The 50 most-cited articles in reverse shoulder arthroplasty

Abstract

Background

Citation analyses have been used to understand the impact that a group of publications has on its field. As the techniques and indications of reverse total shoulder arthroplasty (RTSA) continue to expand, it is important to identify articles that can orient readers to the history, evolution, and current status of the body of RTSA literature. The purpose of this study was to identify and analyze the 50 most-cited articles related to RTSA.

Methods

Various Boolean queries were searched on the Clarivate Analytics Web of Science. Information collected included author name, publication year, country of origin, journal name, article type, total number of citations, and level of evidence.

Results

Top 50 most-cited articles amassed a total of 10,521 citations. The most-cited article was cited a total of 766 times. The most common study designs were case series (28) and cohort studies (9). Authors from the United States (24) contributed the most to included papers, followed by France (19) and Switzerland (8).

Discussion

The most-cited articles on RTSA are expert opinions, case studies, and cohort studies published by American authors. As RTSA continues to grow over the next decade, studies with higher levels-of-evidence may overtake articles included in this analysis.

Introduction

The first reverse shoulder prosthesis was reported in 1987 by Paul Grammont in France to treat end-stage rotator cuff arthropathy and pseudoparalysis. ¹ Since Grammont's original design nearly 35 years ago, reverse total shoulder arthroplasty (RTSA) has become an effective option for treating a wide range of shoulder pathologies across an array of patient populations worldwide.^2–12 In the United States, RTSA has rapidly grown in popularity since its FDA approval in 2003, with annual utilization now surpassing that of anatomic total shoulder arthroplasty (ATSA).^13–15 Dramatic increases seen in the utilization of all shoulder arthroplasty over the last decade in the United States have largely been attributed to expanding use, indications, and familiarity with RTSA.^14,16–22 As indications expand and the aging population grows over the next decade, the overall incidence of RTSA is projected to continue increasing.^15,21,22

Bibliometric or citation analyses have been used across academic literature to better understand and quantify the impact that a group of publications has on its field.^23–27 Numerous past studies in the orthopedic literature have undertaken bibliometric analyses to determine the most influential articles in the field, within subspecialties, and pertaining to specific procedures.^28–34 There has been one bibliometric review presenting the 50 most-cited articles in orthopedic shoulder surgery, however this publication only included 4 arthroplasty studies, none of which involved RTSA. ³⁵ Another citation analysis evaluated the 50 most-cited publications in shoulder arthroplasty research, but this paper only included 18 publications directly relating to RTSA. ³⁶

As RTSA continues to make up a larger proportion of shoulder surgeries and arthroplasties performed in the United States, it is important to identify influential articles in this evolving area of clinical practice and research. Despite this, there has been limited bibliographic analysis dedicated to RTSA to date. While the number of citations is one of many variables to consider when evaluating the “importance” or “influence” of an article, it may help establish a set of “must-read” or “classic” articles that can be used in graduate and continuing medical education to highlight the contribution researchers and authors have made to the field of RTSA and provide historical perspective on RTSA. ³⁵ Therefore, the purpose of this study was to identify the 50 most frequently cited articles related to RTSA in the orthopedic literature. We hypothesized that the publication year would have a significant impact on the number of citations an article generates.

Methods

Institutional review board approval was not obtained due to the public availability of the non-human data collected in this study. Clarivate Analytics Web of Science database was used to perform this analysis in a method similar manner to those outlined in previous orthopedic bibliometric analyses.^28,29,35 On 26 October 2021, various search queries using different Boolean combinations were undertaken until a search yielded the most number of results. The final search-term used to obtain the data in this study was the following: (TOPIC: (reverse OR inverted OR reverse total OR inverted total)) AND (TOPIC: (shoulder arthroplasty OR shoulder replacement)). There were no restrictions on language, journal, or country of origin in this search.

The list of articles that were returned by the aforementioned search-terms were then sorted in a descending fashion according to the number of citations. Titles and abstracts were reviewed to identify articles that were unrelated to RTSA. These studies were then excluded. If an article was a systematic review, only briefly mentioned RTSA, or if RTSA was not the main focus of the article, the article was excluded from this study. For example, one study examining long term outcomes of shoulder arthroplasty that included only a small number of RTSAs was excluded. Similar to inclusion criteria in previous analyses, articles that presented information on indications, procedural descriptions, techniques, outcomes, and outcomes of RTSA were included in this study.^28,29,35 If there was uncertainty after this screening, the full article was reviewed by the senior author (P.J.C.), a board-certified shoulder and elbow orthopedic surgeon, to determine whether it should be included or excluded from the study.

