How to pick the humeral head component

 

It's important to be prepared

Marsh Wren

Union Bay Natural Area, Seattle

March 2020

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).

Shoulder arthritis with bone loss - the value of anatomic versus reverse total shoulder

There is an opportunity to compare the minimum two year outcomes of anatomic and reverse total shoulders for the treatment of glenohumeral osteoarthritis with intact rotator cuff and glenoid bone loss as indicated by Walch classification A2, B2, B3, or C using two recently published series. 

The first is Lateralized Glenosphere Reverse Shoulder Arthroplasty: Inlay and Onlay Designs have Similar Clinical Outcomes in Patients with Glenohumeral Osteoarthritis which presents the outcomes from what the authors characterized as an "off-label indication for RSA" in shoulders with arthritic glenoid bone loss and an intact rotator cuff. The humeral tray design was inlay for 79 patients and onlay for 71 (total 150).  The glenoid types were A2 in 85, B2 in 28, B3 in 29, and C in 8. The authors found no significant differences between inlay and onlay implants in any outcome measure at final follow-up.

The second is Anatomic Total Shoulder Arthroplasty with All-Polyethylene Glenoid Component for Primary Osteoarthritis with Glenoid Deficiencies that included patients having a conventional approach to arthritis with an intact rotator cuff and glenoid bone loss (see this link). Glenoid types were A2 in 97, B2 in 83, and B3 in 52 (total 255)

The sex and age distributions for the two series were comparable. The average improvements in the Simple Shoulder Test scores were also comparable (6.7 for RSA and 6.5 for aTSA).

In the reverse total shoulder series the rates of revision were: inlay, 3.8% vs onlay, 1.4%. The rates of scapular notching were: inlay, 5.1% vs onlay, 7.0%. The rates of acromial stress fracture were: inlay, 0% vs onlay, 2.8%, and the rates of  tuberosity resorption were: inlay, 25% vs onlay, 27%.

In the anatomic total shoulder series the revision rate was 1% (3/255).

Comment: This comparison does not provide evidence that the reverse total shoulder is of greater benefit to patients with intact cuffs and arthritic bone loss in comparison to a conventional anatomic total shoulder. In that "value" can be defined as benefit recognized by the patient (e.g. in the patient self-assessed Simple Shoulder Test) divided by the cost, it is relevant that the cost of a reverse total shoulder is substantially higher than that of an anatomic total shoulder (graphic from Orthopedic Network News Volume 30, Number 1 January 2019)

This is obviously not a randomized controlled trial with long term followup. But it does seem to suggest that the burden of proof may lie with those advocating the RSA for patients with intact cuffs and arthritic bone loss.

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

Follow on facebook: https://www.facebook.com/frederick.matsen

Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

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).

Shoulder joint replacements - what is driving the high costs?

An analysis of costs associated with shoulder arthroplasty

These authors reviewed 361 shoulder arthroplasties performed at their facility in an attempt to identify the patient and procedure characteristics associated with costs.

19% had revision arthroplasty procedures, 32% had anatomic total shoulder arthroplasties, and 66% had reverse total shoulder arthroplasties (RTSAs).

Of the total costs, 58% were operative supply costs, including implants.

Factors associated with increased operative costs included younger age (P . .002), use of an RTSA

(P < .001), use of a bone graft (P < .001) and implant brand.

Comment: As the authors point out there are some modifiable factors that can have a profound effect on the cost of arthroplasty.

First, the actual implant costs are hidden from view. Each hospital confidentially negotiates the actual dollar amounts paid by the medical center for the total joint implants. We are aware that some medical centers will only accept implant prices that are 15% of the median price in the U.S. Thus there is an "invisible" but huge disparity among hospital payments for shoulder implants. If the prices were known and pegged at this low value, it is evident that the total U.S. costs would be dramatically reduced. 

Secondly, there is a trend toward the use of the reverse total shoulder even in cases well suited for an anatomic shoulder arthroplasty. The average selling price for a Reverse Total Shoulder is almost 50% higher than the anatomic total shoulder (See the data below from Orthopaedic Network News, Volume 30, Number 1, January 2019:

We believe that implant pricing should be public. If vendors want to provide discounts for high volume centers, that should be public as well.

We also believe that a reverse total shoulder is usually not necessary for osteoarthritic shoulders with intact rotator cuffs.

These two steps could go a long way to reducing the implant costs for shoulder arthroplasty, which comprise the major component of the overall costs of these procedures.

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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.

How you can support progress in shoulder surgery

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

4063 complications of shoulder arthroplasty - what the literature doesn't tell us

Analysis of 4063 complications of shoulder arthroplasty reported to the US Food and Drug Administration from 2012 to 2016

These authors point out that most of the literature on shoulder arthroplasty failure comes from high-volume centers and that these reports tend to exclude the experience of community orthopedic surgeons, who perform most of the shoulder joint replacements.

They analyzed the failure reports mandated by the US Food and Drug Administration for all hospitals. Each reported event from 2012 to 2016 was characterized by implant, failure mode, and year of surgery.

