Identification of fluoxetine as a direct NLRP3 inhibitor to treat atrophic macular degeneration.

The atrophic form of age-related macular degeneration (dry AMD) affects nearly 200 million people worldwide. There is no Food and Drug Administration (FDA)-approved therapy for this disease, which is the leading cause of irreversible blindness among people over 50 y of age. Vision loss in dry AMD results from degeneration of the retinal pigmented epithelium (RPE). RPE cell death is driven in part by accumulation of Alu RNAs, which are noncoding transcripts of a human retrotransposon. Alu RNA induces RPE degeneration by activating the NLRP3-ASC inflammasome. We report that fluoxetine, an FDA-approved drug for treating clinical depression, binds NLRP3 in silico, in vitro, and in vivo and inhibits activation of the NLRP3-ASC inflammasome and inflammatory cytokine release in RPE cells and macrophages, two critical cell types in dry AMD. We also demonstrate that fluoxetine, unlike several other antidepressant drugs, reduces Alu RNA-induced RPE degeneration in mice. Finally, by analyzing two health insurance databases comprising more than 100 million Americans, we report a reduced hazard of developing dry AMD among patients with depression who were treated with fluoxetine. Collectively, these studies identify fluoxetine as a potential drug-repurposing candidate for dry AMD.

Does timing of total elbow arthroplasty after distal humerus fracture affect 2-year complication rates?

BACKGROUND: Open reduction internal fixation (ORIF) remains the gold standard for adult distal humerus fractures (DHF). However, indications for total elbow arthroplasty (TEA) continue to expand and the incidence of primary and salvage TEA for DHF has increased. The objective of this study was to compare complication and reoperation rate for acute versus delayed primary and salvage TEA performed for DHF. METHODS: Patients who underwent TEA for DHF were identified in the PearlDiver database. Patients were sorted into three cohorts: (1) acute TEA (within 2 weeks of diagnosis), (2) delayed TEA (between 2 weeks and 6 months after diagnosis), and (3) salvage TEA (after failed ORIF, malunion, nonunion, delayed treatment between 6 months-1 year or post-traumatic arthritis). Multivariate analysis was utilized to assess for confounding variables and covariates when identify differences in complications between cohorts. RESULTS: 788 patients underwent acute TEA, 213 patients underwent delayed TEA, and 422 patients underwent salvage TEA after DHF. The incidence of PJI (8.5% vs. 3.4%, odds ratio (OR) 2.60, P=0.002) and triceps injury (2.4% vs. 0.4%, OR 6.29, P=0.012) were higher in the delayed compared to acute cohort. The incidence of revision (8.5% vs. 2.1%, OR 3.76, P< 0.001), periprosthetic fracture (4.3% vs. 1.1%, OR 3.64, P=0.002), PJI (14.7% vs 3.4%, OR 4.36, P< 0.001), triceps injury (2.6% vs. 0.4%, OR 5.70, P=0.008), and wound complications (6.9% vs 2.9%, OR 2.33, P=0.002) were higher in the salvage compared to acute cohort. There was an increased rate of revision (8.5% vs. 1.9%, OR 6.08, P=0.002) in the salvage compared to delayed cohort. CONCLUSION: Patients undergoing salvage TEA after DHF have increased rates of at 2 years postoperatively including revision, periprosthetic fracture, PJI, triceps injury, and wound complications. The salvage cohort also had an increased risk of revision when compared to the delayed cohort. However, other than revision rates, patients in the salvage and delayed cohorts have similar postoperative complication rates.

The Impact of Three-Dimensional Humeral Planning and Standard Transfer Instrumentation on Reconstruction of Native Humeral Anatomy for Anatomic Total Shoulder Arthroplasty.

BACKGROUND: Preoperative three-dimensional CT-based planning for anatomic total shoulder arthroplasty (TSA) has grown in popularity in the past decade with the primary focus on the glenoid. Little research has evaluated if humeral planning has any effect on the surgical execution of the humeral cut or the positioning of the prosthesis. METHODS: Three surgeons performed a prospective study utilizing 3D-printed humeri printed from CTs of existing patients, which were chosen to be -3, -1, 0, 1 and 3 standard deviations of all patients in a large database. A novel 3D printing process was utilized to 3D print not only the humerus, but also all four rotator cuff tendons. For each surgical procedure, the printed humerus was mounted inside a silicon shoulder, with printed musculature and skin, and with tensions similar to human tissue requiring standard retraction and instruments to expose the humerus. Three phases of the study were designed: Phase 1: Humeral neck cuts were performed on all specimens without any preoperative humeral planning, Phase 2: 3D planning was performed, and the cuts and implant selection were repeated, Phase 3: A neck shaft angle guide and digital calipers were used to measure humeral osteotomy thickness to aid in the desired humeral cut. All humeri were digitized. The difference between the prosthetic center of rotation (COR) and ideal COR was calculated. The percentage of patients with a varus neck shaft angle (NSA) was calculated for each phase. The difference in planned and actual cut thickness was also compared. RESULTS: For both 3D change in COR and medial to lateral change in COR, use of preoperative planning alone and with standard transfer instrumentation resulted in a significantly more anatomic restoration of ideal COR. The deviations from planned cut thickness decreased with each phase: Phase 1: 2.6±1.9 mm, Phase 2: 2.0±1.3 mm, Phase 3: 1.4±0.9 mm (p = 0.041 for Phase 3 vs Phase 1). For NSA, in Phase 1: 7/15 (47%) cases were in varus, in Phase 2: 5/15 (33%) were in varus and Phase 3: 1/15 (7%) were in varus (p =0.013 for Phase 3 vs Phase 1). CONCLUSIONS: Use of preoperative 3-D humeral planning for stemless anatomic TSA improved prosthetic humeral center of rotation, whether performed with or without standard transfer instrumentation. The use of a neck-shaft angle cut guide and calipers to measure cut thickness significantly reduced the percentage of varus humeral cuts and deviation from planned cut thickness.

