Risk factors for complications and revision surgery after anatomic and reverse total shoulder arthroplasty

Impact of accumulating risk factors on the incidence of dislocation after primary reverse total shoulder arthroplasty using a medial glenoid-lateral humerus onlay prosthesis

BACKGROUND

The aim of this study was to facilitate preoperative identification of patients at risk for dislocation after reverse total shoulder arthroplasty (rTSA) using the Equinoxe rTSA prosthesis (medialized glenoid, lateralized onlay humerus with a 145° neck-shaft angle) and quantify the impact of accumulating risk factors on the occurrence of dislocation.

METHODS

We retrospectively analyzed 10,023 primary rTSA patients from an international multicenter database of a single platform shoulder prosthesis and quantified the dislocation rate associated with multiple combinations of previously identified risk factors. To adapt our statistical results for prospective identification of patients most at-risk for dislocation, we stratified our data set by multiple risk factor combinations and calculated the odds ratio for each cohort to quantify the impact of accumulating risk factors on dislocation.

RESULTS

Of the 10,023 primary rTSA patients, 136 (52 female, 83 male, 1 unknown) were reported to have a dislocation for a rate of 1.4%. Patients with zero risk factors were rare, where only 12.7% of patients (1268 of 10,023) had no risk factors, and only 0.5% of these (6 of 1268) had a report of dislocation. The dislocation rate increased in patient cohorts with an increasing number of risk factors. Specifically, the dislocation rate increased from 0.9% for a patient cohort with 1 risk factor to 1.0% for 2 risk factors, 1.6% for 3 risk factors, 2.7% for 4 risk factors, 5.3% for 5 risk factors, and 7.3% for 6 risk factors. Stratifying dislocation rate by multiple risk factor combinations identified numerous cohorts with either an elevated risk or a diminished risk for dislocation.

DISCUSSION

This multicenter study of 10,023 rTSA patients demonstrated that 1.4% of the patients experienced dislocation with one specific medialized glenoid-lateralized humerus onlay rTSA prosthesis. Stratifying patients by multiple combinations of risk factors demonstrated the impact of accumulating risk factors on the incidence of dislocation. rTSA patients with the greatest risk of dislocation were those of male sex, age ≤67 years at the time of surgery, patients with body mass index ≥31, patients who received cemented humeral stems, patients who received glenospheres having a diameter >40 mm, and/or patients who received expanded or laterally offset glenospheres. Patients with these risk factors who are considering rTSA using a medial glenoid-lateral humerus should be made aware of their elevated dislocation risk profile.

Shoulder arthroplasty for inflammatory arthritis is associated with higher rates of medical and surgical complications: a nationwide matched cohort analysis from 2016-2020

BACKGROUND

Inflammatory arthritis (IA) represents a less common indication for anatomic and reverse total shoulder arthroplasty (TSA) than osteoarthritis (OA). The safety and efficacy of anatomic and reverse TSA in this population has not been as well studied compared to OA. We analyzed the differences in outcomes between IA and OA patients undergoing TSA.

METHODS

Patients who underwent primary anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) from 2016-2020 were identified in the Premier Healthcare Database. Inflammatory arthritis (IA) patients were identified using International Classification of Diseases, Tenth Revision, diagnosis codes and compared to osteoarthritis controls. Patients were matched in a 1:8 fashion by age (±3 years), sex, race, and presence of pertinent comorbidities. Patient demographics, hospital factors, and patient comorbidities were compared. Multivariate regression was performed following matching to account for any residual confounding and 90-day complications were compared between the 2 cohorts. Descriptive statistics and regression analysis were employed with significance set at P < .05.

RESULTS

Prior to matching, 5685 IA cases and 93,539 OA controls were identified. Patients with IA were more likely to be female, have prolonged length of stay and increased total costs (P < .0001). After matching and multivariate analysis, 4082 IA cases and 32,656 controls remained. IA patients were at increased risk of deep wound infection (OR 3.14, 95% CI 1.38-7.16, P = .006), implant loosening (OR 4.11, 95% CI 1.17-14.40, P = .027), and mechanical complications (OR 6.34, 95% CI 1.05-38.20, P = .044), as well as a decreased risk of postoperative stiffness (OR 0.36, 95% CI 0.16-0.83, P = .002). Medically, IA patients were at increased risk of PE (OR 2.97, 95% CI 1.52-5.77, P = .001) and acute blood loss anemia (OR 1.27, 95% CI 1.12-1.44, P < .0001).

DISCUSSION AND CONCLUSION

Inflammatory arthritis represents a distinctly morbid risk profile compared to osteoarthritis patients with multiple increased surgical and postoperative medical complications in patients undergoing aTSA and rTSA. Surgeons should consider these potential complications and employ a multidisciplinary approach in preoperative risk stratification of IA undergoing shoulder replacement.

Clinical outcomes of anatomic vs. reverse total shoulder arthroplasty in primary osteoarthritis with preoperative external rotation weakness and an intact rotator cuff: a case-control study

BACKGROUND

Anatomic (aTSA) and reverse total shoulder arthroplasty (rTSA) are well-established treatments for patients with primary osteoarthritis and an intact cuff. However, it is unclear whether aTSA or rTSA provides superior outcomes in patients with preoperative external rotation (ER) weakness.

METHODS

A retrospective review of a prospectively collected shoulder arthroplasty database was performed between 2007 and 2020. Patients were excluded for preoperative diagnoses of nerve injury, infection, tumor, or fracture. The analysis included 333 aTSAs and 155 rTSAs performed for primary cuff-intact osteoarthritis with 2-year minimum follow-up. Defining preoperative ER weakness as strength <3.3 kilograms (7.2 pounds), 3 cohorts were created and matched: (1) weak aTSAs (n = 74) vs. normal aTSAs (n = 74), (2) weak rTSAs (n = 38) vs. normal rTSAs (n = 38), and (3) weak rTSAs (n = 60) vs. weak aTSAs (n = 60). We compared range of motion, outcome scores, strength, complications, and revision rates at the latest follow-up.

RESULTS

Despite weak aTSAs having poorer preoperative strength in forward elevation and ER (P < .001), neither of these deficits persisted postoperatively compared with the normal cohort. Likewise, weak rTSAs had poorer preoperative strength in forward elevation and ER, overhead motion, and Constant, Shoulder Pain and Disability Index, and University of California, Los Angeles scores (P < .029). However, no statistically significant differences were found between preoperatively weak and normal rTSAs. When comparing weak aTSA vs. weak rTSA, no differences were found in preoperative and postoperative outcomes, proportion of patients achieving the minimal clinically important difference and substantial clinical benefit, and complication and rate of revision surgery.

CONCLUSIONS

In preoperatively weak patients with cuff-intact primary osteoarthritis, aTSA leads to similar postoperative strength, range of motion, and outcome scores compared with patients with normal preoperative strength, indicating that preoperative weakness does not preclude aTSA use. Furthermore, patients who were preoperatively weak in ER demonstrated improved postoperative rotational motion after undergoing aTSA and rTSA, with both groups achieving the minimal clinically important difference and substantial clinical benefit at similar rates.

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.

Utility of Patient Reported Outcome Measurement Information System measures in predicting shoulder arthroplasty in patients with shoulder osteoarthritis

BACKGROUND

The decision to treat shoulder osteoarthritis (OA) definitively with shoulder arthroplasty (SA) is multifactorial, considering objective findings, subjective information, and patient goals. The first goal of this study was to determine if Patient Reported Outcome Measurement Information System (PROMIS) measures correlated with patients with shoulder OA who underwent SA within 1 year. The second goal of this study was to determine if score cut-offs in PROMIS domains could further discriminate which shoulder OA patients underwent SA within 1 year.

METHODS

This retrospective case-control study examined patients with a diagnosis of shoulder OA who consulted an orthopedic provider from November 1, 2020 to May 23, 2022, and recorded PROMIS measures in the domains of Physical Function, Depression, and/or Pain Interference. A surgical group was defined as patients who underwent SA within 1 year of the most recent PROMIS measures and the nonsurgical patients were defined as the control group. Mean PROMIS scores were compared between the surgical and control groups. Separate logistic regression models controlling for age, race, ethnicity, and comorbidity count were performed for each PROMIS domain as a 1) continuous variable, and then as 2) binary variable defined by PROMIS score cut-off points to determine which scores correlated with undergoing SA to further characterize the potential clinical utility of PROMIS score cut-offs in relating to undergoing SA.

