Severe metallosis following catastrophic failure of total shoulder arthroplasty - a case report.

Metallosis is an unusual but consequential complication arising from orthopedic hardware implantation, characterized by the deposition of metallic particles in the periprosthetic soft tissues. The incidence of metallosis associated with shoulder arthroplasties is exceptionally rare since the shoulder is not a weight-bearing joint, making it less susceptible to mechanical wear and, consequently, to conditions like particle disease and metallosis. Nevertheless, anomalous metal-on-metal interactions can develop in total shoulder arthroplasties if the polyethylene component fails due to wear, fracture, or dissociation. If left unaddressed, metallosis can incite an adverse immune-mediated local tissue response, culminating in joint destruction and adjacent soft tissues and muscle necrosis. In this case report, the diagnosis of metallosis was made in a patient with an anatomic total shoulder arthroplasty using a state-of-the-art photon counting detector CT supplemented by post-processing metal artifact reduction algorithms. This advanced imaging approach was effective in discerning the source of implant failure and in identifying manifestations of severe metallosis including osteolysis and pseudotumor formation. Advanced imaging methods can accurately characterize the severity and extent of metallosis, thereby helping guide surgical planning to mitigate serious complications associated with this condition.

REVERSE SHOULDER ARTHROPLASTY DESIGN: INLAY VS. ONLAY DOES IT REALLY MAKE A DIFFERENCE?

BACKGROUND: The design of reverse shoulder arthroplasty (RSA) implants has evolved significantly over the past 50 years. Today there are many options available that differ in design of the glenoid and humeral components, fixation methods, sizes and modularity. With respect to the humeral component the literature has generally focused on the differences between inlay and onlay designs and the potential impact on outcomes. However, inlay and onlay design represents only one factor of many. METHODS: It is our hypothesis that separating onlay and inlay designs into two distinct entities is an oversimplification as there can be wide overlap of the two designs depending upon surgical technique and the implant selected. As such, the differences between inlay and onlay designs should be measured in absolute terms-meaning combined distalization and lateralization. RESULTS: By reviewing the many factors that can contribute to the glenosphere - humerus realtiuonship the role of inlay and onlay humeral designs as an important distinguishing feature is shown to be limited Preliminary studies suggest that the amount of distalization and lateralization of the construct may be the most accurate method of describing the differences in the constructs. CONCLUSIONS: Inlay and onlay humeral component design represents only one factor of many that may impact outcomes. A more accurate method of defining specific design and technique factors in RSA is the degree of lateralization and distalization.

Optimal combination of arthroplasty type, fixation method and postoperative rehabilitation protocol for complex proximal humerus fractures in the elderly: A network meta-analysis.

