An alternative method for minimizing the risk of notching is to use a glenosphere with an extended neck  that moves the humeral component laterally (rather than inferiorly) away form the the scapular neck resulting in a more anatomic reconstruction.







Some designs of RSA create a major disruption of the normal anatomic relationships of the shoulder while others do not (see this link).  One way to look at this is to consider the arch created by the medial aspect of the humerus and the lateral aspect of the scapula. This arch can be referred to as "Bani's line", described in 1981 (Bandi W Die Läsion der Rotatorenmanschette. Helv Chir Acta 48:537-549). 


 

Some approaches create minimal disruption of the arch (i.e. a more "anatomic" reverse)


While other approaches create greater disruption of the normal relationships as indicated by the break in the arch.


If the arch is disrupted, several things happen: (1) increased stress is put on the acromion and scapular spine leading to an increased risk of acromial and scapular spine fractures, (2) increase stress is placed on the brachial plexus, and (3) the normal alignment of residual infraspinus and subscapularis is disrupted.


To see our technique for reverse total shoulder, click on this link.

To support our research to improve outcomes for patients with shoulder problems, click here.

To subscribe to this blog, enter your email in the box to your right

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

To see our new series of youtube videos on important shoulder surgeries and how they are done, click here.

Be sure to visit "Ream and Run - the state of the art"  regarding this radically conservative approach to shoulder arthritis at this link and this link. Also see the essentials of the ream and run.

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

You may be interested in some of our most visited web pages   arthritis, total shoulder, ream and runreverse total shoulderCTA arthroplasty, and rotator cuff surgery 





Wednesday, December 2, 2020

Chronic, massive, irreparable rotator cuff tears - improvement without surgery.

Nonoperative Treatment of Chronic, Massive Irreparable Rotator Cuff Tears: A Systematic Review with Synthesis of a Standardized Rehabilitation Protocol

These authors conducted a comprehensive review of studies involving clinical outcomes of nonoperative treatment of massive, irreparable rotator cuff tears.


Multiple studies showed significant improvement exceeding the MCID for functional outcome scores following treatment. Several studies demonstrated significant improvements in strength and range of motion. Success of nonoperative treatment ranged from 32-96%. 


Comment: Many options exist for the management of chronic massive irreparable cuff tears.  

By definition, these chronic tears are long standing, so there is no rush to the operating room. 


As this article points out, stiffness is often an important feature of the affected shoulder. This can usually be addressed by gentle progressive home stretching exercises. Here are some of the most effective:


Supine stretch (link)

Table slide (link)

Pulley (link)

Abduction stretch (link)

Cross body (link)

Up the back (link)

Sleeper stretch (link).


These stretches should be carried out multiple times per day with the stretch being held for a slow count of 10. 


Once full comfortable assisted motion has been achieved with the six exercises described above, it's time to work on strengthening, using a simple press-up exercise (link). It is important that the angle of inclination is progressed slowly, assuring that the exercise can be repeated at least 20 times before the angle is increased. 


This simple home program has been successful in restoring substantial shoulder comfort and function for many shoulders that have been referred to us for reconstructive surgery or for a shoulder replacement. 


Finally, it has been demonstrated that the patient's optimism about the success of the non-operative program is a major predictor of its success.


See also this related post: Rotator cuff tears - getting better without surgery.


To support our research to improve outcomes for patients with shoulder problems, click here.To subscribe to this blog, enter your email in the box to your right that looks like the below



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

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

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

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

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






Tuesday, December 1, 2020

Does platelet rich plasma significantly improve patient outcomes for rotator cuff repair?

The clinical efficacy of leukocyte-poor platelet-rich plasma in arthroscopic rotator cuff repair: a meta-analysis of randomized controlled trials


These authors performed a meta-analysis of 10 randomized controlled trials (RCTs) involving 742 patients to evaluate whether leucocyte-poor PRP significantly affects the outcomes of arthroscopic rotator cuff repair.