The top 50 most-cited articles were reviewed by the first three authors (B.D.G, C.A.W, and K.C.W) to obtain author name, publication year, country of origin (where each unique country of origin among the list of authors was counted once), journal name, article type (expert opinion, biomechanical study, case report, case series, case-control study, cohort study, randomized controlled trial, basic science, nonrandomized control trial), total number of citations, and the level of evidence based on the guidelines published by The Journal of Bone and Joint Surgery. ³⁷ Citation density (total number of citations divided by years since publication) was calculated on the basis of another study, ²⁹ and recorded for each of the top 50 studies. All bibliometric metrics and data were recorded per year. The level of evidence and article type were independently determined by the first, second, and third authors. If a consensus on classification could not be reached by these authors, or if there was uncertainty about a classification, the senior author (P.J.C.) was called upon to make a final determination.

Results

The final search-term returned 3234 results on the Clarivate Analytics Web of Science database. The first 66 articles were reviewed in order to identify 50 articles that met the inclusion criteria, and could thus be considered in the top 50 articles relating to RTSA (Figure 1). Articles included in the top 50 were published between 2001 and 2016. More than half of the top 50 articles were published between 2005 and 2009, and 21 articles were published after 2009. Of these articles, the year with the most published articles was 2007 (8), followed by 2011 (7), 2008 (6), and 2009 (6) (Figure 2).

Figure 1.

PRISMA (preferred reporting for systematic reviews and meta-analyses) flowchart used in this review.

Figure 2.

Sum of total top 50 reverse total shoulder arthroplasty articles published per year.

At the time of the search, the top 50 most-cited articles amassed a total of 10,521 citations, with an average of 16 citations per article per year. The most commonly cited article was cited a total of 766 times (Sirveaux et al. ³⁸ ), while the second and third most-cited articles were cited 582 and 567 times, respectively (Werner et al. ³⁹ and Wall et al. ⁴⁰ ). The least cited article (Boileau et al. ⁴¹ 99 citations) had more than 650 fewer citations than the most-cited article. The year with the most total citations amassed across the top 50 articles was 2020 (1023 citations), followed closely by 2015 and 2019 (1020 citations and 1011 citations, respectively). There was significant growth in the number of citations that the top 50 articles collected per year between 2001 and 2015, followed by a relative plateau period with smaller increases and decreases between 2016 and 2021 (Figure 3).

Figure 3.

Total number of citations amassed by the top 50 reverse total shoulder arthroplasty articles per year. 2021 data is through October of this year.

The top 50 most-cited articles were also analyzed and compared on the basis citation density, calculated as the total number of citations divided by years since publication (Table 1). The article with the highest citation density was written by Sirveaux et al. ³⁸ (45.1), while Wall et al. ⁴⁰ and Boileau et al. ² had articles with the second and third highest citation densities, respectively (40.5 and 37.4). Boileau ⁴² was the author of the most recently published article (2016), which ranked 38th in the number of citations (111) and 10th in citation density (22.2). The oldest article included in this study, written by Rittmeister and Kerschbaumer ⁴³ in 2001, ranked 13th in the number of citations (222) and 33rd in citation density (11.1). Articles published in 2010 or after (21) had an average citation density of 15.3, while articles published before 2010 (29) had an average citation density of 18.2.

Table 1.

The top 50 most-cited articles in reverse total shoulder arthroplasty.