PURPOSE: The purpose of this study was to define the optimal combination of surgical technique and postoperative rehabilitation protocol for elderly patients undergoing either hemiarthroplasty (HA) or reverse total shoulder arthroplasty (rTSA) for acute proximal humerus fracture (PHF) by performing a network meta-analysis of the comparative studies in the literature. METHODS: A systematic review of the literature using PRISMA guidelines of MEDLINE, EMBASE, and Cochrane Library was screened from 2007-2023. Inclusion criteria were level I-IV studies utilizing primary HA and/or rTSA published in a peer-reviewed journal, that specified whether humeral stems were cemented or noncemented, specified postoperative rehabilitation protocol, reported results of HA and/or rTSA performed for PHF. Early range of motion (ROM) was defined as the initiation of active ROM at ≤3 weeks after surgery. Level of evidence was evaluated based on the criteria by the Oxford Centre for Evidence-Based Medicine. Clinical outcomes were compared using a frequentist approach to network meta-analysis with a random-effects model that was performed using the netmeta package version 0.9-6 in R. RESULTS: A total of 28 studies (1,119 patients) were included with an average age of 74±3.7 and mean follow-up of 32±11.1 months. In the early ROM cohort (Early), the mean time to active ROM was 2.4±0.76 weeks compared to 5.9±1.04 weeks in the delayed ROM cohort (Delayed). Overall, rTSA-Pressfit-Early resulted in statistically superior outcomes including postoperative forward elevation (126±27.5), abduction (116±30.6), internal rotation (5.27±0.74, corresponding to L3-L1), ASES score (71.8±17), tuberosity union (89%), and lowest tuberosity nonunion rate (9.6%) in patients ≥65 years old with acute PHF undergoing shoulder arthroplasty (all p≤0.05). In total there were 277 (14.5%) complications across the cohorts, of which 89/277 (34%) were in the HA-Cement-Delayed cohort. HA-Cement-Delayed resulted in 2-times higher odds of experiencing a complication when compared to rTSA-Cement-Delayed (p=0.005). Conversely, rTSA-Cement-Early cohort followed by rTSA-Pressfit-Early resulted in a total complication rate of 4.7% and 5.4% (OR, 0.30; p=0.01 & OR, 0.42; p=0.05), respectively. The total rate of scapular notching was higher in the cemented rTSA subgroups (16.5%) versus (8.91%) in the press fit rTSA subgroups (p=0.02). CONCLUSION: Our study demonstrates that patients ≥65 years of age, who sustain a 3-or 4-part PHF achieve the most benefit in terms of range of motion, postoperative functional outcomes, tuberosity union, and overall complication rate when undergoing rTSA with a noncemented stem and early postoperative range of motion when compared to the mainstream preference-rTSA-Cement-Delayed.

Stratification of the Minimal Clinically Important Difference, Substantial Clinical Benefit, and Patient Acceptable Symptomatic State after Total Shoulder Arthroplasty by Implant Type, Preoperative Diagnosis, and Sex.

BACKGROUND: Clinical significance, as opposed to statistical significance, has increasingly been utilized to evaluate outcomes after total shoulder arthroplasty (TSA). The purpose of this study was to identify thresholds of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for TSA outcome metrics and determine if these thresholds are influenced by prosthesis type (anatomic or reverse TSA), sex, or preoperative diagnosis. METHODS: A prospectively collected international multicenter database inclusive of 38 surgeons was queried for patients receiving a primary aTSA or rTSA between 2003 and 2021. Prospectively, outcome metrics including ASES, shoulder function score (SFS), SST, UCLA, Constant, VAS Pain, shoulder arthroplasty smart (SAS) score, forward flexion, abduction, external rotation, and internal rotation was recorded preoperatively and at each follow-up. A patient satisfaction question was administered at each follow-up. Anchor-based MCID, SCB, and PASS were calculated as defined previously overall and according to implant type, preoperative diagnosis, and sex. The percentage of patients achieving thresholds was also quantified. RESULTS: A total of 5,851 total shoulder arthroplasties including aTSA (n=2,236) and rTSA (n=3,615) were included in the study cohort. The following were identified as MCID thresholds for the overall (aTSA + rTSA irrespective of diagnosis or sex) cohort: VAS Pain (-1.5), SFS (1.2), SST (2.1), Constant (7.2), ASES (13.9), UCLA (8.2), SPADI (-21.5), and SAS (7.3), Abduction (13°), Forward elevation (16°), External rotation (4°), Internal rotation score (0.2). SCB thresholds for the overall cohort were: VAS Pain (-3.3), SFS (2.9), SST 3.8), Constant (18.9), ASES (33.1), UCLA (12.3), SPADI (-44.7), and SAS (18.2), Abduction (30°), Forward elevation (31°), External rotation (12°), Internal rotation score (0.9). PASS thresholds for the overall cohort were: VAS Pain (0.8), SFS (7.3), SST (9.2), Constant (64.2), ASES (79.5), UCLA (29.5), SPADI (24.7), and SAS (72.5), Abduction (104°), Forward elevation (130°), External rotation (30°), Internal rotation score (3.2). MCID, SCB, and PASS thresholds varied depending on preoperative diagnosis and sex. CONCLUSION: MCID, SCB, and PASS thresholds vary depending on implant type, preoperative diagnosis, and sex. A comprehensive understanding of these differences as well as identification of clinically-relevant thresholds for legacy and novel metrics is essential to assist surgeons in evaluating their patient's outcomes, interpreting the literature, and counseling their patients preoperatively regarding expectations for improvement. Given that PASS thresholds are fragile and vary greatly depending on cohort variability, caution should be exercised in conflating them across different studies.

