American Shoulder and Elbow Surgeons membership and its association with primary and revision shoulder arthroplasty volume.

BACKGROUND: The overall impact of American Shoulder and Elbow Surgeons (ASES) membership on volume of primary and revision procedures has not been evaluated. The purpose of this study was to examine the association between high-volume primary and revision arthroplasty surgeons and membership in the ASES using recent Medicare data.
METHODS: Data from 2014 for all providers performing primary shoulder arthroplasty (Current Procedural Terminology codes 23470 and 23472) and revision procedures (Current Procedural Terminology codes 23473 and 23474) were identified using the Medicare Physician and Other Supplier Public Use File for 2016. Providers were rank ordered on the basis of the total number of procedures performed and subdivided as ASES members and nonmembers.
RESULTS: ASES members composed 16% of all surgeons performing shoulder arthroplasty but performed 28% of primary arthroplasty and 63% of revision procedures. The mean number of procedures per provider was significantly greater for ASES members compared with non-ASES members (44.2 ± 30.7 vs. 21.4 ± 13.2; P < .001); 70% of the 53 highest volume surgeons were ASES members and performed 71% of all primary and 89% of all revision shoulder arthroplasties among this group.
CONCLUSION: ASES members represent the largest proportion of high-volume shoulder arthroplasty surgeons in the United States and perform a majority of all primary and revision arthroplasties among this group.

Shoulder arthroplasty is considered the fastest growing segment of the arthroplasty market, with an estimated 110,000 shoulder replacements performed in 2016. Subspecialty training in shoulder arthroplasty is often thought to be a conduit for the development of a high-volume arthroplasty practice and the ability to manage complex primary and revision shoulder arthroplasty procedures. Exposure to shoulder arthroplasty can be obtained in shoulder and elbow, sports, adult reconstruction, and hand subspecialty fellowship programs. The American Shoulder and Elbow Surgeons (ASES) has committed itself with a mission to “support the ethical practice of evidence-based, high quality, cost-effective shoulder and elbow care” and has fostered a community of surgeons dedicated to the advancement of shoulder arthroplasty. Members of the ASES often perform high-volume shoulder arthroplasty and are typically comfortable performing complex primary and revision shoulder arthroplasty, creating tertiary referral centers in their respective geographic locations.

Using 2012 Medicare provider data, Somerson et al noted that of the 774 surgeons who performed primary total shoulder arthroplasties on Medicare patients, 40% had completed fellowships in sports medicine, 28% shoulder and elbow, 9% hand, 5.1% adult reconstruction, and 3.1% trauma. Furthermore, 45% of all shoulder arthroplasties were performed in major metropolitan areas, and the presence of an ASES fellowship training program was associated with a greater number of high-volume shoulder surgeons within these geographic regions. The introduction of revision shoulder arthroplasty Current Procedural Terminology codes in 2013 created the opportunity to examine the volume of revision shoulder arthroplasty in the Medicare population. The purpose of this study was to examine the association between high-volume primary and revision arthroplasty surgeons and membership in the ASES. The hypothesis was that whereas primary shoulder arthroplasty surgeries are more commonly performed by non–ASES surgeons, revision shoulder arthroplasty is predominantly performed by ASES members.

Methods

Using the Medicare Physician and Other Supplier Public Use File updated in 2016, surgical volume data from the 2014 calendar year were examined for the Current Procedural Terminology codes related to primary (23470 and 23472) and revision shoulder arthroplasty (23473 and 23474) procedures. Based on the methodology developed to protect patients' privacy, all surgeons who performed <11 of each procedure were excluded by the Centers for Medicare & Medicaid Services. These data represent all procedures performed under traditional Medicare insurance and do not include any patients with managed care or Medicare Advantage insurance plans.