Rank	Article	Number of citations	Citation density a
1	Grammont inverted total shoulder arthroplasty in the treatment of glenohumeral osteoarthritis with massive rupture of the cuff—Results of a multicentre study of 80 shoulders 38	766	45.1
2	Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the delta III reverse-ball-and-socket total shoulder prosthesis 39	582	36.4
3	Reverse total shoulder arthroplasty: A review of results according to etiology 40	567	40.5
4	Neer Award 2005: The Grammont reverse shoulder prosthesis: Results in cuff tear arthritis, fracture sequelae, and revision arthroplasty 2	561	37.4
5	Grammont reverse prosthesis: Design, rationale, and biomechanics 44	545	34.1
6	The reverse shoulder prosthesis for glenohumeral arthritis associated with severe rotator cuff deficiency—A minimum two-year follow-up study of sixty patients 3	510	31.9
7	Reverse total shoulder arthroplasty—Survivorship analysis of eighty replacements followed for five to ten years 45	426	28.4
8	Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency 46	309	23.8
9	Reverse shoulder arthroplasty for the treatment of three- and four-part fractures of the proximal humerus in the elderly—A prospective review of 43 cases with a short-term follow-up 47	287	20.5
10	Predictors of scapular notching in patients managed with the Delta III reverse total shoulder replacement 48	271	19.4
11	Scapular notching in reverse shoulder arthroplasty 49	243	18.7
12	Reverse Shoulder Arthroplasty for the Treatment of Irreparable Rotator Cuff Tear Without Glenohumeral Arthritis 50	238	21.6
13	Grammont reverse total shoulder arthroplasty in patients with rheumatoid arthritis and nonreconstructible rotator cuff lesions 43	222	11.1
14	The use of the reverse shoulder prosthesis for the treatment of failed hemiarthroplasty for proximal humeral fracture 51	205	14.6
15	Three or four parts complex proximal humerus fractures: Hemiarthroplasty versus reverse prosthesis: A comparative study of 40 cases 52	191	15.9
16	Reverse Total Shoulder Arthroplasty 53	189	15.8
17	Reverse Prostheses in Arthropathies With Cuff Tear: Are Survivorship and Function Maintained Over Time? 54	185	18.5
18	Early results of a reverse design prosthesis in the treatment of arthritis of the shoulder in elderly patients with a large rotator cuff tear 55	180	9.5
19	Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: Results after five to fifteen years 56	175	21.9
20	Complications in Reverse Total Shoulder Arthroplasty 57	168	16.8
21	Reverse total shoulder arthroplasty—From the most to the least common complication 58	159	14.5
22	Initial glenoid component fixation in reverse total shoulder arthroplasty: A biomechanical evaluation 59	158	9.9
23	Reverse Total Shoulder Arthroplasty for Primary Glenohumeral Osteoarthritis in Patients with a Biconcave Glenoid 9	158	19.8
24	Reverse total shoulder arthroplasty after failed rotator cuff surgery 60	156	13.0
25	Range of Impingement-Free Abduction and Adduction Deficit After Reverse Shoulder Arthroplasty Hierarchy of Surgical and Implant-Design-Related Factors 61	155	11.9
26	Use of the reverse shoulder prosthesis for the treatment of failed hemiarthroplasty in patients with glenohumeral arthritis and rotator cuff deficiency 62	155	11.1
27	Comparison of Hemiarthroplasty and Reverse Shoulder Arthroplasty for the Treatment of Proximal Humeral Fractures in Elderly Patients 63	144	18.0
28	Treatment of Comminuted Fractures of the Proximal Humerus in Elderly Patients With the Delta III Reverse Shoulder Prosthesis 64	139	10.7
29	Reverse shoulder arthroplasty versus hemiarthroplasty for acute proximal humeral fractures. A blinded, randomized, controlled, prospective study 65	139	19.9
30	The reverse shoulder prosthesis in the treatment of fractures of the proximal humerus in the elderly 66	136	12.4
31	National utilization of reverse total shoulder arthroplasty in the United States 20	135	22.5
32	The reverse total shoulder arthroplasty 67	128	9.1
33	Reverse Total Shoulder Arthroplasty Improves Function in Cuff Tear Arthropathy 4	127	12.7
34	Scapular Notching in Reverse Shoulder Arthroplasty: Is It Important to Avoid It and How? 68	120	12.0
35	Subscapularis insufficiency and the risk of shoulder dislocation after reverse shoulder arthroplasty 69	117	9.8
36	Functional outcomes of reverse shoulder arthroplasty compared with hemiarthroplasty for acute proximal humeral fractures 70	117	14.6
37	Impact of fatty infiltration of the teres minor muscle on the outcome of reverse total shoulder arthroplasty 71	114	8.1
38	Complications and revision of reverse total shoulder arthroplasty 42	111	22.2
39	Reverse Total Shoulder Replacement: Intraoperative and Early Postoperative Complications 72	111	9.3
40	Is Reverse Shoulder Arthroplasty Appropriate for the Treatment of Fractures in the Older Patient?: Early Observations 73	106	10.6
41	An evaluation of the radiological changes around the Grammont reverse geometry shoulder arthroplasty after eight to 12 years 74	106	10.6
42	Evaluation of abduction range of motion and avoidance of inferior scapular impingement in a reverse shoulder model 75	104	8.0
43	Scapula Fractures After Reverse Total Shoulder Arthroplasty: Classification and Treatment 76	104	10.4
44	Indications for Reverse Total Shoulder Arthroplasty in Rotator Cuff Disease 77	101	9.2
45	Reverse shoulder arthroplasty combined with a modified latissimus dorsi and teres major tendon transfer for shoulder pseudoparalysis associated with dropping arm 78	101	7.8
46	Reverse delta-III total shoulder replacement combined with latissimus dorsi transfer—A preliminary report 79	101	7.2
47	Glenoid morphology in reverse shoulder arthroplasty: Classification and surgical implications 80	100	8.3
48	Glenoid loosening and failure in anatomical total shoulder arthroplasty: Is revision with a reverse shoulder arthroplasty a reliable option? 81	100	11.1
49	Effects of Acquired Glenoid Bone Defects on Surgical Technique and Clinical Outcomes in Reverse Shoulder Arthroplasty 82	100	9.1
50	Revision surgery of reverse shoulder arthroplasty 41	99	12.4

