What is the outcome of shoulder joint replacement arthroplasty? - need to consider all three dimensions.

Clinical research on the effectiveness of shoulder arthroplasty commonly focuses on a single dimension (e.g. the amount of improvement in a shoulder score) and seeks to establish a threshold value for this score in determining  "success" (see Quantifying Success After Reverse Total Shoulder Arthroplasty: the Minimal Clinically Important Percentage of Maximal Possible Improvement ).

Actually, there are three important dimensions in documenting the outcome of shoulder joint replacement:

(1) Satisfaction - the degree to which the outcome realized by the patient met their expectations.

(2) The outcome score (e.g. Simple Shoulder Test (SST), ASES, Constant, SANE, SCV)  achieved - for example using the SST, the outcome score is the number of positive responses to twelve questions regarding shoulder comfort and function. 12 "yes" responses would be a perfect score.

(3) The percent of maximum possible improvement (%MPI) in the outcome scare achieved - this is calculated as the amount of improvement divided by the maximum possible improvement (followup SST score - preoperative SST score)/(12 - preoperative score).

Interestingly, these three dimensions are not closely related.

A patient may be well satisfied by a modest final score and a modest improvement if their surgeon set modest expectations before surgery. Dr Neer referred to this as "limited goals" and he was adept at setting reasonable expectations for his patients. 

Let's consider two different patients achieving an SST score of 10 out of 12 at followup. 

Patient "A" had a preoperative SST score of 9  - thus the %MPI would be ((10-9)/(12-9) or 33%. 

Patient "B: had a preoperative SST score of 2 - thus the %MPI would be ((10-2)/(12-2) or 80%.

Both of these patients may be satisfied if the surgeon suggested preoperatively that the expected outcome would be about 10 out of 12 SST functions.

Both of these patients may be unsatisfied if the surgeon suggested preoperatively that the expected outcome would be 12 out of 12 SST functions.

Many publications have advocated defining "thresholds", i.e. certain values for each of these parameters above which the outcome would be defined as being successful and report the percent of patients exceeding the threshold. However, proposed "thresholds" vary for different patient populations, diagnoses and treatments.

It is more useful to present the raw data for each of the three dimensions, for example in 100 patients having total shoulder arthroplasty for osteoarthritis the average final SST score was 10, the average %MPI was 60% and the average patient was very satisfied

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

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

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link)

Shoulder arthroplasty outcomes - it's not academic, it's personal

Many articles written about measuring surgical outcomes fail to emphasize the greatest value of collecting followup data - the opportunity for self-improvement. As the inscription on the Temple of Apollo states: "physician, know thyself".

The phrase "the surgeon is the method" means that each surgeon's indications, technique and outcomes are particular to her or him. While it is of interest to know how patients fare at some famous center, it is more important for each of us to know the characteristics of the patients we treat and how they do with the treatments we provide for them. In order for us to "own our outcomes" we need to collect our results in a systematic way that minimizes selection bias. We need to follow each of our patients long enough to know if our treatment was successful and to ask "if not, why not" (Codman: A Study of Hospital Efficiency).

Yet it is surprising how few surgeons (whether in community or academic practice) have implemented a meaningful followup system that will help improve their practice. The best time to implement such a self-improvement system is now - for surgeons new to practice, start on day one before things get "too busy". It's a gift that will keep on giving.

To attain this goal, a practical method of following patient comfort and function is needed - one that is accessible for all patients treated (including those who cannot use computers or tablets, those who cannot return to the office for periodic followup, and those who have a limited command of the language). An inexpensive, validated method approach is provided by the Simple Shoulder Test, the SST: 12 simple "yes" or "no" questions that can answered with nothing more than a pencil and then mailed in to the surgeon's office. The SST is now being used in multiple languages, including Arabic, Argentinian, Chinese, Dutch, Italian, Japanese, Lithuanian, Persian, Polish, Portuguese, Spanish, and Turkish.

Patients can be encouraged to participate in long term followup with periodic completion of the SST by explaining, "I care about how my patients do over time after their treatment. When patients fill out this simple followup form, it lets me learn how well things are working out and what adjustments I may need to make in my approach to get the best possible results in the future. What I know today is based on past patients helping me in this effort".

