Characteristics of anatomic and reverse total shoulder arthroplasty patients who achieve ceiling scores with 3 common patient-reported outcome measures

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.

Initial clinical experience with a predictive clinical decision support tool for anatomic and reverse total shoulder arthroplasty

PURPOSE

Clinical decision support tools (CDSTs) are software that generate patient-specific assessments that can be used to better inform healthcare provider decision making. Machine learning (ML)-based CDSTs have recently been developed for anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty to facilitate more data-driven, evidence-based decision making. Using this shoulder CDST as an example, this external validation study provides an overview of how ML-based algorithms are developed and discusses the limitations of these tools.

METHODS

An external validation for a novel CDST was conducted on 243 patients (120F/123M) who received a personalized prediction prior to surgery and had short-term clinical follow-up from 3 months to 2 years after primary aTSA (n = 43) or rTSA (n = 200). The outcome score and active range of motion predictions were compared to each patient's actual result at each timepoint, with the accuracy quantified by the mean absolute error (MAE).

RESULTS

The results of this external validation demonstrate the CDST accuracy to be similar (within 10%) or better than the MAEs from the published internal validation. A few predictive models were observed to have substantially lower MAEs than the internal validation, specifically, Constant (31.6% better), active abduction (22.5% better), global shoulder function (20.0% better), active external rotation (19.0% better), and active forward elevation (16.2% better), which is encouraging; however, the sample size was small.

CONCLUSION

A greater understanding of the limitations of ML-based CDSTs will facilitate more responsible use and build trust and confidence, potentially leading to greater adoption. As CDSTs evolve, we anticipate greater shared decision making between the patient and surgeon with the aim of achieving even better outcomes and greater levels of patient satisfaction.

Influence of Lateralization and Distalization on Joint Function after Primary Reverse Total Shoulder Arthroplasty

The purpose of this study was to investigate how lateralization shoulder angle (LSA) and distalization shoulder angle (DSA) are related to clinical and kinematic outcomes after reverse total shoulder arthroplasty. Thirty-three patients were evaluated at least six months postoperatively. The Single Assessment Numeric Evaluation (SANE), Constant Murley Score (CMS), Simple Shoulder Test (SST), and Visual Analogue Scale (VAS) were used. Shoulder kinematics was evaluated with a stereophotogrammetric system. LSA and DSA inter-rater reliability was analysed through the interclass correlation coefficient (ICC). Stepwise forward linear regression analysis was conducted between LSA and DSA with clinical scales and kinematic measures, between which a correlation analysis was conducted. The inter-rater reliability for LSA (mean ICC = 0.93) and DSA (mean ICC = 0.97) results were good to excellent. Greater LSA values were associated with higher peaks of internal rotation (p = 0.012, R2 = 0.188) and range of motion (ROM) (p = 0.037, R2 = 0.133). SANE (p = 0.009), CMS (p = 0.031), and SST (0.026) were positively correlated to external rotation, while VAS (p = 0.020) was negatively related. Abduction peaks were positively related to CMS (p = 0.011) and SANE (p = 0.037), as well as abduction ROM (SANE, p = 0.031; CMS, p = 0.014).

Quantifying success after reverse total shoulder arthroplasty: the substantial clinically important percentage of maximal possible improvement

BACKGROUND

Changes in preoperative to postoperative outcome scores are often used to quantify success after reverse total shoulder arthroplasty (rTSA). However, ceiling effects associated with many outcome scores limit the ability to differentiate success among high-functioning patients. The percentage of maximal possible improvement (%MPI) was introduced to simplify and better stratify patient success. The primary purpose of this study was to define the %MPI thresholds associated with substantial clinical improvement following primary rTSA and compare the rates of success as defined by those achieving the substantial clinical benefit (SCB) compared to the 30% MPI for different outcome scores.

METHODS

A retrospective review was performed of an international shoulder arthroplasty database between 2003 and 2020. All primary rTSAs performed using a single implant system with a minimum 2-year follow-up were reviewed. Preoperative and postoperative outcome scores were evaluated for all patients to calculate improvement. Six outcome scores were assessed: the Simple Shoulder Test (SST), Constant, American Shoulder and Elbow Surgeons (ASES), University of California Los Angeles (UCLA), Shoulder Pain and Disability Index (SPADI), and Shoulder Arthroplasty Smart (SAS) scores. The proportion of patients achieving the SCB and 30% MPI was determined for each outcome score. Thresholds for the substantial clinically important %MPI (SCI-%MPI) were calculated using an anchor-based method for each outcome score and stratified by age and sex.