^a Calculated as total number of number of citations divided by years since publication.

Across the top 50 most-cited RTSA articles, Boileau had the greatest number of publications (6), followed by Cuff, Gerber, Gutierrez, Klein, Levigne, Levy, Melis, and Simovitch with 2 publications each. These articles were published across 9 unique journals, with Journal of Joint and Bone Surgery (American and British Volumes) being the most represented with 20 publications (Table 2). The articles originated from 10 different countries (Figure 4). Authors from the United States (24) contributed the most to included papers, followed closely by authors from France (19) and Switzerland (8) (Figure 4). Of the 10 oldest articles included in the study, French authors contributed to 6 and American authors contributed to 3 of these studies. The most common study design among the top 50 papers was case series (28) followed by cohort study (9) and expert opinion (7) (Table 3). Closely related, the most common levels of evidence were Level IV (29), Level V (11), and Level III (6) (Figure 5).

Table 2.

The top 50 most-cited articles in reverse total shoulder arthroplasty by publishing journal.

Journal	Number of articles
Clinical Orthopaedics and Related Research	8
International Orthopedics	1
The Journal of Bone & Joint Surgery
American Volume	15
British Volume	5
Journal of Orthopaedic Trauma	1
Journal of Shoulder and Elbow Surgery	15
Journal of the American Academy of Orthopedic Surgeons	2
Orthopaedics & Traumatology—Surgery & Research	2
Orthopedics	1

Figure 4.

Geographical distribution of country of origin for authors of the top 50 most-cited articles in reverse total shoulder arthroplasty.

Table 3.

The top 50 most-cited articles in reverse total shoulder arthroplasty by study type.

Type of study	Number of articles
Basic science	1
Biomechanical study	3
Case control	1
Case series	28
Cohort study	9
Expert opinion	7
Randomized controlled trial	1
Case report	0
Nonrandomized control trial	0

Figure 5.

Level of evidence for the top 50 most-cited articles in reverse total shoulder arthroplasty.

Discussion

This bibliometric analysis found that the top 50 most-cited articles in reverse shoulder arthroplasty were overwhelmingly case series studies (28) and studies with Level IV evidence (29), a finding that has been consistent across numerous bibliometric analyses in orthopedic surgery.^{28–31,34,35} RTSA is a relatively new field in orthopedics (especially in the United States, where FDA approval was only obtained in 2003), which is likely a major factor contributing to the prevalence of expert opinion studies and case series in the top 50. This conclusion was consistent with those proposed in bibliometric analyses of other newer fields, such as hip arthroscopy and shoulder arthroscopy.^28,29 Similar to the notion proposed by Barbara et al., we believe that RTSA may be too young to see more randomized control trials, case-control studies, and other higher level-of-evidence studies represented in the top 50 most-cited articles.