The value of systematic followup is shown in the figure below that presents the results of 176 patients having the ream and run procedure for glenohumeral arthritis. The SST score is on the vertical axis and the years after surgery are shown on the horizontal axis. The solid line shows excellent average long-term outcomes (the dotted lines represent the standard deviations). End of story? No! The opportunities for practice improvement lie in the red box. The surgeon can learn by studying each of these cases: wrong indication? wrong patient? wrong implant? wrong technique? wrong rehabilitation? or subtle complication (e.g. delayed Cutibacterium infection)?

An important additional value of the SST is provided by its granularity, which presents data on the ability to perform specific functions before and after surgery in a form that is meaningful to surgeons and patients alike. This is in contrast to presenting the data as single number ASES, Codman, SAS, SANE, or PROMIS score or as the percent of patients that exceeded the minimal clinically important difference (MCID) - neither of which are likely to be as helpful to surgeons and to their patients as information on the improvement in the ability to perform specific shoulder functions.

The figure below shows the preoperative and minimum two year post-operative functions performable by patients with cuff tear arthropathy with retained active elevation having a CTA hemiathroplasty. These are the personal results from an individual surgeon presented in a form easily understood by the surgeon and patients alike.

An additional way of presenting a surgeon's outcome data is discussed by the authors of Quantifying Success After Anatomic Total Shoulder Arthroplasty: the Minimal Clinically Important Percentage of Maximal Possible Improvement. They point to the value of the percent maximal possible improvement (%MPI) as a way of communicating the improvement after shoulder arthroplasty. This concept was introduced in The Prognosis for Improvement in Comfort andFunction After the Ream-and-Run Arthroplastyfor Glenohumeral Arthritis and is defined as the amount of improvement divided by the maximum possible improvement:

%MPI = 100% X (post operative score - preoperative score/(maximum possible score - preoperative score).

For the SST the maximum possible score is 12.

Thus a patient with a preoperative SST score of 2 and a postoperative score of 10 would have achieved 100% X (10-2)/(12-2) or 80% maximum possible improvement.

They conducted a retrospective review of 1,593 primary anatomic total shoulders having a minimum of 2 year followup.

They found that the SST, ASES, UCLA had higher rates of patients achieving a %MPI > 30%, but lower rates of achieving the minimum clinically important difference (MCID). Conversely, the Constant and SAS scores had higher rates of patients achieving the MCID, but a lower rate of achieving %MPI > 30%.

They concluded that the %MPI offers a simple method to quickly assess improvements across patient outcome scores.

If a surgeon knows her or his average %MPI after anatomic shoulder arthroplasty (say 45%) is easy for the patient to understand this information: "in my experience patients with your findings before surgery regain about 45% of their normal comfort and function".

That is easier to understand than the more abstract concept of the MCID:"You have an X% chance of an improvement exceeding a calculated minimal clinically important difference (which may vary according to which procedure is performed as pointed out by the authors of The minimal clinically important differences of the Simple Shoulder Test are different for different arthroplasty types).

An issue with applying the MCID as a threshold for success is that it does not differentiate between different situations in which the improvement exceeded the MCID. For example an improvement after aTSA from 2 to 4 (a modest result) and an improvement from 9 to 11 (an excellent outcome) are not at all the same, even though both had an improvement in excess of the MCID of 1.6 for aTSA. It seems of greater value to use %MPI which is (4-2)/(12-2) or 20% for the first case and (11-9)/(12-9) or 67%.

Comment: Following patients to determine their outcome is the responsibility of each surgeon. As illustrated above, systematic followup can be both simple and powerful. The keys are (1) starting now, (2) using a outcome measure that is both practical and that does not systematically exclude patients because of inability to return to the office or inability to use computers or tablets, (3) analyzing and learning from the causes of failure to achieve the desired result, and (4) sharing the data with patients in a manner they can easily understand.

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

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

Follow on facebook: click on this link

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

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

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link).

After shoulder arthroplasty, how much improvement is clinically significant?

The Minimal Clinically Important Differences of the Simple Shoulder Test Are Different for Different Arthroplasty Types

These authors point out that the benefit to the patient of an arthroplasty is determined from preoperative and postoperative patient self-reported measures of comfort and function.