Surgeons performing primary and revision shoulder arthroplasty were then rank ordered on the basis of the total number of shoulder arthroplasties reported, and the top 50 highest volume surgeons were compared with the remaining population of surgeons. Geographic data using provider state codes were analyzed for the highest volume surgeons. In addition, surgeons were subdivided into ASES members and non–ASES members to facilitate comparisons of the association between primary and revision shoulder arthroplasty volume and ASES membership. Surgeons were considered members of the ASES on the basis of those surgeons listed in the 2016 ASES program.

Statistical analysis was performed with the χ2 test to compare the incidence of procedures within each group; in comparing large sample sizes, the Yates correction was used. Mean differences were tested with an unpaired t-test and Mann-Whitney test for parametric and nonparametric data, respectively. An α value < .05 was deemed significant. The software SPSS version 20 (IBM, Armonk, NY, USA) was used for the analysis.

Results

In 2014, a total of 26,886 shoulder arthroplasties were performed by 1074 surgeons. Among surgeons performing shoulder arthroplasty, there was a significant difference between the number of surgeons who were ASES members (16%, 172 surgeons) and the number of surgeons who were nonmembers (84%, 902 surgeons). ASES members performed 28% of all shoulder arthroplasties (7605 procedures), whereas non–ASES members performed 72% of all shoulder arthroplasties (19,281 procedures). The average number of shoulder arthroplasty procedures performed per provider was significantly greater among ASES members compared with non–ASES members (44.2 ± 30.7 vs. 21.4 ± 13.2 procedures per provider; P < .001). ASES members performed 28% (7370 procedures) of the 26,514 primary shoulder arthroplasties (P < .001). Of the 372 revision shoulder arthroplasties reported in Medicare patients, ASES members performed a significantly larger proportion than non–ASES members, reporting 63% (235 procedures) of all revision surgical procedures (P < .001; Table I).

Table I

Shoulder arthroplasty procedures performed by ASES members and non–ASES members in 2014 based on Medicare Part B data

	ASES members	Non–ASES members	Total	P value
Providers performing shoulder arthroplasty	172 (16%)	902 (84%)	1074	<.001
Shoulder arthroplasty procedures performed	7605 (28%)	19,281 (72%)	26,886	<.001
Primary shoulder arthroplasty	7370 (28%)	19,144 (72%)	26,514	<.001
Revision shoulder arthroplasty	235 (63%)	137 (37%)	372	<.001
Average shoulder arthroplasty procedures per provider	44.2 (SD 30.7)	21.4 (SD 13.2)	25.0 (SD 19.2)	<.001

ASES, American Shoulder and Elbow Surgeons; SD, standard deviation.

The top 50 highest volume surgeons included primary and revision shoulder arthroplasty volume that ranged from a total of 62 to 163 procedures (Table II). The top 53 highest volume surgeons were included as there were 5 surgeons who performed 62 procedures (Appendix A). Florida had the largest number of high-volume surgeons with 7 (6 ASES members and 1 non–ASES member), followed by Ohio with 5 (2 ASES members and 3 non–ASES members). New York, Texas, and California each had 4 surgeons in the top 53 (each had 3 ASES members and 1 non–ASES member). Among the top 53 high-volume surgeons, 70% (37 surgeons) were ASES members (P < .001). Within these top 53 providers, a total of 4473 primary shoulder arthroplasties and 227 revision shoulder arthroplasties were reported. ASES members performed a significantly higher percentage of both primary shoulder arthroplasty volume (71%, 3179 procedures; P < .001) and revision shoulder arthroplasty volume (89%, 202 procedures; P < .001).

Table II

Top 50 providers of shoulder arthroplasty according to 2014 Medicare Part B data

	ASES members	Non–ASES members	Total	P value
Top providers performing shoulder arthroplasty*	37 (70%)	16 (30%)	53	<.001
Shoulder arthroplasty procedures performed	3381 (72%)	1319 (28%)	4700	<.001
Primary shoulder arthroplasty	3179 (71%)	1294 (29%)	4473	<.001
Revision shoulder arthroplasty	202 (89%)	25 (11%)	227	<.001
Average shoulder arthroplasty procedures per provider	91.4 (SD 26.9)	82.4 (SD 18.9)	88.7 (SD 25)	.357

ASES, American Shoulder and Elbow Surgeons; SD, standard deviation.

