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Introduction: There are a variety of baseplate options when performing reverse total shoulder arthroplasty (RTSA). Currently, there is no consensus on the optimal glenoid baseplate. The hypothesis of this study was that the use of lateralized baseplates would improve patient-determined outcomes and postoperative range of motion after RTSA compared with standard baseplates without increasing the risk of complications., Methods: Patients undergoing RTSA were stratified into a standard baseplate group (SBG) and a lateralized baseplate group (LBG). The LBG included 3 mm lateralization, 6 mm lateralization, and full-wedge augmentation (8 mm lateralization). The Western Ontario Osteoarthritis Score, American Shoulder and Elbow Surgeons score, Single Assessment Numeric Evaluation (SANE), and Simple Shoulder Test (SST) were recorded at baseline, 1 year, and 2 years. Range of motion was recorded at baseline and 1 year. Differences in complications between groups were recorded., Results: The LBG included 187 patients, and the SBG included 51 patients. No difference was observed in any patient-determined outcome score at 1-year follow-up. At 2 years, there were greater Western Ontario Osteoarthritis Score (84 ± 16 versus 74 ± 19; P = 0.01), American Shoulder and Elbow Surgeons score (81 ± 15 versus 70 ± 20; P = 0.001), SST (8.0 ± 2.4 versus 6.6 ± 2.6; P = 0.007), and SANE (82 ± 17 versus 68 ± 25; P = 0.0005). The improvement in SST (5.0 ± 2.7 versus 3.3 ± 3.6; P = 0.02) and SANE (54 ± 26 versus 37 ± 30; P = 0.004) at 2 years compared with baseline was greater in the LBG compared with the SBG. No difference was observed in any range-of-motion metric between groups. Total complications were similar between groups ( P = 0.91). Scapular notching was more prevalent in the SBG (7.8% versus 1.6%; P = 0.01)., Conclusion: The LBG had better patient-determined outcome scores compared with the SBG at 2-year follow-up with a similar rate of overall complications but a lower rate of scapular notching. Range of motion was not improved by the use of a lateralized baseplate compared with a standard baseplate., Competing Interests: Keith Baumgarten has disclosures that may be considered as a potential conflict of interest (Stryker/Wright Medical, Miach). Neither Carson Max nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this article., (Copyright © 2024 by the American Academy of Orthopaedic Surgeons.)

Level of Evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: Funding for this study was received from Sophies Minde Ortopedi AS, The South-East Health Authority Norway, and The Research Council of Norway. The funding sources did not play a role in the investigation. The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/I188 )., (Copyright © 2024 by The Journal of Bone and Joint Surgery, Incorporated.)

Aims: Reverse shoulder arthroplasty (RSA) has become the most common type of shoulder arthroplasty used in the UK, and a better understanding of the outcomes after revision of a failed RSA is needed. The aim of this study was to review the current evidence systematically to determine patient-reported outcome measures and the rates of re-revision and complications for patients undergoing revision of a RSA., Methods: MEDLINE, Embase, CENTRAL, and the Cochrane Database of Systematic Reviews were searched. Studies involving adult patients who underwent revision of a primary RSA for any indication were included. Those who underwent a RSA for failure of a total shoulder arthroplasty or hemiarthroplasty were excluded. Pre- and postoperative shoulder scores were evaluated in a random effects meta-analysis to determine the mean difference. The rates of re-revision and complications were also calculated., Results: The initial search elicited 3,166 results and, following removal of duplicates and screening, 13 studies with a total of 1,042 RSAs were identified. An increase in shoulder scores pre- to postoperatively was reported in all the studies. Following revision of a RSA to a further RSA, there was a significant increase in the American Shoulder and Elbow Surgeons Score (mean difference 20.78 (95% CI 8.16 to 33.40); p = 0.001). A re-revision rate at final follow-up ranging from 9% to 32%, a one-year re-revision rate of 14%, and a five-year re-revision rate of 23% were reported. The complication rate in all the studies was between 18.5% and 36%, with a total incidence of 29%., Conclusion: This is the largest systematic review of the outcomes following revision of a RSA. We found an improvement in functional outcomes after revision surgery, but the rates of re-revision and complications are high and warrant consideration when planning a revision procedure., Competing Interests: None declared., (© 2024 The British Editorial Society of Bone & Joint Surgery.)

Aims: We sought to compare functional outcomes and survival between non-smokers, former smokers, and current smokers who underwent anatomical total shoulder arthroplasty (aTSA) in a large cohort of patients., Methods: A retrospective review of a prospectively collected shoulder arthroplasty database was performed between August 1991 and September 2020 to identify patients who underwent primary aTSA. Patients were excluded for preoperative diagnoses of fracture, infection, or oncological disease. Three cohorts were created based on smoking status: non-smokers, former smokers, and current smokers. Outcome scores (American Shoulder and Elbow Surgeons (ASES), Constant-Murley score, Shoulder Pain and Disability Index (SPADI), Simple Shoulder Test (SST), University of California, Los Angeles activity scale (UCLA)), range of motion (external rotation (ER), forward elevation (FE), internal rotation, abduction), and shoulder strength (ER, FE) evaluated at two- to four-year follow-up were compared between cohorts. Evaluation of revision-free survival was performed using the Kaplan-Meier method to final follow-up., Results: We included 428 primary aTSAs with a mean follow-up of 2.4 years (SD 0.6). Our cohort consisted of 251 non-smokers, 138 former smokers who quit a mean 21 years (SD 14) prior to surgery (25 pack-years (SD 22)), and 39 current smokers (23 pack-years (SD 20)). At two- to four-year follow-up, former smokers had less favourable SPADI, SST, and FE strength compared to non-smokers, and current smokers had less favourable SPADI, SST, ASES score, UCLA score, Constant-Murley score, FE, abduction, and ER strength compared to non-smokers. Non-smokers exhibited higher revision-free survival rates at two, five, eight, and ten years postoperatively compared to former smokers and current smokers, who had similar rates., Conclusion: Our study suggests that smoking has a negative effect on aTSA functional outcomes that may persist even after quitting., Competing Interests: K. A. Hao reports consulting fees from LinkBio, unrelated to this study. B. S. Schoch reports royalties or licenses and consulting fees from Responsive Arthroscopy, Inomed, and Exactech, all of which are unrelated to this study. K. W. Farmer reports consulting fees from Arthrex and Exactech, unrelated to this study. T. W. Wright reports royalties or licenses from Exactech and Wolters Kluwer Health, unrelated to this study. J. J. King reports consulting fees from Exactech and LinkBio, unrelated to this study., (© 2024 The British Editorial Society of Bone & Joint Surgery.)

Aims: The objective of this study was to compare simulated range of motion (ROM) for reverse total shoulder arthroplasty (rTSA) with and without adjustment for scapulothoracic orientation in a global reference system. We hypothesized that values for simulated ROM in preoperative planning software with and without adjustment for scapulothoracic orientation would be significantly different., Methods: A statistical shape model of the entire humerus and scapula was fitted into ten shoulder CT scans randomly selected from 162 patients who underwent rTSA. Six shoulder surgeons independently planned a rTSA in each model using prototype development software with the ability to adjust for scapulothoracic orientation, the starting position of the humerus, as well as kinematic planes in a global reference system simulating previously described posture types A, B, and C. ROM with and without posture adjustment was calculated and compared in all movement planes., Results: All movement planes showed significant differences when comparing protocols with and without adjustment for posture. The largest mean difference was seen in external rotation, being 62° (SD 16°) without adjustment compared to 25° (SD 9°) with posture adjustment (p < 0.001), with the highest mean difference being 49° (SD 15°) in type C. Mean extension was 57° (SD 18°) without adjustment versus 24° (SD 11°) with adjustment (p < 0.001) and the highest mean difference of 47° (SD 18°) in type C. Mean abducted internal rotation was 69° (SD 11°) without adjustment versus 31° (SD 6°) with posture adjustment (p < 0.001), showing the highest mean difference of 51° (SD 11°) in type C., Conclusion: The present study demonstrates that accounting for scapulothoracic orientation has a significant impact on simulated ROM for rTSA in all motion planes, specifically rendering vastly lower values for external rotation, extension, and high internal rotation. The substantial differences observed in this study warrant a critical re-evaluation of all previously published studies that examined component choice and placement for optimized ROM in rTSA using conventional preoperative planning software., Competing Interests: S. Poltaretskyi is an employee of Arthrex. P. Raiss is a paid consultant for Arthrex, and also receives speaker payments or honoraria and support for attending meetings and/or travel from Arthrex, and stock or stock options from Zurimed, all of which are unrelated to this study. P. Siegert reports software support from Arthrex for this study. B. C. Werner reports funding from Arthrex for this study, as well as consulting fees from Arthrex and Lifenet, and speaker payments or honoraria from Arthrex which are unrelated to this study. P. Moroder reports software support and article processing charges funding from Arthrex for this study, as well as consulting fees from and a patent submission with Arthrex, which are related to this study. P. Denard reports grant funding from Arthrex for this study, as well as royalties or licenses, consulting fees, and speaker payments or honoraria from Arthrex which are unrelated to this study. P. Denard also reports speaker payments or honoraria from Pacira and stock or stock options from PT Genie, unrelated to this study. B. J. Erickson reports consulting fees from Arthrex, unrelated to this study. J. Griffin reports royalties or licenses, consulting fees, speaker payments or honoraria, support for attending meetings and/or travel, and patents from Arthrex, all of which are unrelated to this study., (© 2024 Moroder et al.)

