Editorial Commentary: Massive Rotator Cuff Tears Benefit From Arthroscopic Repair Regardless of Advanced Goutallier or Hamada Changes.

Massive rotator cuff tears are a challenge to treat, with options available from arthroscopic rotator cuff repair to reverse shoulder arthroplasty. Arthroscopic repair may still be an option even in the setting of advanced Goutallier changes and Hamada grades and regardless of healing. As the lifetime risk of revision for a 55-year-old patient having a reverse shoulder arthroplasty is approximately 1 in 3, arthroscopic surgical management of massive rotator cuff tears should not be discounted. An individualized approach should consider the patient's radiographs (severity of arthritis), function (i.e., acute vs chronic pseudoparalysis), and goals (overhead strength vs pain relief). Younger patients with less arthritis, acute pseudoparalysis, and a focus on pain relief could benefit from arthroscopic treatment.

Home-Based or Supervised Physical Therapy Shows Similar Functional Outcomes and Healing After Massive Rotator Cuff Repair.

PURPOSE: To compare postoperative clinical outcomes at the 3-month, 6-month, 12-month, and latest follow-up in patients undergoing supervised physical therapy (PT) or a home-based exercise program after arthroscopic repair (ARCR) of massive rotator cuff tears (MRCTs). METHODS: A retrospective review was conducted on a prospectively maintained database of patients who underwent either supervised PT or home-based therapy after ARCR of MRCTs between January 2015 and December 2018 at a single center with a minimum 24-month follow-up. At their 2-week postoperative routine follow-up, patients were allowed to choose between home-based and supervised PT. Patient-reported outcomes (PROs) and range of motion (ROM) were collected and compared between cohorts preoperatively and at the 3-month, 6-month, 12-month, and latest follow-up. The percentage of patients reaching or exceeding the minimal clinically important difference (MCID) and patient accepted symptomatic state (PASS) for visual analog scale for pain, American Shoulder and Elbow Surgeon (ASES) score, and Subjective Shoulder Value was recorded for both cohorts at each time point. Complications, healing, satisfaction, and return to work were reported. Healing was evaluated via ultrasound at the latest follow-up. RESULTS: Ninety-nine patients met the study criteria: 61 in the supervised PT cohort and 38 in the home-based cohort. The supervised PT and home-based cohorts returned to the clinic for their most recent follow-up at 53 ± 20 and 55 ± 16 months (P = .496) after surgery, respectively. There was no difference when comparing tendon involvement (supraspinatus, P = .574; infraspinatus, P = .288; subscapularis, P = .592), tear retraction (P = .603), or high-grade fatty infiltration (supraspinatus, P = .684; infraspinatus, P = .397; subscapularis, P = .473) based on preoperative magnetic resonance imaging assessment and surgery-related factors, including anterior (P = .473) or posterior (P = .386) slides, fixation constructs (P = .829), or complete repair (P = .912). Both cohorts showed similar PROs and ROM at baseline. Postoperative PROs and ROM were similar among groups at the 3-month, 6-month, 12-month, and latest follow-up. However, ASES (71.4 vs 61.2; P = .013) and forward flexion (135° vs 118°; P = .023) were significantly higher at 3-month follow-up in the home-based cohort. Both groups comparably achieved MCID and PASS for PROs at the 3-month, 6-month, and 12-month follow-up. At the latest follow-up, the supervised PT and home-based cohort achieved MCID and PASS for visual analog scale (75% vs 81%, P = .573; 70% vs 72%, P = .911), ASES (76% vs 74%, P = .777; 72% vs 72%, P = .873), and Subjective Shoulder Value (82% vs 84%, P = .734; 72% vs 66%, P = .489), respectively. Satisfaction, healing, complication, and return-to-work rates were similar. CONCLUSIONS: Patients undergoing rehabilitation using a home-based protocol showed largely similar functional scores and healing to those with supervised PT after ARCR of MRCTs at the latest follow-up. Although patients with home-based therapy achieved higher forward flexion and ASES at the 3-month follow-up, these became comparable starting at the 6-month postoperative mark. MCID and PASS were achieved similarly for PROs at each time point. LEVEL OF EVIDENCE: Level III, retrospective case series comparison.

High Variability in Standardized Outcome Thresholds of Clinically Important Changes in Shoulder Instability Surgery: A Systematic Review.