The minimal clinically important difference (MCID) for patient reported outcomes, such as the Simple Shoulder Test (SST), is often used to document the amount of improvement that is of importance to the patient; however, the MCID may differ for  different types of shoulder arthroplasty. 

There are two ways the preoperative and postoperative measures of comfort and function can be used to evaluate the outcome of a procedure:

(1) the final value for comfort and function

(2) the amount change: postoperative value minus preoperative value

(3) the percent of maximum possible improvement (%MPI): the maximum possible improvement (MPI) is the difference between a perfect value and the preoperative value. the percent of maximum possible improvement (%MPI) is the amount of improvement (postoperative value minus preoperative value) divided by the the maximum possible improvement (MPI).

While it is most common to compare the amount of change to a value for the minimal clinically important difference, the issue is that it possible for a patient to improve by the MCID but still have a shoulder with severely limited comfort and function (for example, an improvement from a Simple Shoulder Test (SST) value of 1 to 4).

On the other hand, %MPI reflects how much of the possible improvement was realized. For the SST the perfect score is 11. An improvement in SST value from 1 to 4 would give a %MPI of only 28%: the improvement was only 3 whereas the possible improvement was 11:  (4-1)/(12-1).

The objective of this study was to report the MCID of the Simple Shoulder Test (SST) and the MCID of the percentage of maximal possible improvement (%MPI) for five different arthroplasty types: 368 patients undergoing anatomic total shoulder arthroplasty (aTSA), 330 patients undergoing ream-and-run arthroplasty (R&R), 80 patients undergoing reverse total shoulder arthroplasty (rTSA), 53 patients undergoing cuff tear arthropathy arthroplasty (CTAA), and 56 patients undergoing hemiarthroplasty (HA). 

Significant improvements in SST values were seen for all arthroplasty types. 

The MCID for SST change was 2.3 overall but ranged from 1.6 for aTSA to 3.7 for rTSA. 

The MCID for %MPI was 32% overall but ranged from 22% for aTSA to 42% for hemiarthroplasty. 

The pre and postoperative scores for the different procedures are shown below.

The proportion of patients meeting the MCIDs are shown below

Comment: This study indicates that the threshold for clinically significant improvement after arthroplasty are not the same for different arthroplasty types. Surgeons should apply the appropriate threshold to the type of arthroplasty being evaluated.

See this related article:

Substantial Inconsistency and Variability Exists Among Minimum Clinically Important Differences for Shoulder Arthroplasty Outcomes: A Systematic Review

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

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

Follow on facebook: click on this link

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

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

Here are some videos that are of shoulder interest

Shoulder arthritis - what you need to know (see this link).

How to x-ray the shoulder (see this link).

The ream and run procedure (see this link).

The total shoulder arthroplasty (see this link).

The cuff tear arthropathy arthroplasty (see this link).

The reverse total shoulder arthroplasty (see this link).

The smooth and move procedure for irreparable rotator cuff tears (see this link).

Shoulder rehabilitation exercises (see this link).

How can we measure whether our patients have benefitted from treatment? Problems with the MCID; benefit of %MPI

The p value is commonly used to determine whether a change in a patient-reported measure of comfort and function (MCF) is statistically significant. By contrast the minimum clinically important difference (MCID) is a threshold value that can used to try to determine whether the change in a patient-reported measure of comfort and function (MCF) is clinically significant. 

See Minimum Clinically Important Difference - A Metric That Matters in the Age of Patient-Reported Outcomes

While the application of the MCID has gained wide popularity there are are some substantial problems with this metric.

1. There are different methods of calculating the MCID: 

The anchor based method, which is determined by asking a group of patients to indicate at the time of follow-up how their current health state compares to their baseline assessment. The problems here include (a) the MCID depends on patient recall of their baseline (risk of recall bias), (b) variable approaches for determining what is a "meaningful change, (c) the set of patients on which the MCID is determined may not be the same as the set of patients to which the calculated MCID is applied. 

The MCID can also be determined using the distribution method. Again there are varying approaches to this calculation: (a) evaluating the probability that a difference in scores occurred by chance, (b) using sample variation based on the effect size, the standardized response mean (the mean change divided by the standard deviation of score differences), or an internal responsiveness statistic, and (c) calculating the standard error of the mean. 