Prognostic value of the Walch classification for patients before and after shoulder arthroplasty performed for osteoarthritis with an intact rotator cuff.

BACKGROUND: The Walch classification is commonly used by surgeons when determining the treatment of osteoarthritis (OA). However, its utility in prognosticating patient clinical state before and after TSA remains unproven. We assessed the prognostic value of the modified Walch glenoid classification on preoperative clinical state and postoperative clinical and radiographic outcomes in total shoulder arthroplasty (TSA). METHODS: A prospectively collected, multicenter database for a single-platform TSA system was queried for patients with rotator cuff-intact OA and minimum 2 year follow-up after anatomic (aTSA) and reverse TSA (rTSA). Differences in patient-reported outcome scores (Simple Shoulder Test, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Shoulder Pain and Disability Index, visual analog scale for pain, Shoulder Function score), combined patient-reported and clinical-input scores (Constant, University of California-Los Angeles shoulder score, Shoulder Arthroplasty Smart Score), active range of motion values (forward elevation [FE], abduction, external rotation [ER], internal rotation [IR], and radiographic outcomes (humeral and glenoid radiolucency line rates, scapula notching rate) were stratified and compared by glenoid deformity type per the Walch classification for aTSA and rTSA cohorts. Comparisons were performed to assess the ability of the Walch classification to predict the preoperative, postoperative, and improved state after TSA. RESULTS: 1008 TSAs were analyzed including 576 aTSA and 432 rTSA. Comparison of outcomes between Walch glenoid types resulted in 15 pairwise comparisons of 12 clinical outcome metrics, yielding 180 total Walch glenoid pairwise comparisons for each clinical state (preoperative, postoperative, improvement). Of the 180 possible pairwise Walch glenoid type and metric comparisons studied for aTSA and rTSA cohorts, <6% and <2% significantly differed in aTSA and rTSA cohorts, respectively. Significant differences based on Walch type were seen after adjustment for multiple pairwise comparisons in the aTSA cohort for FE and ER preoperatively, the Constant score postoperatively, and for abduction, FE, ER, Constant score, and SAS score for pre- to postoperative improvement. In the rTSA cohort, significant differences were only seen in abduction and Constant score both postoperatively and for pre- to postoperative improvement. There were no statistically significant differences in humeral lucency rate, glenoid lucency rate (aTSA), scapular notching rate (rTSA), complication rates, or revision rates between Walch glenoid types after TSA. CONCLUSION: Although useful for describing degenerative changes to the glenohumeral joint, we demonstrate a weak association between preoperative glenoid morphology according to the Walch classification and clinical state when evaluating patients undergoing TSA for rotator cuff-intact OA. Alternative glenoid classification systems or predictive models should be considered to provide more precise prognoses for patients undergoing TSA for rotator cuff-intact OA.

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.

International consensus statement on the management of glenohumeral arthritis in patients ≤ 50 years old.

