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Follow-up: TSA at U.S. News & World Report Top-Ranked Hospitals in Orthopaedics

Updated: May 21, 2021

Dear CSS Colleagues:

Enclosed is a re-post of an important article I shared with you previously. I am including comments and articles from some of our members. It is important when poorly done research offers conclusions that are misleading, to show studies which give a contrary opinion. In this case, I think you would all agree that there is a value to experience and volume when one considers outcome of shoulder arthroplasty.

Kind Regards,

“JP” Warner MD

Founder, The CSS


Original Posting:

Dear CSS Colleagues:

Enclosed is an article entitled “Total Shoulder Arthroplasty (TSA) at U.S. News & World Report Top-Ranked Hospitals in Orthopaedics – Do Rankings Correlate with Complications and Cost?” by Sridharan and colleagues soon to be published in Seminars in Arthroplasty. I came across this as it was sent to my email and freely available online. As the conclusions and the methodology seemed questionable and the conclusions suspect, I share it with you here. I asked Derek Haas (CEO of Avant-Garde Health, ) to look over this article, and the following are our collective comments. This is relevant as the conclusion of the article is that “high ranked” hospitals are equivalent at 90-days to “low ranked” hospitals in terms of complications. One might also conclude that Value is equivalent or even better at a lower ranked hospital. Here is why we believe the author’s conclusions are erroneous:

1. The data analyzed is from 2011-14 so it is quite dated and may not reflect the current situation.

2. There is no clear presentation of “cost data” and there is little information provided on calculation of costs, so it is impossible to know how 90-day costs were measured and whether or not confounding factors were accounted for.

3. While the outcomes were not statistically significantly different, in 7 of the 9 outcome categories the ranked hospitals were better, in 1 they were tied and 1 they were worse. Since a lot of these adverse event rates are very low there might not have been enough cases to detect a statistically significant difference of this magnitude.

4. They define High-volume as > 23 cases/year and low as <23 cases per year. Learning curves for at least reverse replacement are probably much higher and on the order of 40 cases before complication rates drop from double digits to single digits for a surgeon. (Kempton LB, Ankderson E, Wiater JM: A Complication-based learning curve from 200 reverse shoulder arthroplasties. Clin Orthop Relat Res. 2011 Sep;469(9):2496-504) Finally, it seems, at least to me, that the conclusions of the authors flie in the face of the concept of expertise being correlated to value. Here is a link to a posting I made on this blog on this subject some time ago. There you will find an article which delivers exactly the opposite conclusion to the one above, as well as a commentary on this concept of Volume = Value: .

These are important concepts as they speak to our efforts to measure outcomes and shorten learning curves, all to the benefit of our patients. In the case of the article by Sridharan and colleagues I have to wonder what would happen if the decision-makers and politicians really believed it makes no difference where a patient goes for a shoulder arthroplasty, and that better value is to be achieved at lower ranked facilities if they have lower costs. You be the judge….

Best Regards,

“JP” Warner MD

Founder, CSS


Comments from CSS Members:

Dr. Warner and Colleagues,

To add to what you already have stated, I wanted to bring up an article we recently published in JBJS supporting your comments on the reverse shoulder arthroplasty (see attached). I do believe there is an association with volume and outcomes, and not just surgeon skill level, but also ancillary staff familiarity, protocolized pathways, and sterilization techniques.

Briefly, we utilized the Nationwide Readmissions database to analyze all patients undergoing a reverse shoulder arthroplasty from 2011-2015. We performed a stratum-specific likelihood ratio analysis to help delineate specific volume cut-offs for various hospitals, finding volume cut-offs for best rates of 90-day outcomes was >54-70 RSAs/year, whereas cost and resource utilization cutoffs were best when hospitals performed >100 RSAs/year. For example, 90 day readmissions were lowest for hospitals that did >70 RSAs/year, 90 day revisions were lowest for those that did >54 RSAs/year, and 90 day complications were lowest for those that did >69 RSAs/year. Furthermore, cost, LOS, and non-home discharge rates were the best for hospitals that had >106 RSAs/year.

Although I do realize that the article you were referencing was more in regards to high vs low ranked hospitals, this should not be inferred to high versus low volume hospitals (and as a surrogate high vs low volume surgeons). Our study is in support of prior studies on anatomic TSA by Larry Higgins, Giles Walch, Joe Iannotti and others (see attached some of the many published articles).

Thank you for always keeping us informed and stimulating these discussions.


Eric R. Wagner MD, MS

Shoulder and Upper Extremity Surgery

Emory University


The central problem with the paper is that they are claiming statistical equivalence because "no statistically significant difference was found". This is a common interpretation error.

Although there is a large cohort of patients, the incidence of complications is low and the cohort still may still be underpowered. A formal power analysis is ultimately needed. Finally, the groups may not be equivalent if one group has more complex cases that may result in higher complication rates.


Neal Chen


Please see our prior work where volume was associated with outcomes in the form of quality metrics. That work was motivated in part by a conversation I had with JP.

Kind regards,


Ronald A. Navarro, M.D., FAAOS, FAOA


Director of Clinical Affairs, Department of Clinical Science



Thanks Ron. Excellent work. It still remains the case that there are no volume thresholds for individuals who do complex procedures. But what would solve any question would be ongoing and accurate measurement of outcomes, just as Codman suggested almost 100 years ago.