Posteroinferior glenosphere positioning is associated with improved range of motion following reverse shoulder arthroplasty with a 135° inlay humeral component and lateralized glenoid.

BACKGROUND: Optimal glenosphere positioning in a lateralized reverse shoulder arthroplasty (RSA) to maximize functional outcomes has yet to be clearly defined. Center of rotation (COR) measurements have largely relied on anteroposterior radiographs, which allow assessment of lateralization and inferior position, but ignore scapular Y radiographs, which may provide an assessment of the posterior and inferior position relative to the acromion. The purpose of this study was to evaluate the COR in the sagittal plane and assess the effect of glenosphere positioning with functional outcomes using a 135° inlay stem with a lateralized glenoid. METHODS: A retrospective review was performed on a prospectively maintained multicenter database on patients who underwent primary RSA from 2015 to 2021 with a 135° inlay stem. The COR was measured on minimum 2-year postoperative sagittal plain radiographs using a best-fit circle fit method. A best-fit circle was made on the glenosphere and the center was marked. From there, 4 measurements were made: (1) center to the inner cortex of the coracoid, (2) center to the inner cortex of the anterior acromion, (3) center to the inner cortex of the middle acromion, and (4) center to the inner cortex of the posterior acromion. Regression analysis was performed to evaluate any association between the position of the COR relative to bony landmarks with functional outcomes. RESULTS: A total of 136 RSAs met the study criteria. There was no relation with any of the distances with outcome scores (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, visual analog scale). In regard to range of motion (ROM), each distance had an effect on at least 1 parameter. The COR to coracoid distance had the broadest association with ROM, with improvements in forward flexion (FF), external rotation (ER0), and internal rotation with the arm at 90° (IR90) (P < .001, P = .031, and P < .001, respectively). The COR to coracoid distance was also the only distance to affect the final FF and IR90. For every 1-mm increase in this distance, there was a 1.8° increase in FF and 1.5° increase in IR90 (ß = 1.78, 95% confidence interval [CI] 0.85-2.72, P < .001, and ß = 1.53, 95% CI 0.65-2.41, P < .001; respectively). CONCLUSION: Evaluation of the COR following RSA in the sagittal plane suggests that a posteroinferior glenosphere position may improve ROM when using a 135° inlay humeral component and a lateralized glenoid.

Robert H. Cofield, MD, Award for Best Oral Presentation 2023: Up to 8 mm of glenoid-sided lateralization does not increase the risk of acromial or scapular spine stress fracture following reverse shoulder arthroplasty with a 135° inlay humeral component.

BACKGROUND: Glenoid-sided lateralization in reverse shoulder arthroplasty (RSA) decreases bony impingement and improves rotational range of motion, but has been theorized to increase the risk of acromial or scapular spine fractures (ASFs). The purpose of this study was to assess if glenoid-sided lateralization even up to 8 mm increases the risk for stress fracture following RSA with a 135° inlay humeral component. METHODS: A retrospective review was performed from a multicenter prospectively collected database on patients who underwent primary RSA from 2015 to 2021. All RSAs were performed with a 135° inlay humeral component. Varying amounts of glenoid lateralization were used from 0 to 8 mm. Preoperative radiographs were reviewed for the presence of acromial thinning, acromiohumeral distance (AHD), and inclination. Postoperative implant position (distalization, lateralization, and inclination) as well as the presence of ASF was evaluated on minimum 1-year postoperative radiographs. Regression analyses were performed on component and clinical variables to assess for factors predictive of ASF. RESULTS: Acromial or scapular spine fractures were identified in 26 of 470 shoulders (5.5%). Glenoid-sided lateralization was not associated with ASF risk (P = .890). Furthermore, the incidence of fracture did not vary based on glenoid-sided lateralization (0-2 mm, 7.4%; 4 mm, 5.6%; 6 mm, 4.4%; 8 mm, 6.0%; P > .05 for all comparisons). RSA on the dominant extremity was predictive of fracture (odds ratio [OR] 2.21, 95% confidence interval [CI] 1.20-5.75; P = .037), but there was no relationship between patient age, sex, preoperative acromial thinning, or diagnosis and risk of fracture. Although there was no difference in mean postoperative AHD between groups (P = .443), the pre- to postoperative delta AHD was higher in the stress fracture group (2.0 ± 0.7 cm vs. 1.7 ± 0.7 cm; P = .015). For every centimeter increase in delta AHD, there was a 121% increased risk for fracture (OR 2.21, 95% CI 1.33-3.68; P = .012). Additionally, for every 1-mm increase in inferior glenosphere overhang, there was a 19% increase in fracture risk (P = .025). CONCLUSION: Up to 8 mm of glenoid-sided metallic lateralization does not appear to increase the risk of ASF when combined with a 135° inlay humeral implant. Humeral distalization increases the risk of ASF, particularly when there is a larger change between pre- and postoperative AHD or higher inferior glenosphere overhang. In cases of pronounced preoperative superior humeral migration, it may be a consideration to avoid excessive postoperative distalization, but minimizing bony impingement via glenoid-sided lateralization appears to be safe.