BACKGROUND: The purpose of this study was to implement a modified Delphi technique among a group of experts affiliated with American Shoulder and Elbow Surgeons (ASES) and European Society for Surgery of the Shoulder and Elbow (SECEC) to determine areas of consensus regarding what factors influence their decision to manage a patient surgically and what specific treatment modalities they utilize for patients ≤50 years of age with glenohumeral arthritis. METHODS: The panel of experts comprised 168 shoulder and elbow specialists, 138 ASES and 30 SECEC members. In the first round, an open-ended questionnaire was utilized to solicit features that are important in making decisions regarding treatment. The second round involved ranking the features identified in the first round as to their importance in helping decision making for surgery. The results of round 2 were then utilized and 18 complex surgical cases previously treated by one of the lead authors were provided for the study. One additional case was included to address the management of Cutibacterium acne infection. RESULTS: A total of 159 (95.0%) participants completed the round one survey, 142 (89%) responded to the second and third round surveys. In total 50 individual factors were positively associated with the decision to proceed with surgery. Ten of these were strongly supportive of surgery. Eight out of 18 clinical cases demonstrated > 80% agreement on the surgical treatment modality chosen. Over 90% of respondents chose reverse total shoulder arthroplasty (TSA) to manage pathology when an incompetent rotator cuff was present. Over 90% of respondents managed avascular necrosis with hemiarthroplasty. Over 70% of respondents chose anatomic TSA for inflammatory arthritis with low demand on their shoulder. Overall, 79% of respondents chose a stemless humeral component when a hemiarthroplasty or anatomic TSA was chosen in response to the proposed surgical cases. If arthroscopy was chosen then there was good agreement on 5 core procedures. There was only fair consensus on the approach to C. acnes in patients with glenohumeral osteoarthritis ≤ 50 years of age. CONCLUSION: The optimal treatment of glenohumeral arthritis in patients ≤ 50 years of age remains controversial, and there are many treatment options to consider when responding to the variety of clinical presentations and anatomic pathologies. While physicians and patients engage in the shared decision-making process regarding the final choice for management, this consensus statement serves as a basis for discussion amongst colleagues and between patients and surgeons though it clearly demonstrates that the topic must be further investigated prospectively and with large cohorts.

Impact of mental health on outcomes after total shoulder arthroplasty.

BACKGROUND: Anxiety and depression are the 2 most commonly diagnosed psychiatric disorders in the United States. The effect of these disorders on total shoulder arthroplasty (TSA) outcomes must be appreciated. The purpose of this study was to examine the correlation between a preoperative diagnosis of anxiety and depression and postoperative outcomes after TSA. The secondary goals were to determine whether patients contemporaneously treated with medication for their mental health diagnosis fared better than a cohort treated without medication and to examine the degree to which Patient-Reported Outcomes Measurement Information System Mental Health (PROMIS-MH) scores correlate with patient outcomes. Our hypothesis was that a history of anxiety and/or depression would negatively impact patient outcomes after TSA. METHODS: We performed a retrospective analysis of a prospectively collected cohort at a single institution. Patients undergoing anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) with anxiety and/or depression were identified and compared with a cohort of patients without a mental health diagnosis enrolled in an institutional registry from 2011 to 2020. Demographic characteristics, diagnoses, implant types, range of motion, adverse events, and clinical outcome metric scores-PROMIS-MH score, American Shoulder and Elbow Surgeons score, Constant score, Shoulder Arthroplasty Smart Score-were recorded. Outcomes between cohorts were analyzed using conventional statistics, as well as stratification by the minimal clinically important difference and substantial clinical benefit thresholds where applicable. RESULTS: The study comprised 218 patients (114 rTSA and 95 aTSA patients) with a diagnosis of either anxiety and/or depression and 378 patients (153 rTSA and 217 aTSA patients) with no history. Although both cohorts achieved the minimal clinically important difference and substantial clinical benefit thresholds for the postoperative American Shoulder and Elbow Surgeons score, the cohort with anxiety and/or depression showed lower postoperative outcome scores (P < .05), higher AE rates, and significantly lower preoperative-to-postoperative differences in all variables when compared with the cohort without anxiety and/or depression. There were no differences in outcome scores after rTSA or aTSA between patients being treated for anxiety and/or depression and those not receiving treatment. The PROMIS-MH score was positively correlated with postoperative outcomes and patient satisfaction. CONCLUSION: This study shows that patients with anxiety and/or depression who underwent TSA had inferior postoperative outcomes and higher rates of AEs compared with a cohort without a mental health diagnosis. In addition, patients taking medication for treatment of depression and/or anxiety did not gain any significant benefit in terms of their postoperative shoulder outcomes or satisfaction rate compared with those with this diagnosis but not taking medication. Additionally, we found that, independent of a patient's underlying shoulder pathology or psychiatric diagnosis, lower PROMIS-MH scores were correlated with worse postoperative outcomes.