RESULTS

The surgical group of 478 patients was older (68.2 vs. 63.8 years), more often of White race (82.6% vs. 70.9%), and less often of Hispanic Ethnicity (1.5% vs. 2.9%) than the control group of 3343 patients. Using optimal cut-offs in PROMIS scores, Pain Interference ≥63 (odds ratio [OR] = 2.97 (2.41-3.64), P < .001), Physical Function ≤39 (OR = 1.81 (95% confidence interval, 1.48-2.22), P < .001), and depression ≥49 (OR = 1.82 (95% confidence interval, 1.50-2.22), P < .001) were all found to correlate with undergoing SA within 1 year in multivariable logistic regressions.

CONCLUSION

The results of this study demonstrate that cut-off scores for PROMIS measures differentiated patients undergoing SA within 1 year. These cut-off scores may have clinical utility in aiding in decision-making regarding surgical candidates for SA. Further research is needed to validate these cut-off scores and determine how they relate to patient outcomes after SA.

Revision reverse shoulder arthroplasty for the management of baseplate failure: an analysis of 676 revision reverse shoulder arthroplasty procedures

BACKGROUND

Baseplate failure in reverse shoulder arthroplasty (RSA) is a rare but potentially catastrophic complication owing to poor patient outcomes and significant glenoid bone loss. The purpose of this study was to report on the prevalence, causes, and outcomes of revision RSA (rRSA) for baseplate failure or loosening.

METHODS

A retrospective review of our institutional database was performed to identify all patients treated for a failed RSA from 2006 to 2021 who required revision to another RSA (rRSA) performed by a single surgeon. A total of 676 failed RSA procedures were identified, and further analysis identified 46 patients (6.8%) who underwent rRSA for baseplate failure with a confirmed loose baseplate at the time of rRSA. The primary outcome was repeated failure of the reimplanted baseplate following rRSA. The mode of failure associated with baseplate failure was stratified into 1 of 3 groups: aseptic, septic, or traumatic. Twenty-four patients underwent primary revision, and 22 had undergone >1 previous arthroplasty prior to undergoing re-revision. Five patients underwent previous rRSA for baseplate failure performed by an outside surgeon. The criteria for secondary outcome analysis of final American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, and range of motion were met by 32 patients and 23 patients at 1- and 2-year follow-up, respectively.

RESULTS

Three patients (6.5%) had repeated baseplate failure requiring re-revision; 2 had baseplate failure at <1 year with associated periprosthetic infections and underwent conversion to hemiarthroplasty. The third patient experienced traumatic failure at 10 years and underwent successful rRSA. The mean American Shoulder and Elbow Surgeons scores at 1 and 2 years were 62.3 and 61.7, respectively. There was no significant difference in outcomes based on mode of baseplate failure (P = .232) or total arthroplasty burden (P = .305) at 1 year. There were 13 total complications in 11 patients, 5 of which required reoperation for reasons other than baseplate failure.

CONCLUSION

In this study, rRSA for baseplate failure constituted 6.8% of all revisions performed over a period of 15 years. Re-revision for recurrent baseplate failure was required in 3 of 46 patients (6.5%). Complications and reoperation rates were higher than those for primary RSA but outcomes were comparable for revision of failed anatomic shoulder arthroplasty.

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

BACKGROUND

When patients require reoperation after primary shoulder arthroplasty, revision reverse total shoulder arthroplasty (rTSA) is most commonly performed. However, defining clinically important improvement in these patients is challenging because benchmarks have not been previously defined. Furthermore, although the minimal clinically important difference and substantial clinical benefit are commonly used to assess clinically relevant success, these metrics are limited by ceiling effects that may cause inaccurate estimates of patient success. Our purpose was to define the minimal and substantial clinically important percentage of maximal possible improvement (MCI-%MPI and SCI-%MPI) for commonly used pain and functional outcome scores after revision rTSA and to quantify the proportion of patients achieving clinically relevant success.

METHODS

This retrospective cohort study used a prospectively collected single-institution database of patients who underwent first revision rTSA between August 2015 and December 2019. Patients with a diagnosis of periprosthetic fracture or infection were excluded. Outcome scores included the American Shoulder and Elbow Surgeons (ASES), raw and normalized Constant, Shoulder Pain and Disability Index (SPADI), Simple Shoulder Test (SST), and University of California, Los Angeles (UCLA) scores. We used an anchor-based method to calculate the MCI-%MPI and SCI-%MPI. In addition, we calculated the MCI-%MPI using a distribution-based method for historical comparison. The proportions of patients achieving each threshold were assessed. The influence of sex, type of primary shoulder arthroplasty, and reason for revision rTSA were also assessed by calculating cohort-specific thresholds.

RESULTS

Ninety-three revision rTSAs with minimum 2-year follow-up were evaluated. The mean age of the patients was 67 years; 56% were female, and the average follow-up was 54 months. Revision rTSA was performed most commonly for failed anatomic TSA (n = 47), followed by hemiarthroplasty (n = 21), rTSA (n = 15), and humeral head resurfacing (n = 10). The indication for revision rTSA was most commonly glenoid loosening (n = 24), followed by rotator cuff failure (n = 23) and subluxation and unexplained pain (n = 11 for both). The anchor-based MCI-%MPI thresholds (% of patients achieving) were ASES = 33% (49%), raw Constant = 23% (64%), normalized Constant = 30% (61%), UCLA = 51% (53%), SST = 26% (68%), and SPADI = 29% (58%). The anchor-based SCI-%MPI thresholds (% of patients achieving) were ASES = 55% (31%), raw Constant = 41% (27%), normalized Constant = 52% (22%), UCLA = 66% (37%), SST = 74% (25%), and SPADI = 49% (34%).

CONCLUSIONS

This study is the first to establish thresholds for the MCI-%MPI and SCI-%MPI at minimum 2 years after revision rTSA, providing physicians an evidence-based method to assess patient outcomes postoperatively.

Impact of Deltoid Computer Tomography Image Data on the Accuracy of Machine Learning Predictions of Clinical Outcomes after Anatomic and Reverse Total Shoulder Arthroplasty

Background: Despite the importance of the deltoid to shoulder biomechanics, very few studies have quantified the three-dimensional shape, size, or quality of the deltoid muscle, and no studies have correlated these measurements to clinical outcomes after anatomic (aTSA) and/or reverse (rTSA) total shoulder arthroplasty in any statistically/scientifically relevant manner. Methods: Preoperative computer tomography (CT) images from 1057 patients (585 female, 469 male; 799 primary rTSA and 258 primary aTSA) of a single platform shoulder arthroplasty prosthesis (Equinoxe; Exactech, Inc., Gainesville, FL) were analyzed in this study. A machine learning (ML) framework was used to segment the deltoid muscle for 1057 patients and quantify 15 different muscle characteristics, including volumetric (size, shape, etc.) and intensity-based Hounsfield (HU) measurements. These deltoid measurements were correlated to postoperative clinical outcomes and utilized as inputs to train/test ML algorithms used to predict postoperative outcomes at multiple postoperative timepoints (1 year, 2-3 years, and 3-5 years) for aTSA and rTSA. Results: Numerous deltoid muscle measurements were demonstrated to significantly vary with age, gender, prosthesis type, and CT image kernel; notably, normalized deltoid volume and deltoid fatty infiltration were demonstrated to be relevant to preoperative and postoperative clinical outcomes after aTSA and rTSA. Incorporating deltoid image data into the ML models improved clinical outcome prediction accuracy relative to ML algorithms without image data, particularly for the prediction of abduction and forward elevation after aTSA and rTSA. Analyzing ML feature importance facilitated rank-ordering of the deltoid image measurements relevant to aTSA and rTSA clinical outcomes. Specifically, we identified that deltoid shape flatness, normalized deltoid volume, deltoid voxel skewness, and deltoid shape sphericity were the most predictive image-based features used to predict clinical outcomes after aTSA and rTSA. Many of these deltoid measurements were found to be more predictive of aTSA and rTSA postoperative outcomes than patient demographic data, comorbidity data, and diagnosis data. Conclusions: While future work is required to further refine the ML models, which include additional shoulder muscles, like the rotator cuff, our results show promise that the developed ML framework can be used to evolve traditional CT-based preoperative planning software into an evidence-based ML clinical decision support tool.