Novel 3D MRI-Based Volumetric Assessment of Rotator Cuff Musculature Demonstrates Stronger Correlation with Preoperative Functional Status When Compared to the Goutallier Grading Scheme.

BACKGROUND: The Goutallier classification (GC) is used to assess fatty atrophy in rotator cuff (RC) tears, yet limitations exist. A battery of 3D-magnetic resonance imaging (MRI) volumetric scores (VS) was developed to provide comprehensive characterization of RC pathology. The purposes of this study were to: (1) Describe the correlation between GC and VS for supraspinatus changes in RC tears, (2) Characterize the chronicity of RC tears using the battery of 12 VS measurements, and (3) Compare GC and VS to determine which method most closely corresponds with preoperative patient reported outcome measures (PROMs). METHODS: Preoperative shoulder MRIs were reviewed after arthroscopic RC repair. Preoperative GC stage and Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) and pain interference (PI) scores were collected. The battery of VS included fat infiltration (FIS), muscle size (MSS) and relative volume contribution (RCS) for each RC muscle. Backwards linear regression was performed to compare GC stage with preoperative PROMIS PF/PI to determine which VS measurement most closely correlated with preoperative PROMs. RESULTS: Eighty-two patients underwent RC repair (mean age 55±8.2 years, 63% male, 68% GC stage ≤1). In evaluation of the supraspinatus, there was a moderate positive correlation between GC and FIS (r = 0.459, p < 0.001); strong negative correlations were observed between MSS (r = -0.800, p < 0.001) and RCS (r = -0.745, p < 0.001) when compared to GC. A negligible linear correlation was observed between GC and preoperative PROMIS PF (r = -0.106, p = 0.343) and PI (r = -0.071, p = 0.528). On multivariate analysis, subscapularis MSS (beta > 0, p = 0.064) was a positive predictor, and subscapularis FIS (beta < 0, p = 0.137), teres minor MSS (beta < 0, p = 0.141) and FIS (beta < 0, p = 0.070) were negative predictors of preoperative PF (r = 0.343, p = 0.044); while supraspinatus MSS (beta > 0, p = 0.009) and FIS (beta > 0, p = 0.073), teres minor FIS (beta > 0, p = 0.072) and subscapularis FIS (beta > 0, p = 0.065) were positive predictors of preoperative PI (r = 0.410, p = 0.006). CONCLUSION: Although gold standard in evaluation of RC pathology, GC demonstrated negligible correlation with preoperative functional disability. Alternatively, a battery of 3D VS showed strong correlation with GC through a quantitative, comprehensive evaluation of the RC unit including several moderate predictors of preoperative functional disability.

Preoperative Substance Use Disorder Is Associated With an Increase in 90-Day Postoperative Complications, 1-Year Revisions and Conversion to Arthroplasty Following Arthroscopic Rotator Cuff Repair: Substance Use Disorder on the Rise.

PURPOSE: The purpose of the current study was to use a nationwide administrative-claims database to characterize the substance use disorder trends of patients undergoing arthroscopic rotator cuff repair (RCR). Additionally, we sought to evaluate the influence of preoperative substance use disorder on postoperative outcomes following arthroscopic RCR. METHODS: The Mariner database was used to identify patients undergoing RCR using CPT codes, ages 18-84 years old, from 2010 to 2019. Patients were stratified by substance use, including cannabis, cocaine, nicotine, alcohol, opioids, stimulants, or sedative, as defined by International Classification of Diseases (ICD) codes. Substance use disorders trends were reported. Postoperative outcomes assessed consisted of major complications, minor complications, infections, readmissions, and Emergency Department visits within 90 days of surgery. Additionally, postoperative stiffness, revision surgery, and conversion to arthroplasty within 1 year were evaluated. Multivariate logistic regressions were used to control for demographic and comorbid factors. RESULTS: Substance use trends from 2010 to 2019 show an increase in documentation of substance use in patients undergoing RCR. Individuals with a history of substance use disorder had an increased risk of adverse outcomes, most notably major medical complications (odds ratio [OR]: 1.63; 95% confidence interval [CI]: 1.44-1.86; P < .001), revision surgery (OR: 1.43; 95% CI: 1.30-1.56; P < .001), and conversion to arthroplasty (OR: 1.40; 95% CI: 1.08-1.80; P = .009). Subgroup analysis demonstrated that cannabis users were at higher risk for major medical complications (OR: 1.75; 95% CI: 1.15-2.56; P < .001), conversion to arthroplasty (OR: 3.54; 95% CI: 1.77-6.4; P < .001), and revision (OR: 1.53; 95% CI: 1.12-2.04; P < .05) compared to controls. Additionally, substance use was associated with higher medical costs in terms of procedural cost (ß; $3634: $3,490-3,777) and 90-day postoperative costs (ß: $436; $375-$498). CONCLUSION: Documentation of substance use disorder is increasing in individuals undergoing arthroscopic rotator cuff repair. Substance use is associated with higher rates of postoperative complications, overall costs, and revision surgery following arthroscopic RCR. Nicotine and cannabis use were most commonly associated with increased rates of postoperative complications and treatment failure. LEVEL OF EVIDENCE: IV, retrospective therapeutic case series.