PURPOSE: The purpose of this study was to examine reported MCID and PASS values for PROMs following shoulder instability surgery and assess variability in published values depending on the surgery performed. Secondarily, our aims were to describe the methods used to derive MCID and PASS values in the published literature, including anchor-based, distribution-based, or other approaches, and to assess the frequency of MCID and PASS usage in studies on shoulder instability surgery. METHODS: A systematic review of MCID and PASS values following Bankart, Latarjet, and Remplissage procedures was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The Embase, Pubmed, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were queried from 1985 to 2023. Inclusion criteria included studies written in English, and studies reporting utilization MCID or PASS for patient reported outcome measures (PROMS) following Latarjet, Bankart, Remplissage approaches for shoulder instability surgery. Extracted data included study population characteristics, intervention characteristics, and outcomes of interest. Continuous data were described using median and range. Categorical variables, including PROMs reported and MCID/PASS methods, were described using percentages. As MCID is a patient-level metric and not a group-level metric, the authors validated that all included studies reported proportions (%) of subjects that met or exceeded the MCID. RESULTS: A total of 174 records were screened, and 8 studies were included in this review. MCID was the most widely utilized outcome threshold which was reported in all 8 studies, with only 2 studies reporting both the MCID and the PASS. The most widely studied PROMs were the American Shoulder and Elbow Surgeons (ASES) (range 5.65-9.6 for distribution MCID, 8.5 anchor MCID, 86 anchor PASS); Single Assessment Numeric Evaluation (SANE) (range 11.4-12.4 distribution MCID, 82.5-87.5 anchor PASS); visual analog scale (VAS) (range 1.1-1.7 distribution MCID, 1.5-2.5 PASS); Western Ontario Shoulder Instability Index (WOSI) (range 60.7-254.9 distribution MCID, 126.43 anchor MCID, 571-619.5 anchor PASS); and Rowe scores (range 5.6-8.4 distribution MCID, 9.7 anchor MCID). Notably, no studies reported on substantial clinical benefit (SCB) or maximal outcome improvement (MOI). CONCLUSION: Despite the wide array of available PROMs for assessing shoulder instability surgery outcomes, the availability of clinically significant outcome thresholds such as MCID and PASS remains relatively limited. While MCID has been the most frequently reported metric, there is considerable inter-study variability observed in their values. CLINICAL RELEVANCE: Knowing the outcome thresholds such as MCID and PASS of the PROMs frequently used to evaluate the results of glenohumeral stabilization surgery is fundamental, since they allow us to know what is a clinically significant improvement for the patient.

Identification of ChatGPT-Generated Abstracts Within Shoulder and Elbow Surgery Poses a Challenge for Reviewers.

PURPOSE: To evaluate the extent to which experienced reviewers can accurately discern between AI-generated and original research abstracts published in the field of shoulder and elbow surgery and compare this to the performance of an AI-detection tool. METHODS: Twenty-five shoulder and elbow-related articles published in high-impact journals in 2023 were randomly selected. ChatGPT was prompted with only the abstract title to create an AI-generated version of each abstract. The resulting 50 abstracts were randomly distributed to and evaluated by 8 blinded peer reviewers with at least 5 years of experience. Reviewers were tasked with distinguishing between original and AI-generated text. A Likert scale assessed reviewer confidence for each interpretation and the primary reason guiding assessment of generated text was collected. AI output detector (0-100%) and plagiarism (0-100%) scores were evaluated using GPTZero. RESULTS: Reviewers correctly identified 62% of AI-generated abstracts and misclassified 38% of original abstracts as being AI-generated. GPTZero reported a significantly higher probability of AI output among generated abstracts (median 56%, IQR 51-77%) compared to original abstracts (median 10%, IQR 4-37%; p < 0.01). Generated abstracts scored significantly lower on the plagiarism detector (median 7%, IQR 5-14%) relative to original abstracts (median 82%, IQR 72-92%; p < 0.01). Correct identification of AI-generated abstracts was predominately attributed to the presence of unrealistic data/values. The primary reason for misidentifying original abstracts as AI was attributed to writing style. CONCLUSIONS: Experienced reviewers faced difficulties in distinguishing between human and AI-generated research content within shoulder and elbow surgery. The presence of unrealistic data facilitated correct identification of AI abstracts, whereas misidentification of original abstracts was often ascribed to writing style.

Preoperative 3-dimensional computed tomography bone density measures provide objective bone quality classifications for stemless anatomic total shoulder arthroplasty.