RESULTS

Of total, 2573 shoulders with a mean follow-up of 47 months were included. Outcome scores with known ceiling effects (SST, ASES, UCLA, SPADI) had higher rates of patients achieving the 30% MPI compared to scores without ceiling effects (Constant, SAS). However, scores without ceiling effects had higher rates of patients achieving the SCB. The SCI-%MPI differed among outcome scores, and mean values were 47% for the SST, 35% for the Constant score, 50% for the ASES score, 52% for the UCLA score, 47% for the SPADI score, and 45% for the SAS score. The SCI-%MPI increased in patients older than 60 years (P < .001) except for the SAS and Constant scores. SCI-%MPI was greater in females for all scores assessed except the Constant and SPADI scores (P < .001 for all). The higher SCI-%MPI thresholds in these populations mean that these patients required a greater fraction of the MPI to have substantial improvement.

CONCLUSION

The %MPI judged relative to patient-reported substantial clinical improvement offers an alternative method to quickly assess improvements across patient outcome scores. Given considerable variation in the %MPI corresponding to substantial clinical improvement, we recommend utilizing score-specific estimates of the SCI-%MPI to gauge success when evaluating patients undergoing primary rTSA.

Two-year clinical outcomes and complication rates in anatomic and reverse shoulder arthroplasty implanted with Exactech GPS intraoperative navigation

INTRODUCTION

We compared the 2-year clinical outcomes of both anatomic and reverse total shoulder arthroplasty (ATSA and RTSA) using intraoperative navigation compared to traditional positioning techniques. We also examined the effect of glenoid implant retroversion on clinical outcomes.

HYPOTHESIS

In both ATSA and RTSA, computer navigation would be associated with equal or better outcomes with fewer complications. Final glenoid version and degree of correction would not show outcome differences.

MATERIAL AND METHODS

A total of 216 ATSAs and 533 RTSAs were performed using preoperative planning and intraoperative navigation with a minimum of 2-year follow-up. Matched cohorts (2:1) for age, gender, and follow-up for cases without intraoperative navigation were compared using all standard shoulder arthroplasty clinical outcome metrics. Two subanalyses were performed on navigated cases comparing glenoids positioned greater or less than 10° of retroversion and glenoids corrected more or less than 15°.

RESULTS

For ASTA, no statistical differences were found between the navigated and non-navigated cohorts for postoperative complications, glenoid implant loosening, or revision rate. No significant differences were seen in any of the ATSA outcome metrics besides higher internal and external rotation in the navigated cohort. For RTSA, the navigated cohort showed an ARR of 1.7% (95% CI 0%, 3.4%) for postoperative complications and 0.7% (95% CI 0.1%, 1.2%) for dislocations. No difference was found in the revision rate, glenoid implant loosening, acromial stress fracture rates, or scapular notching. Navigated RTSA patients demonstrated significant improvements over non-navigated patients in internal rotation, external rotation, maximum lifting weight, the Simple Shoulder Test (SST), Constant, and Shoulder Arthroplasty Smart (SAS) scores. For the navigated subcohorts, ATSA cases with a higher degree of final retroversion showed significant improvement in pain, Constant, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), SST, University of California-Los Angeles shoulder score (UCLA), and Shoulder Pain and Disability Index (SPADI) scores. No significant differences were found in the RTSA subcohort. Higher degrees of version correction showed improvement in external rotation, SST, and Constant scores for ATSA and forward elevation, internal rotation, pain, SST, Constant, ASES, UCLA, SPADI, and SAS scores for RTSA.

CONCLUSION

The use of intraoperative navigation shoulder arthroplasty is safe, produces at least equally good outcomes at 2 years as standard instrumentation does without any increased risk of complications. The effect of final implant position above or below 10° of glenoid retroversion and correction more or less than 15° does not negatively impact outcomes.

Quantifying success after anatomic total shoulder arthroplasty: the substantial clinically important percentage of maximal possible improvement

BACKGROUND

Percentage maximal possible improvement (%MPI) has been described as a threshold by which to evaluate patient improvement after anatomic total shoulder arthroplasty (aTSA) that has favorable psychometric properties. The primary purpose of this study was to define the percentage maximal possible improvement (%MPI) thresholds associated with substantial clinical improvement following primary anatomic total shoulder arthroplasty (aTSA) and compare the rates of success as defined by those achieving the substantial clinical benefit (SCB) compared with the 30% MPI for different outcome scores.