Staging Bilateral Hip Arthroscopies Less Than 1 Year Apart May Reduce the Risk of Revision Surgery.

PURPOSE: To identify the influence of timing between staged bilateral hip arthroscopy on 90-day postoperative medical complications and 2-year surgical complications including revision, conversion to total hip arthroplasty (THA), and infection. METHODS: The Mariner data set of the PearlDiver all-payer claims database was queried for patients undergoing staged bilateral hip arthroscopy. Patients were stratified into cohorts based on time between arthroscopies: (1) ≤3 months, (2) 3 to ≤6 months, (3) 6 to ≤12 months, and (4) >1 year. Multivariate logistic regression was utilized to control for any confounding variables. RESULTS: In total, 998 patients underwent staged bilateral hip arthroscopy out of 38,080 patients who underwent primary hip arthroscopy. The 2-year revision rate was 7.6% for all patients undergoing bilateral hip arthroscopy, while 1.9% of patients underwent conversion to THA. Patients with arthroscopy procedures staged less than 1 year apart (cohorts 1, 2, and 3) had significantly decreased risk of revision compared to the greater than 1 year cohort (P = .008, .025, and .044, respectively). There were no differences in rates of major medical, minor medical, or remaining surgical complications between the cohorts. Direct comparisons between the cohorts staged ≤1 year apart showed no significant differences in medical or surgical complications (P > .05). CONCLUSIONS: The revision rate in all patients undergoing staged bilateral hip arthroscopy was 7.6%. Staging hip arthroscopy ≤1 year apart was associated with a decreased risk of revision when compared to the staged cohort >1 year. Among those staged less than 1 year, the timing of staging had no association with rates of medical or surgical complications. Patients who are indicated for bilateral hip arthroscopy may benefit from staging under 1 year apart to reduce the risk of revision surgery. Optimal timing decisions may be patient specific and rely on the duration of symptoms, severity of pathology, or progression of rehabilitation after the index procedure. LEVEL OF EVIDENCE: III, retrospective comparative study.

Social Determinants of Health Disparities Are Associated With Increased Costs, Revisions, and Infection in Patients Undergoing Arthroscopic Rotator Cuff Repair.

PURPOSE: The purpose of this study was to use a national claims database to assess the impact of pre-existing social determinants of health disparities (SDHD) on postoperative outcomes following rotator cuff repair (RCR). METHODS: A retrospective review of the Mariner Claims Database was used to capture patients undergoing primary RCR with at least 1 year of follow-up. These patients were divided into two cohorts based on the presence of a current or previous history of SDHD, encompassing educational, environmental, social, or economic disparities. Records were queried for 90-day postoperative complications, consisting of minor and major medical complications, emergency department (ED) visits, readmission, stiffness, and 1-year ipsilateral revision surgery. Multivariate logistic regression was employed to assess the impact of SDHD on the assessed postoperative outcomes following RCR. RESULTS: 58,748 patients undergoing primary RCR with a SDHD diagnosis and 58,748 patients in the matched control group were included. A previous diagnosis of SDHD was associated with an increased risk of ED visits (OR 1.22, 95% CI 1.18-1.27; P < .001), postoperative stiffness (OR 2.53, 95% CI 2.42-2.64; P < .001), and revision surgery (OR 2.35, 95% CI 2.13-2.59; P < .001) compared to the matched control group. Subgroup analysis revealed educational disparities had the greatest risk for 1-year revision (OR 3.13, 95% CI 2.53-4.05; P < .001). CONCLUSIONS: The presence of a SDHD was associated with an increased risk of revision surgery, postoperative stiffness, emergency room visits, medical complications, and surgical costs following arthroscopic RCR. Overall, economic and educational SDHD were associated with the greatest risk of 1-year revision surgery. LEVEL OF EVIDENCE: III, retrospective cohort study.

Interpositional scaffold anchor rotator cuff footprint tear repair: excellent survival, healing, and early outcomes.