The meta-analysis showed that in comparison to controls, treatment with leukocyte-poor PRP was associated with 

(1) statistically significantly less postoperative pain than the control in the short-term and long-term, however, the changes in

the VAS were below the MCID. 

(2) statistically significantly higher patient reported outcomes, however, the changes in the Constant and UCLA scores were below the MCID.

(3) statistically lower rates of retears 


The authors concluded that "leukocyte-poor PRP is associated with lower retear rates in the medium and long term regardless of the tear size and methods used for rotator cuff repair. However, the use of leukocyte-poor PRP in terms of postoperative pain and patient reported outcomes failed to show clinically meaningful effects."


Comment: We should consider how to best assess the value (benefit to the patient/cost) of leukocyte-poor PRP. 


This quote from a PRP vendor (see this link) is of interest:


"We make no bones about promoting platelet-rich plasma (PRP) therapy as a way of increasing revenues and expanding a medical practice. Both PRP and stem cell therapies are gaining wider acceptance along with a growing body of evidence proving their effectiveness. But there is an elephant in the room that, unfortunately, is hindering the growth of PRP therapy in this country. That elephant is disguised as America’s insurance companies.

It is no secret that health insurance providers are not convinced of the efficacy or usefulness of PRP therapy. That, despite growing demand for PRP therapy training among doctors looking to meet increasing demand among patients. It is also no secret that the vast majority of patients who inquire about PRP therapy never go through with it after they find out they have to pay out of pocket."


To support our research to improve outcomes for patients with shoulder problems, click here.
To subscribe to this blog, enter your email in the box to your right that looks like the below



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

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

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

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

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






How fragile is our knowledge about shoulder arthroplasty?

Statistical Fragility of Randomized Clinical Trials in Shoulder Arthroplasty


The Fragility Index (FI) is a tool for assessing the robustness of a "statistically significant" result from clinical research. The FI is defined as the number of patients in a study that would flip an outcome from being statistically significant to not  statistically significant or vice versa. 


Let's consider an example of a randomized controlled trial of 50 patients in which no patients were lost to two year followup. All 25 patients receiving "my prosthesis" improved by the MCID while only 19 patients receiving "your prosthesis" improved by the MCID. Fischer's exact test declares me the winner with p = 0.022! 


Hang on. Without asking me, my fellow reanalyzed the data and found that actually one more of your patients achieved the MCID. No big deal? Except that with your 20 successes, p became 0.050, no statistically significant difference. 




This is an example of a study with a fragility index of 1: only one patient needed to flip in order for the statistically significant result to become statistically insignificant.


Now let's add another dose of reality. Actually we enrolled 54 patients in this study, but 4 were lost to followup. That's a 93% followup rate - Spectacular! However, this same fellow had the nerve to point out that with the outcome of 4 patients being unknown and a fragility index of only 1, the outcome for those 4 patients could easily have flipped the significance of the result in either direction. 


Reference: see this link.





With that introduction, the primary purpose of this study was to evaluate the statistical robustness of clinical trials with regards to shoulder arthroplasty using FI. The secondary goal of this study is to identify trial characteristics associated greater statistical fragility.


The authors found a total of 13 randomized controlled trials (RCTs) on shoulder arthroplasty were identified and evaluated, and were found to have a median sample size of 47 patients and a median number of 7 patients lost to follow-up


The median FI was 6.


A majority of outcomes (74.4%) had a Fragility Index that was less than the number of patients lost to follow-up and the majority of outcomes (89.7%) were statistically not significant.


The take home point is that we readers need to be aware of the fragility of the statistical result, even if p<.05.  


The thinkers among you will be interested in:


Sir Austin Bradford Hill (1897-1991) and Richard Doll were the first scientists to establish the causation of cancer by cigarette smoking. Even though Hill pioneered the randomized clinical trial, he recognized that there were many circumstances in clinical research were the RCT could not be used.