Eric- I think your sentiments should be sent in as a response, letter to editor, to the article to seminars in arthroplasty. Maybe even from Codman Shoulder Society and authored or written by you. I think this is a dangerous article am that could be misconstrued and used as negative leverage.

Hope all well- Mike

Michael T. Freehill, MD, FAOA, FAAOS

Associate Professor Orthopaedic Surgery

Stanford University School of Medicine


I love this idea to write it on behalf of Codman Shoulder Society. Thanks you Mike! Agree it is a dangerous article that can be easily misconstrued.

-Eric Wagner



Very well organized.

It goes without saying that there are identical trends across all surgical specialties. There are many papers of the highest quality to support the inverse relationship between surgeon and hospital volume and complications.

When it comes to cardiac surgery, it is not only outcomes but it is mortality that is most robustly associated inversely with surgeon and hospital volume. The New England Journal of Medicine showed in a 2019 article highly correlative inverse relationship for TAVR surgery, echoing a classic NEJM 2003 article assessing outcomes and operative mortality for eight separate cardiothoracic operations. In their conclusions they stated that operative mortality is largely mediated by surgeon volume, and that “patients could often improve their chances of survival substantially by selecting surgeons who perform the operations frequently.” (Birkmeyer et al NEJM 2003; 349:2117)

In other words, when life is on the line, be very careful whom you select to care for your heart. It should be no different when selecting the surgeon who would operate on your shoulder or elbow.


Dave Schneider


Hi Bob and Michael:

I know you both are likely very busy but I thought you might be interested in a update of our Value-Based Care Commitment at MGH:

Enclosed is a posting to Codman Shoulder Society (CSS) and comments from some of our members. Derek Haas helped me with the comments and he has become a real partner with our CSS organization and the MGH. The enclosed document and articles presents on the question of Volume/Experience vs Value and highlights a recent article which concludes there is no real affect. This faulty conclusion is based on poor methodology and we provide many articles to show the alternative conclusion.

More importantly, Avant-Garde Health (Derek Haas et al) have been arm in arm with our initiative to promote value in shoulder care. Recently Derek started an initiative to create a Multicenter Study Group for Value-Based Care in the case of Shoulder Surgery. Our initial two meetings brought in almost 20 individuals interested to participate. This included Johns Hopkins, Rush, Rothman, Emory, HSS and many others.

At MGH, I’m happy to say that our VP, Greg Pauly, has offered the possibility of a Gainsharing/Co-management model for our New Ambulatory Care Center. With the help of Avant-Garde Health (now contracted with MGH Orthopedics), we will be analyzing cost drivers and looking for savings for the hospital. This could yield significant revenue back to our Dept. to allow for support of our Mission including funding for Educational programs as well as physician bonuses to further motivate behavioral changes in order to reduce cost. This hospital-Ortho Dept. alignment has never happened before.

I thought you might be interested in these initiatives as they were very much based on the seeds you and Michael Porter planted for me back in 2012. I’ve been carefully trying to grow these into flowering plants that yield value both inside and outside the MGH.

Kind Regards,

JP Warner, MD



Thanks for sharing this provocative dialogue. You, and preferably the Codman Society as a group, should respond. At a minimum, the point that Eric made is extremely important to state. The unit of analysis for assessing outcomes is the surgeon, not the hospital. A hospital’s ranking is likely determined by its best surgeons, not its average or worst ones. Even at high quality hospitals, such as MGH and BWH, you and Larry Higgins have documented the enormous variation in the number of shoulder surgeries performed by orthopedic surgeons at both institutions. High volume surgeons, such as you and Larry, could have zero complications from your surgeries, while the total number of complications at MGH and BWH could be high, and arising from the patients of surgeons on your staff that perform fewer than two dozen per year. The idea that you can infer the surgery quality of individual surgeons from the aggregate data at the hospital level should have been noticed in the reviewing process for the forthcoming paper, and caused it to be a rejected, not a publishable, paper.

Bob Kaplan


Thank you Bob. Sadly, reviewers are typically Orthopedic Surgeons who have no understanding or inclination to further understand the essential elements of value which you present below. When the article comes out I’ll write a letter to the Editor about it, but as insurance companies and politicians may read literature, from time to time, this is a troubling message.

On another note, our paper on TDABC analysis of postoperative Telehealth virtual visits vs in-office visits was rejected by the Journal of Bone and Joint Surgery. I won’t bore you with the details but one reviewer really liked it and seemed to be ignored by the Editor and one reviewer indicated he was unfamiliar with TDABC methodology but questioned many of the premises of the paper based on his personal experience and opinion. I’ll be writing a critical rebuttal to the editor requesting the second reviewer be disqualified based on opinion-driven review and lack of accounting knowledge. This is one more frustrating aspect of healthcare as individuals with the ability to control change and access to important studies, can be so poorly qualified to judge what is of value.

Thanks for all your help.

I’ll keep you informed, especially on Avant-Garde Health and MGH and Codman Shoulder Society Partnerships.

Best Regards,

JP Warner

gilles walch
Download PDF • 160KB
Singh et al
. - 2014 - The effect of surg
Download - 2014 - THE EFFECT OF SURG • 171KB
Sridharan et al- Seminars in Arthroplast
Download • 668KB
Farley, Schwartz, Wagner, Volume RSA, JB
Download • 1.56MB
Volume and Outcomes Shoulder Arthroplast
Download • 201KB
SSLR Total Shoulder, Iannotti, JSES 2017
Download • 488KB


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