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 and 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 vs. 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 3 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 and 1 year or post-traumatic arthritis). Multivariate analysis was used to assess for confounding variables and covariates when identifying differences in complications between cohorts. RESULTS: A total of 788 patients underwent acute TEA, 213 patients underwent delayed TEA, and 422 patients underwent salvage TEA after DHF. The incidence of periprosthetic joint infection (PJI) (8.5% vs. 3.4%, odds ratio [OR] 2.60, P = .002) and triceps injury (2.4% vs. 0.4%, OR 6.29, P = .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 = .002), PJI (14.7% vs 3.4%, OR 4.36, P < .001), triceps injury (2.6% vs. 0.4%, OR 5.70, P = .008), and wound complications (6.9% vs 2.9%, OR 2.33, P = .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 = .002) in the salvage compared to delayed cohort. CONCLUSION: Patients undergoing salvage TEA after DHF have increased rates of revision, periprosthetic fracture, PJI, triceps injury, and wound complications at 2 years post-operatively. 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 3-dimensional humeral planning and standard transfer instrumentation on reconstruction of native humeral anatomy for anatomic total shoulder arthroplasty.

BACKGROUND: Preoperative 3-dimensional (3D) computed tomography (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 using 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 used to 3D print not only the humerus but also all 4 rotator cuff tendons. For each surgical procedure, the printed humerus was mounted inside a silicone 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. In phase 1, humeral neck cuts were performed on all specimens without any preoperative humeral planning; in phase 2, 3D planning was performed, and the cuts and implant selection were repeated; in phase 3, a neck-shaft angle (NSA) 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 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 = .041 for phase 3 vs. phase 1). For NSA, in phase 1, 7 of 15 (47%) cases were in varus; in phase 2, 5 of 15 (33%) were in varus; and in phase 3, 1 of 15 (7%) cases was in varus (P = .013 for phase 3 vs. phase 1). CONCLUSIONS: Use of preoperative 3D humeral planning for stemless anatomic TSA improved prosthetic humeral COR, whether performed with or without standard transfer instrumentation. The use of an NSA cut guide and calipers to measure cut thickness significantly reduced the percentage of varus humeral cuts and deviation from planned cut thickness.

Machine Learning Models Can Define Clinically Relevant Bone Density Subgroups based on Patient Specific Calibrated CT Scans in Patients Undergoing Reverse Shoulder Arthroplasty.

BACKGROUND: Reduced bone density is recognized as a predictor for potential complications in reverse shoulder arthroplasty (RSA). While humeral and glenoid planning based on preoperative computed tomography (CT) scans assist in implant selection and position, reproducible methods for quantifying the patients' bone density are currently not available. The purpose of this study was to perform bone density analyses including patient specific calibration in an RSA cohort based on preoperative CT imaging. It was hypothesized that preoperative CT bone density measures would provide objective quantification of the patients' humeral bone quality. METHODS: This study consisted of three parts, (1) analysis of a patient-specific calibration method in cadaveric CT scans, (2) retrospective application in a clinical RSA cohort, and (3) clustering and classification with machine learning models. Forty cadaveric shoulders were scanned in a clinical CT and compared regarding calibration with density phantoms, air muscle, and fat (patient-specific) or standard Hounsfield unit. Post-scan patient-specific calibration was used to improve the extraction of three-dimensional regions of interest for retrospective bone density analysis in a clinical RSA cohort (n=345). Machine learning models were used to improve the clustering (Hierarchical Ward) and classification (Support Vector Machine (SVM)) of low bone densities in the respective patients. RESULTS: The patient-specific calibration method demonstrated improved accuracy with excellent intraclass correlation coefficients (ICC) for cylindrical cancellous bone densities (ICC>0.75). Clustering partitioned the training data set into a high-density subgroup consisting of 96 patients and a low-density subgroup consisting of 146 patients, showing significant differences between these groups. The SVM showed optimized prediction accuracy of low and high bone densities compared to conventional statistics in the training (accuracy=91.2%; AUC=0.967) and testing (accuracy=90.5 %; AUC=0.958) data set. CONCLUSION: Preoperative CT scans can be used to quantify the proximal humeral bone quality in patients undergoing RSA. The use of machine learning models and patient-specific calibration on bone mineral density demonstrated that multiple 3D bone density scores improved the accuracy of objective preoperative bone quality assessment. The trained model could provide preoperative information to surgeons treating patients with potentially poor bone quality.