He was particularly interested in proving causation; he developed nine criteria and used them to convince the scientific community that smoking caused cancer. Here are the Hill Criteria:

(1) the strength of the association
(2) the consistency of the observed association
(3) the specificity of the association
(4) the temporal relationship of the association
(5) the biological gradient (dose/response relationship)
(6) the biological plausibility – the mechanism by which local anesthetics cause chondrolysis is consistent with the current understanding of mechanisms of cytotoxicity; 
(7) coherence - does the cause-and-effect interpretation of the data conflict with the generally known facts of the natural history and biology?
(8) experimental evidence
(9) analogy 

You may be interested in his writing "The Environment and Disease: Associationor Causation?"

He concludes this article with the following 'poke' at those of us who excessively emphasize "p<":

“I wonder whether the pendulum has not swung too far – not only with the attentive pupils but even with the statisticians themselves. To decline to draw conclusions without standard errors can surely be just as silly? Fortunately I believe we have not yet gone so far as our friends in the USA where, I am told, some editors of journals will return an article because tests of significance have not been applied. Yet there are innumerable situations in which they are totally unnecessary – because the difference is grotesquely obvious, because it is negligible, or because, whether it be formally significant or not, it is too small to be of any practical importance. What is worse the glitter of the t table diverts attention from the inadequacies of the fare. Only a tithe, and an unknown tithe, of the factory personnel volunteer for some procedure or interview, 20% of patients treated in some particular way are lost to sight, 30% of a randomly-drawn sample are never contracted. The sample may, indeed, be akin to that of the man who, according to Swift, ‘had a mind to sell his house and carried a piece of brick in his pocket, which he showed as a pattern to encourage purchasers.’ The writer, the editor and the reader are unmoved. The magic formulae are there.
Of course I exaggerate. Yet too often I suspect we waste a deal of time, we grasp the shadow and lose the substance, we weaken our capacity to interpret the data and to take reasonable decisions whatever the value of P. And far too often we deduce ‘no difference’ from ‘no significant difference.’ Like fire, the chi-squared test is an excellent servant and a bad master.”


Our approach to the ream and run can be viewed by clicking here.




Our approach to total shoulder arthroplasty can be viewed by clicking here.
To support our research to improve outcomes for patients with shoulder problems, click here.
To subscribe to this blog, enter your email in the box to your right that looks like the below



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

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

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

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

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





Total shoulder and ream and run: the importance of patient optimism.

Drivers of Lower Inpatient Hospital Costs and Greater Improvements in Health-Related Quality of Life for Patients Undergoing Total Shoulder and Ream-and-Run Arthroplasty


These authors sought to determine the patient factors associated with lower costs and improved health-related quality of life (HRQoL) in two anatomic shoulder arthroplasty procedures – total shoulder arthroplasty (TSA, n=222) and ream-and-run arthroplasty (n=211).


For the optimism score, the patient indicated his or her optimism for a positive outcome from surgery on a 0 to 10 scale, on which 10 was maximally optimistic.


In the TSA group, total hospital costs were lower for female sex, lower ASA score, diagnoses other than capsulorrhaphy arthropathy, lower pain scores, and higher SANE scores. Female sex was an independent predictor of lower total costs. 


Greater QALY gains were associated with insurance other than worker’s compensation, diagnosis of chondrolysis, and higher optimism. A diagnosis of capsulorrhaphy arthropathy was the only independent predictor of greater QALY gains. 


In the ream-and-run group, lower total costs were associated with older age, lower BMI, lower ASA score, insurance other than Medicaid, diagnoses other than capsulorrhaphy arthropathy, no history of previous surgery, higher preoperative SST scores, and higher preoperative SF-36 physical component summary scores were associated with lower total costs. Lower BMI was an independent predictor of lower costs. 


Greater QALY gains were independently associated with higher preoperative optimism.


Comment: This study is important in that it identifies factors associated with lower costs and greater improvements in quality of live. Of particular interest is the predictive value of a simple assessment of the patient's preoperative optimism.