BACKGROUND: Reproducible methods for determining adequate bone densities for stemless anatomic total shoulder arthroplasty (aTSA) are currently lacking. The purpose of this study was to evaluate the utility of preoperative computed tomography (CT) imaging for assessing the bone density of the proximal humerus for supportive differentiation in the decision making for stemless humeral component implantation. It was hypothesized that preoperative 3-dimensional (3-D) CT bone density measures provide objective classifications of the bone quality for stemless aTSA. METHODS: A 3-part study was performed that included the analysis of cadaveric humerus CT scans followed by retrospective application to a clinical cohort and classification with a machine learning model. Thirty cadaveric humeri were evaluated with clinical CT and micro-CT (µCT) imaging. Phantom-calibrated CT data were used to extract 3-D regions of interest and defined radiographic scores. The final image processing script was applied retrospectively to a clinical cohort (n = 150) that had a preoperative CT and intraoperative bone density assessment using the "thumb test," followed by placement of an anatomic stemmed or stemless humeral component. Postscan patient-specific calibration was used to improve the functionality and accuracy of the density analysis. A machine learning model (Support vector machine [SVM]) was utilized to improve the classification of bone densities for a stemless humeral component. RESULTS: The image processing of clinical CT images demonstrated good to excellent accuracy for cylindrical cancellous bone densities (metaphysis [ICC = 0.986] and epiphysis [ICC = 0.883]). Patient-specific internal calibration significantly reduced biases and unwanted variance compared with standard HU CT scans (P < .0001). The SVM showed optimized prediction accuracy compared with conventional statistics with an accuracy of 73.9% and an AUC of 0.83 based on the intraoperative decision of the surgeon. The SVM model based on density clusters increased the accuracy of the bone quality classification to 87.3% with an AUC of 0.93. CONCLUSIONS: Preoperative CT imaging allows accurate evaluation of the bone densities in the proximal humerus. Three-dimensional regions of interest, rescaling using patient-specific calibration, and a machine learning model resulted in good to excellent prediction for objective bone quality classification. This approach may provide an objective tool extending preoperative selection criteria for stemless humeral component implantation.

Preoperative diagnosis and rotator cuff status impact functional internal rotation following reverse shoulder arthroplasty.

PURPOSE: This study aimed to evaluate whether functional internal rotation (fIR) following reverse shoulder arthroplasty (RSA) differs based on diagnosis of either: primary osteoarthritis (OA) with intact rotator cuff, massive irreparable rotator cuff tear (MICT) or cuff tear arthropathy (CTA). METHODS: A retrospective review was carried out on RSAs performed by a single surgeon with the same implant over a 5-year period. Minimum 2-year follow-up was available in 235 patients; 139 (59.1%) were female, and the mean patient age was 72 ± 8 years. Additional clinical evaluation included the Subjective Shoulder Value and Constant score. Postoperative internal rotation was categorized as type I: hand to the buttock or hip; type II: hand to the lower lumbar region; or type III: smooth motion to at least the upper lumbar region. Type I was considered "nonfunctional" internal rotation, and type II and III were fIR. RESULTS: Preoperatively, internal rotation was classified as type I in 60 patients (25.5%), type II in 114 (48.5%), and type III in 62 (26%). Postoperatively, internal rotation was classified as type I in 70 patients (30%), type II in 86 (36%), and type III in 79 (34%). Compared with preoperative status, fIR improved significantly in OA patients (P < .001), with 49 (52.6%) classified as type II or III postoperatively. In CTA patients, there was no significant change (P = .352). In patients with MICTs, there was a significant loss in fIR postoperatively (P = .003), with 25 patients (30.8%) deteriorating to type I after having either type II or III preoperatively, and only 5 patients (6.1%) improving to either type II or III. CONCLUSIONS: Patients who undergo RSA for primary OA have a better chance of postoperative fIR improvement. A decrease in fIR is common after RSA for MICTs.

Functional Internal Rotation is Associated with Subscapularis Tendon Healing and Increased Scapular Tilt after Grammont style BIO RSA with 155° humeral implant.