Clinical outcomes of anatomical versus reverse total shoulder arthroplasty in patients with primary osteoarthritis, an intact rotator cuff, and limited forward elevation

Aims

Both anatomical and reverse total shoulder arthroplasty (aTSA and rTSA) provide functional improvements. A reported benefit of aTSA is better range of motion (ROM). However, it is not clear which procedure provides better outcomes in patients with limited foward elevation (FE). The aim of this study was to compare the outcome of aTSA and rTSA in patients with glenohumeral osteoarthritis (OA), an intact rotator cuff, and limited FE.

Methods

This was a retrospective review of a single institution's prospectively collected shoulder arthroplasty database for TSAs undertaken between 2007 and 2020. A total of 344 aTSAs and 163 rTSAs, which were performed in patients with OA and an intact rotator cuff with a minimum follow-up of two years, were included. Using the definition of preoperative stiffness as passive FE ≤ 105°, three cohorts were matched 1:1 by age, sex, and follow-up: stiff aTSAs (85) to non-stiff aTSAs (85); stiff rTSAs (74) to non-stiff rTSAs (74); and stiff rTSAs (64) to stiff aTSAs (64). We the compared ROMs, outcome scores, and complication and revision rates.

Results

Compared with non-stiff aTSAs, stiff aTSAs had poorer passive FE and active external rotation (ER), whereas there were no significant postoperative differences between stiff rTSAs and non-stiff rTSAs. There were no significant differences in preoperative function when comparing stiff aTSAs with stiff rTSAs. However, stiff rTSAs had significantly greater postoperative active and passive FE (p = 0.001 and 0.004, respectively), and active abduction (p = 0.001) compared with stiff aTSAs. The outcome scores were significantly more favourable in stiff rTSAs for the Shoulder Pain and Disability Index, Simple Shoulder Test, American Shoulder and Elbow Surgeons score, University of California, Los Angeles score, and the Constant score, compared with stiff aTSAs. When comparing the proportion of stiff aTSAs versus stiff rTSAs that exceeded the minimal clinically important difference and substantial clinical benefit, stiff rTSAs achieved both at greater rates for all measurements except active ER. The complication rate did not significantly differ between stiff aTSAs and stiff rTSAs, but there was a significantly higher rate of revision surgery in stiff aTSAs (p = 0.007).

Conclusion

Postoperative overhead ROM, outcome scores, and rates of revision surgery favour the use of a rTSA rather than aTSA in patients with glenohumeral OA, an intact rotator cuff and limited FE, with similar rotational ROM in these two groups.

No difference in complications between two-week vs. six-week duration of sling immobilization after reverse total shoulder arthroplasty

Background

The purpose of our study was to compare the outcomes and complications after a two- vs. six-week duration of sling immobilization following reverse total shoulder arthroplasty (rTSA).

Methods

We conducted a retrospective review from our institutional database on 960 patients treated by primary rTSA between 2011 and 2021. Patients were separated into two cohorts of postoperative sling immobilization (a two-week and six-week group). Multivariate analysis was conducted to evaluate what factors were associated with patients experiencing either a postoperative complication or requiring reoperation.

Results

A total of 276 patients were instructed to keep their operative arm in a sling for six weeks postoperatively, and 684 patients discontinued use at two weeks. There was no difference in postoperative complication rate (15.0% vs. 12.0%, P = .21), dislocation rate (P = .79), acromion stress fractures (P = .06), implant loosening (P = .15), and periprosthetic joint infections (P = .48) between the six- and two-week sling cohorts. In the immediate 90-day postoperative time period, no difference was seen in the reoperation rates (P = .73).

Discussion

Shorter duration of sling immobilization (two weeks) does not incur additional risk of complications compared to standard duration (six weeks) of sling immobilization following rTSA.

Developing a machine learning algorithm to predict the probability of aseptic loosening of the glenoid component after anatomical total shoulder arthroplasty: protocol for a retrospective, multicentre study

INTRODUCTION

Despite technological advancements in recent years, glenoid component loosening remains a common complication after anatomical total shoulder arthroplasty (ATSA) and is one of the main causes of revision surgery. Increasing emphasis is placed on the prevention of glenoid component failure. Previous studies have successfully predicted range of motion, patient-reported outcomes and short-term complications after ATSA using machine learning methods, but an accurate predictive model for (glenoid component) revision is currently lacking. This study aims to use a large international database to accurately predict aseptic loosening of the glenoid component after ATSA using machine learning algorithms.

METHODS AND ANALYSIS

For this multicentre, retrospective study, individual patient data will be compiled from previously published studies reporting revision of ATSA. A systematic literature search will be performed in Medline (PubMed) identifying all studies reporting outcomes of ATSA. Authors will be contacted and invited to participate in the Machine Learning Consortium by sharing their anonymised databases. All databases reporting revisions after ATSA will be included, and individual patients with a follow-up less than 2 years or a fracture as the indication for ATSA will be excluded. First, features (predictive variables) will be identified using a random forest feature selection. The resulting features from the compiled database will be used to train various machine learning algorithms (stochastic gradient boosting, random forest, support vector machine, neural network and elastic-net penalised logistic regression). The developed and validated algorithms will be evaluated across discrimination (c-statistic), calibration, the Brier score and the decision curve analysis. The best-performing algorithm will be used to create an open-access online prediction tool.

ETHICS AND DISSEMINATION

Data will be collected adhering to the WHO regulation on data sharing. An Institutional Review Board review is not applicable. The study results will be published in a peer-reviewed journal.

The lifetime revision risk of primary anatomic and reverse total shoulder arthroplasty

BACKGROUND

Implant survival in total shoulder arthroplasty (TSA) is currently defined with reference to a set time period (eg, 5-year implant survival). This is a difficult concept for patients to understand, especially for younger patients who have more years of life remaining. Our study aims to calculate a patient's lifetime revision risk after primary anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty-a more meaningful projection of revision risk over a patient's remaining lifetime.

METHODS

The New Zealand Joint Registry (NZJR) and national death data was used to calculate the incidence of revision and mortality in all patients who underwent primary aTSA and rTSA in New Zealand between 1999 and 2021. Lifetime revision risk was calculated using previously described methods, and this risk was stratified by age (46-90 years, 5-year bins), sex, and procedure type (aTSA and rTSA).

RESULTS

In total, there were 4346 patients in the aTSA cohort and 7384 patients in the rTSA cohort. Lifetime revision risk was highest in the youngest age group (46-50 years) at 35.8% (95% CI 34.5%-37.0%) for aTSA and 30.9% (95% CI 29.9%-32.0%) for rTSA, with risk decreasing with increasing age. Across all age groups, the lifetime revision risk was higher for aTSA compared to rTSA. By sex, females reported higher lifetime revision risk for each age group in the aTSA cohort whereas males reported higher lifetime revision risk for each group in the rTSA cohort.

CONCLUSIONS

Our study demonstrates that younger patients have higher lifetime revision risk after total shoulder arthroplasty. Our results highlight the long-term revision risks associated with the trend of offering shoulder arthroplasty to younger patients. The data may be used among various health care stakeholders to inform the surgical decision-making process and plan for future health care resource use.

Quantifying success after first revision reverse total shoulder arthroplasty: the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptomatic state

BACKGROUND

When patients require revision of primary shoulder arthroplasty, revision reverse total shoulder arthroplasty (rTSA) is most commonly performed. However, defining clinically important improvement in these patients is challenging because benchmarks have not been previously defined. Our purpose was to define the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for outcome scores and range of motion (ROM) after revision rTSA and to quantify the proportion of patients achieving clinically relevant success.

METHODS

This retrospective cohort study used a prospectively collected single-institution database of patients undergoing first revision rTSA between August 2015 and December 2019. Patients with a diagnosis of periprosthetic fracture or infection were excluded. Outcomes scores included the ASES, raw and normalized Constant, SPADI, SST, and University of California, Los Angeles (UCLA) scores. ROM measures included abduction, forward elevation (FE), external rotation (ER), and internal rotation (IR) score. Anchor-based and distribution-based methods were used to calculate the MCID, SCB, and PASS. The proportions of patients achieving each threshold were assessed.