Cadaveric and computer simulations suggest lateral humeral offset (LHO) and humeral retroversion (HR) are associated with strength and range of motion (ROM) after reverse total shoulder arthroplasty (rTSA), butin vivodata is lacking. This study aimed to evaluate the effects of implant parameters (i.e. LHO and HR) on strength and ROM. LHO and HR were measured using pre-operative and post-operative computed tomography (CT) scans. Postoperative strength was measured across three planes of motion using a Biodex isokinetic dynamometer. Postoperative active and passive ROM during forward elevation, external rotation (ER), and internal rotation (IR) were assessed using a goniometer or spinal level. 30 rTSA patients (14 M, 16F, age: 71.8 ± 6.7yrs) participated with an average postoperative follow-up of 2.4 ± 1.1 years. Regarding strength, higher post-op LHO values were predictive of greater postoperative strength across all movements. However, lateralization of the implant beyond pre-op values (i.e. post-op LHO > pre-op LHO) was associated with poorer strength performance across all ranges of motion. Similar to strength outcomes, greater deviations from pre-op LHO was predictive of poorer IR ROM. Lastly, patients with minimal deviations in HR (post-op HR within 10° of pre-op HR) and minimal deviations in LHO (post-op LHO ≤ pre-op LHO) displayed the greatest postoperative ER ROM. Anatomic restoration of LHO combined with anatomic restoration of HR may be ideal for maximizing strength and ROM following rTSA. Overlateralization beyond anatomic may have negative consequences. Optimal implant lateralization and version may need to be individualized based on preoperative values., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: This systematic review and meta-analysis compared clinical outcome measures in patients undergoing reverse shoulder arthroplasty (RSA) for proximal humerus fracture (PHF) with healed versus non-healed greater tuberosity (GT)., Methods: We performed a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines querying PubMed/MEDLINE, EMBASE, Web of Science, and Cochrane for studies that stratified results by the GT healing status. Studies that did not attempt to repair the GT were excluded. We extracted and compared clinical outcomes including postoperative forward flexion (FF), external rotation (ER), internal rotation (IR), Constant score, and complications and revision rates., Results: Of the included patients, 295 (78.5%) demonstrated GT healing while 81 did not (21.5%). The healed GT cohort exhibited increased postoperative FF (P < .001), ER (P < .001), IR (P = .006), and Constant score (P = .006) compared to the non-healed GT cohort. The overall dislocation rate was 0.8% with no study differentiating GT status of dislocation cases., Conclusion: Healing of the GT after RSA for PHF yields improved postoperative range of motion and strength, whereas patient-reported pain and function were largely not affected by GT healing indicating merit to RSA for PHF regardless of the likelihood of the GT healing., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Purpose: The aim of this study was to observe the effects of changing humeral tray thickness on the resultant of intraoperative glenohumeral joint loads using a load-sensing system (LSS)., Methods: An rTSA was performed on fresh frozen full-body cadaver shoulders by using an internal proprietary LSS on the humeral side. The glenohumeral loads (Newtons) and the direction of the resultant force applied on the implant were recorded during four standard positions (External rotation, Extension, Abduction, Flexion) and three "complex" positions of Activity Daily Life ("behind back", "overhead reach" and "across chest"). For each position, the thickness was increased from 0 to 6 mm in a continuous fashion using the adjustment feature of the humeral system. Each manoeuvre was repeated three times., Results: All shoulder positions showed a high repeatability of the glenohumeral load magnitude measured with an intra-class correlation coefficient of over 0.9. For each position, we observed a strong but no linear correlation between humeral tray thickness and joint loads. It was a cubical correlation (r s = 0,91) with a short ascending phase, then a plateau phase, and finally a phase with an exponential growth of the loads on the humeral implant. In addition, an increase in trail-poly thickness led to a recentering of force application at the interface of the two glenohumeral implants., Conclusion: This study provides further insight into the effects of humeral implant thickness on rTSA glenohumeral joint loads during different positions of the arm. Data obtained using this type of device could guide surgeons in finding the proper implant balance during rTSA., (© 2024. The Author(s) under exclusive licence to SICOT aisbl.)

Purpose: A retrospectively analyze of instability after RSA in terms of aetiology, treatment and final functional outcome., Methods: A bicentric retrospective study of 31 patients (mean age 67.6 years; 42-83) treated for RSA instability using RSA Arrow System (FH Orthopedics, Mulhouse, France), mean follow-up 41months (range 12-158). Aetiologies for dislocation were evaluated using a previously described classification system for RSA instability. Actions performed during the Revision Surgeries were analyzed and grouped into five categories. Clinical outcome measures included range of motion, SSV, VAS, Constant-Murley scores, satisfaction level and recurrence of instability., Results: The most frequent aetiology for RSA instability was loss of compression (18), followed by impingement (8) and loss containment (5). Total RSA revision (bipolar procedure) involving both distalization and lateralization occurred in 13 instances. Isolated distalization through the humerus was performed in ten patients and Isolated lateralization through the glenoid in three patients. Three cases of components exchange due to mechanical failure were noted. Bone graft was used in nine instances. Three patients (10%) suffered recurrent instability following Revision Surgery and required an additional stabilizing procedure. At final follow-up all 31 RSA were reported as stable with a mean VAS of 1.1, SSV 54.5%, constant score 48.3, constant ponderate 74.9%., Conclusion: The management of unstable RSA represent a challenge that can be successfully overcome with a revision surgery with compromised functional results. Loss of compression was the most common cause for primary and recurrent RSA instability that were treated principally with bipolar revisions involving component lateralization and distalization., (© 2024. The Author(s) under exclusive licence to SICOT aisbl.)

Background: Total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) are used in the management of end-stage glenohumeral arthritis. Improvement in shoulder function and resolution of symptoms are high priorities for patients. The aim of this study was to compare patient-reported outcome measures (PROMs) following TSA and HA., Methods: Records from the National Joint Registry of England, Wales, Northern Ireland, and the Isle of Man were linked to the PROMs data set. The study included anatomic shoulder arthroplasties performed for osteoarthritis in patients with an intact rotator cuff. Patients with preoperative and postoperative Oxford Shoulder Scores (OSSs) were included. The improvement in OSS at 6 months and 5 years and the trend in scores over time were analyzed for each prosthesis. A cohort of 2002 patients were matched on 10 variables using propensity scores. OSSs at 6 months following TSA vs. HA were compared in the matched sample., Results: There was a significant improvement in the OSS in both groups (P < .001). At 6 months, the OSSs were superior following TSA compared with HA (median 42 vs. 36, P < .001). The median score at 5 years was 44 following TSA and 35 following HA. Score distributions were skewed toward the maximum score. The highest possible score (48) was achieved in 28% (134 of 478) of TSAs and 9% (20 of 235) of HAs at 5 years. The improvement in the preoperative to 6-month OSS reached the minimal clinically important difference of 5.5 in 92% (1653 of 1792) of TSAs and in 80% (416 of 523) of HAs. At 5 years, this improvement was maintained in 91% (339 of 374) of TSAs and 78% (136 of 174) of HAs., Conclusion: TSA resulted in superior OSSs at 6 months in patients with osteoarthritis. The median OSS improved from 6 months to 5 years following TSA; however, there was a small decline in scores following HA. A ceiling effect was shown in the OSS following TSA at 5 years., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Acute unreconstructible 3- or 4-part proximal humerus fractures can be treated with hemiarthroplasty or reverse polarity shoulder arthroplasty. Randomized trials using implants from multiple different companies or uncemented implants have found superior results with reverse polarity arthroplasty., Hypothesis: We tested the hypothesis that cemented reverse polarity arthroplasty produces a superior outcome compared to cemented hemiarthroplasty using one implant system in patients aged 65 years and over at 12 months follow-up as measured with the Constant Score., Methods: A prospective patient and assessor blinded multicenter randomized controlled trial was conducted of shoulder hemiarthroplasty or reverse polarity arthroplasty in patients aged 65 years and older with acute 3- and 4-part proximal humerus fracture not amenable to osteosynthesis. The primary outcome was the Constant Score at 12 months with total follow-up to 24 months. Block randomization by site was undertaken using random number generation and sealed envelopes. Power analysis indicated that 17 patients were required in each arm to achieve 80% power with an alpha-value of 5%. Secondary outcome measures were the difference in the mean Constant Score, Quick Disabilities of the Arm Shoulder and Hand Questionnaire (QuickDASH), Oxford Shoulder Score, American Shoulder and Elbow Surgeons Score, and EQ5D-5L up to 2 years; differences in complication rate at 1 and 2 years; differences in revision and implant failure at 1 and 2 years., Results: Eighteen patients were randomized to hemiarthroplasty and 18 to reverse polarity arthroplasty across 4 sites. The primary outcome as measured by the Constant Score at 12 months was better in the reverse polarity shoulder arthroplasty group (mean 51.1, s.d. 14.9) compared to the hemiarthroplasty group (mean 35.0, s.d. 13.5) (P = .004). No significant difference was reported at 24 months but this may be due to high rates of attrition (22%). The mean EQ-5D-5 L patient rated health status score was significantly higher in the reverse polarity shoulder arthroplasty group compared to the hemiarthroplasty group at 12 months. One hemiarthroplasty was revised due to implant uncoupling and one reverse polarity shoulder replacement was revised due to instability. No other complications were recorded., Discussion: Treatment of unreconstructible 3- or 4-part proximal humerus fractures with reverse polarity shoulder arthroplasty results in a superior outcome compared to shoulder hemiarthroplasty at 12 months measured with the Constant Score with no increased risk of failure up to 24 months in patients age 65 years and over. High attrition rates are observed in this older population due to cognitive decline and death from other causes., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Several surgeons state that their best anatomic total shoulder arthroplasty (aTSA) outperforms their best reverse total shoulder arthroplasty (rTSA) when performed for rotator cuff-intact glenohumeral osteoarthritis. We identified the top-performing aTSAs and rTSAs at short-term follow-up and compared their clinical performance at midterm follow-up to validate this common claim., Methods: A retrospective review of a multicenter shoulder arthroplasty database was conducted. All shoulders undergoing primary aTSA or rTSA for rotator cuff-intact glenohumeral osteoarthritis between 2007 and 2020 were reviewed. Shoulders with a follow-up clinical visit between 2 and 3 years and a clinical follow-up of minimum 5 years were included. Two separate cohorts were identified: patients with a top 20% (1) American Shoulder and Elbow Surgeons (ASES) score and (2) Shoulder Arthroplasty Smart (SAS) score at 2 to 3 years of follow-up. Clinical outcomes including range of motion, outcome scores, and rates of complications and revision surgeries were compared at minimum 5-year follow-up., Results: The ASES score cohort comprised 185 aTSAs (mean age 67 years, 42% female) and 49 rTSAs (mean age 72 years, 45% female). The SAS score cohort comprised 145 aTSAs (mean age 67 years, 59% female) and 42 rTSAs (mean age 71 years, 57% female). Active external rotation (ER) was greater after aTSA at midterm follow-up in both ASES and SAS score cohorts; however, preoperative to postoperative improvement was equivalent. Postoperative ER and SAS scores were greater after aTSA in both cohorts ( P < 0.05); however, no other significant differences in any preoperative or postoperative clinical outcomes were present ( P > 0.05), and patients achieved the minimal clinically important difference and substantial clinical benefit at similar rates for all outcomes. No difference was found in the incidence of complications and revision surgeries between top-performing aTSAs and rTSAs., Conclusion: Among top-performing shoulder arthroplasties at early follow-up, aTSA does not appear to outperform rTSA, except superior ER at midterm follow-up., Level of Evidence: Retrospective comparative cohort study, Level Ⅲ., (Copyright © 2024 by the American Academy of Orthopaedic Surgeons.)