PURPOSE: Shoulder function limitation duration after a full-thickness rotator cuff tendon (RCT) tear may influence post-repair healing and outcomes. A suture anchor was developed to improve footprint repair fixation and healing through biological fluid delivery and scaffold augmentation. The primary multicenter study objective was to evaluate RCT repair failure rate based on 6-month MRI examination, and device survival at 1-year follow-up. The secondary objective was to compare the clinical outcomes of subjects with shorter- and longer-term shoulder function limitation duration. METHODS: Seventy-one subjects (46 men) with moderate-to-large RCT tears (1.5-4 cm), at a median 61 years of age (range = 40-76), participated in this study. Pre-repair RCT tear location/size and 6-month healing status were confirmed by an independent radiologist. Subjects with shorter- (Group 1: 17.8 ± 21 days, n = 37) and longer-term (Group 2: 185.4 ± 89 days, n = 34) shoulder function limitation durations were also compared over 1 year for active mobility, strength, American Shoulder and Elbow Surgeon's Shoulder Score (ASES score), Veterans RAND 12 Item Health Survey (VR-12), and visual analog scale (VAS) pain and instability scores. RESULTS: Three of the 52 subjects [5.8%] who underwent 6-month MRI experienced a re-tear at the original RCT footprint repair site. By the 1-year follow-up, overall anchor survival was 97%. Although Group 2 displayed lower ASES and VR-12 scores pre-repair (ASES = 40.1 ± 17 vs. 47.9 ± 17; VR-12 physical health (PH) = 37.2 ± 9 vs. 41.4 ± 8) (p ≤ 0.048), at 3-month post-RCT repair (ASES = 61.3 ± 19 vs. 71.3 ± 20; VR-12 PH = 40.8 ± 8 vs. 46.8 ± 9) (p ≤ 0.038), and at 6-month post-RCT repair (ASES = 77.4 ± 18 vs. 87.8 ± 13; VR-12 PH = 48.9 ± 11 vs. 54.0 ± 9) (p ≤ 0.045), by 1-year post-RCT repair, groups did not differ (n.s.). Between-groups VR-12 mental health score differences were not evident at any time period (n.s.). Shoulder pain and instability VAS scores also did not differ (n.s.), displaying comparable improvement between groups from pre-RCT repair to 1-year post-RCT repair. Groups had comparable active shoulder mobility and strength recovery at each follow-up (n.s.). CONCLUSION: At 6-month post-RCT repair, only 3/52 of patients [5.8%] had a footprint re-tear, and at 1-year follow-up, overall anchor survival was 97%. Use of this scaffold anchor was associated with excellent early clinical outcomes regardless of shoulder function impairment duration. LEVEL OF EVIDENCE: II.

Economic and educational disparities are associated with an increased risk of revision surgery following shoulder arthroplasty.

BACKGROUND: There is limited literature exploring how nonmedical factors such as social determinants of health (SDOHs) are associated with postoperative outcomes following shoulder arthroplasty. METHODS: A retrospective cohort review of the Pearl Diver Database was used to capture patients undergoing either primary anatomic total or reverse shoulder arthroplasty from the fourth quarter of 2015 to the third quarter of 2019 with at least 1 year of active longitudinal follow-up. Patients with proximal humeral fractures, stress fractures, or septic arthritis were excluded. The included patients were then divided into 2 cohorts based on the presence of current SDOHs or a history of SDOHs. The SDOH cohort comprised 4 non-mutually exclusive categories: economic, educational, social, and environmental disparities. Subsequently, a control cohort was matched at a 1:1 ratio to the SDOH cohort. Primary outcome measures were assessed using a logistic regression and consisted of the following 90-day postoperative complications: minor and major medical complications and infection. Emergency department (ED) visits and readmissions for any cause were also assessed. Additionally, the following 1-year outcomes were assessed: aseptic loosening, instability, and revision arthroplasty. Surgical costs and 90-day postoperative costs were collected using averaged insurance reimbursements for both the control and SDOH cohorts. RESULTS: There were 5190 patients in each cohort. Economic disparities made up the largest portion of the SDOH cohort (n = 4631, 89.2%), followed by social (n = 741, 14.3%), environmental (n = 417, 8.0%), and educational (n = 99, 1.9%) disparities. Compared with the control cohort, SDOHs were associated with an increased risk of major complications (2.3% vs. 1.4%; odds ratio [OR], 1.55; 95% confidence interval [CI], 1.29-1.87; P < .001), minor complications (5.7% vs. 3.8%; OR, 1.62; 95% CI, 1.21-1.95; P = .001), readmissions (4.3% vs. 2.8%; OR, 1.56; 95% CI, 1.26-1.84; P < .001), and ED visits (15.2% vs. 11.0%; OR, 1.45; 95% CI, 1.29-1.63; P < .001) within 90 days following surgery. Additionally, SDOHs were associated with an increased risk of aseptic loosening (1.1% vs. 0.6%; OR, 1.85; 95% CI, 1.20-2.65; P = .006), instability (4.0% vs. 2.2%; OR, 1.80; 95% CI, 1.43-2.28; P < .001), and ipsilateral revision (9.2% vs. 7.6%; OR, 1.24; 95% CI, 1.08-1.43; P < .001) at 1 year postoperatively compared with the control cohort. CONCLUSION: SDOHs are associated with increased rates of adverse outcomes following shoulder arthroplasty including revision surgery, ED visits, length of stay, and overall cost compared with matched controls without SDOHs. Specifically, economic and educational disparities are associated with increased rates of adverse outcomes following surgery including revision surgery, ED visits, length of stay, and overall cost.

The use of causal language and inferences in observational shoulder arthroplasty database studies.

