Has anatomic TSA become a ‘lost art’ with the increased use of RSA?
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Anatomic TSA may produce the best shoulder
Since the FDA approved reverse shoulder arthroplasty in 2004, the orthopedic world has become enamored with this technology.
My personal observations from an established shoulder specialty practice are that the reverse prosthesis has become the colloquial hammer in a world of shoulder pathology that increasingly looks like nails. While the value of RSA is unarguably in treating many complex shoulder conditions, I maintain that anatomic TSA remains the treatment of choice in most cases of glenohumeral arthritis with an intact rotator cuff.
General orthopedic surgeons and shoulder surgeons alike have increased their use of RSA since its introduction, even in patients with an intact rotator cuff. This trend has occurred both in Europe and North America. Reasons for this include that RSA tends to be a more forgiving procedure, relying less on technical specifics (soft tissue balancing, implant size, etc.) to achieve a consistent result. Additionally, subscapularis dehiscence, a potentially devasting complication in anatomic TSA, has little impact on the clinical results of RSA.
Although I concede that RSA is preferred in certain cases of primary osteoarthritis (severe glenoid bone loss), I continue to opt for anatomic TSA in most of my patients with glenohumeral arthritis and an intact rotator cuff. The native shoulder is a miraculous anatomic structure. Whether one believes in intelligent design, the “big bang,” evolution or a combination thereof, one cannot deny the superlative form and function of the nonpathological human shoulder. I maintain that if the human shoulder is better in a reverse configuration, humans would have already evolved to have a reverse shoulder without the use of metal or plastic.
Additionally, my best results in my anatomic TSA patients far exceed my best results in my reverse patients. Other authors have reported similar findings. Although anatomic TSA may take a little more time and technical expertise to perform and carries with it the possibility of subscapularis failure, I continue to strive to obtain the best shoulder possible for my patients, and this is done with anatomic TSA in the majority of my patients.
- References:
- Edwards TB, et al. Shoulder Arthroplasty, 2nd Edition. Elsevier, Philadelphia, 2019.
- Kiet TK, et al. J Shoulder Elbow Surg. 2015;doi:10.1016/j.jse.2014.06.039.
T. Bradley Edwards, MD, is at the Fondren Orthopedic Research Institute and Texas Orthopedic Hospital in Houston.
RSA, anatomic TSA both show promise
Innovation in shoulder arthroplasty products along with expanding indications has led to the increased incidence of shoulder arthroplasty nearing 200,000 cases per year. Utilization of reverse shoulder arthroplasty has also increased substantially, approaching 70% of all cases. Many surgeons have advocated RSA for shoulder arthritis, particularly as patients age. Understanding of the complication rates for both anatomic and reverse shoulder arthroplasty have further refined the indications.
Anatomic TSA results in published studies have routinely demonstrated superior outcomes for range of motion and patient-reported outcomes scores vs. RSA. The primary causes for revisions of anatomic TSA are failure of the rotator cuff and loosening of the glenoid component. With the availability of 3D surgical planning and improved prosthetic design, surgeons are more capable of reproducing the premorbid humeral and glenoid anatomy. Results from anatomic TSA have improved over time. However, when there is compromised rotator cuff function, the results of RSA equal or surpass the outcomes with anatomic TSA, and current literature would suggest RSA has improved longevity in this patient population.
Early generation shoulder implants created challenges to reproduce the center of rotation of the humeral head and achieve anatomic correction of glenoid deformity. The surgeon was the method required to obtain good results when minimal implant options existed. Today’s surgeons have more tools at their disposal with regard to preoperative planning and the ability to achieve anatomic restoration through better understanding of the pathologic shoulder, implant design options and improved surgical techniques. The “art” has perhaps become less challenging, allowing lower volume surgeons to achieve the results previously only possible in experts’ hands. The results of anatomic TSA continue to improve.
The functional results in terms of range of motion and strength for everyday life and light recreational activities favor anatomic TSA over RSA. Clinically relevant subscapularis failure is rare. However, glenoid loosening, as well as revision challenges due to osteolysis, remains a persistent issue. Similarly, advances in RSA have allowed surgeons to achieve good results despite significant shoulder pathology. RSA results continue to improve, as well, but complications, including scapular spine stress fractures, remain a significant problem. In older patients, RSA patient-reported outcomes are similar to anatomic TSA. Remarkably, in the presence of rotator cuff disease and significant glenoid deformity, RSA offers a more predictable outcome and lower revision rates.
The “art” of anatomic shoulder replacement is not lost and, in fact, has substantially improved over time.
- References:
- Gill DRJ, et al. Clin Orthop Relat Res. 2021;doi:10.1097/CORR.0000000000001869.
- Kim H, et al. J Orthop Traumatol. 2022;doi:10.1186/s10195-022-00625-y.
- Poondla RK, et al. J Shoulder Elbow Surg. 2021;doi:10.1016/j.jse.2020.08.030.
Evan S. Lederman, MD, is chief of sports medicine at Banner Health and clinical professor of orthopedic surgery at University of Arizona College of Medicine — Phoenix in Phoenix.
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