RESULTS

Ninety-three revision rTSAs with minimum 2-year follow-up were evaluated. Mean age was 67 years, 56% were female, and average follow-up was 54 months. Revision rTSA was performed most commonly for failed anatomic TSA (n = 47), followed by hemiarthroplasty (n = 21), rTSA (n = 15), and resurfacing (n = 10). The indication for revision rTSA was most commonly glenoid loosening (n = 24), followed by rotator cuff failure (n = 23), subluxation and unexplained pain (n = 11 for both). The anchor-based MCID thresholds (% of patients achieving) were as follows: ASES, 20.1 (42%); normalized Constant, 12.6 (80%); UCLA, 10.2 (54%); SST, 0.9 (78%); SPADI, -18.4 (58%); abduction, 13° (83%); FE, 18° (82%); ER, 4° (49%); and IR, 0.8 (34%). The SCB thresholds (% of patients achieving) were as follows: ASES, 34.1 (25%); normalized Constant, 26.6 (43%); UCLA, 14.1 (28%); SST, 3.9 (48%); SPADI, -36.4 (33%); abduction, 20° (77%); FE, 28° (71%); ER, 15° (15%); and IR, 1.0 (29%). The PASS thresholds (% of patients achieving) were as follows: ASES, 63.5 (53%); normalized Constant, 59.1 (61%); UCLA, 25.4 (48%); SST, 7.0 (55%); SPADI, 42.4 (59%); abduction, 98° (61%); FE, 110° (56%); ER, 19° (73%); and IR, 3.3 (59%).

CONCLUSIONS

This study establishes thresholds for the MCID, SCB, and PASS at minimum 2-years after revision rTSA, providing physicians an evidence-based method to counsel patients and assess patient outcomes postoperatively.

Similar rates of revision surgery following primary anatomic compared with reverse shoulder arthroplasty in patients aged 70 years or older with glenohumeral osteoarthritis: a cohort study of 3791 patients

BACKGROUND

Reverse total shoulder arthroplasty (RTSA), initially indicated for cuff tear arthropathy, is increasingly used to treat elderly patients with primary glenohumeral osteoarthritis (GHOA) and an intact rotator cuff. This is often done to avoid revision surgery in elderly patients for rotator cuff failure with anatomic total shoulder arthroplasty (TSA) despite traditionally good outcomes of TSA. We sought to determine whether there was a difference in outcomes in patients aged ≥70 years who received RTSA vs. TSA for GHOA.

METHODS

A retrospective cohort study was conducted using data from a US integrated health care system's shoulder arthroplasty registry. Patients aged ≥70 years who underwent primary shoulder arthroplasty for GHOA with an intact rotator cuff were included (2012-2021). RTSA was compared with TSA. Multivariable Cox proportional hazard regression was used to evaluate all-cause revision risk during follow-up, whereas multivariable logistic regression was used to evaluate 90-day emergency department (ED) visits and 90-day readmissions.

RESULTS

The final study sample comprised 685 RTSA patients and 3106 TSA patients. The mean age was 75.8 years (standard deviation, 4.6 years), and 43.4% of patients were men. After accounting for confounders, we observed no significant difference in all-cause revision risk for RTSA vs. TSA (hazard ratio, 0.79; 95% confidence interval [CI], 0.39-1.58). The most common reason for revision following RTSA was glenoid component loosening (40.0%). Over half of revisions following TSA were for rotator cuff tear (54.0%). No difference based on procedure type was observed in the likelihood of 90-day ED visits (odds ratio, 0.94; 95% CI, 0.71-1.26) and 90-day readmissions (odds ratio, 1.32; 95% CI, 0.83-2.09).

CONCLUSION

RTSA and TSA for GHOA with an intact rotator cuff in patients aged ≥70 years had a similar revision risk, as well as a similar likelihood of 90-day ED visits and readmissions. Although revision risk was similar, the most common causes of revision were different, with rotator cuff tears in TSA patients and glenoid component loosening in RTSA patients.

Reverse shoulder arthroplasty renders better clinical scores at a minimum follow-up of two years for patients with no rotator cuff deficiency operated by the deltopectoral approach

PURPOSE

The purpose of this multi-centre study was to report outcomes of a large cohort of reverse shoulder arthroplasty (RSA) at a minimum follow-up of two years and to determine patient and surgical factors that influence postoperative outcomes. The hypothesis was that surgical indication, surgical approach, and implant design would affect clinical outcomes significantly.

METHODS

The authors reviewed records of 743 RSAs in patients with primary osteoarthritis (OA) with or without rotator cuff (RC) tears, secondary OA due to RC tears, and irreparable massive rotator cuff tears (mRCT). The deltopectoral (DP) approach was used in 540 and the anterosuperior (AS) approach in 203. Pre- and postoperative Constant scores (CS) were recorded. Multivariable linear analyses were performed to determine if CS was associated with indications for surgery, surgical approach, or implant design.

RESULTS

Of the 743 shoulders, 193 (25.7%) were lost to follow-up, 16 (2.1%) died, and 33 (4.4%) were revised, leaving 501 for analysis. At a mean follow-up of 3.2 ± 0.9 years, net improvement in CS was 29.2 ± 17.0. Multivariable analyses revealed that postoperative CS decreased with age and was worse in shoulders that had preoperative rotator cuff deficiency and in shoulders operated by the AS approach. Multivariable analyses also revealed worse net improvement in shoulders operated for secondary OA due to RC tears or for irreparable mRCT, as well as shoulders operated by the AS approach.

CONCLUSION

This large multi-centre study confirms that, at two or more years following RSA, Constant scores are not associated with implant design, but rather with rotator cuff deficiency and surgical approach. Multivariable analysis revealed that postoperative CS was worse for shoulders with preoperative rotator cuff deficiency and for shoulders operated by the AS approach. Multivariable analysis also revealed that net improvement in CS was worse in shoulders treated for secondary OA due to RC tears and for shoulders with irreparable mRCT, as well as for shoulders operated by the AS approach.

Incidence of primary anatomic and reverse total shoulder arthroplasty in patients less than 50 years of age and high early revision risk

BACKGROUND

Compared with the overall incidence of shoulder arthroplasty (SA), the relative risk and burden of revision may vary among patients specifically 40-50 years of age and less than 40 years of age. Our aim was to investigate the incidence of primary anatomic total SA and reverse SA, rate of revision within 1 year, and determine the associated economic burden in patients younger than 50 years.

METHODS

A total of 509 patients less than 50 years old who underwent SA were included, using a national private insurance database. Costs were based on the grossed covered payment. Multivariate analyses were performed to identify risk factors associated with revisions within 1 year of the index procedure.

RESULTS

SA incidence in patients less than 50 years old increased from 2.21 to 2.5 per 100,000 patients from 2017 to 2018. The overall revision rate was 3.9% with a mean time to revision of 96.3 days. Diabetes was a significant risk factor for revision (P = .043). Surgeries performed in patients less than 40 years old cost more than those performed in patients aged 40-50 years for both primary ($41,943 ± $23,842 vs. $39,477 ± $20,874) and revision cases ($40,370 ± $21,385 vs. $31,669 ± $10,430).

CONCLUSIONS

This study demonstrates that the incidence of SA in patients less than 50 years old is higher than previously reported in the literature and most commonly reported for primary osteoarthritis. Given the high incidence of SA and subsequent high early revision rate in this subset population, our data portend a large associated socioeconomic burden. Policymakers and surgeons should use these data for implementing training programs focused on joint sparing techniques.

The Value of Computer-Assisted Navigation for Glenoid Baseplate Implantation in Reverse Shoulder Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Glenoid baseplate malpositioning during reverse total shoulder arthroplasty can contribute to perimeter impingement, dislocation, and loosening. Despite advances in preoperative planning, conventional instrumentation may lead to considerable inaccuracy in implant positioning unless patient-specific guides are used. Optical navigation has the potential to improve accuracy and precision when implanting a reverse shoulder arthroplasty baseplate. This systematic review aimed to analyze the most recent evidence on the accuracy and precision of glenoid baseplate positioning using intraoperative navigation and its potential impact on component selection and surgical time.

METHODS

We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. The PubMed, Scopus, and EMBASE databases were queried in July 2022 to identify all studies that compared navigation vs. conventional instrumentation for reverse shoulder arthroplasty. Data of deviation from the planned baseplate version and inclination, the use of standard or augmented glenoid components, and surgical time were extracted. Quantitative analysis from the included publications was performed using the inverse-variance approach and Mantel-Haenszel method.