Although the percentage distribution among the different failure modes was relatively consistent over the years of this study, the percentage distribution of these failure modes differed substantially among different implant manufacturers.

For the 1673 anatomic arthroplasties, the most common failure modes were glenoid component failure (20.4%), rotator cuff/subscapularis tear (15.4%), pain/stiffness (12.9%), dislocation/instability (11.8%), infection (9%), and humeral component loosening (5.1%).

For the 2390 reverse arthroplasties, the most common failure modes were dislocation/instability (32%), infection (13.8%), glenosphere-baseplate dissociation (12.2%), failed/loosened baseplate (10.4%), humeral component dissociation/tray fracture (5.5%), difficulty inserting the baseplate (4.8%), and difficulty inserting the glenosphere (4.2%).

The percentage distribution of the failure modes also differed substantially from those published in a recent review of the literature.

They concluded that the publicly available Food and Drug Administration database reveals modes of shoulder arthroplasty failure that are not emphasized in the published literature, such as rotator cuff tear, infection, and postoperative pain/stiffness for anatomic total shoulder arthroplasty and implant dissociation and baseplate failure for reverse shoulder arthroplasty.

Comment: This study points to the utility of the freely accessible FDA MAUDE database as a resource for identifying failure modes for shoulder arthroplasty not readily identified in the published literature. Some modes of failure appear in the MAUDE data base long before they appear in the published literature, such as the dissociation of the glenosphere from the the baseplate as shown below.

=====
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.

How you can support progress in shoulder surgery

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

Why not just do a reverse total shoulder?

Comparative analysis of anatomic and reverse total shoulder arthroplasty: in-hospital outcomes and costs

There has been a rapid rise in the number of reverse total shoulders done each year. Reverse shoulder arthroplasty accounted for 42% of all primary shoulder arthroplasty procedures in 2011. The concomitant diagnosis of osteoarthritis and rotator cuff impairment was found in only 29.8% of reverse shoulder arthroplasty cases.

These authors used the Nationwide Inpatient Sample database from 2011, the first year that reverse total shoulder arthroplasty received a unique ICD 9 procedure code, to locate an estimated 51,052 patients undergoing total shoulder arthroplasty. These were separated into anatomic total shoulder arthroplasty (58%) and reverse total shoulder arthroplasty (43%). 

In that 44% of the reverse total shoulders in this study were performed for the diagnosis of osteoarthritis, the authors raise concerns about the appropriateness of the indications for these procedures.

Patients having reverse total shoulders were older, more likely to be female, had lower income, were more likely to be on Medicaid, had more co-morbidities, had more medical complications and had higher hospital costs ($64,383 vs $53,006) than those having anatomic arthroplasty. They observed that implant costs were about $3,000 greater for the reverse total shoulder.

They found that reverse total shoulder was an independent risk factor for inpatient morbidity, mortality, and hospital costs. Even when the analysis was adjusted for age, gender, race, and comorbidities, patients undergoing reverse shoulder replacement were at higher risk for in-hospital death, multiple perioperative complications, prolonged hospital stay, increased hospital cost, and nonroutine discharge.

Comment:  The choice of procedure for an individual depends on the diagnosis, the patient's health and expectations, and the experience and judgment of the surgeon. It is a surprise that almost half of the shoulder arthroplasties being done these days are reverses. This is not our practice. In fact, we find that many patients referred to us for a reverse are better served by other options.

It will be interesting to see if this trend continues based on the assessed value of the procedure, or whether the increased cost vs. reimbursement and the more frequent adverse outcomes may start to swing the pendulum in the other direction.

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Consultation for those who live a distance away from Seattle.

Click here to see the new Shoulder Arthritis Book

Click here to see the new Rotator Cuff Book

To see the topics covered in this Blog, click here

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

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

Conversion of an anatomic to a reverse total shoulder, when is a 'platform' prosthesis of benefit? Reprise

Due to the great interest in this subject, we're repeating this post with some additional thoughts.

An anatomic arthroplasty can fail for many reasons, including malposition, instability, delayed cuff failure and pseudo paralysis. In these situations consideration can be given to conversion of the anatomic prosthesis to a reverse total shoulder as shown here. As demonstrated in that post out preferred method for managing a failed anatomic arthroplasty is to completely remove the existing implant, obtain cultures, and then implant the reverse prosthesis. This approach allows full access to the glenoid and optimal positioning of the humeral component of the reverse. Removal of the anatomic implant is almost always possible and is particularly straightforward if it was inserted using impaction grafting.

In certain cases, such as that shown here, a well fixed stem can be retained and the proximal end converted to a reverse total shoulder with insertion of a glenosphere. Here's another post regarding conversion with retention of the anatomic stem.

Recently, there has been the advent of 'platform' prostheses, in which a humeral stem is fixed in the humeral canal that can be attached to either an anatomic or a reverse proximal humeral prosthesis. For examples, see here, here, here, and here.