Impact of cervical spine pathology on outcomes after total shoulder arthroplasty.

BACKGROUND: Cervical spine pathology can affect the supporting muscles and function of the shoulder and contribute to shoulder and arm pain and hence may impact postoperative outcomes following shoulder arthroplasty. The purpose of this study was to evaluate the impact of a history of cervical spine arthrodesis and its timing, before or after total shoulder arthroplasty (TSA), on the outcomes of TSA. Our hypothesis is that a history of cervical arthrodesis (CA) will negatively impact patient outcomes after shoulder arthroplasty. METHODS: A retrospective analysis was performed on a prospectively collected cohort at a single institution. Anatomic (aTSA) and reverse TSA (rTSA) patients with CA were identified and compared to a cohort of patients without CA (NCA) enrolled in an institutional registry from 2011 to 2020. Demographic characteristics, diagnoses, implant type, range of motion, adverse events, and clinical outcome metric scores (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES], Constant, Shoulder Function score, patient satisfaction) were recorded. Outcomes between cohorts were analyzed using conventional statistics as well as stratification by minimal clinically important difference and substantial clinical benefit (SCB) thresholds where applicable. RESULTS: Of the 573 TSAs evaluated, 48 (20a CA-aTSA and 28 CA-rTSA) had a history of CA and 525 (280 NCA-aTSA and 245 NCA-rTSA) had no history of CA. The CA-TSA (aTSA and rTSA) had lower Constant, ASES, and Shoulder Function scores postoperatively as well as less improvement in active external rotation and an overall lower satisfaction rating (P < .05 for all) compared with NCA-TSA. The adverse event rate in the CA-TSA cohort was higher compared with the NCA-TSA cohort (25% vs. 6.5% [rTSA; P = .004] and 24.5% vs. 11% [aTSA; P = .068]). Optimal cutoff analysis showed that a time from CA to TSA of greater than 1.33 years had a sensitivity of 75.0% and specificity of 75.0% in predicting achievement of SCB for ASES score. CONCLUSION: The current study demonstrates that patients with a history of CA undergoing shoulder arthroplasty results in lower postoperative functional outcomes, lower satisfaction, and higher rates of postoperative adverse events requiring surgical revision when compared to a cohort without a history of CA. Additionally, the current study demonstrates that a time interval of at least 16 months between CA and shoulder arthroplasty optimizes the chances of achieving SCB for ASES score.

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.

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 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 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.

Augmented baseplates yield optimum outcomes when compared with bone graft augmentation for managing glenoid deformity during reverse total shoulder arthroplasty: a retrospective comparative study.