RESULTS

Of the 2,048 records identified in the initial query, only 10 articles met the inclusion and exclusion criteria, comprising 667 shoulders that underwent reverse total shoulder arthroplasty. The pooled mean difference (MD) of the deviation from the planned baseplate position for the clinical studies was -0.44 (95% confidence interval [CI], -3.26; p = 0.76; I2 = 36%) for version and -8.75 (95% CI, -16.83 to -0.68; p = 0.02; I2 = 83%) for inclination, both in favor of navigation. The odds ratio of selecting an augmented glenoid component after preoperative planning and navigation-assisted surgery was 8.09 (95% CI, 3.82-17.14; p < 0.00001; I2 = 60%). The average surgical time was 12 minutes longer in the navigation group (MD 12.46, 95% CI, 5.20-19.72; p = 0.0008; I2 = 71%).

CONCLUSIONS

Preoperative planning integrated with computer-assisted navigation surgery seems to increase the accuracy and precision of glenoid baseplate inclination compared with the preoperatively planned placement during reverse total shoulder arthroplasty. The surgical time and proportion of augmented glenoid components significantly increase when using navigation. However, the clinical impact of these findings on improving prosthesis longevity, complications, and patient functional outcomes is still unknown.

LEVEL OF EVIDENCE

Level III, systematic review and meta-analysis. See Instructions for Authors for a complete description of levels of evidence.

Comparison of long-term clinical and radiological outcomes for cemented keel, cemented peg, and hybrid cage glenoids with anatomical total shoulder arthroplasty using the same humeral component

Aims

The aim of this study was to longitudinally compare the clinical and radiological outcomes of anatomical total shoulder arthroplasty (aTSA) up to long-term follow-up, when using cemented keel, cemented peg, and hybrid cage peg glenoid components and the same humeral system.

Methods

We retrospectively analyzed a multicentre, international clinical database of a single platform shoulder system to compare the short-, mid-, and long-term clinical outcomes associated with three designs of aTSA glenoid components: 294 cemented keel, 527 cemented peg, and 981 hybrid cage glenoids. Outcomes were evaluated at 4,746 postoperative timepoints for 1,802 primary aTSA, with a mean follow-up of 65 months (24 to 217).

Results

Relative to their preoperative condition, each glenoid cohort had significant improvements in clinical outcomes from two years to ten years after surgery. Patients with cage glenoids had significantly better clinical outcomes, with higher patient-reported outcome scores and significantly increased active range of motion, compared with those with keel and peg glenoids. Those with cage glenoids also had significantly fewer complications (keel: 13.3%, peg: 13.1%, cage: 7.4%), revisions (keel: 7.1%, peg 9.7%, cage 3.5%), and aseptic glenoid loosening and failure (keel: 4.7%, peg: 5.8%, cage: 2.5%). Regarding radiological outcomes, 70 patients (11.2%) with cage glenoids had glenoid radiolucent lines (RLLs). The cage glenoid RLL rate was 3.3-times (p < 0.001) less than those with keel glenoids (37.3%) and 4.6-times (p < 0.001) less than those with peg glenoids (51.2%).

Conclusion

These findings show that good long-term clinical and radiological outcomes can be achieved with each of the three aTSA designs of glenoid component analyzed in this study. However, there were some differences in clinical and radiological outcomes: generally, cage glenoids performed best, followed by cemented keel glenoids, and finally cemented peg glenoids.

How common is nerve injury after reverse shoulder arthroplasty? A systematic review

BACKGROUND

Nerve injury following reverse shoulder arthroplasty (RSA) is a known risk factor with wide ranging incidences reported. This systematic review evaluates the overall incidence of nerve injury following primary and revision RSA and summarizes the characteristics of the nerve injuries reported in the current literature.

METHODS

A systematic review was performed using separate database searches (Pubmed, Embase, Web of Science, Cochrane) following the PRISMA guidelines. Search criteria included the title terms "reverse shoulder," "reverse total shoulder," "inverted shoulder," and "inverted total shoulder" with publication dates ranging from 01/01/2010 to 01/01/2022. Studies that reported neurological injuries and complications were included and evaluated for primary RSA, revision RSA, number of nerve injuries, and which nerves were affected.

RESULTS

After exclusion, our systematic review consisted of 188 articles. A total of 40,146 patients were included, with 65% female. The weighted mean age was 70.3 years. The weighted mean follow-up was 35.4 months. The rate of nerve injury after RSA was 1.3% (510 of 40,146 RSAs). The rate of injury was greater in revision RSA compared to primary RSA (2.4% vs. 1.3%). Nerve injury was most common in RSAs done for a primary diagnosis of acute proximal humerus fracture (4.0%), followed by cuff tear arthropathy (3.0%), DJD (2.6%), and inflammatory arthritis (1.7%). Massive rotator cuff tears and post-traumatic arthritis cases had the lowest nerve injury rates (1.0% and 1.4%, respectively). The axillary nerve was the most commonly reported nerve that was injured in both primary and revision RSA (0.6%), followed by the ulnar nerve (0.26%) and median nerve (0.23%). Brachial plexus injury was reported in 0.19% of overall RSA cases.

CONCLUSION

Based on current English literature, nerve injuries occur at a rate of 1.3% after primary RSA compared with 2.4% after revision RSA. The most common nerve injury was to the axillary nerve (0.64%), with the most common operative diagnosis associated with nerve injury after RSA being acute proximal humerus fracture (4.0%). Surgeons should carefully counsel patients prior to surgery regarding the risk of nerve injury.

The Association of Benign Prostatic Hyperplasia on Postoperative Complications and Periprosthetic Joint Infections Following Total Shoulder Arthroplasty

Background

A recently proposed risk factor for periprosthetic joint infections (PJI) in men is benign prostatic hyperplasia (BPH). The objective was to explore the association of BPH on 1) 90-day complications, 2) length of stay (LOS), 3) readmission rates, and 4) healthcare expenditures following total shoulder arthroplasty (TSA).

Methods

A retrospective query was performed using a nationwide claims database from January 2005 to March 2014 for male patients undergoing primary TSA. The study cohort included 5067 patients with BPH while 50,720 patients served as the comparison cohort. Logistic regression determined the association of BPH on complications and readmissions. A p value less than 0.001 was significant.

Results

Patients with BPH had higher incidence and odds (36.8 vs. 6.2%; OR: 2.73, p < 0.0001) of all ninety-day medical complications including PJIs (0.49 vs. 0.32%; OR: 1.54, p < 0.001). BPH patients had longer in-hospital LOS (3- vs. 2-days, p < 0.0001). Study group patients had higher 90-day episode of care reimbursements ($13,653 vs. $12,688), p < 0.0001).

Conclusions

BPH is associated with increased complications and healthcare expenditures following total shoulder arthroplasty. The investigation can be used to educate BPH patients of the possible adverse events which may occur within ninety-days following primary TSA for the treatment of glenohumeral osteoarthritis.

Survivorship after reverse total shoulder arthroplasty and predictors of 1-year and overall mortality

BACKGROUND

Patient survivorship and risk factors of mortality after reverse total shoulder arthroplasty (RTSA) are seldom and inadequately studied. The purpose of this study was to evaluate the mortality rates and predictors of 1-year and overall mortality after RTSA.

METHODS

We retrospectively reviewed 1518 consecutive adult patients who underwent RTSA at our institution. The Social Security Death Index and institutional electronic medical records were queried to verify patient living status. Patients were censored at date of death if deceased, the date that living status was verified if alive, or latest follow-up if living status could not be verified. Mortality rates and risk factors of 1-year and overall mortality after RTSA were identified on univariate and multivariate analysis.

RESULTS

Mean follow-up was 5.1 ± 3.8 years. Thirty-day (0.1%), 90-day (0.7%), and 1-year (1.8%) mortality rates were low but increased to 11% at 5 years. Increased odds of 1-year mortality were independently associated with heart disease (odds ratio [OR] 2.64, 95% confidence interval [CI] 1.07-6.50, P = .035) and use of a cemented stem (OR 2.64, 95% CI 1.04-6.69, P = .041). Independent risk factors of overall mortality included older age at surgery (hazard ratio [HR] 1.05, 95% CI 1.03-1.07, P < .001), minority ethnicity (protective risk factor, HR 0.37, 95% CI 0.15-0.91, P = .031), heart disease (HR 1.42, 95% CI 1.00-2.02, P = .048), diabetes mellitus (HR 1.47, 95% CI 1.04-2.08, P = .028), tobacco use (HR 1.79, 95% CI 1.08-2.98, P = .025), post renal transplant (HR 12.69, 95% CI 3.92-41.05, P < .001), chronic liver failure (HR 4.40, 95% CI 1.38-14.09, P = .013), and receiving a cemented stem (HR 1.60, 95% CI 1.13-2.26, P = .008).