As a result, there is substantial variation in the values used for the MCID for each patient-reported measure of comfort and function. 

2. Regardless of how it is determined, the calculated value for an MCID depends on a host of variables, including the characteristics of the patients included in the calculation group (age, sex, co-morbidities, socioeconomic status, length of followup, etc (see this link)). It is also affected by the diagnoses being treated and by the type of treatment being investigated. Thus an MCID calculated for a reverse total shoulder for patients treated in Boston is likely to be different from an MCID calculated for anatomic total shoulder arthroplasty treated in Denver. A given value of the MCID may not be generalizable.

3. The use of MCID dichotomizes patients into those who do and those who do not improve by the threshold. For example if one applies an MCID of 15 to the ASES score, a patient that improved by 16 points would be considered a success and one that improved by 14 points would be a failure, even though the amount of improvement was essentially the same.

4. Improvements in the MCID along the continuum of scores are not the same: consider two patients that improved by an MCID of 16: (a) patient #1 that improved from an ASES score of 80 to 96 - a really good result and (b) patient #2 that improved from an ASES score of 10 to 26 - still has a bad shoulder.

We have found that the percent of maximal possible improvement (%MPI) (see this link) avoids many of the problems with the MCID (see MCID vs %MPI at this link). 

The %MPI is determined using the simple formula;

(post treatment score minus pre treatment score)

divided by

(maximum possible score minus preoperative score)

In comparison to the problems with the MCID, the %MPI has the following attributes:

1. There is no reliance on a calculated threshold value

2. The %MPI can be applied to any patient population without concern for its relevance

3. The results are not dichotomized into success or failure, but are expressed as a continuum that expresses the relative amount of improvement

4. It does not equate an improvement at the low end of the scare to the same amount of improvement at the high end of the scale.

5. The concept of percent maximum possible improvement is easier to explain to patients than the MCID (see this link).

6. It is relatively independent of which patient-reported measure of comfort and function is used (see this link); thus it enables comparison of outcomes among studies using different outcome measures.

So, considering two hypothetical patients: (a) patient #1 that improved from an ASES score of 80 to 96 - a really good result and (b) patient #2 that improved from an ASES score to 10 to 26 - still has a bad shoulder. Yet both improved by the ASES MCID of16.

However,

patient #1 had a %MPI of 80% 

    (96-80)/(100-80)

patient #2 had a %MPI of 17%

((26-10)/(100-10)

The results are quite different. Even though both patients exceeded the MCID of 15, patient #1 is likely to be more pleased with the outcome than patient #2.

As we consider how to assess the success of shoulder arthroplasty from the patient's standpoint, we should look at the real data, as presented in what we refer to as a Codman Graph. Take a look at each patient and decide whether the MCID or the %MPI best presents the outcome.

Of course, it is not an "either/or" situation. Authors can employ both the MCID and the %MPI. In fact, comparing and contrasting the two is of interest. Future studies should assess whether the MCID or the %MPI is more strongly associated with patient satisfaction.

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)

Shoulder arthritis - x-ray appearance (see this link)

The smooth and move for irreparable cuff tears (see this link)

The total shoulder arthroplasty (see this link).

The ream and run technique is shown in this link.

The cuff tear arthropathy arthroplasty (see this link).

The reverse total shoulder arthroplasty (see this link).

Shoulder rehabilitation exercises (see this link).

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

Note that author has no financial relationships with any orthopaedic companies

How surgeons can improve their surgical outcomes.

This post was prompted by a recent article, Strategies for Effective Implementation of Patient-Reported Outcome Measures in Arthroplasty Practice, that highlighted some of the challenges of using information technology to capture meaningful data on the comfort and function of patients before and sequentially after treatment. 

Now may be an opportune time to re-examine the purpose and practicality of documenting the patient's condition over time.