BACKGROUND: While forward flexion consistently improves after reverse shoulder arthroplasty (RSA), restoration of internal rotation behind the back (IR1) is much less predictable. This study aims to evaluate the role of the subscapularis tendon in restoration of IR and identify other factors that may influence IR such as anterior scapular tilt and postoperative passive internal rotation at 90° of abduction (IR2). The hypothesis was that IR1 is positively associated with both subscapularis healing, postoperative passive IR2, and anterior scapular tilt. METHODS: A retrospective review was performed on a consecutive series of Grammont style BIO (bony increased offset) RSAs performed by a single surgeon between January 2014 and December 2015. Inclusion criteria were: (1) primary RSA for rotator cuff arthropathy, massive irreparable rotator cuff tear, or primary osteoarthritis with B2 glenoid morphology, (2) minimum of two years clinical follow-up, and (3) complete intraoperative repair of a repairable subscapularis tendon. The primary outcomes were postoperative return of IR1 compared to postoperative IR2, healing rate of subscapularis tendon, and scapular tilt. RESULTS: The cohort included 77 patients, aged 72.6±7.0 years at index surgery and comprising 32 men (42%) and 45 women (58%). At a mean follow-up of 3.3±1.0 years, ultrasound evaluation revealed a successful repair of the subscapularis in 41 patients (53%). Healed subscapularis repair was significantly associated with greater IR1 (85% vs. 53%, p=0.031). A multivariate logistic regression revealed functional postoperative IR1 was independently associated with subscapularis healing (OR, 4.3; 95%CI [1.1-20.2]; p=0.046) as well as greater anterior tilt (OR, 1.2; 95%CI [1.1-1.5]; p=0.008) and postoperative IR2 (OR, 1.09; 95%CI [1.05-1.14]; p<0.001) but lower postoperative passive abduction (OR, 0.96; 95%CI [0.92-1.00], p=0.045). The area under receiver operating characteristic curve obtained with the Youden index was 0.88 with a sensitivity of 81.8% and specificity of 90.6%. CONCLUSIONS: This study revealed that in a Grammont-type RSA, postoperative IR1 recovery is first associated with subscapularis tendon healing, followed by IR2 and finally the ability to tilt the scapula anteriorly. Better understanding of these factors preoperatively may provide greater insight on expected return of functional internal after RSA.

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.

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.

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.

Surgical Management of Massive Irreparable Cuff Tears: Superior Capsule Reconstruction and Rotator Cable Reconstruction.

PURPOSE OF REVIEW: Massive irreparable rotator cuff tears (MIRCTs) present treatment challenges. Recently, superior capsule reconstruction (SCR) and anterior cable reconstruction have emerged as surgical options, but no single approach is superior. This review provides an overview of SCR and cable reconstruction techniques, including biomechanical studies, clinical outcomes, and surgical considerations. RECENT FINDINGS: Biomechanical studies show SCR with autografts or allografts improves glenohumeral stability and mechanics. Clinical outcomes of SCR demonstrate improved range of motion, function scores, and pain relief in short-term studies. Anterior cable reconstruction reduces superior humeral head translation and subacromial pressures in biomechanical models. Early clinical studies report improved rotator cuff healing and outcomes for cable reconstruction in specific irreparable tear patterns. SCR and cable reconstruction are viable surgical options for MIRCTs based on early encouraging results. However, higher-level comparative studies with long-term follow-up are still needed. Careful consideration of tear pattern, patient factors, and surgical goals is required to optimize treatment of MIRCTs. Further research is necessary to determine the optimal role for these procedures.

Glenoid lateralization in reverse shoulder arthroplasty: metal vs. bone offset in different implant designs.

Background: Higher bone or metal glenoid offset in reverse shoulder arthroplasty (RSA) reduces scapular notching, improves range of motion (ROM), and reduces postoperative instability. This retrospective multicenter study compared two implant designs to evaluate the short-term clinical and radiologic results of bone increased offset RSA (BIO-RSA) and metal increased offset RSA (MIO-RSA) in reverse shoulder. We hypothesized no difference between groups. Methods: This study analyzed n = 62 BIO-RSA and n = 90 MIO-RSA cases with a mean follow-up of 29.7 ± 6.0 months (BIO-RSA, range 24-49 months) and 24.0 ± 1.1 months (MIO-RSA, range 22-28 months). A 145°-onlay humeral stem was utilized in BIO-RSA cases, while a 135°-semi-inlay humeral stem was implanted in all MIO-RSA cases. Preoperative and postoperative radiologic imaging was reviewed to identify signs of scapular notching. Additionally, lateralization was evaluated according to Erickson et al. The constant score, subjective shoulder value, and ROM were evaluated during the baseline and follow-up consultations, and the findings of both groups were subsequently compared. Results: Scapular notching was observed in 7.0% (n = 8) of MIO-RSA cases and 8.1% (n = 5) of BIO-RSA cases (P = .801). MIO-group had a higher lateralization angle (P = .020) and the BIO-group had a higher distalization angle (P = .005). At baseline, mean constant score in the MIO-RSA group was higher than in the BIO-RSA group (P < .001), and it significantly increased to 67.8 ± 12.1P (MIO-RSA) and 69.5 ± 12.3P (BIO-RSA) to a similar level (P = .399). ROM improved in both groups with no significant difference between the two groups at follow-up. Conclusion: BIO-RSA and MIO-RSA in two distinct implant designs provide comparable short-term outcomes with a similar increase in shoulder function with notable variations in the lateralization and distalization angles between both implants. Scapular notching was rarely seen and unaffected by the method of glenoid lateralization. Follow-up investigations of both techniques are necessary to complement and track changes in the long-term outcome.