The top 53 providers were included because providers ranked 49 to 53 each performed an equivalent number of shoulder arthroplasty procedures (62).

Discussion

Results of this study highlight the important influential role of the ASES among surgeons who perform high-volume primary and revision shoulder arthroplasty. Among the highest volume surgeons, 70% were ASES members, and 71% of the primary and 89% of the revision shoulder arthroplasties were performed by ASES members.

Interestingly, ASES members performed only 28% of all reported primary shoulder arthroplasties. This is consistent with the findings reported by Hasan et al, who examined the 1998 New York State Center for Medical Consumers database and found that 75% of surgeons who performed shoulder arthroplasty in New York State operated on only 1 or 2 cases. ASES members are often clustered around major metropolitan centers, which have been shown to contain 45% of surgeons who perform >10 shoulder arthroplasties per year.

Revision shoulder arthroplasties, however, were done predominantly by the ASES membership, who performed 63% of all reported revisions. This is not surprising as revisions are typically considered challenging and complex procedures often requiring tertiary referral. The ASES members are committed to the education and investigation of complex shoulder disease and have often created tertiary referral centers for shoulder arthroplasty. The members coordinate annual educational materials, surgical technique courses, journals, and textbooks that help facilitate the management of complex revision shoulder arthroplasty procedures and as a result often create referral networks for these more difficult cases. Furthermore, the ASES sponsors 26 fellowships and promotes both resident and fellow education with great focus on primary and revision shoulder arthroplasty. With the nearly exponential growth of primary shoulder arthroplasty in the past 10 years, the demands for revision shoulder arthroplasty will inevitably increase. Based on the trends observed in this study, the ASES membership will likely bear the burden of a growing demand for revision shoulder arthroplasty.

The positive impact of high surgical volume on the outcomes and complications of shoulder arthroplasty have been well established. Hammond et al reported lower complication rates and length of stay among high-volume surgeons; Singh et al observed improved perioperative metrics, including length of stay, blood loss, and operative times, and Jain et al reported a lower mortality rate when shoulder arthroplasty was performed by higher volume surgeons. Surgeons experienced in higher volume shoulder arthroplasty may be more familiar with the demands of challenging disease and more efficient in the process of care delivery for shoulder arthroplasty, which becomes routine for the surgeon, the hospital, and the entire clinical team.

This study is not without limitations. The data used for this analysis represent only those cases reported by Medicare fee-for-service payments. With an estimated 100,000 shoulder replacements performed in 2014, the 26,886 Medicare shoulder arthroplasty cases represent only a small fraction of the annual cases performed. The assumption is that practice trends observed for Medicare patients would similarly apply to other non–Medicare-insured populations. In addition, surgeons were included only if >10 cases were reported. This likely excluded a large number of surgeons as many shoulder arthroplasties are performed by surgeons who do <5 cases per year.2, 5 As noted, Hasan et al found that in 1998, 75% of shoulder arthroplasty surgeons in New York State performed only 1 or 2 cases. This is further evidenced by the fact that of the 349 ASES members in the United States, only 172 were captured in this analysis. This observation was more likely to influence the numbers of primary arthroplasty, as 61% (227/372 procedures) of the revision shoulder arthroplasties but only 17% (4473/26,514 procedures) of primary shoulder arthroplasties were performed by the top 50 highest volume surgeons. Furthermore, coding practices are critical to the validity of the reported data. If coding was not done accurately, reported primary and revision arthroplasty cases may not be representative of actual practice. Finally, the ASES has recently expanded membership to include candidate members who will be inducted into the society in 2017. ASES members included in this analysis were members as of 2016. With the expanding membership, the proportion of shoulder arthroplasties performed by ASES members will likely increase.