For us, the most important reason for recording patient-reported data is to learn for different groups of patients what is and what is not working in our hands. Only our patients can teach us if we're going about treatment in the most effective way. But in order to gather actionable intelligence, we must strive to "follow each of our patients long enough to learn if the treatment was successful and if not to ask "why not"?" (see A Study in Hospital Efficiency: As Demonstrated by the Case Report of First Five Years of Private Hospital). Whatever method is applied, the principal priority is to capture data on the highest possible percentages of patients being treated. Patients at increased risk for treatment failure - for example, those who are socially disadvantaged, less well educated, who are not fluent in English, who live in remote rural settings, who have co-morbidities - are subject to systematic exclusion if followup depends on hooking up with a computer or tablet or traveling to the office for an examination of range of motion.

By contrast the most user-friendly and inclusive approach is a short questionnaire that can be filled either in the office or at home (see this link). This approach eliminates the travel and technology hurdles that can create a non-response bias in the data.

For shoulder surgery, we've found that the 12 "yes" or "no" questions of the Simple Shoulder Test (SST - see this link) enable the capture the information from a high percentage of the patients at a year after surgery: in a recent comparison the 2 year non-response rate for the SST was 13% while the 1 year non-response rate for the PROMIS system was 33% (see this link).

The SST does not require scoring but rather enables the surgeon and the patients to identify the specific functions that were improved after treatment - e.g. the ability to sleep on the affected side, or the ability to reach over head - in contrast to a "score", the significance of which is more difficult to communicate. 

While the minimal clinically important difference (MCID) for the SST has been well studied (see this link), again this concept is harder to discuss with patients. Instead, we've found that the percent of maximal possible improvement (%MPI) is more straightforward: "our experience with shoulders like yours is that we can improve comfort and function X% of the way to normal" (see MCID vs %MPI at this link).

The bottom line is that by engaging our patients by emphasizing the importance of their providing us with longitudinal updates on their comfort and function, we can learn which treatments work best for which patients with which diagnoses and which do not.

Only our patients can teach us why those in the red rectangle did not get the outcome that they and we desired. For our learning, the individuals in the red rectangle have more to teach than the curves showing the mean ± standard deviation.

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)

Shoulder arthritis - x-ray appearance (see this link)

The smooth and move for irreparable cuff tears (see this link)

The total shoulder arthroplasty (see this link).

The ream and run technique is shown in this link.

The cuff tear arthropathy arthroplasty (see this link).

The reverse total shoulder arthroplasty (see this link).

Shoulder rehabilitation exercises (see this link).

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

Note that author has no financial relationships with any orthopaedic companies

 

The problem of subscapularis failure after shoulder arthroplasty.

 Clinically significant subscapularis failure after anatomic shoulder arthroplasty: is it worth repairing?

These authors point out that the reported rates of subscapularis (SC) failure after arthroplasty vary considerably, due in large part to the silent nature of its clinical presentation in many cases. In one series, ultrasound evidence of complete SC failure after anatomic total shoulder arthroplasty (TSA) was found in 13% of patients at a minimum follow-up of 8 months, but the majority of patients did not show any clinical signs of failure.

They  point out that symptomatic subscapularis failure after TSA is difficult to treat. The point out that treatment options for symptomatic SC failure include nonoperative treatment, soft-tissue repair, tendon transfer, or revision to reverse total shoulder arthroplasty (RSA). Traditionally, soft-tissue repair has been performed when there is adequate and good-quality tissue to substantiate the potential for healing. Augmentation with a graft or tendon transfer is an option if tissue quality is poor or the native SC is not repairable. It has been shown, however, that pectoralis

major tendon transfer for irreparable SC failure after TSA carries a high risk of failure, particularly if there is anterior subluxation of the humeral head. SC repairs without augmentation also carry a significant risk of failure.RSA has shown acceptable survivability and low complication rates in the setting of TSA revision, however not specifically to address SC failure.

They reviewed their one year outcomes of patients undergoing reoperation for SC failure after TSA. Of the 25 patients, 15 had had lesser tuberosity osteotomies, 5 had had peels, and 2 had had tenotomies.  9 had injuries. The average time to revision surgery was 7 months.  Patients underwent either revision SC repair (N=17) or revision to reverse shoulder arthroplasty (N=8). 

Patients who initially underwent SC repair were significantly younger than patients who underwent revision to reverse shoulder arthroplasty (mean age, 59.3 years vs. 70.3 years; P .004), had a better comorbidity profile (mean Charlson Comorbidity Index, 2.2

vs. 3.6; P .04), and had a more acute presentation (mean time between injury and surgery, 9.1 weeks vs. 28.5 weeks; P ..03). Patients who underwent SC repair also had a significantly higher reoperation rate (52.9% vs. 0.0%, P ..01). 