METHODS

A retrospective review was performed of an international shoulder arthroplasty database between 2003 and 2020. All primary aTSAs performed using a single implant system with minimum 2-year follow-up were reviewed. Pre- and postoperative outcome scores were evaluated for all patients to calculate improvement. Six outcome scores were assessed: the Simple Shoulder Test (SST), Constant, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), University of California-Los Angeles shoulder score (UCLA), Shoulder Pain and Disability Index (SPADI), and Shoulder Arthroplasty Smart (SAS) scores. The proportion of patients achieving the SCB and 30% MPI were determined for each outcome score. Thresholds for the substantial clinically important %MPI (SCI-%MPI) were calculated using an anchor-based method for each outcome score and stratified by age and sex.

RESULTS

A total of 1593 shoulders with a mean follow-up of 59.3 months were included. Outcome scores with known ceiling effects (SST, ASES, UCLA) had higher rates of patients achieving the 30% MPI but not the previously reported SCB compared to scores without ceiling effects (Constant, SAS). The SCI-%MPI differed among outcome scores, and mean values were as follows: 48% for the SST, 39% for the Constant score, 53% for the ASES score, 55% for the UCLA score, 50% for the SPADI score, and 42% for the SAS score. The SCI-%MPI increased in patients older than 60 years (P ≤ .006 for all) and was greater in females for all scores assessed except the Constant score (P < .001 for all), meaning that patients with higher thresholds required a greater fraction of the maximum possible improvement for a given score to have substantial improvement.

CONCLUSION

The %MPI judged relative to patient-reported substantial clinical improvement offers a new method to assess improvements across patient outcome scores. Given considerable variation in the %MPI corresponding to substantial clinical improvement, we recommend utilizing score-specific estimates of the SCI-%MPI to gauge success when evaluating patients undergoing primary aTSA.

Quantifying success after reverse total shoulder arthroplasty: the minimal clinically important percentage of maximal possible improvement

BACKGROUND

In high functioning patients, the ceiling effect associated with many patient-reported outcome measures (PROMs) limits the ability to appropriately stratify success. The percentage maximal possible improvement (%MPI) was introduced as another evaluation tool, with a proposed threshold of success at 30%. It remains unclear if this threshold correlates with perceived patient success following shoulder arthroplasty. The purpose of this study was to compare the proportion of patients that achieved the minimal clinically important difference (MCID) and %MPI for different outcome scores and to define the %MPI thresholds associated with patient satisfaction following primary reverse total shoulder arthroplasty (rTSA).

METHODS

A retrospective review was performed of an international shoulder arthroplasty database between 2003 and 2020. All primary rTSAs performed using a single implant system with minimum 2-year follow-up were reviewed. Pre- and postoperative outcome scores were evaluated for all patients to determine the raw improvement and %MPI. The proportion of patients achieving the MCID and 30% MPI were determined for each outcome score. Thresholds for the minimal clinically important %MPI (MCI-%MPI) were calculated using an anchor-based method for each outcome score and stratified by age and sex.

RESULTS

A total of 2573 shoulders with a mean follow-up of 47 months were included. Outcome scores with known ceiling effects (Simple Shoulder Test [SST], Shoulder Pain and Disability Index [SPADI], University of California-Los Angeles shoulder score [UCLA]) had higher rates of patients achieving the 30% MPI but not the previously reported MCID. Inversely, outcome scores without significant ceiling effects (Constant and Shoulder Arthroplasty Smart [SAS] scores) had higher rates of patients achieving the MCID, but not the 30% MPI. The MCI-%MPI differed among outcome scores and mean values were as follows: 33% for the SST, 27% for the Constant score, 35% for the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score, 43% for the UCLA score, 34% for the SPADI score, and 30% for the SAS score. The MCI-%MPI increased with greater age for SPADI (P < .04) and SAS (P < .01) scores, meaning that patients with higher thresholds required a greater fraction of the possible improvement for a given score to be satisfied but did not reach statistical significance for other scores. Females had a greater MCI-%MPI for the SAS and ASES scores and a lower MCI-MPI% for the SPADI score.

CONCLUSION

The %MPI offers a simple method to quickly assess improvements across patient outcome scores. However, the %MPI that represents patient improvement after surgery is not uniformly the previously established 30% threshold. Surgeons should use score-specific estimates of the MCI-%MPI to gauge success when evaluating patients undergoing primary rTSA.