CONCLUSIONS

RTSA carries a low risk of short-term mortality postoperatively. When counseling patients preoperatively, surgeons should consider the predictors of mortality after RTSA reported herein to ensure appropriate patient selection and counseling.

Survivorship analysis of revision reverse total shoulder arthroplasty

BACKGROUND

The expansion of indications for reverse total shoulder arthroplasty (RTSA) has resulted in a rapid increase in the incidence of subsequent revision procedures. The purpose of this study was to identify the incidence and risk factors for re-revision shoulder arthroplasty after first revision RTSA.

METHODS

We retrospectively queried our institutional shoulder arthroplasty database of prospectively collected data from 2003 to 2019. To assess revision implant survival, patients were censored on the date of re-revision surgery or, if the revision arthroplasty was not revised, at the most recent follow-up or their date of death. Patients with a prior infection, concern for infection at the time of revision, antibiotic spacer, or oncologic indication for primary arthroplasty were excluded. A total of 186 revision RTSAs were included, with 32 undergoing re-revision shoulder arthroplasty. The Kaplan-Meier method and bivariate Cox regression were used to assess the relationship of patient and surgical characteristics on implant survivorship. Multivariate Cox regression was performed to identify independent predictors of re-revision.

RESULTS

Re-revision shoulder arthroplasty was most commonly performed for instability (34%), infection (28%), and glenoid loosening (19%). Overall re-revision rates at 6 months (7%), 1 year (9%), and 2 years (13%) were relatively low; however, the rate of re-revision increased at 5 years (35%). Men underwent re-revision more often than women within the first 6 months after revision RTSA (12% vs. 2%; P = .025), but not thereafter. On multivariate analysis, increased estimated blood loss was associated with a greater risk of undergoing re-revision shoulder arthroplasty (hazard ratio: 41.16 [3.34-506.50]; P = .004).

CONCLUSION

The rate of re-revision after revision RTSA is low in the first 2 years postoperatively (13%) but increases to 35% at 5 years. Increased estimated blood loss, which may reflect greater operative complexity, was identified as a risk factor that may confer an increased chance of re-revision after revision RTSA. Knowledge of risk factors for re-revision after revision RTSA can aid surgeons and patients in preoperative counseling.

Safety and short-term outcomes of anatomic vs. reverse total shoulder arthroplasty in an ambulatory surgery center

BACKGROUND

A scarcity of literature exists comparing outcomes of outpatient anatomic (aTSA) and reverse total shoulder arthroplasty (rTSA). This study was performed to compare early outcomes between the 2 procedures in a freestanding ambulatory surgery center (ASC) and to determine if the addition of preoperative interscalene nerve block (ISNB) with periarticular liposomal bupivacaine injection (PAI) in the postanesthesia care unit (PACU) would improve outcomes over PAI alone.

METHODS

Medical charts of all patients undergoing outpatient primary aTSA or rTSA at 2 ASCs from 2012 to 2020 were reviewed. A total of 198 patients were ultimately identified (117 aTSA and 81 rTSA) to make up this retrospective cohort study. Patient demographics, PACU outcomes, complications, readmissions, reoperations, calls to the office, and unplanned clinic visit rates were compared between procedures. PACU outcomes were compared between those receiving ISNB with PAI and those receiving PAI alone.

RESULTS

Patients undergoing rTSA were older (61.1 vs. 55.7 years, P < .001) and more likely to have American Society of Anesthesiologists (ASA) class 3 (51.9% vs. 41.0%, P = .050) compared to patients having aTSA. No patient required an overnight stay. Time in the PACU before discharge (89.1 vs. 95.6 minutes, P = .231) and pain scores at discharge (3.0 vs. 3.0, P = .815) were similar for aTSA and rTSA, respectively. One intraoperative complication occurred in the aTSA group (posterior humeral circumflex artery injury) and 1 in the rTSA group (calcar fracture) (P = .793). Ninety-day postoperative total complication (7.7% vs. 7.4%), shoulder-related complication (6.0% vs. 6.2%), medical-related complication (1.7% vs. 1.2%), admission (0.8% vs. 2.5%), reoperation (2.6% vs. 1.2%), and unplanned clinic visit (6.0% vs. 6.1%) rates were similar between aTSA and rTSA, respectively (P ≥ .361 for all comparisons). At 1 year, there were 8 reoperations and 15 complications in the aTSA group compared with 1 reoperation and 8 complications in the rTSA group (P = .091 and P = .818, respectively). Patients who had ISNB spent less time in PACU (75 vs. 97 minutes, P < .001), had less pain at discharge (0.2 vs. 3.9, P < .001), and consumed less oral morphine equivalents in the PACU (1.2 vs. 16.6 mg, P < .001).

CONCLUSION

Early postoperative outcomes and complication rates were similar between the 2 groups, and all patients were successfully discharged home the day of surgery. The addition of preoperative ISNB led to more efficient discharge from the ASC with less pain in the PACU.

Higher rates of mortality and perioperative complications in patients undergoing primary shoulder arthroplasty and a history of previous stroke

BACKGROUND

Cerebrovascular accidents (CVAs), or strokes, are the second most common cause of mortality and third most common cause of disability worldwide. Although advances in the treatment of strokes have improved survivorship following these events, there remains a limited understanding of the effect of a prior stroke and sequelae on patients undergoing shoulder arthroplasty (SA). This study aimed to determine the outcomes of patients with a history of stroke with sequela undergoing primary SA.

METHODS

Over a 30-year time period (1990-2020), 205 primary SAs (32 hemiarthroplasties [HAs], 56 anatomic total shoulder arthroplasties [aTSAs], and 117 reverse shoulder arthroplasties [RSAs]) were performed in patients who sustained a previous stroke with sequela and were followed for a minimum of 2 years. This cohort was matched (1:2) according to age, sex, body mass index, implant, and year of surgery with patients who had undergone HA or aTSA for osteoarthritis or RSA for cuff tear arthropathy. Mortality after primary SA was individually calculated through a cumulative incidence analysis. Implant survivorship was analyzed with a competing risk model selecting death as the competing risk.

RESULTS

The stroke cohort sustained 38 (18.5%) surgical and 42 (20.5%) medical perioperative complications. Compared with the control group, the stroke cohort demonstrated higher rates of any surgical complication (18.5% vs 10.7%; P = .007), instability (6.3 % vs 1.7%; P = .002), venous thromboembolism (3.4% vs 0.5%; P = .004), pulmonary embolus (2.0% vs 0%; P = .005), postoperative stroke (2.4% vs 0%; P = .004), respiratory failure (1.0% vs 0%; P = .045), any medical complication (20.5% vs 7.3%; P < .001), and 90-day readmission (16.6% vs 4.9%; P < .001). Additionally, RSA in the stroke cohort was associated with higher reoperation (8.5% vs 2.6%; P = .011) and revision rates (6.8% vs 1.7%; P = .013) compared with the matched cohort. Subsequent cumulative incidences of death at 1, 2, 5, 10, 15, and 20 years were 4.4% vs 3.4%, 10.7% vs 5.1%, 25.6% vs 14.7%, 51.6% vs 39.3%, 74.3% vs 58.6%, and 92.6% vs 58.6% between the stroke and matched cohorts, respectively (P < .001).

CONCLUSIONS

A preoperative diagnosis of a stroke in patients undergoing primary SA is associated with higher rates of perioperative complications and mortality when compared to a matched cohort. This information should be considered to counsel patients and surgeons to optimize care and help mitigate risks associated with the perioperative period.

No Strength Differences Despite Greater Posterior Rotator Cuff Intramuscular Fat in Patients With Eccentric Glenohumeral Osteoarthritis

BACKGROUND

When nonoperative measures do not alleviate the symptoms of glenohumeral osteoarthritis (OA), patients with advanced OA primarily are treated with anatomic total shoulder arthroplasty (TSA). It is unknown why TSAs performed in patients with eccentric (asymmetric glenoid wear) compared with concentric (symmetric glenoid wear) deformities exhibit higher failure rates, despite surgical advances. Persistent disruption of the posterior-to-anterior rotator cuff (RC) force couple resulting from posterior RC intramuscular degeneration in patients with eccentric deformities could impair external rotation strength and may contribute to eventual TSA failure. Pain and intramuscular fat within the RC muscles may impact external rotation strength measures and are important to consider.