A stemless anatomic shoulder arthroplasty design provides increased cortical medial calcar bone loading in variable bone densities compared to a short stem implant.

Background: Several studies have reported proximal bone resorption in stemless and press-fit short-stem humeral implants for anatomic total shoulder arthroplasty. The purpose of this biomechanical study was to evaluate implant and cortical bone micromotion of a cortical rim-supported stemless implant compared to a press-fit short stem implant during cyclic loading and static compression testing. Methods: Thirty cadaveric humeri were assigned to 3 groups based on a previously performed density analysis, adopting the metaphyseal and epiphyseal and inferior supporting bone densities for multivariate analyses. Implant fixation was performed in stemless implant in low bone density (SL-L, n = 10) or short stem implant in low bone density (Stem-L, n = 10) and in stemless implant in high bone density (SL-H, n = 10). Cyclic loading with 220 N, 520 N, and 820 N over 1000 cycles at 1.5 Hz was performed with a constant valley load of 25 N. Optical recording allowed for spatial implant tracking and quantification of cortical bone deformations in the medial calcar bone region. Implant micromotion was measured as rotational and translational displacement. Load-to-failure testing was performed at a rate of 1.5 mm/s with ultimate load and stiffness measured. Results: The SL-H group demonstrated significantly reduced implant micromotion compared to both low-density groups (SL-L: P = .014; Stem-L: P = .031). The Stem-L group showed significantly reduced rotational motion and variance in the test results at the 820-N load level compared to the SL-L group (equal variance: P = .012). Implant micromotion and reversible bone deformation were significantly affected by increasing load (P < .001), metaphyseal cancellous (P = .023, P = .013), and inferior supporting bone density (P = .016, P = .023). Absolute cortical bone deformation was significantly increased with stemless implants in lower densities and percentage reversible bone deformation was significantly higher for the SL-H group (21 ± 7%) compared to the Stem-L group (12 ± 6%, P = .017). Conclusion: A cortical rim-supported stemless implant maintained proximally improved dynamic bone loading in variable bone densities compared to a press-fit short stem implant. Biomechanical time-zero implant micromotion in lower bone densities was comparable between short stem and stemless implants at rehabilitation load levels (220 N, 520 N), but with higher cyclic stability and reduced variability for stemmed implantation at daily peak loads (820 N).

Are Lower Passive Anterior Elevation and External Rotation at 6 Weeks Postoperatively Associated With Healing of Isolated Arthroscopic Supraspinatus Repairs?

BACKGROUND: Despite advancements in surgical technique, failure of tendon healing remains a common problem after arthroscopic rotator cuff repair (ARCR). PURPOSE/HYPOTHESIS: The purpose of this study was to examine the relationship between range of motion (ROM) recovery and healing after ARCR. It was hypothesized that an early loss of ROM would be associated with tendon healing. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: This was a retrospective comparative study of primary ARCR of isolated full-thickness supraspinatus (SSN) tendon tears. Cases were retrieved from a prospective rotator cuff repair database and divided into 2 groups based on healing (healed/nonhealed). A standardized clinical evaluation was performed before and at 6 weeks, 3 months, and 6 months after surgery. Collected data included passive and active ROM, visual analog scale for pain, and Constant score. Healing was assessed by ultrasound at 6 months. RESULTS: Of 1397 eligible ARCRs, 1207 were included. The healing rate was 86.7%. Age was higher in the nonhealed group (57.8 ± 7.9 years vs 61.6 ± 8.8 years; P < .001). Patients with healed repairs had a larger decrease in passive anterior elevation (AE) from the preoperative to the 6-week postoperative visit (-31°± 28° vs -18°± 26°; P < .001), followed by a more substantial increase throughout the remaining follow-up period (32°± 23° vs 18°± 21°; P < .001). At 6 months postoperatively, there was no difference in AE between groups (159°± 17° vs 161°± 14°; P > .999). External rotation elbow at side (ER1) and internal rotation hand in the back (IR1) followed similar courses of recovery. Passive and active ROM had a strong positive correlation at each follow-up. Age (odds ratio [OR], 1.79; 95% CI, 1.45-2.23; P < .001) and 6-week passive AE (OR, 1.33; 95% CI, 1.20-1.48; P < .001) and ER1 (OR, 1.15; 95% CI, 1.03-1.29; P = .017) were predictors for nonhealing. CONCLUSION: Lower passive AE and ER1 at 6 weeks postoperatively and younger age are associated with healing after ARCR of isolated SSN tendon tears. At 6 months postoperatively, there were no differences in ROM, regardless of tendon healing.

