Thomas Wright, MD
This study focused on the effects and risks of bilateral reverse shoulder arthroplasty (rTSA) on internal rotation (IR) in 57 patients. Data was recorded up to two years after the second surgery. The study found that only 15 percent of patients had insufficient IR in both shoulders after 12 months and 5 percent after 24 months. Patients who had insufficient baseline IR in their second shoulder and insufficient IR 12 month post op after their first shoulder had a 100 percent risk of having insufficient IR in both shoulders. The conclusion of this article is a recommendation to use staged bilateral rTSA over the use of a hemiathroplasty. The authors found that the majority of patients would undergo the surgery again, as it does provide benefits, like reduction in pain, regardless of the issues with IR.
The authors of this study focused on the risks of staged bilateral rTSA on internal rotation. I agree with their concern, as bilateral decreased IR could result in difficulties with toileting. In my practice, I stage my bilateral cases; however the timing is up to the patient. I will proceed with the second surgery no sooner than 12 weeks, but I do not recommend waiting as long as a year. In 2014, we published an article on bilateral rTSA1 in which we found all patients eventually had enough IR to allow toileting with at least one shoulder. I agree with the authors and do not recommend using a hemiarthroplasty in the second shoulder, based on the positive results that we had with rTSA.
Although the article showed a 100 percent failure rate in achieving sufficient IR in the second shoulder when it comes to patients who have both insufficient baseline IR and insufficient IR 12 months post op in their first shoulder, we have not noted that to be a problem.
One example is a 79 year old male with symptomatic cuff tear arthropathy on the right and a failed total shoulder arthroplasty (TSA) on the left due to rotator cuff insufficiency.Because of the predictable nature of performing an rTSA as a primary, the right side was addressed first. At three months post-op he had IR to L5.