Bilateral total shoulder arthroplasty: A systematic review of clinical outcomes

Does achieving clinically important thresholds after first shoulder arthroplasty predict similar outcomes of the contralateral shoulder?

BACKGROUND

Patients are increasingly undergoing bilateral total shoulder arthroplasty (TSA). At present, it is unknown whether success after the first TSA is predictive of success after contralateral TSA. We aimed to determine whether exceeding clinically important thresholds of success after primary TSA predicts similar outcomes for subsequent contralateral TSA.

METHODS

We performed a retrospective review of a prospectively collected shoulder arthroplasty database for patients undergoing bilateral primary anatomic (aTSA) or reverse (rTSA) total shoulder arthroplasty since January 2000 with preoperative and 2- or 3-year clinical follow-up. Our primary outcome was whether exceeding clinically important thresholds in the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score for the first TSA was predictive of similar success of the contralateral TSA; thresholds for the ASES score were adopted from prior literature and included the minimal clinically important difference (MCID), the substantial clinical benefit (SCB), 30% of maximal possible improvement (MPI), and the patient acceptable symptomatic state (PASS). The PASS is defined as the highest level of symptom beyond which patients consider themselves well, which may be a better indicator of a patient's quality of life. To determine whether exceeding clinically important thresholds was independently predictive of similar success after second contralateral TSA, we performed multivariable logistic regression adjusted for age at second surgery, sex, BMI, and type of first and second TSA.

RESULTS

Of the 134 patients identified that underwent bilateral shoulder arthroplasty, 65 (49%) had bilateral rTSAs, 45 (34%) had bilateral aTSAs, 21 (16%) underwent aTSA/rTSA, and 3 (2%) underwent rTSA/aTSA. On multivariable logistic regression, exceeding clinically important thresholds after first TSA was not associated with greater odds of achieving thresholds after second TSA when success was evaluated by the MCID, SCB, and 30% MPI. In contrast, exceeding the PASS after first TSA was associated with 5.9 times greater odds (95% confidence interval 2.5-14.4, P < .001) of exceeding the PASS after second TSA. Overall, patients who exceeded the PASS after first TSA exceeded the PASS after second TSA at a higher rate (71% vs. 29%, P < .001); this difference persisted when stratified by type of prosthesis for first and second TSA.

CONCLUSIONS

Patients who achieve the ASES score PASS after first TSA have greater odds of achieving the PASS for the contralateral shoulder regardless of prostheses type.

Outcomes after bilateral shoulder arthroplasty: a systematic review

The purpose of this systematic review was to report outcomes after bilateral shoulder arthroplasty including bilateral total shoulder arthroplasty (TSA), bilateral reverse shoulder arthroplasty (RSA), and ipsilateral TSA with contralateral RSA (TSA/RSA). Two reviewers independently performed a PRISMA-guided systematic search using MEDLINE/PubMed, Embase, and Cochrane Database of Systematic Reviews up to May 11, 2021. The databases were queried using the following search terms: (["bilateral" OR "contralateral"] AND "shoulder" AND ["arthroplast∗" OR "replacement"]). A total of 486 titles/abstracts were screened for eligibility and 19 studies were included in the final analysis. Risk of bias was assessed using Methodological Index for Nonrandomized Studies and Modified Coleman Methodology scores. Analysis compared overall results for bilateral shoulder arthroplasty and sub-group analyses compared TSA (all shoulders from bilateral TSA patients and the TSA shoulder in TSA/RSA patients) to RSA (all shoulders from bilateral RSA patients and the RSA shoulder in TSA/RSA patients), first shoulder arthroplasty to second contralateral shoulder arthroplasty, and interval between arthroplasty (IBA) <20 months to IBA ≥20 months. Nineteen studies analyzed bilateral TSA (n = 3), bilateral RSA (n = 7), and TSA/RSA (n = 8). The mean Methodological Index for Nonrandomized Studies was 18 and mean Modified Coleman Methodology Score was 74, with 63.2% of studies demonstrating level III evidence. A total of 2729 patients (30.4% male; mean age 72.2 years, mean follow-up 47.3 months, mean IBA 20 months) were analyzed. Postoperative forward flexion (142.0° vs. 129.6°), external rotation (ER) (42.5° vs. 25.6°), and internal rotation (60% reaching T12-T8 vs 85.7% reaching L3-L1) were higher for TSA when compared to RSA. Patient reported outcome measures such as Constant-Murley (73.2 vs. 59.2), American Shoulder and Elbow Surgeons (87.9 vs. 77.7), and Single Assessment Numeric Evaluation (SANE) (86.9 vs. 67.8) were higher for TSA when compared to RSA. Patients with IBA ≥20 months demonstrated greater ER and patient satisfaction than patients with IBA <20 months. Postoperative complication rates were 15.1% for TSA and 10.6% for RSA, while reoperation and revision rates were 13.7% for TSA and 7.1% for RSA. Bilateral shoulder arthroplasty results in improvements in motion, strength, pain, function, and high satisfaction. Bilateral TSA is associated with greater improvement in motion and function than bilateral RSA but higher complication, reoperation, and revision rates. IBA ≥20 months is associated with greater ER and satisfaction than IBA <20 months.

Side-to-side differences in postoperative function and patient satisfaction after bilateral total shoulder arthroplasties

BACKGROUND

As the number of anatomic and reverse total shoulder arthroplasty (TSA) procedures increase, there will be a natural increase in patients who undergo staged bilateral TSA procedures. Bilateral TSAs have been shown to improve patient outcomes; however, it is unknown whether these patients experience side-to-side differences in clinical outcomes and satisfaction between shoulders. Understanding these differences is imperative for accurate patient and provider expectations.

METHODS

An international multicenter registry was used to identify patients who underwent staged bilateral TSAs from April 2007 to October 2019 with a minimum of 2-year follow-up. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) outcomes and satisfaction ratings were compared between dominant and nondominant shoulders, and first and second arthroplasties. Side-to-side differences in postoperative ASES and unequal satisfaction ratings were also explored by using regression analyses to identify potential factors influencing these differences.

RESULTS

A total of 60 patients (22 bilateral anatomic TSAs, 38 bilateral reverse TSAs) were identified for inclusion. Group analyses revealed that bilateral TSA patients demonstrated similar functional outcomes and satisfaction regardless of dominance and surgery sequence. Type of TSA, specifically bilateral reverse TSAs, significantly predicted greater side-to-side differences in postoperative ASES scores (P = .025), indicating reverse TSA patients demonstrated greater between-sides differences in postoperative functional outcomes compared with those undergoing anatomic TSAs. Additionally, a larger proportion of bilateral reverse TSA patients reported unequal satisfaction between shoulders (31.6%) compared with anatomic TSA patients (9.1%). Logistic regression analysis revealed that greater side-to-side differences in postoperative ASES scores were found to increase the likelihood of reporting unequal satisfaction between shoulders (odds ratio 1.11, P < .001), which may explain this outcome.

CONCLUSIONS

Most patients who undergo bilateral TSAs can expect similar outcomes on both shoulders regardless of dominance and surgery sequence. However, we did find patients who had discordant results between shoulders. Those who underwent reverse TSAs more frequently reported unequal satisfaction with their TSA procedures, which is likely due to larger side-to-side differences in postoperative function. It is unclear why these differences occurred, but this information may be important for providers to remember when counseling these patients for accurate postoperative expectations.