Obesity is associated with improvement in functional outcome but lower internal rotation after reverse shoulder arthroplasty.

Background: The role of obesity as an independent risk factor for increased complications following reverse shoulder arthroplasty (RSA) continues to generate debate. While no standardized body mass index (BMI) cutoff values for shoulder arthroplasty exist, many surgeons are concerned about the potential for poor outcomes and decreased range of motion (ROM) in patients with a high BMI. The purpose of this study was to compare functional outcomes in obese and nonobese patients preoperatively and at short-term follow-up after RSA. Methods: A retrospective review was performed of a prospectively maintained, multicenter database of primary RSAs performed by 14 surgeons between 2015 and 2019 with minimum 2-year follow-up. A total of 245 patients met the study criteria, including 111 obese (BMI >30) and 134 nonobese (BMI <30) patients. Patient-reported outcomes (PROs) as well as ROM measurements were compared between the 2 groups. Results: At baseline, obese patients had significantly lower American Shoulder and Elbow Surgeons (36.6 vs. 42.0, P = .014), Western Ontario Osteoarthritis of the Shoulder scores (33.1 vs. 37.8, P = .043), external rotation at 90° (19° vs. 28°, P = .007), internal rotation (IR) spinal level (L5 vs. L4, P = .002), and belly press strength (P = .003) compared to the nonobese cohort. There were no statistical differences in 2-year outcomes (PROs, ROM, and strength) other than a worse IR (spinal level) in the low BMI group (L4 vs. L3, P = .002). In linear regression analyses controlling for confounding variables, increasing BMI was negatively correlated with preoperative external rotation (B = -0.591, P = .034) and preoperative IR spinal level (B = 0.089, P = .002). Increasing BMI was not correlated with postoperative external rotation at 90° (B = 0.189, P = .490) but was associated with worse postoperative IR by spinal level (B = 0.066, P = .043). Conclusions: Obese patients have greater restrictions in external and internal rotation as well as American Shoulder and Elbow Surgeons and Western Ontario Osteoarthritis of the Shoulder scores at baseline prior to RSA. However, there are no major differences in postoperative PROs or ROM measurements between obese and nonobese patients apart from a worse active IR by spinal level in the obese group (L4 vs. L3, P = .002). This study suggests that an RSA procedure does not need to be restricted solely based on BMI.

Determining minimal clinically important difference and patient-acceptable symptom state after arthroscopic isolated subscapularis repair.