PURPOSE: The purpose of this study was to compare the outcomes of primary reverse total shoulder arthroplasty (rTSA) using glenoid bone grafting (BG rTSA) with primary rTSA using augmented glenoid baseplates (Aug rTSA) with a minimum 2-year follow-up. METHODS: A total of 520 primary rTSA patients treated with 8° posterior glenoid augments (n = 246), 10° superior glenoid augments (n = 97), or combined 10° superior/8° posterior glenoid augments (n = 177) were compared with 47 patients undergoing glenoid bone grafting for glenoid bone insufficiency. The mean follow-up was 37.0(±16) and 53.0(±27) months, respectively. Outcomes were analyzed preoperatively and at the latest follow-up using conventional statistics and stratification by minimum clinically important difference (MCID) and substantial clinical benefit (SCB) thresholds where applicable. Radiographs were analyzed for baseplate failure, and the incidences of postoperative complications and revisions were recorded. RESULTS: The glenoid Aug rTSA cohort had greater improvements in patient-reported outcome measures (PROMs) and range of motion when compared with the BG rTSA group at a minimum of 2-year follow-up, including Simple Shoulder Test, Constant score, American Shoulder and Elbow Surgeons score, University of California Los Angeles score, Shoulder Pain and Disability Index score, shoulder function, Shoulder Arthroplasty Smart score, abduction, and external rotation (P < .05). Patient satisfaction was higher in the Aug rTSA group compared with the BG rTSA group (P = .006). The utilization of an augmented glenoid component instead of glenoid bone grafting resulted in approximately 50% less total intraoperative time (P < .001), nearly 33% less intraoperative blood loss volume (P < .001), approximately 3-fold less scapular notching (P < .01), and approximately 8-fold less adverse events requiring revision (P < .01) when compared with the BG rTSA cohort. Aside from SCB for abduction, the Aug rTSA cohort achieved higher rates of exceeding MCID and SCB for every PROM compared with BG rTSA. More specifically, 77.6% and 70.2% of the Aug rTSA achieved SCB for American Shoulder and Elbow Surgeons and Shoulder Pain and Disability Index vs. 55% and 48.6% in the BG rTSA, respectively (P = .003 and P = .013). CONCLUSION: The present midterm clinical and radiographic study demonstrates that the utilization of an augmented baseplate for insufficient glenoid bone stock is superior as judged by multiple PROMs and range of motion metrics when compared with bone graft augmentation at minimum 2-year follow-up. In addition, when analyzed according to MCID and SCB thresholds, the use of augmented baseplates outperforms the use of glenoid bone grafting. Complication and revision rates also favor the use of augmented glenoid baseplates over glenoid bone grafting. Long-term clinical and radiographic follow-up is necessary to confirm that these promising midterm results are durable.

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.

Are Age and Patient Gender Associated With Different Rates and Magnitudes of Clinical Improvement After Reverse Shoulder Arthroplasty?

BACKGROUND: An improved understanding of how gender differences and the natural aging process are associated with differences in clinical improvement in outcome metric scores and ROM measurements after reverse total shoulder arthroplasty (rTSA) may help physicians establish more accurate patient expectations for reducing postoperative pain and improving function. QUESTIONS/PURPOSES: (1) Is gender associated with differences in rTSA outcome scores like the Simple Shoulder Test (SST), the UCLA Shoulder score, the American Shoulder and Elbow Surgeons (ASES) Shoulder score, the Constant Shoulder score, and the Shoulder Pain and Disability Index (SPADI) and ROM? (2) Is age associated with differences in rTSA outcome scores and ROM? (3) What factors are associated with the combined interaction effect between age and gender? (4) At what time point during recovery does most clinical improvement occur, and when is full improvement reached? METHODS: We quantified and analyzed the outcomes of 660 patients (424 women and 236 men; average age, 72 ± 8 years; range, 43-95 years) with cuff tear arthropathy or osteoarthritis and rotator cuff tear who were treated with rTSA by 13 shoulder surgeons from a longitudinally maintained international database using a linear mixed effects statistical model to evaluate the relationship between clinical improvements and gender and patient age. We used five outcome scoring metrics and four ROM assessments to evaluate clinical outcome differences. RESULTS: When controlling for age, men had better SST scores (mean difference [MD] = 1.41 points [95% confidence interval {CI}, 1.07-1.75], p < 0.001), UCLA scores (MD = 1.76 [95% CI, 1.05-2.47], p < 0.001), Constant scores (MD = 6.70 [95% CI, 4.80-8.59], p < 0.001), ASES scores (MD = 7.58 [95% CI, 5.27-9.89], p < 0.001), SPADI scores (MD = -12.78 [95% CI, -16.28 to -9.28], p < 0.001), abduction (MD = 5.79° [95% CI, 2.74-8.84], p < 0.001), forward flexion (MD = 7.68° [95% CI, 4.15-11.20], p < 0.001), and passive external rotation (MD = 2.81° [95% CI, 0.81-4.8], p = 0.006). When controlling for gender, each 1-year increase in age was associated with an improved ASES score by 0.19 points (95% CI, 0.04-0.34, p = 0.011) and an improved SPADI score by -0.29 points (95% CI, -0.46 to 0.07, p = 0.020). However, each 1-year increase in age was associated with a mean decrease in active abduction by 0.26° (95% CI, -0.46 to 0.07, p = 0.007) and a mean decrease of forward flexion by 0.39° (95% CI, -0.61 to 0.16, p = 0.001). A combined interaction effect between age and gender was found only with active external rotation: in men, younger age was associated with less active external rotation and older age was associated with more active external rotation (ß0 [intercept] = 11.029, ß1 [slope for age variable] = 0.281, p = 0.009). Conversely, women achieved no difference in active external rotation after rTSA, regardless of age at the time of surgery (ß0 [intercept] = 34.135, ß1 [slope for age variable] = -0.069, p = 0.009). Finally, 80% of patients achieved full clinical improvement as defined by a plateau in their outcome metric score and 70% of patients achieved full clinical improvement as defined by a plateau in their ROM measurements by 12 months followup regardless of gender or patient age at the time of surgery with most improvement occurring in the first 6 months after rTSA. CONCLUSIONS: Gender and patient age at the time of surgery were associated with some differences in rTSA outcomes. Men had better outcome scores than did women, and older patients had better outcome scores but smaller improvements in function than did younger patients. These results demonstrate rTSA outcomes differ for men and women and for different patient ages at the time of surgery, knowledge of these differences, and also the timing of improvement plateaus in outcome metric scores and ROM measurements can both improve the effectiveness of patient counseling and better establish accurate patient expectations after rTSA. LEVEL OF EVIDENCE: Level III, therapeutic study.