Background: Avascular necrosis (AVN) of the humeral head is characterized by osteonecrosis secondary to disrupted blood flow to the glenohumeral joint. Following collapse of the humeral head, arthroplasty, namely, total shoulder arthroplasty (TSA) or humeral head arthroplasty (hemiarthroplasty), is recommended standard of care. The literature is limited to underpowered and small sample sizes in comparing arthroplasty modalities. Therefore, the aims of this study were (1) to compare the 10-year survivorship of TSA and hemiarthroplasty in the treatment of AVN of the humeral head and (2) to identify differences in their revision etiologies., Methods: Patients who underwent primary TSA and hemiarthroplasty for AVN were identified using the PearlDiver database. TSA patients were matched by age, gender, and Charlson Comorbidity Index (CCI) to the hemiarthroplasty cohort in a 4:1 ratio because TSA patients were generally older, sicker, and more often female. The 10-year cumulative incidence rate of all-cause revision was determined using Kaplan-Meier survival analysis. Multivariable analysis was conducted using Cox proportional hazard modeling. χ 2 analysis was conducted to compare the indications for revisions between matched cohorts including periprosthetic joint infection (PJI), dislocation, mechanical loosening, broken implants, periprosthetic fracture, and stiffness., Results: In total, 4825 patients undergoing TSA and 1969 patients undergoing hemiarthroplasty for AVN were included in this study. The unmatched 10-year cumulative incidence of revision for patients who underwent TSA and hemiarthroplasty was 7.0% and 7.7%, respectively. The matched 10-year cumulative incidence of revision for patients who underwent TSA and hemiarthroplasty was 6.7% and 8.0%, respectively. When comparing the unmatched cohorts, TSA patients were at significantly higher risk of 10-year all-cause revision (HR: 1.39; P = .017) when compared to hemiarthroplasty patients. After matching, there was no significant difference in risk of 10-year all-cause revision (HR: 1.29; P = .148) and no difference in the observed etiologies for revision (P > .05 for all)., Conclusion: After controlling for confounders, only 6.7% of TSA and 8.0% hemiarthroplasties for humeral head AVN were revised within 10 years of index surgery. The demonstrated high and comparable long-term survivorship for both modalities supports the utilization of either for the AVN induced humeral head collapse., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: Accurate insertion of the glenoid guide pin in shoulder arthroplasty (RSA) is important for obtaining optimized glenoid component position and orientation. The objective of this study was to evaluate and compare the accuracy of 3 glenoid guide pin insertion techniques: (1) traditional software planning using freehand guide pin insertion (freehand), (2) guide pin insertion utilizing patient-specific instrumentation (PSI), and (3) using a mixed-reality navigation (MR-NAV) system., Methods: Twenty (20) computed tomography (CT) scans were obtained from patients exhibiting glenoid erosion patterns according to the Walch and Favard classifications. Cases were planned using validated 3-dimensional (3D) preoperative planning software. The CT data were then used to 3D print triplicate plastic models of each glenoid to evaluate the 3 guide pin insertion techniques. The first technique employed traditional software planning with freehand guide pin insertion. The second method used preoperatively planned PSI guides, whereas the third used an MR-NAV system, which provided real-time holographic guidance during guide pin insertion. Once all guide pins had been inserted into the models, an independent optical tracking system and custom digitization device was used to quantify the position and orientation of each guide pin relative to the glenoid. The outcomes for this study included the absolute mean error in guide pin inclination, version, and entry point relative to the preoperative plan. The absolute Total Global Error was also assessed, which was defined as the sum of the absolute guide pin orientation and position error relative to the preoperative plan., Results: No statistically significant differences between MR-NAV and PSI were found for the inclination error (2° ± 1° vs. 2° ± 1°; P = .056), version error (1° ± 1° vs. 1° ± 1°; P > .99), and Total Global Error (5 ± 1 [mm + deg] vs. 5 ± 1 [mm + deg], P > .99), respectively. The freehand technique produced significantly greater error than MR-NAV and PSI for inclination (5° ± 3°, P ≤ .017), version (4° ± 3°, P ≤ .032), and Total Global Error (8 ± 3 [mm + deg], P < .001). No statistically significant differences in the entry point error were observed between all guide pin insertion methods (P ≥ .058)., Discussion: These results demonstrate that the precision and accuracy of MR-NAV is comparable to PSI and superior to a freehand technique for glenoid guide pin insertion in vitro. Further study is needed to compare the accuracy of these techniques intraoperatively, in addition to assessing a potential learning curve between surgeons of varying experience with the MR-NAV system., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: Walch B2 glenoids can present a challenge to shoulder arthroplasty surgeons. Short-term studies have demonstrated that corrective reaming to 10° of retroversion in anatomic total shoulder arthroplasty (aTSA) can result in good outcomes; however, there is little data reporting the long-term outcomes in this cohort. B2 glenoids treated with high-side reaming present a theoretical risk of early glenoid component failure as one may ream into the subchondral bone. This study aimed to demonstrate that (1) B2 glenoids treated with corrective reaming have durable results and (2) offer similar results to Walch A1/2 in long-term follow-up., Methods: Patients who underwent aTSA by a single surgeon (E.L.F.) were identified from a shoulder arthroplasty registry. Inclusion criteria included Walch A1, A2, or B2 glenoid; a diagnosis of primary shoulder osteoarthritis; and a minimum radiographic and clinical follow-up of 5 years. Forty-three patients with B2 glenoids were compared to a cohort of 42 patients with A1 or A2 glenoids. Preoperative computed tomography (CT) and radiographs were used to assess deformity, glenoid version, and posterior subluxation of the humeral head. Postoperatively, patients were assessed with radiographs and patient-reported outcome measures including American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score, Simple Shoulder Test (SST) score, and visual analog scale (VAS)., Results: Eighty-five shoulders (82 patients, 42 B2 and 43 A1/A2 glenoids) with an average follow-up of 9.4 years were included. In the B2 cohort, the average retroversion was 21.1° and posterior subluxation was 69.4% compared with 10.6° (P < .001) and 57.5% (P < .001), respectively, in the A1 or A2 cohort. The cohort demographics were similar except for male sex (B2 69.8% vs. A1 or A2 37.2%, P = .008). There was no difference between the cohorts in their improvement in ASES (P = .807), SST (P = .586), and VAS (P = .930) scores. There was no difference in lateral humeral offset (P = .889) or acromial humeral interval (P = .468) between initial postoperative and final follow-up visits. Survivorship for B2 glenoids was 97.6%, 94.1%, and 73.3% at 5, 10, and 15 years, respectively, compared with 97.6%, 91.9%, and 83.5% in type A glenoids. The revision rate was similar between the 2 groups (P = .432). Lazarus score (P = .682) and rates of humeral radiolucency (P = .366) and humeral osteolysis (P = .194) were similar between the 2 cohorts at final follow-up., Conclusion: Asymmetric reaming of patients with B2 glenoids is a reliable method of glenoid preparation with excellent mid- to long-term clinical results, patient-reported outcomes, and low revision rates similar to their A1 and A2 counterparts., (Published by Elsevier Inc.)