At final follow-up, functional outcomes scores and patient satisfaction rates were not significantly different between treatment groups.

Comment: Subscapularis failure is easier to prevent than to treat.

First of all the subscapularis needs to be released to avoid undue tension after surgery.

Secondly, the repair needs to be technically well done and secure. 

It is also important to avoid stretching in external rotation for the first 3 months after surgery.

Signs of subscapularis failure include increased external rotation

and a weak belly press.

When the subscapularis fails, the residual tendon is often of poor quality.

Thus, a "repair" needs reinforcement with a graft.

As shown in this case

=====

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

==

==

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

Reverse total shoulder in younger patients at 5 years - %MPI

Reverse shoulder arthroplasty in patients younger than 65 years, minimum 5-year follow-up


These authors evaluated their  minimum 5-year (average 6.3 year) functional outcomes of reverse total shoulder (RTSA) in 52 patients younger than 65 years (average 58±5 years, 67% female)

Abduction, forward flexion, internal rotation, and Simple Shoulder Test, Constant, American Shoulder and Elbow Surgeons, University of California–Los Angeles, Shoulder Pain and Disability Index, and visual analog scale scores all showed statistically significant improvements greater than the minimum clinically important difference at the time of last follow-up. 

Three patients (5.8%) required revision surgery after a mean of 7.5  years and 1 more suffered an acromial stress fracture, bringing the total complication rate to 7.7%.

Five patients (9.6%) demonstrated scapular notching, one of whom required revision arthroplasty. 

Comment: These are encouraging results. As shown in a prior post (see this link), longer followup will be informative.

We note that these authors used several outcome metrics. This gives us the chance to compare the percent of maximal possible improvement among these scores. Note in the chart below made from their data, the %MPI is about the same with each of the different metrics.

==

To see a YouTube of our technique for a reverse total shoulder arthroplasty, click on this link.

=====

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

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'

Outcomes of arthroscopic rotator cuff repairs

Establishing clinically significant outcome after arthroscopic rotator cuff repair

These authors assessed the minimal clinical important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for 288 patients having cuff repairs using the  American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Single Assessment Numeric Evaluation (SANE), and Constant-Murley (Constant) scores preoperatively and 1 year postoperatively

The MCID, SCB, and PASS were, respectively, 11.1, 17.5, and 86.7 for ASES, 4.6, 5.5, and 23.3 for the Constant score, and 16.9, 29.8, and 82.5 for the SANE score. 

Factors such as current smoking, type of repair, Workers’ compensation, and preoperative were inconsistently associated with these outcomes.

Comment: This study did not include two important determinants of the outcome from cuff repair surgery: the size of the cuff tear and the integrity of the cuff at followup.

While there are many approaches to outcome measurement, one that is easy for surgeons to use and patients to understand is the percent of maximum possible improvement (%MPI) as explained here:

Determining the minimal clinically important difference for the American Shoulder and Elbow Surgeons score, Simple Shoulder Test, and visual analog scale measuring pain after shoulder arthroplasty.

Primary anatomic total shoulder arthroplasty (TSA), primary reverse TSA, or hemiarthroplasty was performed in 326 patients. The SST score, ASES score, and VAS pain score were collected preoperatively and at a minimum of 2 years postoperatively (mean, 3.5 years).

The minimal clinically important differences (MCIDs) were calculated for the ASES score, SST score, and VAS pain score using a 4-item anchor question evaluating improvement after treatment. Patients were asked the following: “Since your shoulder replacement surgery, please rate your response to treatment: A, none—no good at all, ineffective treatment; B, poor—some effect but unsatisfactory; C, good—satisfactory effect with occasional episodes of pain or stiffness; D, excellent—ideal response, virtually pain free.” Patients were classified by the anchor question as having “no change” (A group [none] and B group [poor] combined) or “change” (C group [good]). The D group (excellent) was not included in the analysis because this was considered beyond minimal change.

The MCIDs for the ASES score, SST score, and VAS pain score were 20.9 (P < .001), 2.4 (P < .0001), and 1.4 (P = .0158), respectively. 