Background: Minimal Clinically Important Difference (MCID) and Patient-Acceptable Symptomatic State (PASS) have emerged as patient-based treatment assessments. However, these have not been investigated in patients undergoing arthroscopic isolated subscapularis repair (AISR). The primary purpose of this study was to determine the MCID and PASS for commonly used patient-reported outcomes in individuals who underwent AISR. The secondary purpose was to assess potential associations between preoperative and intraoperative patient characteristics and the MCID and PASS. Methods: A retrospective analysis was conducted on prospectively collected data for patients who underwent primary AISR between 2011 and 2021 at a single institution, with minimum 2-year postoperative follow-up. Functional outcomes were assessed using the American Shoulder and Elbow Surgeons (ASES) score, Subjective Shoulder Value (SSV), and Visual Analog Scale (VAS) pain scale. The MCID was determined using the distribution-based method, while PASS was evaluated using area under the curve analysis. To investigate the relationship between preoperative variables and the achievement of MCID and PASS thresholds, Pearson and Spearman coefficient analyses were employed for continuous and noncontinuous variables, respectively. Results: A total of 77 patients with a mean follow-up of 58.1 months were included in the study. The calculated MCID values for VAS pain, ASES, and SSV were 1.2, 10.2, and 13.2, respectively. The PASS values for VAS pain, ASES, and SSV were 2.1, 68.8, and 68, respectively. There was no significant correlation between tear characteristics and the likelihood of achieving a MCID or PASS. Female sex, worker's compensation status, baseline VAS pain score, and baseline ASES score, exhibited weak negative correlations for achieving PASS for VAS pain and ASES. Conclusion: This study defined the MCID and PASS values for commonly used outcome measures at short-term follow-up in patients undergoing AISR. Tear characteristics do not appear to impact the ability to achieve a MCID or PASS after AISR. Female sex, worker's compensation claim, and low baseline functional scores have weak negative correlations with the achievement of PASS for VAS pain and ASES scores.

Reverse shoulder arthroplasty for massive rotator cuff tears without glenohumeral arthritis can improve clinical outcomes despite history of prior rotator cuff repair: A systematic review.

IMPORTANCE: Reverse shoulder arthroplasty (RSA) is often used to surgically address massive irreparable rotator cuff tears (MIRCT) without arthritis. The impact of prior attempted rotator cuff repair (RCR) on outcomes is unclear. OBJECTIVE: The purpose of this systematic review was to compare functional outcomes, range of motion, and complications in patients with a MIRCT without arthritis who underwent RSA as a primary procedure versus after prior RCR. EVIDENCE REVIEW: A systematic review was performed on RSA for a MIRCT. The search was conducted from February to March of 2022 using the MEDLINE database. Patient-reported outcome measures (PROs), range of motion (ROM), and complications were extracted. These outcomes were weighted and analysed based on whether the reverse was performed as the primary procedure or following a prior RCR. FINDINGS: Seven studies were included in the analysis, consisting of 343 cases in the primary RSA group and 95 cases in the prior RCR group, with a mean follow-up of 40.8 months. There were no demographic differences between cohorts. Postoperative PROs and ROM were comparable between groups, although the prior RCR group had a higher maximal percentage of improvement (MPI%) for the Constant-Murley Score and Simple Shoulder Test. There was a higher risk for complications (relative risk [RR] 6.26) and revisions (RR 3.91) in the prior RCR group. The most common complications were acromial stress fractures and prosthetic dislocation. CONCLUSION AND RELEVANCE: Patients undergoing RSA for MIRCT following a prior RCR have functional outcomes that are largely comparable to those who have a primary RSA, but they may be at higher risk of complications and revision. LEVEL OF EVIDENCE: IV.

Clinical Outcomes and Tendon Healing After Arthroscopic Isolated Subscapularis Tendon Repair: Results at Midterm Follow-up.

Background: Few studies have reported clinical outcomes and tendon healing rates after arthroscopic isolated subscapularis (SSC) repair (AISR). Purpose/Hypothesis: The primary purpose of this study was to evaluate clinical outcomes and tendon healing after AISR. It was hypothesized that AISR would result in satisfactory clinical outcomes along with a high rate of tendon healing at the midterm follow-up. The secondary purpose was to assess the influence of tear size and muscle atrophy on SSC tendon healing and patient-reported outcomes. It was hypothesized that both would be negatively correlated with healing but would have no effect on clinical outcomes . Study Design: Case series; Level of evidence, 4. Methods: A retrospective analysis was conducted on prospectively collected data for 77 patients who underwent primary AISR between 2011 and 2021 at a single institution, with a minimum 2-year postoperative follow-up for all patients. Functional outcomes were assessed using the American Shoulder and Elbow Surgeons (ASES) score, the Subjective Shoulder Value (SSV), and the visual analog scale for pain. Repair techniques and concomitant procedures were also collected. SSC tendon healing was evaluated via ultrasound at the final follow-up. Linear regression analysis was performed to determine factors affecting SSC healing. Results: The mean follow-up was 58.1 ± 3.3 months. ASES scores significantly improved from 41.5 to 81.6, and the SSV improved from 38.2 to 80.5 (P < .01 for both). Among the 40 patients (51.9%) who underwent postoperative ultrasound, 87.5% showed complete tendon healing. There were no significant differences in outcome scores between healed and unhealed tendons. Increased muscle atrophy and larger tears were correlated with failure of SSC healing (ß = -0.285 [P = .015] and ß = -0.157 [P = .045], respectively). Conclusion: Improved clinical outcomes and an overall high rate of tendon healing were seen at the midterm follow-up after AISR. Smaller tear sizes with less muscle atrophy were correlated with improved tendon healing. However, even when the tendon incompletely healed, the procedure improved functional outcomes.