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 3-dimensional (3D) magnetic resonance imaging (MRI) volumetric scores (VSs) was developed to provide comprehensive characterization of RC pathology. The purposes of this study were to (1) describe the correlation between GC and VSs for supraspinatus changes in RC tears, (2) characterize the chronicity of RC tears using a battery of 12 VS measurements, and (3) compare GC and VSs 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 VSs included fat infiltration (FIS), muscle size (MSS), and relative volume contribution (RCS) for each RC muscle. Backward linear regression was performed to compare GC stage with preoperative PROMIS PF and 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 < .001); strong negative correlations were observed between MSS (r = -0.800, P < .001) and RCS (r = -0.745, P < .001) when compared to GC. A negligible linear correlation was observed between GC and preoperative PROMIS PF (r = -0.106, P = .343) and PI (r = -0.071, P = .528). On multivariate analysis, subscapularis MSS (ß >0, P = .064) was a positive predictor and subscapularis FIS (ß <0, P = .137), teres minor MSS (ß <0, P = .141), and FIS (ß <0, P = .070) were negative predictors of preoperative PF (r = 0.343, P = .044); in contrast, supraspinatus MSS (ß >0, P = .009) and FIS (ß >0, P = .073), teres minor FIS (ß >0, P = .072), and subscapularis FIS (ß >0, P = .065) were positive predictors of preoperative PI (r = 0.410, P = .006). CONCLUSION: Although the criterion standard in evaluation of RC pathology, GC demonstrated negligible correlation with preoperative functional disability. Alternatively, a battery of 3D VSs showed strong correlation with GC through a quantitative, comprehensive evaluation of the RC unit including several moderate predictors of preoperative functional disability.

Arthroscopy Within Three Months Prior to Unicompartmental Knee Arthroplasty is Associated with an Increased Rate of Periprosthetic Joint Infection.

INTRODUCTION: Arthroscopy remains a commonly performed procedure in patients who have meniscal or other osteochondral pathology prior to ultimately being indicated for unicompartmental knee arthroplasty (UKA). The purpose of this study was to examine the timing of knee arthroscopy prior to UKA and its association with 2-year periprosthetic joint infection (PJI) rates and medical and surgical complications. METHODS: Patients undergoing UKA who had history of ipsilateral arthroscopy within two years prior to the UKA were identified in a national insurance database. A control cohort of propensity matched patients who did not have a history of arthroscopy was identified. Study cohorts were established based on timing of the arthroscopic procedure: 0 to 3, 3 to 6, 6 to12, and 12 to 24 months prior to UKA. Patients were included if they had 2-year postoperative follow-up after UKA. The 90-day rates of postoperative medical and 2-year surgical complications were recorded. Multivariate analysis was conducted to account for confounding variables and covariates. RESULTS: A final cohort of 3,471 patients met inclusion criteria. Patients undergoing UKA within three months of the arthroscopic procedure demonstrated a higher incidence of PJI when compared to the control cohort (3.30 versus 1.12%, P = 0.012). Additionally, there was an increased rate of periprosthetic fracture observed in those undergoing UKA within three months of arthroscopy when compared to the control (1.10 versus 0.20%, P = 0.010). CONCLUSION: Patients undergoing ipsilateral arthroscopy within three months of a UKA demonstrated a nearly three-fold increased incidence of PJI when compared to the control. There was no increased incidence of PJI when UKA was staged greater than three months after arthroscopy. These findings provide insight for preoperative considerations for arthroplasty surgeons in this patient population.

A two-year comparison of reverse total shoulder arthroplasty mini-humeral tray and augmented mini-glenoid baseplate implants vs. standard implants.