BACKGROUND: Over the last few decades, several databases and clinical registries have been used to generate studies for orthopedic surgery research including shoulder arthroplasty. Observational database studies present data that are best used to provide information regarding associations between variables but is unable to prove causation. Yet, there remains a tendency for authors to use causal language and conclusive statements in published shoulder arthroplasty literature using such databases. METHODS: We systematically identified administrative database and registry studies on shoulder arthroplasty in 5 orthopedic journals from January 2020 to December 2021. Papers were independently graded by 2 reviewers for the presence, absence, or inconsistent use of causal language throughout the publication. χ2 analyses were conducted to determine the relationship between causality language and article characteristics including the journal of publication. RESULTS: There were 65 eligible articles. According to the reviewers, 67.7% of titles and abstracts were either consistently causal or inconsistently causal in language and inference. On reviewing the full text, 69.2% were found to contain some degree of causal language (38.5% consistently causal, 30.8% inconsistently causal). There were no statistically significant associations between the journal and title and abstract final grading (P = .863) or the journal and full-text grading (P = .726). CONCLUSION: The use of causal language remains highly prevalent in observational database studies related to shoulder arthroplasty. Understanding the limitations of observational database studies is paramount for accurate interpretation of these publications.

Short-term functional outcomes of reverse shoulder arthroplasty following three-dimensional planning is similar whether placed with a standard guide or patient-specific instrumentation.

BACKGROUND: Preoperative assessment of the glenoid and surgical placement of the initial guidewire are important in implant positioning during reverse total shoulder arthroplasty (rTSA). Three-dimensional (3D) computed tomography and patient-specific instrumentation (PSI) have improved the placement of the glenoid component, but the impact on clinical outcomes remains unclear. The purpose of this study was to compare short-term clinical outcomes after rTSA based on an intraoperative technique for central guidewire placement in a cohort of patients who had preoperative 3D planning. METHODS: A retrospective matched analysis was performed from a multicenter prospective cohort of patients who underwent rTSA with preoperative 3D planning and a minimum of 2-year clinical follow-up. Patients were divided into 2 cohorts based on the technique used for glenoid guide pin placement: (1) standard manufacture guide (SG) that was not customized or (2) PSI. Patient-reported outcomes (PROs), active range of motion, and strength measures were compared between the groups. The American Shoulder and Elbow Surgeons score was used to assess the minimum clinically important difference, substantial clinical benefit, and patient acceptable symptomatic state. RESULTS: One hundred seventy-eight patients met the study criteria: 56 underwent SGs and 122 underwent PSI. There was no difference in PROs between cohorts. There were no significant differences in the percentage of patients who achieved an American Shoulder and Elbow Surgeons minimum clinically important difference, substantial clinical benefit, or patient acceptable symptomatic state. Improvements in internal rotation to the nearest spinal level (P < .001) and at 90° (P = .002) were higher in the SG group, but likely explained by differences in glenoid lateralization used. Improvements in abduction strength (P < .001) and external rotation strength (P = .010) were higher in the PSI group. CONCLUSION: rTSA performed after preoperative 3D planning leads to similar improvement in PROs regardless of whether an SG or PSI is used intraoperatively for central glenoid wire placement. Greater improvement in postoperative strength was observed with the use of PSI, but the clinical significance of this finding is unclear.

Stemless components lead to improved radiographic restoration of humeral head anatomy compared with short-stemmed components in total shoulder arthroplasty.

BACKGROUND: Restoring the native center of rotation (COR) in total shoulder arthroplasty (TSA) has been shown to improve postsurgical function, subjective outcomes, and implant longevity. The primary purpose of this study was to compare postoperative radiographic restoration of the humeral COR between short-stem and stemless humeral implants by evaluating the mean COR shift between the 2 techniques. Secondary outcomes evaluated were comparisons of COR shift outliers, humeral head implant thickness and diameter, direction of COR shift, and neck-shaft angle (NSA). METHODS: This study was a multicenter retrospective comparative study using a consecutive series of primary anatomic TSA patients who received either a short-stem or stemless humeral implant. Radiographically, COR and NSA were measured by 2 fellowship-trained surgeons using the best-fit circle technique on immediate postoperative Grashey radiographs. RESULTS: A total of 229 patients formed the final cohort for analysis that included 89 short stems and 140 stemless components. The mean COR shift for short stems was 2.7 mm (±1.4 mm) compared with 2.1 mm (±0.9 mm) for stemless implants (P < .001). The percentage of short-stem implant patients with a >2 mm COR difference from native was 66.0% (n = 62) compared with 47.4% (n = 64) for stemless (P = .006). The percentage of short-stem patients with a >4 mm COR difference from native was 17.0% (n = 16) compared with 3.0% (n = 4) for stemless (P < .001). The mean humeral implant head thickness for short stems was 18.7 ± 2.2 mm compared with 17.2 ± 1.3 mm for stemless implants (P < .001). The mean humeral head diameter for short stems was 48.7 ± 4.4 mm compared with 45.5 ± 3.5 mm for stemless implants (P < .001). The NSA for the short-stem cohort was 136.7° (±3.6°) compared with 133.5° (±6.0°) for stemless (P < .001). CONCLUSIONS: Stemless prostheses placed during TSA achieved improved restoration of humeral head COR and were less likely to have significant COR outliers compared with short-stem implants.