Background: Reverse total shoulder arthroplasty (RTSA) has become an increasingly popular treatment strategy in the management of complex proximal humeral fractures (PHFs). However, no definitive consensus has been reached regarding the optimal surgical timing of RTSA following PHF, particularly considering nonoperative management is often a viable option. Therefore, the aim of this study was (1) to identify optimal timing intervals that maximize the likelihood of revision following RTSA and (2) to determine differences in revision etiologies using the identified timing intervals., Methods: A retrospective cohort analysis of patients undergoing PHF-indicated RTSA from 2010 to 2021 was conducted using a national administrative claims database. Stratum-specific likelihood ratio (SSLR) analysis was conducted to determine data-driven timing strata between PHF and RTSA that maximized the likelihood of revision surgery within 2 years of RTSA. To control for confounders, multivariable regression analysis was conducted to confirm the identified data-driven strata's association with 2-year revision rates as well as compare the likelihood of various indications for revision including mechanical loosening, dislocation, periprosthetic joint infection (PJI), and periprosthetic fracture (PPF)., Results: In total, 11,707 patients undergoing TSA following PHF were included in this study. SSLR analysis identified 2 timing categories: 0-6 weeks and 7-52 weeks from the time of PHF to TSA surgery. Relative to the 0-6-week cohort, the 7-52-week cohort was more likely to undergo revision surgery within 2 years (OR 1.93, P < .001). Moreover, the 7-52-week cohort had significantly higher odds of revision indicated for dislocation (OR 2.24, P < .001), mechanical loosening (OR 1.71, P < .001), PJI (OR 1.74, P < .001), and PPF (OR 1.96, P < .001)., Conclusions: Using SSLR, we were successful in identifying 2 data-driven timing strata between PHF and RTSA that maximized the likelihood of 2-year revision surgery. As it can be difficult to determine whether RTSA or nonoperative management is initially more appropriate, considering the results of this study, an early trial of 4-6 weeks of nonoperative management may be appropriate without altering the risks associated with RTSA., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Intraoperative navigation is a novel technology that can provide real-time feedback to the surgeon during implantation and enhance the accuracy and precision of glenoid component positioning. Applications of intraoperative navigation systems have demonstrated increased precision in baseplate version and inclination, as well as improved baseplate screw placement, with fewer screws used and greater purchase length achieved when compared to standard instrumentation. Early clinical studies have shown favorable results, with significantly improved patient-reported and clinical outcomes and decreased complications. The implementation of intraoperative navigation is associated with a short learning curve and a minimal increase in operative time. Nevertheless, further research is necessary to substantiate the clinical benefit of navigation and evaluate its economic cost-effectiveness and impact on implant survival. Augmented reality and robotic-assisted surgery are additional emerging technologies that, while novel, hold the potential to further advance the field of shoulder arthroplasty., Competing Interests: CONFLICT OF INTEREST: Joseph A. Abboud would like to disclose royalties from a company or supplier, DJO Global, Zimmer-Biomet, Smith and Nephew, Stryker, Globus Medical, Inc.; research support from a company or supplier as a PI from Lima Corporation-Italy, Orthofix, Arthrex, OREF; royalties, financial or material support from Wolters Kluwer; and board member/committee appointments for a society, American Shoulder and Elbow Society, Pacira. Lawrence V. Gulotta would like to disclose royalties from a company or supplier, Exactech, Inc.; personal fees from a company or supplier, Zimmer-Biomet, Smith and Nephew, Inc.; stock or share ownership, Imagen, Responsive Arthroscopy, Inc. No other potential conflict of interest relevant to this article was reported., (Copyright © 2024 by The Korean Orthopaedic Association.)

Reverse total shoulder arthroplasty (RSA) was historically reserved for the elderly, low-demand patient with rotator cuff arthropathy (RCA) or as a salvage procedure after failed primary arthroplasty. Surgeon expertise and the advancement of implant design has allowed RSA to now become commonplace not only for RCA but also for glenohumeral osteoarthritis. RSA provides a robust glenoid baseplate fixation, which allows for easier and more reliable bone grafting or augmentation when needed. For patients with severe glenoid bone loss, RSA has been shown to have superior or equivalent patient-reported outcomes and shoulder range of motion when compared with total shoulder arthroplasty., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: The benefits of reverse shoulder arthroplasty compared to nonoperative treatment for patients presenting with complex proximal fractures have been rarely explored. The aim of this prospective study was to compare the functional results of reverse shoulder arthroplasty with those of nonsurgical treatment in patients with displaced proximal humeral fractures., Methods: A multicentric prospective randomized control trial of patients older than 70 years who sustained an acute proximal humeral fracture (3 or 4 parts), with less than 3 weeks of evolution, and had no previous condition or surgery on the affected shoulder was conducted. Patients were randomly assigned to the intervention group (implantation of a reverse shoulder arthroplasty and tuberosities reattachment) or the control group (nonoperative treatment). Functional outcome was assessed using the Constant-Murley score (CMS) at the 1-year follow-up. Complications and reinterventions were considered secondary outcomes. The power of the study relied on the inclusion of 81 patients to recognize a statistically significant difference of 10 points between CMS scores in the groups. Analysis was performed based on the intention to treat principle., Results: Eighty-one patients were randomized to surgical treatment or nonoperative treatment, while 66 patients completed the 1-year follow-up evaluation. There was no significant difference between the groups in terms of age (76.1 yo vs. 77.43 yo, P = .43), sex (81.08% women in the surgical group vs. 84.09% in the nonoperative group, P = .72), or type of fracture according to Neer's classification system (P = .06). At the 1-year follow-up, the group assigned to undergo the intervention had better functional outcomes than the nonoperative treatment group (mean CMS; 61.24, SD: 13.33 vs. mean CMS: 52.44, SD: 16.22, P: .02), with a mean difference of 8.84 points, 95% CI (1.57, 16.11). Two patients in the intervention group (6.5%) suffered major complications (periprosthetic joint infection and axillary nerve palsy). No major complications were observed in the nonoperative group. One patient in the intervention group underwent secondary surgery for a periprosthetic joint infection., Conclusions: Treatment with reverse shoulder arthroplasty provides superior functional outcomes compared with conservative treatment for patients presenting with an acute proximal humeral fracture. The difference in CMS is close to the clinically significant thresholds, and some harms are associated with the operative treatment., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: Superior augment use may help avoid superior tilt while minimizing removal of inferior glenoid bone. Therefore, our goal was to compare superior augments vs. no-augment baseplates in reverse shoulder arthroplasty (RSA) for patients with rotator cuff dysfunction and no significant superior glenoid erosion., Methods: A multicenter retrospective analysis of 145 patients who underwent RSA with intraoperative navigation (Equinoxe GPS; Exactech) and 3-year follow-up (mean 32 months' follow-up, range 20-61 months) who had preoperative superior inclination less than 10° and retroversion less than 15°. Patient demographics, radiographic measurements, surgical characteristics, patient-reported outcomes at preoperative and postoperative visit closest to 3 years, and adverse events at final follow-up were obtained. Operative time, planned inclination, and planned version of the baseplate were obtained. χ 2 test was used to compare categorical variables, and Student t test was used to compare the augment and no-augment cohorts., Results: The study population consisted of 54 superior augment patients and 91 no-augment patients. The augment cohort had lower body mass index (27.2 vs. 29.4, P = .023) and higher native superior inclination (5.9° vs. 1.4°, P < .001). No difference between the augment and no-augment cohorts was found regarding age (P = .643), gender (P = .314), medical comorbidities (P > .05), surgical indication (P = .082), and native glenoid version (P = .564). The augment cohort had higher internal rotation score (4.6 vs. 3.9, P = .023), and all remaining range of motion (ROM) and patient-reported outcomes (PROs) preoperatively were not significantly different. At final follow-up, active ROM in all planes was not different between the cohorts. Regarding PROs, the postoperative Shoulder Arthroplasty Smart score was significantly higher (78.0 vs. 73.6, P = .042), and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score trended toward higher (83.6 vs. 77.5, P = .063) in the augment cohort. The augment cohort had a significantly lower proportion of patients who planned to have superior baseplate tilt (1.9% vs. 14.3%, P = .012) and had greater mean inclination correction (6.3° vs. 1.3°, P < .001), compared with the no-augment cohort. Adverse events were rare, and there was no significant difference found between the augment and no-augment cohorts (5.6% vs. 3.3%, P = .509)., Discussion: Superior augmented baseplate in RSA with minimal superior glenoid erosion is associated with similar ROM and adverse events with somewhat improved postoperative PROs compared with nonaugmented baseplates at the 3-year follow-up. Additionally, superior augments resulted in a greater proportion of baseplates planned to avoid superior tilt, and trended toward shorter operative times. Further investigation of long-term glenoid baseplate loosening is imperative to fully understand the cost-effectiveness of superior augments in the setting of minimal glenoid deformity., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The purpose of this study was to evaluate the influence of humeral position of the Affinis Short implant in stemless anatomic total shoulder arthroplasties (STSAs) on clinical and radiologic results and mid- to long-term survival in the treatment of primary osteoarthritis (OA) of the shoulder., Methods: Eighty patients treated with a stemless shoulder arthroplasty for OA of the shoulder were evaluated with a mean follow-up of 92 ± 14 months (range 69-116 months) by the Constant Score (CS), Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH), and active range of motion (ROM). Radiographic assessment for bone adaptations and humeral implant position was performed by plain radiographs. Comparison of the pre- and postoperative centers of rotation (CORs) was used to assess the restoration of the geometry of the humeral head. The appraisal of proper humeral component positioning was correlated with the functional outcomes. A Kaplan-Meier analysis was performed to investigate the influence of humeral implant position compared to survival time. Complications were noted., Results: The ROM (P < .001), CS (P < .001), and DASH scores (P < .001) showed significant improvements after surgery for the entire series. The COR restoration was anatomic in 75% (n = 60) of all implants and in 25% (n = 20) nonanatomic implants (pre- and postoperative COR deviation of 2.7 ± 1.8 mm vs. 5.1 ± 3.2 mm, P = .0380). The humeral component position did not affect the functional outcome whereas the 10-year unadjusted cumulative survival rate for the anatomic group was significantly higher in comparison with the nonanatomic group (96.7% vs. 75%, P = .002). The radiologic evaluation revealed minor periprosthetic bone adaptions in various forms without clinical significance or further intervention. No revision was necessary because of a failed fixation of the stemless humeral component., Conclusions: Regarding the treatment of primary OA of the shoulder, STSA shows excellent long-term survival and clinical outcomes. In particular, STSA implants are able to restore the geometry of the humeral head. Nonanatomic reconstruction may influence the survival over the long term in different pathways. Further studies are necessary to elucidate the effect of humeral component position in STSA on function, pain, and implant survival rates., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Reverse shoulder arthroplasty (RSA) is a common procedure for treating a variety of shoulder pathologies. However, many patients struggle with postoperative internal rotation (IR) deficits, which often hinder their activities of daily living. The conjoint tendon provides an anatomic barrier that can impede the postoperative IR of the shoulder, and this study aims to evaluate the effect of a conjoint tendon lengthening on the glenohumeral range of motion (ROM) following RSA., Methods: This study used ten fresh-frozen cadaver specimens of the upper extremity. An RSA was implanted using a standard deltopectoral approach, and the ROM was assessed postimplantation. Following this, the conjoint tendon was identified and lengthened using a tendon sheath z-plasty, and the ROM was rerecorded. Statistical significance for the ROM gains after conjoint tendon lengthening was determined with a significance level of P < .05., Results: Following the lengthening of the conjoint tendon, there were statistically significant improvements in all ROMs (P < .05). Subjects demonstrated a notable gain in IR to the back by 10.3 cm (P < .01), and all ROMs increased by at least 10°, except for forward flexion, which increased by 6° (P < .001)., Conclusions: This study suggests that lengthening the conjoint tendon improves postoperative ROM of the glenohumeral joint after RSA, offering a potential solution to considerable IR deficits that are commonly encountered post-RSA. Subsequent clinical and biomechanical studies should assess the stability of the shoulder joint following conjoint tendon lengthening., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