As RTSA and its body of literature evolve over time, it is likely that the results and observations seen in this study will also evolve. One might expect that more randomized control trials and case-control studies will replace the expert-opinions and case series that currently predominate the top 50. Indeed, this is a trend that has been observed in bibliometric analyses of procedures with longer histories, such as hip and knee arthroplasty.^34,83 Because these study designs inherently minimize systematic-errors and research bias, their results are more likely to drastically shift clinical practice, thus becoming more heavily cited by subsequent studies in the field.

Although many of the top 50 most-cited RTSA studies are of a lower level-of-evidence, we do not believe that this detracts from their quality, or significance to the field of shoulder arthroplasty. The citation frequency of a scientific journal article is dependent on many factors including, but not limited to, the relevance and novelty of the findings, the quality of the work, the rigor of the research methodology and study design, and the ability of the work to change clinical practice or influence future research inquiries. Groundbreaking procedures, treatments, ideas, and research are often presented initially through observational studies with lower level-of-evidence. ³⁵ As RTSA is still in its relatively early stages, many of today's most-cited articles may form the foundation that current and future higher level-of-evidence studies build upon in their research. Indeed, some of these studies may eventually be included in future analyses of the top 50 most-cited RTSA studies.

One interesting finding uncovered in this analysis was the large number of top 50 studies published between 2005 and 2009, with the majority of studies being published in or before 2009 (Figure 2). This is consistent with Barbera et al.'s finding that most-cited hip arthroscopy studies were published following 2007 with the largest spike in publications occurring in 2009. ²⁸ Additionally, this aligns with the large spikes in publication seen in 2007 and 2005 for the most-cited shoulder arthroscopy studies examined by Moore et al. ²⁹ Although it was unclear what actually contributed to the increases seen in the two aforementioned studies, the spike in our study was likely due this being the “earliest” period for RTSA in the United States. Numerous bibliometric analyses in orthopedics have shown that “time since publication” contributes significantly to the number of citations a study can amass.^{25,28,29,32,35} Simply put, the longer a study has been published, the longer amount of time it has to obtain more citations. While this probably explains the relative spike seen between 2001 and 2009 in our study of RTSA, it could not explain why specifically the period from 2005 to 2009 had such a high prevalence of publications. Other bibliometric analysis mention a phenomenon called “obliteration by incorporation” proposed by Garfield et al. where new knowledge dominates in a field of research and frequency of citation decreases over time. ⁸⁴ Essentially, as knowledge becomes widely accepted it stops getting cited. Accumulating citations being a time-dependent process versus obliteration by incorporation likely means there is a sweet-spot that will favor certain articles based on when the bibliometric analysis was conducted, with the case of RTSA likely being 2005–2009.

In addition to the length of time since publication, we found that the publishing journal and authors’ country of origin may contribute to the total number of citations an article obtains. Almost half of the 50 most-cited articles were published in either the British or American Volumes of the Journal of Joint and Bone Surgery, with the Journal of Shoulder and Elbow Surgery publishing the second most articles. These observations were not surprising as these journals are popular, high-impact journals at the forefront of arthroplasty, and specifically shoulder arthroplasty. The majority of studies in the top 50 most-cited RTSA articles were produced by authors from the United States, a trend that has been seen in bibliometric analyses across orthopedic surgery and various other medical specialties.^{24,28,29,31,35,85,86} It is unclear whether this observation points to biases in the publication process against non-American authors, the massive volume of research produced in the United States, or likely, some combination of both factors. Interestingly, French authors (19) were the second largest contributors to articles in the top 50, and also contributed to a majority (6) of the 10 oldest articles in the top 50 most-cited articles in this study. This unique trend likely reflects the large, pioneering contribution that French surgeons and researchers played in the development of the original reverse shoulder prosthesis.^1,87