BACKGROUND: Patients who undergo reverse total shoulder arthroplasty (RTSA) are getting younger with greater function expectations. This retrospective, longitudinal study of prospectively collected data compared perceived shoulder function and strength, active shoulder mobility, radiographic evidence of scapular notching, and implant survival over the initial 2-years post-RTSA among patient groups who received either standard central fixation point liner and glenoid baseplate implants, or lower size profile mini-humeral tray with offset trunnion options and mini-augmented glenoid baseplate implants. MATERIALS AND METHODS: Patients who underwent primary RTSA using standard central fixation point liner and glenoid baseplate implants (Group 1, n = 180) were compared with patients who underwent primary RTSA using lower size profile mini-humeral tray with offset trunnion options and mini-augmented glenoid baseplate implants (Group 2, n = 53) for active shoulder mobility, American Shoulder and Elbow Surgeons (ASES) score, perceived ability to lift 10 lbs (4.5 kg) overhead, radiographic evidence of scapular notching, and implant survival. Data was collected pre-surgery, 6-weeks, 6-months, 1-year, and 2-years post-RTSA (p ≤ 0.05). RESULTS: More Group 2 patients had more complex B or C Walch glenoid morphology, while Group 1 had more A1 or A2 types (p ≤ 0.001). Group 2 had greater active shoulder flexion at 6-months, 1-year, and 2-years (p ≤ 0.018) and external rotation (in adduction) at 6-months and 2-years (p ≤ 0.004) compared to Group 1, with higher ASES scores at 6-months and 2-years (p ≤ 0.026) (with small-to-medium effect sizes), and with more patients meeting or exceeding the minimal clinically important difference (MCID) at 2-years (p = 0.045) and patient acceptable symptomatic state (PASS) levels at 6-months, 1-year and 2-years (p ≤ 0.045). Scapular notching was identified in six of 53 (11.3%) Group 2 patients and in 32 of 180 (17.7%) Group 1 patients. Group 1 patients had more grade 2 or greater scapular notching grades compared to Group 2 (p = 0.04). Implant survival was comparable with Group 1 = eight of 180 (4.4%) and Group 2 = 1 of 53 (1.9%) of patients requiring removal for 95.6% and 98.1% implant survival, respectively. CONCLUSION: Limited scapular notching and excellent implant survival was observed in both groups. Despite including individuals with more complex glenoid deficiency, patients receiving the lower size profile implants generally displayed better active shoulder mobility and perceived shoulder function compared to those who received standard implants. These patients also more frequently met or exceeded the MCID by 2-years post-RTSA and PASS levels by 6-months, 1-year, and 2-years post-RTSA, with lower scapular notching grades. LEVEL OF EVIDENCE: Retrospective comparative study.

Mini-augmented glenoid baseplate and mini-humeral tray reverse total shoulder arthroplasty implant comparisons: two-year clinical outcomes.

BACKGROUND: Augmented glenoid baseplate and offset humeral tray reverse total shoulder arthroplasty (RTSA) implants may decrease the mechanical impingement that creates scapular notching and improve shoulder function. This study evaluated the clinical efficacy of three different RTSA glenoid baseplate and offset humeral tray combinations for patient-reported shoulder function, pain and instability, radiographic imaging evidence of glenoid baseplate or humeral stem subsidence and migration, bony changes associated with implant loosening, and scapular notching over the initial 2 years post-RTSA. Primary outcomes included active shoulder mobility, perceived function, pain, instability, scapular notching, and implant survival. METHODS: Sixty-seven patients from 6 research sites received one of three different glenoid baseplate and humeral tray combinations. Group 1 (n = 21) received a mini-augmented glenoid baseplate with a standard humeral tray; Group 2 (n = 23) received a standard glenoid baseplate and a mini-humeral tray with 3 trunnion offset options; Group 3 (n = 23) received both a mini-augmented glenoid baseplate and a mini-humeral tray with 3 trunnion offset options. Subjects underwent radiologic evaluation, completed the ASES scale, the EQ-5D-5L quality of life scale, VAS shoulder pain and instability questions, and active shoulder mobility measurements pre-operatively, and 6-weeks, 6-months, 1-2 years post-RTSA. RESULTS: Improved active shoulder mobility, quality of life, perceived function, decreased shoulder pain and instability, excellent implant survival and minimal scapular notching were observed for all groups. Group 3 had better overall active shoulder mobility than the other groups and better perceived function than Group 1. CONCLUSION: The group that received the mini-augmented glenoid baseplate and mini-humeral tray combination had better overall active shoulder flexion, external rotation at 90° abduction, and internal rotation. This group also had better perceived shoulder function compared to the group that received a mini-augmented glenoid baseplate with a standard humeral tray.

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.

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.

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.

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.

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.

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.