Quantifying success after anatomic total shoulder arthroplasty: the minimal clinically important percentage of maximal possible improvement

INTRODUCTION

Changes in pre- to postoperative outcome scores are often used to quantify success after anatomic total shoulder arthroplasty (aTSA). However, ceiling effects associated with many outcome scores limit the ability to differentiate success among high-functioning patients. The percentage maximal possible improvement (%MPI) was introduced to better stratify patient success; however, it is unclear if the 30% threshold first proposed correlates with perceived patient success across all outcome scores. The purpose of this study was to compare the proportion of patients that achieved the minimal clinically important difference (MCID) and %MPI for different outcome scores and to define the %MPI thresholds associated with patient satisfaction following primary aTSA.

METHODS

A retrospective review was performed of an international shoulder arthroplasty database between 2003 and 2020. All primary aTSAs performed using a single implant system with minimum 2-year follow-up were reviewed. Pre- and postoperative outcome scores were evaluated for all patients to calculate improvement. The proportion of patients achieving the MCID and 30% MPI were determined for each outcome score. Thresholds for the minimal clinically important %MPI (MCI-%MPI) were calculated using an anchor-based method for each outcome score and stratified by age and sex.

RESULTS

1593 shoulders with a mean follow-up of 59.3 months were included. Outcome scores with known ceiling effects (Simple Shoulder Test [SST], American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES], University of California-Los Angeles shoulder score [UCLA]) had higher rates of patients achieving the 30% MPI but not the previously reported MCID. Inversely, outcome scores without significant ceiling effects (Constant and Shoulder Arthroplasty Smart [SAS] scores) had higher rates of patients achieving the MCID but not the 30% MPI. The MCI-%MPI differed among outcome scores, and mean values were as follows: 33% for the SST, 24% for the Constant score, 32% for the ASES score, 38% for the UCLA score, 30% for the Shoulder Pain and Disability Index score, and 33% for the SAS score. The MCI-%MPI increased with greater age (P < .003) and females had thresholds greater than or equal to males for all scores assessed, meaning that patients with higher thresholds required a greater fraction of the possible improvement for a given score to be satisfied.

CONCLUSION

The %MPI offers a simple method to quickly assess improvements across patient outcome scores. However, the %MPI that represents patient improvement after surgery is not uniformly the previously established 30% threshold. Surgeons should use score-specific estimates of the MCI-%MPI to gauge success when evaluating patients undergoing primary aTSA.

Mid-Term to Long-Term Follow-Up of Stemless Anatomic Total Shoulder Arthroplasty

Background

The purpose was to report mid-term to long-term clinical outcomes in a multicentre series of patients who received stemless total shoulder arthroplasty (TSA). The hypothesis was that stemless TSA would be a safe and effective treatment with satisfactory clinical outcomes.

Methods

Authors retrospectively reviewed records of 62 stemless TSAs implanted between March 2013 and December 2014. Six were excluded because they had fractures or muscular impairment, which left 56: primary osteoarthritis (n = 49), rheumatoid arthritis (n = 4), avascular necrosis (n = 1), or glenoid dysplasia (n = 2). Outcomes were absolute Constant Score (CS), age-/sex-adjusted CS, and the American Shoulder and Elbow Surgeons (ASES) score. Proportions of patients that achieved substantial clinical benefits for absolute CS and ASES scores were determined.

Results

Of the 56 patients, 8 (14%) died (unrelated to TSA), 5 (9%) were lost to follow-up, and 2 (4%) refused participation. One patient was reoperated for infection with implant removal (excluded from analysis), and one for periprosthetic fracture without implant removal. At 7.6 ± 0.5 years (range 6.8-9.3), the remaining 40 patients, aged 71.0 ± 8.5 years, achieved net improvements of 40.7 ± 15.8 (CS), 62%±23% (age-/sex-adjusted CS), and 59.7 ± 16.4 (ASES). Of patients with complete absolute CS (n = 37) and ASES score (n = 28), respectively, 33 (89%) and 27 (96%) achieved substantial clinical benefits.

Conclusions

Stemless TSA yields improvements in functional outcomes at mid-term to long-term that exceed the substantial clinical benefits of the absolute CS and ASES score at a mean follow-up of 7.6 years. Although the findings of this study revealed low complications and revision rates, more studies are needed to confirm long-term benefits of stemless TSA.

Level of evidence

IV, case series.