Conclusion

ASES members represent the largest proportion of high-volume shoulder arthroplasty surgeons in the United States. Among the highest volume surgeons, 71% of all primary and 89% of all revision shoulder arthroplasties were performed by ASES members.

Disclaimer

Jonathan C. Levy is a paid consultant for DJO Orthopaedics and Globus Medical and receives royalties from DJO Orthopaedics and Innomed. All the other authors, their immediate families, and any research foundations with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.

The top 53 highest volume total shoulder arthroplasty surgeons according to Medicare Physician and Other Supplier Public Use File data from calendar year 2014

Rank	First name	Last name	State	ASES membership	Primary shoulder arthroplasties	Revision shoulder arthroplasties	Total
1	John	Sperling	MN	Yes	140	23	163
2	Mark	Frankle	FL	Yes	117	31	148
3	Sumant	Krishnan	TX	Yes	116	21	137
4	Reuben	Gobezie	OH	Yes	123	13	136
5	Sean	Grey	CO	No	135		135
6	Jonathan	Levy	FL	Yes	121	12	133
7	Gerald	Williams	PA	Yes	123		123
8	J Michael	Wiater	MI	Yes	115		115
9	David	Weinstein	CO	Yes	104	11	115
10	Armodios	Hatzidakis	CO	Yes	86	27	113
11	Thomas	Edwards	TX	Yes	94	14	108
12	Steven	Hammerman	TX	No	92	12	104
13	Steven	Hattrup	AZ	Yes	102		102
14	Ryan	Krupp	KY	Yes	100		100
15	Kurt	Bormann	MO	No	99		99
16	David	Collins	AR	Yes	86	13	99
17	Patrick	St.Pierre	CA	Yes	94		94
18	Derek	Cuff	FL	Yes	93		93
19	Gregory	Nicholson	IL	Yes	92		92
20	Jeffrey	Lovallo	VA	No	91		91
21	Kary	Schulte	IA	No	89		89
22	Jacob	Stueve	KS	No	88		88
23	Richard	Kirby	WA	No	84		84
24	Kirk	Jensen	CA	Yes	83		83
25	Laurence	Higgins	MA	Yes	82		82
26	Anand	Murthi	MD	Yes	70	12	82
27	David	Dines	NY	Yes	81		81
28	Nathan	Everding	NY	Yes	80		80
29	Kevin	Setter	NY	No	65	13	78
30	Robert	Nowinski	OH	No	77		77
31	Norman	Boardman	VA	Yes	76		76
32	Brian	Cohen	OH	No	75		75
33	Ryan	Simovitch	FL	Yes	75		75
34	Thomas	Throckmorton	TN	Yes	75		75
35	Joseph	Mileti	OH	No	74		74
36	Lawrence	Gulotta	NY	Yes	61	13	74
37	Andrew	Jawa	MA	Yes	73		73
38	Erich	Lingenfelter	MO	Yes	72		72
39	Thomas	Wright	FL	Yes	71		71
40	Edward	Craig	MN	Yes	70		70
41	Matthew	Smith	MO	Yes	70		70
42	Brian	Schofield	FL	No	69		69
43	Jeffrey	Adams	TN	No	67		67
44	Scott	Jacobson	OR	Yes	67		67
45	Curtis	Noel	OH	Yes	66		66
46	William	Pennington	WI	No	65		65
47	Richard	Barton	LA	Yes	64		64
48	Heinz	Hoenecke	CA	Yes	63		63
49	Shadley	Schiffern	NC	No	62		62
50	Thomas	Thomas	CA	No	62		62
51	Wayne	Burkhead	TX	Yes	62		62
52	Mark	Lazarus	PA	Yes	62		62
53	Mark	Mighell	FL	Yes	50	12	62

ASES, American Shoulder and Elbow Surgeons.

Based on Centers for Medicare & Medicaid Services methodology to protect patients' confidentiality, procedures were reported for each provider only if that provider performed at least 11 of a given procedure within the calendar year.