Attention should be called to the papers that may be highly cited but are nonetheless outdated. Within the top third of papers, there are antiquated techniques described including six involving the approach or exposure, six regarding the positioning of implants, four about the use of drains, and three referencing patient selection. Four papers mentioned using the transacromial approach to the shoulder, which has been largely replaced by the deltopectoral and anterolateral approaches.^38,43,45,54 Two papers describe removing the tuberosities with or without re-attachment, which is no longer practiced, but rather the tuberosities are retained even if selective rotator cuff muscles are routinely released.^47,52 Initial RTSA designs moved the glenoid center of rotation laterally, which decreased the moment arm and increased the force necessary by the deltoid muscle that contributed to acromion stress fractures. Medializing the glenoid center of rotation was thought to be the solution, however, the rise in incidence of scapular notching and glenoid loosening has caused a shift back toward lateralizing the center of rotation. Despite this, four of the top 50 articles in RTSA promote medialization.^40,44,53,88 Two articles describe uncommonly used version of the glenoid and/or humeral component with Werner et al. describing glenoid retroversion of up to 10° and maintaining less than 20° of humeral retroversion, while Bufquin et al. utilized neutral version of the humeral component.^39,47 Furthermore, drains were once thought to be necessary due to enlargement of the subacromial space during RTSA as discussed by four of the top 50 articles.^39,45,48,53 However, it has since been shown that drains provide may provide limited benefit and actually increase complications. ⁸⁹ Lastly, indications are constantly expanding, and occasionally contracting, for various procedures in orthopedic surgery, and we feel it should be noted that RTSA is no longer reserved for those >70 years of age, as some of the top 50 articles recommend.^2,44,45

Similar to sentiments expressed by Namdari et al., we believe quantifying the top 50 most-cited articles in RTSA can provide orthopedists, from new residents to experienced attending shoulder surgeons, with a helpful “short-list” of articles that can orient the reader to the current status and evolution of the body of RTSA literature. ³⁵ Especially as RTSA is poised to continue growing over the next decade, the articles included in this analysis can be used to build the foundation and perspective needed for critically-analyzing the next wave of research on this evolving topic. However, characterizing all studies as “must reads” for new residents as well as experienced surgeons based on their citation number/density may be problematic. For example, Boulahia et al.'s study reports early results of reverses for rotator cuff arthropathy. ⁵⁵ Early results are undoubtedly useful to surgeons at the time of publication and to guide future research, but may not be particularly useful to surgeons when longer term data is readily available. Additionally, certain articles have lost relevance as techniques and implants have changed. Farshad and Gerber's study is a review of complication-rates from 2010, with the most common reported complication being scapular notching. ⁵⁸ A more recent 2020 article by Parada et al. found a much lower rate of scapular notching. ⁹⁰ Klein et al.'s article is a 2008 cohort study looking specifically at the Delta III implant, which has since been updated and is no longer in use. ⁶⁴ With these concerns in mind, we believe that the “top articles” generated from this bibliometric analysis should be used to guide an initial selection of influential and important articles on RTSA; extra effort and discretion should be taken to refine any reading-list based on the most recent updates and evolutions to the field.

Limitations

Citation analyses, including this study, are associated with many limitations. First, using 50 articles as a cutoff was arbitrary, and there may have been other important and influential articles that were omitted. Second, a “snowball effect,” as described in other bibliometric analyses, may have artificially inflated the number of citations an article received.^31,32,35 This theory states that authors are more likely to cite an article because it was previously cited, rather than citing it based on content or quality. Third, the total number of citations or citation density of an article can be artificially inflated by self-citations. In this case, authors who regularly publish are more likely to cite their own work and increase their number of citations. Fourth, authors are more likely to cite articles published in journals where they are seeking publication acceptance. Fifth, although inclusion and exclusion criteria were clearly defined and based on previous bibliometric analyses in orthopedics, there was still some degree of inherent subjectivity in the selection of each article. In light of this, the authors incorporated various levels of article-review, across different levels of experience, to mitigate any bias or subjectivity in this regard.

Conclusions

A large proportion of the most-cited articles on RTSA are expert opinions, case studies, and cohort studies published by American authors. Additionally, the majority of articles were published between 2005 and 2009, likely owing to the relatively recent introduction of RTSA in the United States. As RTSA continues to grow over the next decade, studies with higher levels-of-evidence are expected to become more prominent in the field and may overtake articles included in this analysis. Ultimately, quantifying the top 50 most-cited articles in RTSA can provide a helpful “short-list” that will orient readers and provide a historical perspective on the current status and evolution of RTSA literature.