Biomechanical characteristics of subscapularis-sparing approach for anatomic total shoulder arthroplasty.

BACKGROUND: A technique for retaining the superior 50% of the subscapularis insertion for anatomic total shoulder arthroplasty has been described. This cadaveric study biomechanically evaluates this subscapularis-sparing approach and compares it with a complete subscapularis release and repair technique to determine whether there is a higher load to failure. MATERIALS AND METHODS: Twelve matched pairs of human cadaveric arms were distributed into 3 test groups. Group 1 consisted of specimens with and without a 100% subscapularis release. Group 2 consisted of specimens with and without an inferior 50% subscapularis release. Group 3 consisted of specimens with either an inferior 50% or 100% release of the subscapularis footprint and repair. All tendon repairs were performed using bone tunnels and sutures. Specimens were biomechanically tested using non-destructive cyclic and tensile failure-inducing loads. RESULTS: In matched pairs, the following comparative results were obtained: native intact subscapularis specimens exhibited a load to failure of 1341.20 ± 380.10 N compared with 380.10 ± 138.79 N in the 100% release specimens (P = .029), native intact subscapularis specimens exhibited a load to failure of 1209.74 ± 342.18 N compared with 744.33 ± 211.77 N in the 50% release specimens (P = .057), and 50% release and repair specimens exhibited a load to failure of 704.62 ± 165.53 N compared with 305.52 ± 91.39 N in the 100% release and repair group (P = .029). CONCLUSION: Preservation of the superior 50% of the subscapularis demonstrates a higher load to failure compared with complete subscapularis release and repair using bone tunnels.

Outcomes of reverse total shoulder arthroplasty in a senior athletic population.