It is important to recognize that in a reverse, (1) the glenosphere is placed inferiorly on the glenoid face, (2) the proximal humeral part of the reverse is bigger than that of an anatomic humeral arthroplasty and (3) the soft tissue tensioning considerations of a reverse are different from those of an anatomic arthroplasty. Therefore, the proximal-distal positioning of the humeral component needs to be fine tuned to achieve the ideal reverse arthroplasty. While some systems provide various adaptors to adjust the height, inclination and version of the proximal humeral prosthesis, the flexibility in positioning is limited by the use of the 'platform' fixed in the humeral canal.

Fortunately, we now have a clearer understanding of the indications for a reverse total shoulder, so that the needs for convertible prostheses is diminishing. For example, it is becoming evident that proximal humeral fractures in elderly individuals are often best managed by a primary reverse total shoulder - the idea of 'trying' an anatomic arthroplasty that is convertible to a reverse later is not so appealing. Similarly, individuals with arthritis, cuff deficiency, and instability are also best managed by a primary reverse.

See related post here.

One of the aspects lacking in articles about platform and other types of new shoulder prostheses is the incremental cost of the implant. This information is necessary to determine the value (benefit/cost) of the device. The question becomes, for 100 anatomic arthroplasties, how many successful conversions to reverses would be necessary to justify the incremental cost of (1) the implant and (2) the learning curve?

In our practice, revision of an anatomic to a reverse prosthesis is required almost exclusively in cases where the index procedure is done elsewhere. Often there are problems with stem fixation or positioning that require stem removal, even if 'in theory' the platform stem is convertible to a reverse.

One of the advantages of fixation of a humeral stem with impaction grafting is that - should conversion to a reverse prosthesis be required - the stem can be easily removed and the reverse stem inserted at the desired height and version.

Finally, infection with Propionibacterium is now recognized as a not unusual complication of shoulder arthroplasty. A well fixed stem for a platform prosthesis makes prosthesis exchange complicated
===
Consultation for those who live a distance away from Seattle.

Click here to see the new Shoulder Arthritis Book

Click here to see the new Rotator Cuff Book

To see the topics covered in this Blog, click here

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

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

Conversion of an anatomic to a reverse total shoulder, when is a 'platform' prosthesis of benefit?

An anatomic arthroplasty can fail for many reasons, including malposition, instability, delayed cuff failure and pseudo paralysis. In these situations consideration can be given to conversion of the anatomic prosthesis to a reverse total shoulder as shown here. As demonstrated in that post out preferred method for managing a failed anatomic arthroplasty is to completely remove the existing implant, obtain cultures, and then implant the reverse prosthesis. This approach allows full access to the glenoid and optimal positioning of the humeral component of the reverse. Removal of the anatomic implant is almost always possible and is particularly straightforward if it was inserted using impaction grafting.

In certain cases, such as that shown here, a well fixed stem can be retained and the proximal end converted to a reverse total shoulder with insertion of a glenosphere. Here's another post regarding conversion with retention of the anatomic stem.

Recently, there has been the advent of 'platform' prostheses, in which a humeral stem is fixed in the humeral canal that can be attached to either an anatomic or a reverse proximal humeral prosthesis. For examples, see here, here, here, and here.

It is important to recognize that in a reverse, (1) the glenosphere is placed inferiorly on the glenoid face, (2) the proximal humeral part of the reverse is bigger than that of an anatomic humeral arthroplasty and (3) the soft tissue tensioning considerations of a reverse are different from those of an anatomic arthroplasty. Therefore, the proximal-distal positioning of the humeral component needs to be fine tuned to achieve the ideal reverse arthroplasty. While some systems provide various adaptors to adjust the height, inclination and version of the proximal humeral prosthesis, the flexibility in positioning is limited by the use of the 'platform' fixed in the humeral canal.

Fortunately, we now have a clearer understanding of the indications for a reverse total shoulder, so that the needs for convertible prostheses is diminishing. For example, it is becoming evident that proximal humeral fractures in elderly individuals are often best managed by a primary reverse total shoulder - the idea of 'trying' an anatomic arthroplasty that is convertible to a reverse later is not so appealing. Similarly, individuals with arthritis, cuff deficiency, and instability are also best managed by a primary reverse.

See related post here.

One of the aspects lacking in articles about platform and other types of new shoulder prostheses is the incremental cost of the implant. This information is necessary to determine the value (benefit/cost) of the device. The question becomes, for 100 anatomic arthroplasties, how many successful conversions to reverses would be necessary to justify the incremental cost of (1) the implant and (2) the learning curve?

In our practice, revision of an anatomic to a reverse prosthesis is required almost exclusively in cases where the index procedure is done elsewhere. Often there are problems with stem fixation or positioning that require stem removal, even if 'in theory' the platform stem is convertible to a reverse.

One of the advantages of fixation of a humeral stem with impaction grafting is that - should conversion to a reverse prosthesis be required - the stem can be easily removed and the reverse stem inserted at the desired height and version.

Finally, infection with Propionibacterium is now recognized as a not unusual complication of shoulder arthroplasty. A well fixed stem for a platform prosthesis makes prosthesis exchange complicated
===
Consultation for those who live a distance away from Seattle.

Click here to see the new Shoulder Arthritis Book

Click here to see the new Rotator Cuff Book

To see the topics covered in this Blog, click here

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

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