QUESTIONS/PURPOSES

(1) Is there relative shoulder external rotation weakness in patients with eccentric compared with concentric deformities? (2) Is there higher resting or torque-dependent pain in patients with eccentric compared with concentric deformities? (3) Do patients with eccentric deformities have higher posterior-to-anterior RC intramuscular fat percent ratios than patients with concentric deformities?

METHODS

From February 2020 to November 2021, 65% (52 of 80) of patients with OA met study eligibility criteria. Of these, 63% (33 of 52) of patients enrolled and provided informed consent. From a convenience sample of 21 older adults with no history of shoulder pain, 20 met eligibility criteria as control participants. Of the convenience sample, 18 patients enrolled and provided informed consent. In total for this prospective, cross-sectional study, across patients with OA and control participants, 50% (51 of 101) of participants were enrolled and allocated into the eccentric (n = 16), concentric (n = 17), and control groups (n = 18). A 3-degree-of-freedom load cell was used to sensitively quantify strength in all three dimensions surrounding the shoulder. Participants performed maximal isometric contractions in 26 1-, 2-, and 3-degree-of-freedom direction combinations involving adduction/abduction, internal/external rotation, and/or flexion/extension. To test for relative external rotation weakness, we quantified relative strength in opposing directions (three-dimensional [3D] strength balance) along the X (+adduction/-abduction), Y (+internal/-external rotation), and Z (+flexion/-extension) axes and compared across the three groups. Patients with OA rated their shoulder pain (numerical rating 0-10) before testing at rest (resting pain; response to "How bad is your pain today?") and with each maximal contraction (torque-dependent pain; numerical rating 0-10). Resting and torque-dependent pain were compared between patients with eccentric and concentric deformities to determine if pain was higher in the eccentric group. The RC cross-sectional areas and intramuscular fat percentages were quantified on Dixon-sequence MRIs by a single observer who performed manual segmentation using previously validated methods. Ratios of posterior-to-anterior RC fat percent (infraspinatus + teres minor fat percent/subscapularis fat percent) were computed and compared between the OA groups.

RESULTS

There was no relative external rotation weakness in patients with eccentric deformities (Y component of 3D strength balance, mean ± SD: -4.7% ± 5.1%) compared with patients with concentric deformities (-0.05% ± 4.5%, mean difference -4.7% [95% CI -7.5% to -1.9%]; p = 0.05). However, there was more variability in 3D strength balance in the eccentric group (95% CI volume, % 3 : 893) compared with the concentric group (95% CI volume, % 3 : 579). In patients with eccentric compared with concentric deformities, there was no difference in median (IQR) resting pain (1.0 [3.0] versus 2.0 [2.3], mean rank difference 4.5 [95% CI -6.6 to 16]; p = 0.61) or torque-dependent pain (0.70 [3.0] versus 0.58 [1.5], mean rank difference 2.6 [95% CI -8.8 to 14]; p = 0.86). In the subset of 18 of 33 patients with OA who underwent MRI, seven patients with eccentric deformities demonstrated a higher posterior-to-anterior RC fat percent ratio than the 11 patients with concentric deformities (1.2 [0.8] versus 0.70 [0.3], mean rank difference 6.4 [95% CI 1.4 to 11.5]; p = 0.01).

CONCLUSION

Patients with eccentric deformities demonstrated higher variability in strength compared with patients with concentric deformities. This increased variability suggests patients with potential subtypes of eccentric wear patterns (posterior-superior, posterior-central, and posterior-inferior) may compensate differently for underlying anatomic changes by adopting unique kinematic or muscle activation patterns.

CLINICAL RELEVANCE

Our findings highlight the importance of careful clinical evaluation of patients presenting with eccentric deformities because some may exhibit potentially detrimental strength deficits. Recognition of such strength deficits may allow for targeted rehabilitation. Future work should explore the relationship between strength in patients with specific subtypes of eccentric wear patterns and potential forms of kinematic or muscular compensation to determine whether these factors play a role in TSA failures in patients with eccentric deformities.

Comparison of Reverse and Anatomic Total Shoulder Arthroplasty in Patients With an Intact Rotator Cuff and No Previous Surgery

INTRODUCTION

This study's purpose is to compare clinical and radiographic outcomes of primary anatomic total shoulder arthroplasty (aTSA) and primary reverse total shoulder arthroplasty (rTSA) patients with osteoarthritis (OA) and an intact rotator cuff with no previous history of shoulder surgery using a single platform TSA system at a minimum follow-up of 2 years.

METHODS

A total of 370 aTSA patients and 370 rTSA patients matched for age, sex, and length of follow-up from an international multi-institutional Western Institutional Review Board approved registry with a minimum 2-year follow-up were reviewed for this study. All patients had a diagnosis of OA, an intact rotator cuff, and no previous shoulder surgery. All patients were evaluated and scored preoperatively and at latest follow-up using six outcome scoring metrics and four active range of motion measurements.

RESULTS

Mean follow-up was 41 months, and the mean age was 73 years. Preoperatively, the rTSA patients had lower outcome metrics and less motion. Postoperatively, aTSA and rTSA patients had similar clinical outcomes, motion, and function, with the only exception being greater external rotation in aTSA exceeding the minimal clinically important difference. Pain relief was excellent, and patient satisfaction was high in both groups. Humeral radiolucent lines were similar in both groups (8%). Complications were significantly higher with aTSA (aTSA = 4.9%; rTSA = 2.2%; P = 0.045), but revisions were similar (aTSA = 3.2%; rTSA = 1.4%; P = 0.086).

CONCLUSION

At a mean of 41 month follow-up, primary aTSA and rTSA patients with OA and an intact rotator cuff with no previous history of shoulder surgery had similar clinical and radiographic outcomes. Greater external rotation was noted in aTSA patients at follow-up. However, aTSA patients had a significantly greater rate of complications compared with rTSA patients. rTSA is a viable treatment option in patients with an intact rotator cuff and no previous shoulder surgery, offering similar clinical outcomes with a lower complication rate.

LEVEL OF EVIDENCE

Level III.

The influence of prior dental pathology on medical complications and peri-prosthetic joint infections following primary shoulder arthroplasty

PURPOSE

Antibiotic prophylaxis before invasive dental procedures is a common practice in the USA. Consensus regarding the influence of prior dental pathology (DP) on postoperative complications is lacking. The objectives are to determine the association of DP prior to shoulder arthroplasty (SA) on: (1) lengths of stay (LOS), (2) medical complications, (3) readmissions, (4) implant-related complications including peri-prosthetic joint infections (PJIs) and (5) healthcare expenditures.

METHODS

The PearlDiver database was queried for primary shoulder arthroplasty from 2010 to 2020. Patients with history of dental caries or dental implant placement before SA represented the study group (n = 1419). Patients without prior DP represented controls (n = 7062). Study group patients were 1:5 ratio matched to controls by age, sex, and comorbidities. Outcomes included LOS, 90-day complications, readmissions, 2-year implant-related complications, and healthcare reimbursements. Logistic regression was used to calculate odds ratios (OR) of complications and readmissions. T tests compared LOS and costs. P values < 0.003 were significant.

RESULTS

LOS (2.17 vs. 2.07 days; p = 0.071) were similar between groups. Patients with DP had higher 90-day medical complications compared to controls (OR: 1.74, p < 0.0001), including myocardial infarctions (2.2% vs. 0.8%; OR: 2.79, p < 0.0001), acute kidney injuries (8.3% vs. 4.6%; OR: 1.92, p < 0.0001), and pneumonias (8.7% vs. 5.3%; OR: 1.72, p < 0.0001). Readmission rates (1.97% vs. 1.54%; p = 0.248) were similar. Two-year implant complications were higher in patients with DP compared to controls (16.1% vs. 11.5%; OR: 1.38, p = 0.0003), including dislocations (6.4% vs. 4.5%; OR: 1.45, p = 0.002) and mechanical loosenings (4.0% vs. 2.4%; OR: 1.67, p = 0.001); however, PJIs were similar (2.2% vs. 1.9%; OR: 1.12, p = 0.583). Healthcare expenditures between groups were similar ($12,611 vs. $12,059; p = 0.075).

CONCLUSION

Patients with prior DP have higher 90-day medical complications and 2-year implant-related complications. Two-year incidence of PJIs were similar between groups. These findings can help shoulder surgeons counsel patients with a pertinent dental history.

LEVEL OF EVIDENCE III

Retrospective comparative study.