BACKGROUND: This study evaluated the clinical and radiographic outcomes of reverse total shoulder arthroplasty (RTSA) in a senior athletic population playing both low- and high-impact sports. MATERIALS AND METHODS: We evaluated 41 RTSAs performed in 40 patients who continued to play both low- and high-impact sports after surgery. The mean age was 73 years, and the mean follow-up period was 43 months, with a minimum of 35 months. Clinical and radiographic outcomes were examined. RESULTS: Ninety-five percent of patients indicated that they were able to return to sports at the same level as before surgery or at a higher level, and only 13% reported increased pain after playing their sport after undergoing an RTSA. The median American Shoulder and Elbow Surgeons score improved from 31 preoperatively to 72 postoperatively (P < .001). The median Constant score improved from 25 preoperatively to 83 postoperatively (P < .001). The median Subjective Shoulder Value improved from 27% preoperatively to 90% postoperatively (P < .001), and the median visual analog scale score improved from 7.2 preoperatively to 1.1 postoperatively (P < .001). The overall complication rate was 7%. One zone of lucency was noted in 17% of humeral stems, with 1 case of early subsidence but no cases with loosening at final follow-up. The glenoid notching rate was 7%, with no cases of glenoid subsidence, lucency, or loosening. CONCLUSION: RTSA in senior athletes can be safely performed with good clinical results. No prominent mode of mechanical or clinical failure has been identified with short-term follow-up.

Magnetic Resonance Imaging of the Shoulder: Interpretation of Common Orthopaedic Injuries.

Magnetic resonance imaging (MRI) is frequently obtained to assess for pathology in the setting of shoulder pain and dysfunction. MRI of the shoulder provides diagnostic information that helps optimize patient management and surgical planning. Both general and subspecialized orthopaedic surgeons routinely order and review shoulder MRIs in practice. Therefore, familiarity with the MRI appearance of common shoulder pathologies is important. This document reviews the most common shoulder pathologies using a standardized MRI interpretative approach. Instructional videos demonstrating a musculoskeletal radiologist interpreting normal and abnormal shoulder MRIs are also provided.

Planned Glenoid Implant Utilization: A Comparison of Preoperative Planning with and Without Computer-Assisted Navigation.

BACKGROUND: Preoperative planning for anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) is becoming increasingly common. While preoperative planning allows surgeons to determine individualized implant types, utilization of intraoperative navigation improves the accuracy of implant placement and may increase confidence in the preoperative plan. The purpose of this study was to evaluate and compare the rate at which surgeons use a glenoid implant different than their preoperative plan with and without the use of computer navigation. METHODS: A retrospective review of a multicenter prospectively collected shoulder arthroplasty database was conducted between 2016 and 2022. Inclusion criteria were primary aTSA or rTSA with an available preoperative plan and record of the actual implant used. Change in glenoid implant was defined as a deviation in the final implant from the preoperative plan in regard to backside shape (nonaugmented vs augment or differing augment shape). RESULTS: We included 1,915 shoulder arthroplasties (525 aTSA, 1,390 rTSA) performed with preoperative planning and intraoperative navigation and 110 shoulder athroplasties (37 aTSA, 73 rTSA) performed with preoperative planning alone. Overall, the final glenoid implant deviated from the preoperative plan less frequently when intraoperative navigation was used compared with preoperative planning alone (1.9% [n = 36] versus 7.3% [n = 8], P = 0.002). When stratified by procedure, deviation from the preoperative plan occurred significantly less for rTSA when preoperative planning was used with intraoperative navigation versus planning alone (2% [n = 29] versus 11% [n = 8], P < 0.001; OR = 0.17 [95% CI = 0.07 to 0.46]), but not aTSA (1% [n = 7] versus 0% [n = 0], P = 1). Use of intraoperative navigation was independently associated with lower odds of deviation from the preoperative plan on multivariable logistic regression (OR = 0.25 [95% CI = 0.11 to 0.56], P = 0.001). CONCLUSION: Use of intraoperative navigation is associated with increased adherence to the preoperative plan for primary rTSA. Use of navigation may increase surgeon confidence despite known limitations of glenoid visualization during this procedure. This may offer advantages in outpatient surgery centers and smaller hospitals where inventory space may be limited. LEVEL OF EVIDENCE: Ⅲ, retrospective cohort study.