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 (β = 1.78, 95% confidence interval [CI] 0.85-2.72, P < .001, and β = 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., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The purpose of this study was to define the optimal combination of surgical technique and postoperative rehabilitation protocol for elderly patients undergoing either hemiarthroplasty (HA) or reverse total shoulder arthroplasty (rTSA) for acute proximal humerus fracture (PHF) by performing a network meta-analysis of the comparative studies in the literature., Methods: A systematic review of the literature using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines of MEDLINE, EMBASE, and Cochrane Library was screened from 2007 to 2023. Inclusion criteria were level I-IV studies utilizing primary HA and/or rTSA published in a peer-reviewed journal, that specified whether humeral stems were cemented or noncemented, specified postoperative rehabilitation protocol, and reported results of HA and/or rTSA performed for PHF. Early range of motion (ROM) was defined as the initiation of active ROM at ≤3 weeks after surgery. Level of evidence was evaluated based on the criteria by the Oxford Centre for Evidence-Based Medicine. Clinical outcomes were compared using a frequentist approach to network meta-analysis with a random-effects model that was performed using the netmeta package version 0.9-6 in R., Results: A total of 28 studies (1119 patients) were included with an average age of 74 ± 3.7 and mean follow-up of 32 ± 11.1 months. In the early ROM cohort (Early), the mean time to active ROM was 2.4 ± 0.76 weeks compared to 5.9 ± 1.04 weeks in the delayed ROM cohort (Delayed). Overall, rTSA-Pressfit-Early resulted in statistically superior outcomes including postoperative forward elevation (126 ± 27.5), abduction (116 ± 30.6), internal rotation (5.27 ± 0.74, corresponding to L3-L1), American Shoulder and Elbow Surgeons score (71.8 ± 17), tuberosity union (89%), and lowest tuberosity nonunion rate (9.6%) in patients ≥65 year old with acute PHF undergoing shoulder arthroplasty (all P ≤ .05). In total there were 277 (14.5%) complications across the cohorts, of which 89/277 (34%) were in the HA-Cement-Delayed cohort. HA-Cement-Delayed resulted in 2-times higher odds of experiencing a complication when compared to rTSA-Cement-Delayed (P = .005). Conversely, rTSA-Cement-Early cohort followed by rTSA-Pressfit-Early resulted in a total complication rate of 4.7% and 5.4% (odds ratios, 0.30; P = .01 & odds ratios, 0.42; P = .05), respectively. The total rate of scapular notching was higher in the cemented rTSA subgroups (16.5%) vs. (8.91%) in the press fit rTSA subgroups (P = .02)., Conclusion: Our study demonstrates that patients ≥65 years of age, who sustain a 3-or 4-part PHF achieve the most benefit in terms of ROM, postoperative functional outcomes, tuberosity union, and overall complication rate when undergoing rTSA with a noncemented stem and early postoperative ROM when compared to the mainstream preference-rTSA-Cement-Delayed., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: Reverse total shoulder arthroplasty (RTSA) is a common procedure utilized to address degenerative pathologies of the glenohumeral joint and rotator cuff. Increased reliance on patient-reported outcome measures (PROMs) have placed emphasis on the utilization of the minimum clinically important difference (MCID), substantial clinical benefit (SCB), patient acceptable symptom state (PASS), and maximal outcome improvement (MOI) thresholds to assess the clinical efficacy of RTSA. In this study, we systematically reviewed the MCID, SCB, PASS, and MOI thresholds reported for PROMs following RTSA., Methods: PubMed, Embase, MEDLINE, Cochrane Library, and Google Scholar were queried for articles from January 1, 2000 to August 31, 2023 reporting MCID, SCB, PASS, or MOI values for PROMs following RTSA. Patient demographic data, study characteristics, MCID/SCB/PASS/MOI thresholds, and threshold calculation methods were extracted., Results: One hundred and forty-one articles were screened with 39 ultimately included, comprising 11,984 total patients that underwent RTSA. 34 (87%) studies reported MCID thresholds, 20 (51%) reported SCB, 5 (13%) reported PASS, and 2 (5%) reported MOI. 25/39 (64%) studies referenced a previous study when reporting MCID, SCB, PASS, or MOI values, 11 (28%) used an anchor-based method to calculate threshold values, 1 (3%) used a distribution-based method, and 2 (5%) used both anchor and distribution methods. There were 19 newly calculated MCID (11), SCB (5), PASS (1), and MOI (2) thresholds. For 5 of the 6 most utilized PROMs (ASES, SST, Constant, UCLA, and SPADI), the range of reported MCID values exceeded 50% of the most common threshold. For 3 of 6, the range of SCB values exceeded 25% of the most common threshold., Conclusion: There is substantial variability in the MCID and SCB threshold values reported in the RTSA literature. Standardizing the methodologic calculation and utilization of MCID, SCB, PASS, and MOI thresholds for RTSA may allow for improved assessment of PROMs., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: Computer simulation has indicated a significant effect of scapulothoracic orientation and posture on range of motion (ROM) after reverse total shoulder arthroplasty (RTSA). We analyzed this putative effect on the clinical and radiologic outcome post-RTSA., Methods: We retrospectively assessed 2-year follow-up data of RTSA patients treated at our clinic between 2008 and 2019. Patients were categorized into posture types A, B, and C based on an established method using scapular internal rotation on preoperative cross-sectional imaging. We compared differences in clinical ROM, pain, Subjective Shoulder Value, Constant Score, Shoulder Pain and Disability Index (SPADI), quality of life (EuroQol-5 Dimensions-5 Level utility index), and radiologic outcomes between posture types using linear regression analyses., Results: Of 681 included patients, 225 had type A posture, 326 type B, and 130 type C. Baseline group characteristics were comparable, although the type C group had a higher proportion of females (60% [A], 64% [B], 80% [C]) with lower abduction strength (0.7 kg [A], 0.6 kg [B], 0.3 kg [C]) and a slightly higher proportion with a Grammont design RTSA (41% [A], 48% [B], 54% [C]). There were significant adjusted differences in mean (±standard deviation) active flexion (A: 137° ± 21°; B: 136° ± 20°; C: 131° ± 19°) and passive flexion (A: 140° ± 19°; B: 138° ± 19°; C: 134° ± 18°), active (A: 127° ± 26°; B: 125° ± 26°; C: 117° ± 27°) and passive abduction (A: 129° ± 24°; B: 128° ± 25°; C: 121° ± 25°), SPADI (A: 81 ± 18; B: 79 ± 20; C: 73 ± 23), and pain (A: 1.2 ± 1.7; B: 1.6 ± 2.2; C: 1.8 ± 2.4) between posture types at 2 years (P ≤ .035). A higher distalization shoulder angle was associated with better abduction in type C patients (P = .016). Type C patients showed a trend toward a higher complication rate (3.9% vs. 1.1% [A], 3.2% [B]) (P = .067)., Conclusions: Type C posture influences the 2-year clinical outcome of RTSA patients in terms of worse flexion, abduction, SPADI, and pain. Scapulothoracic orientation and posture should be considered during the patient selection process, preoperative planning, and implantation of an RTSA., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The prevalence of reverse total shoulder arthroplasty (rTSA) has grown rapidly. As indications for the procedure expand, the proportion of patients who have satisfactory outcomes after rTSA has not been well defined. This systematic literature review explores overall patient satisfaction after rTSA and defines patient satisfaction based on indication for surgery., Methods: A literature search was performed for studies describing patient satisfaction after rTSA in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Papers were included if they investigated patient satisfaction after rTSA at a minimum of 2-year follow-up. Data were collected on patient demographics, including age, gender, and body mass index. Follow-up duration, indication for surgery, and patient reported outcome measures relating to patient satisfaction were also recorded., Results: There were a total of 5234 patients and 5288 shoulders from the 45 included studies. The overall study population was 61.2% female and the average age was 71.1 years (range 23-99). Satisfaction results were recorded at final follow-up, with average follow-up of 49.1 months (range 24-228). Overall patient satisfaction ranged from 77.7% to 87.8%, depending on patient satisfaction patient reported outcome measures. When stratified by diagnosis, patients with a diagnosis of glenohumeral osteoarthritis (GHOA) rated better satisfaction on all metrics when compared to patients with a diagnosis of cuff tear arthropathy or massive rotator cuff tear., Conclusion: This systematic review demonstrated that patients who undergo rTSA for either GHOA, cuff tear arthropathy, or massive rotator cuff tear are generally satisfied with their procedure, with the rate of satisfaction highest in GHOA. Focusing on patient satisfaction may provide the best overall assessment of health care quality in a very understandable and tangible form. Overall satisfaction rate is valuable information for patient education and can be utilized as part of effective surgical counseling., (Published by Elsevier Inc.)

