DISCUSSION
Utilization of TSA has continued to rise; however, access to this cost-effective procedure was recently demonstrated to be limited.11 In a separate analysis, we established the continued rise in use of TSA in the Medicare population, coupled with an increase in the number of surgeons routinely performing TSA.2 Multiple analyses have demonstrated the importance of high-volume surgeons and hospitals familiar with the intricacies of shoulder arthroplasty concepts in minimizing complications, improving the quality and decreasing the cost of TSA.6,10,17 Specifically, Singh and colleagues18 demonstrated from a multi-center registry that surgeons and hospitals with greater shoulder arthroplasty volumes had decreased intra-operative blood loss, operative time, and hospital length of stay. As the demand for TSA, both anatomic and reverse, continues to rise, it is imperative that the healthcare delivery system is optimized to provide the best possible care. Before we can determine whether specialized training in shoulder arthroplasty influences surgical outcomes, characteristics and training of surgeons performing TSA should be described.
The number of surgeons performing >10 TSA in the Medicare population rose significantly between 2012 and 2014 (29.3%). However, the number of TSAs per surgeon over this time period remained consistent (approximately 25 per surgeon). Furthermore, the increase in the number of surgeons performing a reportable volume of TSA by 2014 was from the addition of already active surgeons (ie, the growth in TSA was not from the addition of newly trained arthroplasty surgeons but originated from the existing orthopedic surgeon workforce). In a recently published analysis, Somerson and colleagues, 11 using this same dataset, demonstrated persistent limitations in access to high-volume TSA surgeons. In a more recent analysis, we showed that while still lacking for some patients, access to a high-volume TSA surgeon has improved significantly over the past 3 years, with 96.9% of the United States population residing within 200 kilometers of a high-volume TSA surgeon (>20 Medicare cases).2 This analysis validates those findings, with the caveat that the average annual volume per surgeon is not increasing. What remains unknown, due to limitations of this dataset, is how many surgeons are not identified because they are performing ≤10 TSA each year or are performing TSA in non-Medicare patients.
With the specialization of healthcare delivery, specifically in orthopedics, it is imperative that mechanisms for providing specialty-focused care be established. However, the proportion of their practice that surgeons dedicate to TSA was unknown. This study demonstrates that this proportion is increasing. Including non-arthroplasty procedures, more than half (58%) of the procedures performed by this surgeon cohort were shoulder-specific. Furthermore, this analysis demonstrates that surgeons performing TSA have significant case diversity, including nearly half of the cohort performing TKA. Repeated evidence has demonstrated the effect of case volume on improved outcomes following orthopedic procedures.8,19–21 The pre-existing location-based model for delivering orthopedic care supports case diversity; however, this model continues to be challenged with high-volume centers of excellence and patient travel.22–24 Hip and knee arthroplasty experienced a similar surge in demand, with a subsequent shift in care to high-volume surgeons and centers.25 Shoulder and elbow fellowship-trained surgeons would need to nearly quadruple their current Medicare TSA volume to meet the entire current demand for TSA in the Medicare population (and this does not account for TSA performed by very low-volume surgeons not included in this cohort). With increased utilization of TSA, policymakers and the orthopedic community must determine the structure of delivery (centers of excellence or medium-volume disseminated throughout the country) that is optimal.
For those surgeons consistently performing TSA over the study period, fellowship training was diverse. While the current focus in orthopedics is on case volume, research in other specialties, namely general surgery, has provided repeated evidence that surgical specialization (more so than high case volume) provides improved outcomes.26–29Furthermore, Leopold and colleagues30 demonstrated an inverse relationship between competency in performing a procedure and confidence in one’s ability to do so. In their study, educational intervention provided improved competency in the procedure. Less than one-third (29.8%) of TSA in this cohort were performed by a shoulder and elbow fellowship-trained surgeon consistently performing this procedure. Approximately another quarter (26.2%) were performed by consistent TSA surgeons trained in sports surgery. Meanwhile, 34.6% of TSA in this study cohort were performed by a surgeon who did not consistently meet the minimum threshold in all study years (16,435 TSA; 22.8%) or by a surgeon performing TSA without fellowship training (8,489 TSA; 11.8%). There has been a trend toward orthopedic subspecialty training with an increased demand for fellowship-trained surgeons.31 Despite this and the complexities of TSA, many continue to be performed by surgeons with an inconsistent volume and those without arthroplasty-specific fellowship training. The available evidence supports a push toward the fellowship-trained, high-volume TSA surgeon in providing reproducible high-quality shoulder arthroplasty care. For now, that surgeon is more likely to be earlier in his/her career and reside in large, referral-based centers surrounded by other surgeons performing TSA.
These findings must be considered in the light of the study limitations. First, this is a large publicly available database. While this type of database provides a unique opportunity to assess the geographic distributions and characteristics of orthopedic surgeons, specifically those performing TSA, it completely prevents any assessment of the relationship between these findings and quality. As such, while the reader may generate hypotheses regarding the implications of our findings on the quality of TSA delivery, the true effects cannot be determined. In the same vein, for the purpose of privacy, surgeons performing ≤10 TSA were not included in this dataset. This limitation prevents the identification of low-volume TSA surgeons. Also, it is likely that the observed increase in surgeons over time is likely a reflection of small increases in volume for surgeons already performing TSA. Lastly, a web-based search was undertaken to identify surgeons’ self-reported fellowship training. The results of this web-based search could not be validated, and it is possible that fellowship training, or the lack thereof, was mischaracterized and simply not obtainable through a web-based search. Furthermore, it is not possible to fully assess the extent of high-quality TSA training in these various fellowships.
CONCLUSION
In just the past decade, the utilization of TSA in the Medicare population has increased significantly. However, this increase was not achieved by the addition of highly specialized, high-volume surgeons but by the addition of many surgeons performing lower numbers of TSA surgeries. Furthermore, for those performing this cost-effective procedure, TSA constitutes a relatively small proportion of the surgeries they perform. Shoulder and elbow fellowship-trained surgeons currently account for a low percentage of the overall number of surgeons performing TSA. The implications of these findings must be considered and investigated.