Benign prostatic hyperplasia is associated with increased 90-day medical complications but not peri-prosthetic joint infections following reverse shoulder arthroplasty

INTRODUCTION

Studies have shown male sex to be a predisposing factor for peri-prosthetic joint infections (PJIs). Symptomatic benign prostatic hyperplasia (BPH) has been suggested as an additional risk for PJI. This study aimed to assess the impact of BPH on (1) lengths of stay (LOS), (2) complications (medical and implant-related), (3) readmission rates, and (4) healthcare expenditures after reverse shoulder arthroplasty (RSA).

METHODS

Utilizing a nationwide sample from the 2010-2020 PearlDiver insurance database, an analysis was performed retrospectively for all males who underwent primary RSA. Males with BPH (n = 2,184) represented the study group and were ratio-matched with men without a history of BPH (n = 10,832) in a 1:5 manner by medical comorbidities. T-tests compared LOS and healthcare expenditures. Multivariate logistic regression models were used to determine the effect of BPH on 90-day medical complications, 2-year implant complications, and readmissions. A p value less than 0.001 was statistically significant.

RESULTS

In-hospital LOS (1.96 days vs. 1.99 days, p = 0.683) did not significantly differ between cohorts. Males with BPH had significantly greater occurrence and odds (34.3% vs. 21.2%, odds ratio (OR):1.84, p < 0.0001) of all 90-day medical complications, including urinary tract infections (9.3% vs. 3.1%, OR:3.23, p < 0.0001), pneumonias (6.0% vs. 3.9%, OR:1.61, p < 0.0001), and acute kidney injuries (7.7% vs. 5.0%, OR:1.60, p < 0.0001). Two-year implant-related complications were comparable between study and control groups (12.2% vs 10.9%, OR:1.14, p = 0.073), including PJIs (2.3% vs. 2.2%, OR:1.02, p = 0.874). Readmission rates (1.88% vs. 2.11%, p = 0.482) and average global 90-day reimbursements ($26,301 vs. $24,399), p = 0.535) were similar between men with and without BPH.

DISCUSSION

Males with a history of BPH have greater rates of medical complications, including UTIs and acute kidney injuries, within 90 days following RSA. BPH does not appear to be a risk factor for 2-year implant-related complications including PJIs.

LEVEL OF EVIDENCE

III.

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

BACKGROUND

Legacy shoulder outcome scores have postoperative ceiling scores effects when quantifying clinical outcomes for anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty patients. This study uses data from an international database of a single shoulder prosthesis using data from 30 different clinical sites to quantify and compare the percentage of aTSA and rTSA patients achieving postoperative ceiling scores with multiple outcome measures and defines the patient demographics, comorbidities, implant, and operative parameters associated with ceiling scores for each outcome measure.

METHODS

Clinical outcomes for 1817 aTSA and 2635 rTSA patients between 2007 and 2019 were quantified with the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Simple Shoulder Test (SST), the University of California, Los Angeles (UCLA), Constant, and Shoulder Arthroplasty Smart (SAS) scores. The number of aTSA and rTSA patients with ceiling scores were calculated and sorted into those that achieved ceiling scores with the SST, ASES, and UCLA measures and compared to patients without ceiling scores. A univariate and multivariate analysis then identified the patient demographics, comorbidities, and implant and operative parameters associated with ceiling scores for each outcome measure.

RESULTS

aTSA patients achieved ceiling scores at a significantly greater rate than rTSA patients for all outcome measures, except SAS. The SST score was the most susceptible to ceiling scores (aTSA = 43.4%, rTSA = 34.1%, P < .0001), followed by the ASES (aTSA = 23.7%, rTSA = 13.3%, P < .0001) and UCLA (aTSA = 22.2%, rTSA = 10.6%, P < .0001) scores. Ceiling scores were least likely with the Constant (aTSA = 0.4%, rTSA = 0%, P = .0060) and SAS (aTSA = 0.1%, rTSA = 0%, P = .0750) scores. Male patients had a significantly higher ceiling score rate than female patients using the SST and ASES scores, and no differences in ceiling score rates were observed with the UCLA, Constant, or SAS scores. Finally, we identified numerous patient demographic, comorbidity, implant, and operative parameters associated with SST, ASES, and UCLA ceiling scores for aTSA and rTSA patients.

DISCUSSION

Postoperative ceiling scores occur at a high rate for aTSA and rTSA patients with the SST, ASES, and UCLA scores. Those most susceptible to ceiling scores are aTSA patients treated with cage glenoids, aTSA patients of lower body mass index, rTSA patients of male gender, rTSA patients with osteoarthritis diagnosis, and rTSA patients with subscapularis repair. Clinical researchers should consider using alternative scores, such as the SAS score, to ensure a more normalized distribution of data and more accurately quantify aTSA and rTSA outcomes.

Protocol for a multicenter, randomised controlled trial of surgeon-directed home therapy vs. outpatient rehabilitation by physical therapists for reverse total shoulder arthroplasty: the SHORT trial

Background

Reverse total shoulder arthroplasty (RTSA) has emerged as a successful surgery with expanding indications. Outcomes may be influenced by post-operative rehabilitation; however, there is a dearth of research regarding optimal rehabilitation strategy following RTSA. The primary purpose of this study is to compare patient reported and clinical outcomes after RTSA in two groups: in one group rehabilitation is directed by formal, outpatient clinic-based physical therapists (PT group) as compared to a home therapy group, in which patients are instructed in their rehabilitative exercises by surgeons at post-operative appointments (HT group). Secondary aims include comparisons of complications, cost of care and quality of life between the two groups.

Methods

This randomised controlled trial has commenced at seven sites across the United States. Data is being collected on 200 subjects by clinical research assistants pre-operatively and post-operatively at 2, 6, and 12 weeks, 6 months, 1 and 2 year visits. The following variables are being assessed: American Shoulder and Elbow Surgeons (ASES), pain level using the numeric pain scale, the Single Assessment Numeric Evaluation (SANE) score, and shoulder active and passive range of motion for analysis of the primary aim. Chi square and t-tests will be used to measure differences in baseline characteristics of both groups. Repeated measures linear mixed effects modeling for measurement of differences will be used for outcomes associated with ASES and SANE and scores, and range of motion measures. Secondary aims will be analyzed for comparison of complications, cost, and quality of life assessment scores using data obtained from the PROMIS 29 v. 2, questionnaires administered at standard of care post-operative visits, and the electronic health record. Subjects will be allowed to crossover between the PT and HT groups, and analysis will include both intention-to-treat including patients who crossed over, and a second with cross-over patients removed, truncated to the time they crossed over.

Discussion

RTSA is being performed with increasing frequency, and the optimal rehabilitation strategy is unclear. This study will help clarify the role of formal physical therapy with particular consideration to outcomes, cost, and complications. In addition, this study will evaluate a proposed rehabilitation strategy.

Trial registration

This study is registered as NCT03719859 at ClincialTrials.gov.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40945-021-00121-2.

Good long-term patient-reported outcome after shoulder arthroplasty for cuff tear arthropathy

Background

The use of the reverse shoulder arthroplasty (RSA) for cuff tear arthropathy (CTA) has increased within the last decades, but there is still limited information about the long-term outcome and how it performs in comparison with hemiarthroplasty (HA). The aim of this study was to compare the long-term patient-reported outcomes of RSA and HA for CTA.

Methods

We included all patients with CTA, who according to the Danish Shoulder Arthroplasty Registry, underwent either HA or RSA between 2006 and 2010. Patients who were alive were sent the Western Ontario Osteoarthritis of the Shoulder (WOOS) questionnaire in 2020. One hundred twenty (65%) patients returned a complete questionnaire. The linear regression model was used to compare RSA and HA. Sex, age, and previous surgery were included in the multivariable model.

Results

Forty-two HAs and 78 RSAs were evaluated with a mean follow-up time of 11.5 and 10.6 years, respectively. The mean WOOS score was 66.7 for HA and 71.7 for RSA. The difference of 5.0 was neither statistically significant nor clinically important (95% confidence interval: -4.3 to 14.2, P = .17), nor were there any significant risk of a worse WOOS score for sex, age, or previous surgery.

Conclusion

To our knowledge, this is the first study to compare the long-term patient-reported outcomes of HA and RSA for CTA. Our results indicate that RSA is a reliable and durable treatment option for CTA with good long-term results. Based on this observational study, it is not possible to make safe estimates about the effect of RSA compared with HA, but similar to RSA, HA was associated with relatively good long-term results.