Background: Reverse shoulder arthroplasty (RSA) aims to restore function in patients with rotator cuff failure and joint arthropathy. After surgery, patients are routinely referred to a rehabilitation specialist to regain range of motion, strength, and function. A key element in these programs is active exercises. The exercises are often selected based on assumed muscle activity, investigated by electromyography (EMG). In particular, in this patient population, activation of the deltoid and the scapular muscles is the focus of exercise therapy. Currently, most studies investigating muscle activity levels during exercises are performed on healthy individuals. To our knowledge, no study exists analyzing EMG activity during exercises in a population of shoulder arthroplasty patients. Therefore, the study aimed to analyze activity in the shoulder girdle muscles during 6 commonly used rehabilitation exercises 12 weeks after reverse shoulder arthroplasty surgery., Methods: Forty-four patients (50 shoulders) participated in this cross-sectional study, 12 weeks postoperatively (mean 99.18 ± 12.8 days), aged 68.9 ± 7.75 years. Surface EMG activity was measured in 10 shoulder girdle muscles: the 3 trapezius parts, serratus anterior, the 3 deltoid parts, latissimus dorsi, and 2 pectoralis major parts during 6 exercises, 3 in a closed chain, and 3 open chain elevation exercises., Results: Gravity-minimized exercises (horizontal plane) show low activity for almost all muscles. Vertical closed kinetic chain exercises show an increased activity compared to horizontal plane exercises. Open kinetic chain exercises against gravity showed the greatest activity in deltoid and upper trapezius. For the other muscles, no consistency in progression was found., Conclusion: This study offers a progression of exercises for patients after reverse shoulder arthroplasty based on increased muscle activity., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The purpose of this study is to systematically review the evidence in the literature to ascertain the functional outcomes, range of motion (ROM), and complication and reoperation rates after revision reverse shoulder arthroplasty (RSA) for a failed primary total shoulder arthroplasty (TSA) or hemiarthroplasty (HA)., Methods: Two independent reviewers performed the literature search based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the EMBASE, MEDLINE, and The Cochrane Library databases. Studies were included if they reported clinical outcomes for revision RSA for a failed primary TSA or HA., Results: Our review found 23 studies including 1041 shoulders (627 TSA and 414 HA) meeting our inclusion criteria. The majority of patients were female (66.1%), with an average age of 69.0 years (range: 39-93 years) and a mean follow-up of 46.3 months. American Shoulder and Elbow Surgeons and visual analog scale pain scores improved from 32.6 to 61.9 and 6.7 to 2.7, respectively. ROM results include forward flexion, abduction, and external rotation, which improved from 59.4° to 107.7°, 50.7° to 104.4°, and 19.8° to 26.3°, respectively. Only 1 of the 10 studies reporting internal rotation found a statistically significant difference, with the mean internal rotation improving from S1-S3 preoperatively to L4-L5 postoperatively for patients undergoing HA. The overall complication rate and reoperation rate were 23.4% and 12.5%, respectively. The most common complications were glenoid component loosening (6.0%), fracture (periprosthetic, intraoperative, or other scapula fractures) (n = 4.7%), and infection (n = 3.3%)., Conclusions: Revision RSA for a failed primary TSA and HA has been shown to result in excellent functional outcomes and improved ROM, suggesting that patients who have failed TSA or HA may benefit from a revision RSA., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: Insufficient tuberosity healing is the most common reason for poor outcome after treatment of proximal humerus fractures (PHFs) using hemiarthroplasty (HA). In these cases, revision to reverse total shoulder arthroplasty (RTSA) can improve function and reduce pain in the short term, however, long-term results remain scarce. Aim of this study was to evaluate the clinical and radiological mid- to long-term results in patients with a revision RTSA after failed HA for PHF., Methods: In this retrospective study all patients that received a revision to RTSA after failed fracture HA between 2006 and 2018 were included. A total of 49 shoulders in 48 patients (38 female, 10 male; mean age 82 ± 9 years) were identified in our database. A total of 20 patients (17 female, 3 male; mean age was 79 ± 9 years) were available for follow-up examination after a mean time period of approximately eight years (3-14 years) after revision surgery. At final follow-up, patients were assessed using a subjective shoulder value (SSV), range of motion (ROM), visual analogue score (VAS), the Constant Score (CS) and the 12-Item Short Form Survey (SF-12)., Results: At final follow-up, mean CS was 55 ± 19 (19-91), VAS averaged 3 ± 3 (0-8) and mean SSV was 61 ± 18% (18-90%). Mean SF-12 was 44 (28-57) with a mean physical component summary (PCS) of 38 (21-56) and a mean mental component summary (MCS) of 51 (29-67). On average active forward flexion (FF) was 104° (10-170°), active abduction (ABD) was 101° (50-170°), active external rotation (ER) was 19° (10-30°) and active internal rotation (IR) of the lumbosacral transition was reached. Three patients presented with a periprosthetic humeral fracture after RTSA implantation and underwent a reoperation (15%) during follow-up period., Conclusions: Revision RTSA results in promising clinical results in patients after initial failed HA after PHF. A complication and reoperation rate of 15% is tolerable in consideration of satisfactory functional and psychological outcome., Trial Registration: Retrospectively registered., (© 2024. The Author(s).)