Influence of backside seating parameters and augmented baseplate components in virtual planning for reverse shoulder arthroplasty.

BACKGROUND: The primary goal of this investigation was to examine the influence of a backside seating percentage variable on volume of reamed bone and contact area in virtual planning for glenoid baseplate placement for reverse total shoulder arthroplasty (RTSA). The secondary goal was to assess how the option of augmented glenoid baseplate components affected reamed volume and cortical contact area of virtually positioned baseplates. METHODS: Nine surgeons virtually planned 30 RTSA cases using a commercially available software system. The 30 cases were chosen to span a spectrum of glenoid deformity. The study consisted of 3 phases. In phase 1, cases were planned with the backside seating percentage blinded and without the option of augmented baseplate components. In phase 2, the backside seating parameter was unblinded. In phase 3, augmented baseplate components were added as an option. Implant version and inclination were recorded. By use of computer-assisted design models, total volume of bone reamed, as well as reamed cortical volume and cancellous volume, was calculated. Total, cortical, and cancellous baseplate contact areas were also calculated. Finally, total glenoid lateralization was calculated for each phase and compared. RESULTS: Mean implant version was clinically similar across phases but was statistically significantly lower in phase 3 (P = .006 compared with phase 1 and P = .001 compared with phase 2). Mean implant inclination was clinically similar across phases but was statistically significantly lower in phase 3 (P < .001). Phase 3 had statistically significantly lower cancellous and total reamed bone volumes compared with phase 1 and phase 2 (P < .001 for all comparisons). Phase 3 had statistically significantly larger cortical contact area, lower cancellous contact area, and larger total contact area compared with phase 1 and phase 2 (P < .001 for all comparisons). Phase 3 had significantly greater glenoid lateralization (mean, 10.5 mm) compared with phase 1 (mean, 7.8 mm; P < .001) and phase 2 (mean, 7.9 mm; P < .001). CONCLUSIONS: Across a wide range of glenoid pathology during virtual surgical planning, experienced shoulder arthroplasty surgeons chose augmented baseplates frequently, and the option of a full-wedge augmented baseplate resulted in statistically significantly greater correction of glenoid deformity, improved total and cortical baseplate contact area, less cancellous reamed bone, and greater glenoid lateralization. Backside seating information does not have a significant impact on how glenoid baseplates are virtually positioned for RTSA, nor does it impact the baseplate contact area or volume of reamed bone.

Infection Risk Increases After Total Hip Arthroplasty Within 3 Months Following Intra-Articular Corticosteroid Injection. A Meta-Analysis on Knee and Hip Arthroplasty.

BACKGROUND: Much debate continues regarding the risk of postoperative infection after intra-articular corticosteroid injection prior to total joint arthroplasty. The aim of this study was to evaluate the risk of periprosthetic joint infection (PJI) or other complications after joint arthroplasty in patients who received preoperative corticosteroids injections. METHODS: A literature search was performed on PubMed, Web of Science, and Cochrane Library through January 4, 2022. Of 4,596 studies, 28 studies on 480,532 patients were selected for qualitative analysis. Studies describing patients receiving corticosteroids injections before joint arthroplasty (hip, knee) were included in the systematic review. A meta-analysis was performed of studies focusing on corticosteroids injections and PJI. Assessment of risk of bias and quality of evidence was based on the "Downs and Black's Checklist for Measuring Quality". RESULTS: A significant association (odds ratio: 1.55, P = .001, 95% confidence interval: 1.357-1.772) between PJI and corticosteroids injections was found for total hip arthroplasty (THA). No association was found for knee arthroplasty procedures. The risk of PJI is statistically higher (odds ratio: 1.20, P = .045, 95% confidence interval: 1.058-1.347) if the injections are performed within 3 months preoperatively in THA patients. CONCLUSION: Patients undergoing THA who previously received intra-articular injections of corticosteroids may expect a statistically higher risk of developing PJI. On the contrary, no association between corticosteroids injections and PJI could be seen in total knee arthroplasty patients. In addition, injection timing plays an important role: surgeons should refrain from administering corticosteroids injections within 3 months before hip arthroplasty, as it appears to be less safe than waiting a 3-month interval.

High Prevalence of Causal Language and Inferences in Observational Hip and Knee Arthroplasty Database Studies: A Review of Papers Published Across Four Orthopaedic Journals.

BACKGROUND: The use of administrative databases and clinical registries in lower extremity arthroplasty research is growing. Such observational studies are unable to fully control for confounders and cannot establish causality. However, many authors use causal language when describing their aims or findings, potentially misleading readers. We examined the prevalence of causal language and inferences in the lower extremity arthroplasty literature. METHODS: We systematically identified administrative database and registry studies on hip and knee arthroplasty that were published in 4 orthopaedic journals in 2020. Articles were graded independently by two reviewers for the presence of causal language in both the title and abstract and the full text. Chi-squared analyses were conducted to determine the relationship between the causality grading and article characteristics including the journal of publication. RESULTS: Of 116 eligible articles, we classified 79.3% of titles and abstracts as either consistently causal or inconsistently causal, with only 20.7% as consistently noncausal. A total of 40.5% of full texts were consistently causal, 49.1% were inconsistent, and 10.3% were consistently noncausal. Chi-squared analyses revealed no statistically significant association between the title and abstract's grading and the journal (P = .720) nor with the use of a database or registry (P = .716). CONCLUSION: Causal language and inferences were present in 79.3% of titles and abstracts of lower extremity arthroplasty observational database studies published in 2020. The high prevalence of causal language and inferences in the arthroplasty literature may mislead readers.