Duration of follow-up and type of arthroplasty (anatomic TSA vs reverse TSA) did not have a significant effect on the MCIDs (P > .1) except shorter follow-up correlated with a larger MCID for the ASES score (P = .0081). 

Younger age correlated with larger MCIDs for all scores (P < .024). Female sex correlated with larger MCIDs for the VAS pain score (P = .123) and ASES score (P = .05).

Patients treated with a shoulder arthroplasty require a 1.4-point improvement in the VAS pain score, a 2.4-point improvement in the SST score, and a 21-point improvement in the ASES score to achieve a minimal clinical importance difference from the procedure.

Comment: MCID is one way of looking at the amount of improvement, but it has a problem. Consider two patient having a shoulder arthroplasty, each with an improvement of 3 in the SST score (both exceeding the 2.4 MCID improvement).

Their outcomes are not the same. For that reason we use both the preoperative to postoperative change in the SST as well as the percent of maximal possible improvement to characterize the result:

Here we can see that Smith only improved by 27% of the maximal possible improvement, whereas Jones improved by 75% of the maximal possible improvement (even though the improvement in both cases exceeded the MCID).

Predicting outstanding results after anatomic total shoulder arthroplasty using percentage of maximal outcome improvement

These authors sought to determine the percentage of maximal improvement in the Simple Shoulder Test (SST) or American Shoulder and Elbow Surgeons (ASES) score associated with “excellent” patient satisfaction after total shoulder arthroplasty (TSA).

For 301 and 319 patients with at least 2 years’ follow-up for the SST score and ASES score, respectively, they used receiver operating curve analysis to determine that 72.1% of maximal improvement in the SST score and 75.6% of maximal improvement were the thresholds for excellent satisfaction.

Comment: This article is most reassuring. First of all it supports the concept that use of the percent maximal possible improvement renders similar results for different outcome scoring systems. In their study improvement of 70-76% of the maximal possible improvement was associated with an "excellent" clinical outcome whether the Simple Shoulder Test or the ASES score was used. 

Second, The SST scores improved from 27% to 77% of the maximum score of 12; similarly,  the ASES improved from 31% to 81% of the maximum score of 100.

Third, the distribution of preoperative SST scores for total shoulder patients in this paper 

was virtually identical to that for total shoulders (shown in green below) in a recent paper from a different group of surgeons writing on the "Tipping Point" for surgery (see this link).

The average SST score before total shoulder arthroplasty for patients in both centers was 3.

Thus there is reassuring consistency in the results for different patient reported outcome scales and in the results between different centers.

Here's another related post showing the consistency among outcome scales:

Establishing maximal medical improvement after anatomic total shoulder arthroplasty 

These authors conducted a systematic review  of 13 studies reporting sequential followup of 984 patients at several time points, up to a minimum of 2 years after total shoulder. Assessment for clinically significant improvements between time intervals was made by using the minimal clinically important difference specific to each patient-reported outcome measure.

Clinically significant improvements in patient-reported outcome scores were noted up to 1 year following TSA, but no further clinical significance was seen from 1 year to 2 years.

For both the subjective and objective outcomes, the majority of improvements occurred in the first 3 months after the procedure.

These authors found similar results for reverse total shoulders as shown in this link.

Comment: It is of interest and importance that the Simple Shoulder Test results of our recent, currently unpublished 11 international center study including 1270 patients receiving anatomic total shoulders with a standard (non-augmented) all polyethylene glenoid component (shown below):  

are virtually identical to the Simple Shoulder Test results from this systematic review (shown below):

It also of interest that in this systematic review, the normalized outcomes are essentially independent of the patient reported outcome scale used:

Thus measuring the outcomes of shoulder arthroplasty can be simplified: (1) any of the validated patient reported scoring systems can be used and (2) the one year results are as good as the two year year results (the "standard" requirement for 2 year followup may not be necessary for TSAs). In order for new total shoulder systems to demonstrate that they offer increased value over current approaches, their one year outcomes need to exceed those shown here.

We can conclude that most of the common outcome scores yield similar results and that the percent of maximal possible improvement provides an easy way for patients and surgeons to understand the results.

===
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'