Objective: To analyze the effectiveness of tuberosity suture combined with autogenous bone grafting in reverse total shoulder arthroplasty for elderly patients with proximal humerus fracture., Methods: A clinical data of 28 patients with fresh proximal humerus fractures, who met the selection criteria and admitted between June 2014 and April 2022, was retrospectively analyzed. There were 7 males and 21 females. Age ranged from 65 to 81 years, with an average of 73.8 years. The causes of injury were 21 cases of fall, 6 cases of traffic accident, and 1 case of falling from height. The time from injury to operation ranged from 5 to 20 days with an average of 9.2 days. There were 8 cases of Neer three-part fracture and 20 cases of four-part fracture. The reverse total shoulder arthroplasty was performed, and the greater and lesser tuberosities were sutered and reconstructed with autogenous bone grafting. After operation, the Constant score, American Society for Shoulder Surgery (ASES) score, and visual analogue scale (VAS) score were used to evaluate shoulder function and pain; and the active range of motion of the shoulder joint was recorded, including flexion, external rotation, and internal rotation. X-ray films were taken to observe the position of prosthesis. According to the evaluation criteria proposed by Boileau, the healing of greater tuberosity was evaluated, and the effectiveness was compared between the patients with healed and non-healed (displacement and absorption) greater tuberosity., Results: All incisions healed by first intention after operation. All patients were followed up 24-106 months, with an average of 60.9 months. At last follow-up, the VAS score of shoulder joint ranged from 0 to 6 (mean, 1.1). The Constant score ranged from 45 to 100 (mean, 80.1). The ASES score ranged from 57 to 100 (mean, 84.7). The active range of motions of shoulder joint were 60°-160° (mean, 118°) in flexion, 0°-50° (mean, 30°) in external rotation, and corresponding to reaching the S 5 -T 8 vertebral body level in internal rotation. During follow-up, no shoulder joint re-dislocation or severe shoulder instability occurred, and no revision surgery was performed. X-ray film reexamination showed that there was no loosening of the prosthesis. According to the evaluation criteria proposed by Boileau, the greater tuberosity fused in 22 cases (78.6%), displaced in 3 cases (10.7%), and absorbed in 3 cases (10.7%). The shoulder joint function and pain related evaluation indicators in the healed group were significantly better than those in the non-healed group ( P <0.05)., Conclusion: Tuberosity suture combined with autogenous bone grafting is a relatively simple procedure that provides a reliable fixation for the anatomic recovery of greater and lesser tuberosities and is beneficial for the recovery of shoulder function in elderly patients with proximal humeral fractures.

Introduction: In reverse shoulder arthroplasty (RSA) new designs enable greater amounts of lateralization to prevent instability and scapular notching and increase range of motion, however, excessive lateralization leads to stress upon the acromion that can result in scapular spine fatigue fractures. Aim of this study was to gender- and size-specifically assess the influence of glenosphere size and different humeral designs on lateralization, distalization, and bony impingement-free range of motion (ROM) in patients undergoing RSA., Methods: Computed tomography scans from 30 osteoarthritic patients (f:15, m:15) and 20 cuff tear arthropathy patients (f:10, m:10) were used to virtually simulate RSA implantation. The efficacy of an inlay Grammont-type system vs. an onlay lateralizing system combined with different glenosphere sizes (36 mm vs. 42 mm) in achieving ROM, lateralization, and distalization was evaluated. Moreover, gender and patient's constitution were correlated to humeral size by radiologically measuring the best-fit circle of the humeral head., Results: A different amount of relative lateralization was achieved in both genders using large glenospheres and onlay designs. Latter yielded a higher ROM in all planes for men and women with a 42 mm glenosphere; with the 36 mm glenosphere, an increased ROM was observed only in men. The 155° inlay design led to joint medialization only in men, whereas all designs led to lateralization in women. When adjusting the absolute amount of lateralization to humerus' size (or patient's height), regardless of implant type, women received greater relative lateralization using 36 mm glenosphere (inlay: 1%; onlay 12%) than men with 42 mm glenosphere (inlay: -3%; onlay: 8%)., Conclusion: The relative lateralization achieved using onlay design is much higher in women than men. Small glenospheres yield greater relative lateralization in women compared to large glenospheres in men. Humeral lateralization using onlay designs should be used cautiously in women, as they lead to great relative lateralization increasing stress onto the acromion., Level of Evidence: Basic Science Study, Computer Modeling., (© 2024. The Author(s).)

With the rising prevalence of shoulder arthroplasty, the incidence of revision shoulder arthroplasty is also increasing. The complexity of these revision procedures poses significant challenges, with bone loss being a critical factor impacting treatment outcomes. Addressing substantial humeral bone defects is crucial for ensuring implant stability and functionality. A comprehensive literature review was conducted using PubMed, Medline, and Google Scholar to identify existing classification systems for proximal humeral bone loss in the context of revision shoulder arthroplasty. The study assessed the advantages and limitations of these classifications, using this information to propose a new diagnostic and therapeutic algorithm. Several classification systems for proximal humeral bone loss were identified. McLendon et al. classify proximal humeral bone loss based on a 5-cm bone loss threshold and suggest an allograft prosthesis composite for losses exceeding this limit. Boileau's system stratifies bone loss into four types based on the extent of loss, with specific recommendations for each category. The PHAROS classification provides a detailed anatomical assessment but lacks quantitative precision. The proposed PHBL-SCORe system offers a novel algorithm incorporating preoperative radiographic measurements to determine the percentage of bone loss and guide treatment options. Proximal humeral bone loss presents significant challenges in revision shoulder arthroplasty, necessitating precise preoperative planning and classification to guide surgical intervention. Existing classification systems provide valuable frameworks but often rely on average population values, neglecting individual anatomical variations. The proposed PHBL-SCORe system offers a patient-specific approach, improving the accuracy of bone loss assessment and optimizing treatment strategies. Implementing this classification in clinical practice could enhance surgical outcomes and reduce complications associated with rRSA (revision Reverse Shoulder arthroplasty). Further studies are required to validate this algorithm and explore its long-term efficacy in diverse patient populations., (© 2024. The Author(s).)

Background: Scapular notching is a common complication of reverse total shoulder arthroplasty (RTSA). Although the notching rate has reduced significantly thanks to modifications to the surgical technique and humeral and glenoid components, uncontrollable polyethylene (PE)-induced osteolysis can still occur. In contrast to conventional-bearing (CB-RTSA), inverted-bearing RTSA (IB-RTSA) systems, with PE glenospheres and metal or ceramic humeral liners, avoid PE abrasion through scapulohumeral contact. If present, the resulting notch has a different size and configuration than with CB-RTSA. Thus, a modified notching classification seems reasonable. Even in CB-RTSA, the early stages of notching show a different configuration than implied by the established Nerot-Sirveaux classification; therefore, a modification of the classification system is recommended., Methods: In a prospective multicentre study, 250 cases underwent IB-RTSA. Of these, 39 died, and 28 were lost to follow-up for other reasons, leaving 183 shoulders for the final follow-up examination at a mean of 120.7 months (range 84.1-172.4 months). In the CB-RTSA group, we retrospectively evaluated radiographs of 59 consecutive patients with a follow-up ranging from 2 to 7 years. We analysed the appearance, evolution over time, and location of bone loss on the scapular neck according to the modified Nerot-Sirveaux classification., Results: In IB-RTSA, notching resulted in a new morphological configuration: In contrast to the Nerot-Sirveaux classification, notching began far from the baseplate as an impression or abrasion of the humeral component in the inferior scapular rim. Due to simultaneous mechanical ablation, the defect gradually enlarged, but usually did not contact the baseplate or extend beyond the inferior peg. No signs of PE-induced osteolysis were found. The notching rate reached 19% after 2 years and approached 36% after 10 years. Most shoulders had grade 0 notching (64%), followed by grade 1 (29%); extensive erosion (grade 4) was not observed. In the CB-RTSA group, a small bony impression or erosion without signs of PE-induced osteolysis was observed medial to the scapular neck, without contact with the metaglene in the early phase, which was similar to the impression of the humeral component in IB-RTSA. The notching rate was 86% for CB-RTSA., Conclusions: A new classification was developed for IB-RTSA, which corresponds to the pathophysiological processes and is compatible with the existing Nerot-Sirveaux classification. Bone erosion in CB-RTSA is not adequately represented by the established classification in the early stages. For this reason, a supplement to the existing classification is presented., Level of Evidence: Level 4, Case Series, Treatment Study., (© 2024. The Author(s).)