The really interesting questions are (1) whether optimism should be considered in decision making and (2) whether preoperative optimism is a modifiable factor.


Our approach to the ream and run can be viewed by clicking here.




Our approach to total shoulder arthroplasty can be viewed by clicking here.
To support our research to improve outcomes for patients with shoulder problems, click here.
To subscribe to this blog, enter your email in the box to your right that looks like the below



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

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

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

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

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



Monday, November 23, 2020

Reverse total shoulder - notching damages both bone and polyethylene

Wear and Damage in Retrieved Humeral Inlays of Reverse Total Shoulder

Arthroplasty – Where, How Much and Why?


These authors sought to quantify the linear and volumetric wear in reverse total shoulder arthroplasties (RTSA), and to qualitatively assess the PE damage modes to describe the material degradation in 39 retrieved humeral PE inlays from failed of RTSAs.





Damage on the rim of the humeral PE inlays was more frequent and severe than on the articulation surface. Irrespective of the damage mode, the inferior rim zone sustained the greatest amount of wear damage followed by the posterior zone.


Burnishing, scratching, pitting and embedded particles are most likely to occur in the articular surface area, whereas surface deformation, abrasion, delamination and gross material degradation are predominantly present in the inferior and posterior rim zones. 


The retrieved inlays exhibited a mean volumetric wear rate of 296.9 cubic mm/year. 


Components from shoulders with scapular notching showed a five-fold increase in polyethylene wear rate in comparison to those from non-notched shoulders. 







Comment: Much attention has been directed at measuring the amount of scapular bone lost from notching. 

However, as this article points out, the amount of polyethylene lost from the humeral poly cup may be of equal or greater importance.


When the poly cup is worn, polyethylene debris can cause immune cell activation, which results in inflammation in the periprosthetic tissues. In turn, this inflammation may initiate joint pain, stiffness and periprothetic osteolysis that can lead to loosening of the implant (see this link).


The best "treatment" for notching is "prevention" by assuring that there is plenty of clearance between the medial aspected of the humeral poly and the lateral aspect of the scapular neck.
























To see our technique for reverse total shoulder, click on this link.

To support our research to improve outcomes for patients with shoulder problems, click here.

To subscribe to this blog, enter your email in the box to your right

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

To see our new series of youtube videos on important shoulder surgeries and how they are done, click here.

Be sure to visit "Ream and Run - the state of the art"  regarding this radically conservative approach to shoulder arthritis at this link and this link. Also see the essentials of the ream and run.

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

You may be interested in some of our most visited web pages   arthritis, total shoulder, ream and runreverse total shoulderCTA arthroplasty, and rotator cuff surgery 

Sunday, November 22, 2020

Total shoulder arthroplasty for type B2 and B3 glenoid using standard glenoid components without version correction

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

These authors evaluated the ability of shoulder arthroplasty using a standard all-polyethylene 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 that was a minimum of 2 years. 



The Simple Shoulder Test (SST) score improved from 3.2 ± 2.1 points preoperatively to 9.9 ± 2.4 points

postoperatively 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 at a mean time of 2.9 ± 1.5 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 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 other glenoid types (A1 - 67%, A2 - 85%, B1 - 74%, C - 75%).


The authors concluded that shoulder arthroplasty with a standard glenoid inserted without changing version can significantly improve patient comfort and function and consistently center the humeral head on the glenoid face in shoulders with type-B2 and B3 glenoids, achieving >80% osseous integration into the central peg. These clinical and radiographic outcomes for type- B2 and B3 glenoids were not inferior to those outcomes for other glenoid types.


Another interesting aspect was the comparison of data from this study obtained with axillary x-rays to published data for CT scans for the typical glenoid version and decentering seen with different glenoid types.








Our approach to total shoulder arthroplasty can be viewed by clicking here.
To support our research to improve outcomes for patients with shoulder problems, click here.
To subscribe to this blog, enter your email in the box to your right that looks like the below



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

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

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

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

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