The Bear Hug Test Improves Sensitivity Compared With the Belly Press Test for Identifying Subscapularis Tendon Tears, but Both Tests Miss the Majority of Partial Tears.

Purpose: To investigate the performance of the bear hug (BH) and belly press (BP) tests in diagnosing tears of the subscapularis (SSC). Methods: A retrospective review was conducted on prospectively maintained data on patients who underwent arthroscopic rotator cuff repair (ARCR) of SSC tears between 2011 and 2021. A control group also was obtained of ARCRs with an intact SSC tendon. All examinations and ARCRs were performed by one high-volume shoulder surgeon. The BH test and BP test results were compared with arthroscopic findings as the gold-standard diagnostic modality. Tear type was classified based on the Lafosse classification. Sensitivity, specificity, positive and negative predictive values, false-positive and false-negative rates, and accuracy were calculated for both tests. Results: A total of 1,122 patients were included for analysis, 866 with intraoperatively confirmed SSC tears (77%) and 256 without (23%). The BH test diagnosed SSC tears with a sensitivity of 46.1% and a specificity of 83.2%, whereas the BP test diagnosed tears with a sensitivity of 23.3% and a specificity of 93.4%. Overall, both tests missed SSC tears in 42.3% (n = 475) of cases. The BH test had accuracy rates of 25.9% for SSC type I tear, 48.7% for type II tear, 65% for type III tear, and 81.7% for type IV-V tear. In contrast, the BP test had accuracy rates of 7.6% for type I tear, 14.7% for type II tear, 42% for type III tear, and 68.7% for type IV-V tear. Conclusions: The BH test had greater sensitivity than the BP test in identifying SSC tears. Both tests showed low accuracy in identifying SSC tears as tear size decreased. Combining both tests did not provide any additional benefits over using the BH test alone. Level of Evidence: Level III, diagnostic study.

Both Radiologists and Surgeons Miss a Substantial Number of Subscapularis Tears on Magnetic Resonance Imaging Examination Prior to Shoulder Arthroscopy.

Purpose: To compare radiologist and surgeon magnetic resonance imaging (MRI) interpretations of subscapularis (SSC) tears against intraoperative arthroscopic examination. Methods: We conducted a retrospective review of prospectively maintained data on patients who underwent arthroscopic rotator cuff repair with and without SSC tears between 2011 and 2022. The radiologists' assessments of SSC integrity were extracted from the MRI reports. One high-volume fellowship-trained shoulder surgeon assessed all MRI scans for the presence or absence of SSC tears. Radiologist and surgeon MRI-based assessments were compared against the diagnostic gold standard (intraoperative arthroscopic examination) and classified according to the Lafosse classification. Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated. Results: A total of 1,090 patients were included for analysis, 839 with intraoperatively confirmed SSC tears (77%) and 251 without such tears (23%). Radiologists diagnosed SSC tears with a sensitivity of 56.0% (470 of 839 patients) and specificity of 67.3% (169 of 251 patients) via MRI, whereas the surgeon diagnosed SSC tears with a sensitivity of 71.4% (599 of 839 patients) and specificity of 78.1% (196 of 251 patients). Overall, radiologists only correctly identified 56% of SSC tears whereas the shoulder surgeon correctly identified approximately 71.4% of tears. When considering arthroscopically confirmed tear size, that is, intact, partial, full thickness [upper border], and complete, the radiologists' diagnosis rates with MRI were 67.3%, 40.4%, 64.6%, and 78.3%, respectively, and the surgeon's diagnosis rates were 78.1%, 52.7%, 81.9%, and 97.5%, respectively. Conclusions: In a community practice, radiologists miss approximately 50% of SSC tears on MRI examination. A shoulder surgeon with the benefit of clinical examination misses 28.6% of tears on MRI. Accuracy increases as tear size increases, with radiologists detecting 40.4% of partial tears and 78.3% of complete tears and a surgeon detecting 52.7% and 97.5%, respectively. Level of Evidence: Level III, diagnostic study (nonconsecutive patients).