Total Hip Arthroplasty in Patients Who Have Respiratory Disease Who use Supplemental Home Oxygen.

BACKGROUND: The purpose of this study is to investigate the association between supplemental home oxygen prior to surgery and both medical and surgical complications after primary elective total hip arthroplasty (THA) in patients who have respiratory disease (RD). METHODS: The Mariner database was used to identify patients who have RD who received primary elective THA from 2010 to 2020. The THA patient cohorts consisted of 20,872 patients who had RD prescribed home oxygen and 69,520 patients who had RD without home oxygen. For patients who had a diagnosis of RD and were prescribed supplemental home oxygen (O2) and those who were not, the rates of postoperative medical and surgical complications, hospital readmissions, and emergency room visits were determined. Reimbursements and lengths of stay were also determined. Logistic regression analyses were utilized to compare both cohorts to matched cohorts without RD, as well as to each other directly. RESULTS: In comparison to the matched control group, the RD with home oxygen group had a significantly higher rate of pneumonia (odds ratio [OR] 4.27, P < .0001), pulmonary embolism (OR 1.81, P < .0001), periprosthetic joint infection (OR 1.21, P < .0001), and periprosthetic fracture (OR 1.81, P = .001). The RD with home oxygen cohort also had a significantly higher incidence of pneumonia (OR 2.16, P < .0001), periprosthetic joint infection (OR 1.38, P < .0001), and periprosthetic fracture (OR 1.24, P = .009) compared to RD patients who did not have home oxygen. CONCLUSION: Supplemental home oxygen use prior to surgery is associated with a significantly higher risk of postoperative medical and surgical complications after elective THA.

Osteopetrosis is Associated With an Increased Risk for Intraoperative Periprosthetic Fracture in Total Hip Arthroplasty but not in Total Knee Arthroplasty.

BACKGROUND: Osteopetrosis is a rare, inherited disorder in which bone remodels to become pathologically dense. There has been a paucity of data evaluating medical and surgical complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA) in this patient population. The objective of this study was to evaluate osteopetrosis as a potential risk factor for medical and surgical complications following THA and TKA. METHODS: Patients who had a diagnosis of osteopetrosis and underwent THA or TKA from 2010 to 2020 were identified in a national database. A total of 534 THA and 972 TKA patients who had osteopetrosis were identified and compared with matched cohorts of 2,670 and 4,860 patients, respectively. The rates of postoperative medical and surgical complications, hospital readmissions, and emergency room visits were calculated. In addition, reimbursements and lengths of stay were determined. Osteopetrosis patients were then compared to a 5:1 matched cohort without osteopetrosis using logistic regression analyses to control for additional confounding factors. RESULTS: The osteopetrosis THA group had a substantially higher incidence of intraoperative periprosthetic fracture compared to the matched cohort (1.12% versus 0.19%, Odds Ratio 5.88, P = .005). Patients who had a history of osteopetrosis were not found to be at a significantly increased risk for other investigated medical or surgical complications compared to matched controls following THA or TKA. CONCLUSION: Patients who had a history of osteopetrosis undergoing elective primary THA are associated with a significantly increased risk for intraoperative periprosthetic fracture. Patients with a history of osteopetrosis undergoing elective primary TKA were not found to be at an increased risk for any of the investigated complications.

Increased Dislocation Rates After Total Hip Arthroplasty in Patients With Prior Isolated Sacroiliac Joint Arthrodesis.

BACKGROUND: While stiffness of the lumbosacral spine is a known predictor of instability following total hip arthroplasty (THA), little is known about the medical- and surgical-related outcomes following THA in patients who have prior isolated sacroiliac (SI) joint arthrodesis. METHODS: 197 patients who had a history of isolated SI joint arthrodesis who subsequently underwent elective primary THA for a diagnosis of osteoarthritis (THA-SI) from 2015 to 2021 were identified in a national administrative database. Using propensity score matching and logistic regression analyses, this cohort was compared to two groups of patients: patients who did not have any history of lumbar or SI arthrodesis and patients undergoing primary THA who had a history of lumbar arthrodesis without extension into the SI joint (THA-LF). RESULTS: The THA-SI group had a significantly higher incidence of dislocation (odds ratio 2.06, 95% confidence interval 1.04-4.04, P = .037) with no increased incidence of medical complications or other surgical complications when compared to patients without a history of SI or lumbar arthrodesis. There were no significant differences in any complications in THA-SI patients when compared to THA-LF patients. CONCLUSION: Patients who had prior isolated SI joint arthrodesis undergoing primary THA demonstrated a two-fold increased incidence of dislocation when compared to those who did not have prior SI arthrodesis, although the risk of complications in this population was similar to that observed in patients who had prior isolated lumbar spine arthrodesis.