Introduction: The older generation of high thickness metal-backed glenoid prostheses had a high failure rate. The goal of our study was to analyze the medium-term clinical and radiological results of a technically modified generation of metal backed glenoids with 35% decrease in thickness., Methods: Thirty-nine patients (43 shoulders) with a mean age of 66.5 years at surgery were examined from two to ten years (mean 71.2 months) using the Constant-Score, Subjective Shoulder Value and X-ray in a.p. and axial view. Indication for surgery included patients with glenoid types B1, B2, or B3 and/or posterior subluxation but intact rotator cuff, or patients who did not want a reverse prosthesis and had high functional demands. Inclusion criteria comprised participation in a clinical and radiological follow-up examination, along with a minimum follow-up duration of 24 months. Additionally, in all cases, the Constant Score and the Subjective Shoulder Value (PROM) had to be determined. Exclusion criteria were an incomplete dataset, implantation of a different prosthesis type, and failure to meet the minimum follow-up time., Results: The absolute Constant Score (CS) improved significantly (p < 0.0001) from 43 ± 13 (range: 20-69) points before to 80 ± 13 (range: 46-98) points after surgery. The only preoperative negative influencing factor on the result was the glenoid protrusion according to Lévigne (p = 0.0150). No significant differences in functional outcomes were found between glenoid types A2, B1, B2 and B3. Radiolucent lines at the interface were observed in a total of four patients (13%). Radiological signs of glenoid osteolysis were seen in six patients (20%). Humeral upward migration was observed in four patients (13%) and posterior shoulder joint decentering occurred in one patient (3%). Implant-specific complications occurred in three cases (7%). Due to a massive rotator cuff tear, two cases (4.7%) had to be converted to a reversed implant, with the primary metal component remaining in place. If the implant-specific and rotator cuff-associated complications are summarized, the rate is 11.7%. All components that required conversion to an reverse implant have so far remained free of complications., Conclusion: Favorable clinical results can be achieved, especially in patients with an eccentric glenoid type. Severe preoperative glenoid erosion (Walch A2, B2, B3) does not appear to have any influence on postoperative functional results. The complication and revision rates are significantly better than in previous studies with conventional metal-backed glenoid components. Conversion of the anatomical glenoid component to a reverse system was always possible and good clinical results were achieved., Competing Interests: Declarations Ethics approval and consent to participate This study was approved by the Institutional Review Board of the Ludwig-Maximilians-University Munich, Germany (Project No. 23-0155). All data for the study were collected on the basis of a normal standardized clinical investigation. All patients provided written consent for the use of their anonymous data. Financial interests Peter Habermeyer has received patent royalties from Arthrex Inc. Patric Raiss is a paid Consultant for Arthrex Inc. Jeremy Rapaport and Petra Magosch declare they have no financial interests. Conflict of interest Peter Habermeyer receives patent royalties from Arthrex Inc. Jeremy Rapaport and his immediate family, and any research foundation with which they are affiliated did not receive any financial payments or other benefits from any commercial entity related to the subject of this article. Patric Raiss is a paid Consultant for Arthrex Inc. Petra Magosch and her immediate family, and any research foundation with which they are affiliated did not receive any financial payments or other benefits from any commercial entity related to the subject of this article., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: The radiographic evaluation of novel cementless anatomic polyethylene (PE) glenoid components featuring a titanium-coated back is still unclear. This study explores potential radiolucent lines (RLL) between the radiopaque titanium layer and sclerotic convex reamed bone in an intermodal comparison analysis with computed tomography (CT) scans., Materials and Methods: Eight RM pressfit vitamys glenoids (Mathys ® ) were implanted into cadaveric scapulae. In the CT scans, glenoids were quantified by evaluating ideal complete bony support (NO GAP) and gap between bone and titanium coating (GAP). X-rays were in perfect 0-degree projection and tilted in ± 10° and ± 20° mediolateral (ml) and craniocaudal (cc) directions. Radiographs evaluated were graded as NO RLL, RLL (gap > 1 mm) or DL (double line, gap < 1 mm) in an intermodal comparison of CT and X-ray findings., Results: The inter-rater (Cohen's = 0.643) and intra-rater reliability (Cohen's = 0.714) were good. The overall evaluation showed a significant agreement between (NO) RLL on X-ray and (NO) GAP on CT (p < 0.001). The - 10-degree ml projection showed good agreement between CT and X-ray (Cohen's = 0.628). Adequate agreement was shown at 0 degrees (Cohen's = 0.386), + 10 degrees ml (Cohen's = 0.338), and + 20 degrees cc (Cohen's = 0.327). Compared to the scenario DL = NO RLL, the true a.p. view showed better sensitivity when the DL is classified as RLL. Conversely, the true a.p. view demonstrated both better specificity and significant agreement between the X-ray and CT findings in scenario when DL = No RLL., Conclusion: Standard true a. p. projections are reliable in ruling out gaps when no RLL or DL is visible and the detection of RLL shows high intermodal agreement. Varying agreement across tilting angles emphasizes the importance of a comprehensive approach in evaluating bone support and CT is indispensable for a scientifically reliable assessment., Level of Evidence: Level III Treatment Study., Competing Interests: Declarations Competing interests The authors declare that they have no conflict of interest., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Reverse shoulder arthroplasty (RSA) with concurrent latissimus dorsi transfer (LDT) is a potential treatment option for restoration of external rotation (ER). Biomechanical studies have emphasized the importance of the insertion site location for achieving optimal outcomes. In this systematic review and meta-analysis, we aimed to describe what insertion sites for LDT are utilized during concomitant RSA and their associated clinical outcomes., Methods: A systematic review and meta-analysis were performed per PRISMA guidelines. We queried PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases to identify articles reporting on patients who received RSA with LDT to restore ER and specified the site of tendon transfer insertion on the humerus. We first describe reported insertion sites in the literature. Secondarily, we present preoperative and postoperative range of motion and Constant score for different insertion sites as well as reported complications., Results: Sixteen studies, analyzed as 19 separate cohorts (by insertion site and tendon-transfer), reporting on 264 RSAs with LDT (weighted mean age 66 years, follow-up 39 months, 61% female) were evaluated. Of these, 143 (54%) included a concomitant teres major transfer (LDT/TMT) and 121 (46%) were LDT-only. Fourteen cohorts (14/19, 74%) reported insertion at the posterolateral aspect of the greater tuberosity, four cohorts (4/19, 21%) reported insertion site at the lateral bicipital groove, and one cohort (1/19, 5%) reported separate LDT and TMT with insertion of the TMT to the posterolateral aspect of the greater tuberosity and LDT to the lateral bicipital groove. Meta-analysis revealed no differences in range of motion or Constant score based on humeral insertion site or whether the LDT was transferred alone or with TMT. Leading complications included dislocation, followed by infection and neuropraxia. No discernible correlation was observed between postoperative outcomes and the strategies employed for tendon transfer, prosthesis design, or subscapularis management., Conclusion: The posterolateral aspect of the greater tuberosity was the most-utilized insertion site for LDT performed with RSA. However, in the current clinical literature, LDT with or without concomitant TMT result in similar postoperative ROM and Constant score regardless of insertion site. Analysis of various proposed transfer sites reinforce the ability of LDT with RSA to restore both FE and ER in patients with preoperative active elevation and external rotation loss. Meta-analysis revealed significant improvements in range of motion and Constant score regardless of humeral insertion site or whether the LDT was transferred alone or with TMT, although future studies are needed to determine whether an ideal tendon transfer technique exists., Level of Evidence: IV., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Background: Reverse shoulder arthroplasty (RSA) is a well-recognized treatment for many shoulder conditions, including rotator cuff arthropathy, primary glenohumeral joint arthritis, and rheumatoid arthritis, and can be used in both trauma and revision settings. Over the past 10 years, its popularity in New Zealand has been increasing, with a 6%-7% annual growth rate during this period. Stemless RSA designs have the following proposed advantages: They can preserve humeral bone stock, they can limit periprosthetic fractures, and they can be indicated in patients with abnormal diaphyseal humeral anatomy. To date, only 1 study has evaluated the outcomes of the Lima SMR Stemless implant. We present our data with an aim to report how the stemless reverse arthroplasty compares to a conventional stemmed implant., Methods: We performed a retrospective review of a consecutive series of patients treated at a single institution between 2015 and 2020. The endpoint was defined as final follow-up at a minimum of 2 years. Patients were excluded from the final analysis if they underwent revision. Thirty-three patients were identified as having undergone stemless RSA. Thirty patients had patient-reported outcome measures and radiographs at a minimum of 2 years' follow-up. Three patients had undergone revision within 2 years. The same sample size of stemmed RSAs (n = 33) was selected for comparison., Results: A total of 60 patients were included in the final analysis, of whom 30 underwent stemless RSA and 30 underwent stemmed RSA. The demographic characteristics of the 2 groups were comparable except age at operation, which showed a statistically significant difference (P = .001): 77 years (stemmed) vs. 65 years (stemless). The mean Oxford Shoulder Score was 40.1 in the stemless group vs. 40 in the stemmed group. The mean American Shoulder and Elbow Surgeons score was 72.9 in the stemless group vs. 79 in the stemmed group. Patient-reported outcome measures, pain scores, and satisfaction ratings were not statistically significantly different between the 2 groups. In terms of radiographic data, subsidence was observed in 2 patients in the stemless RSA group but the patients had no clinical symptoms. Also in the stemless RSA group, 1 patient had an acromial stress fracture and 1 patient had a superficial wound infection successfully treated with oral antibiotics. In terms of revisions in the stemless RSA group, 1 patient underwent revision owing to chronic infection, 1 underwent revision as a result of a periprosthetic fracture after a fall, and 1 underwent revision for gross instability., Conclusions: The early results of sRSA are promising, and the stemless implant shows similar outcomes to a conventional stemmed implant., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Purpose: The aim of the present systematic review is to collect all the available evidence regarding the clinical and radiological results of revision to reverse shoulder arthroplasty (RSA) of modular anatomic shoulder prostheses (TSA) using a convertible metal-backed glenoid (MBG)., Methods: This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies investigating revision of TSA to RSA utilizing a convertible MBG and reporting clinical and radiological outcomes were identified., Results: A total of five studies on the use of convertible modular glenoid component in the setting of TSA revision to RSA were finally included in the present systematic review. A total of 60 procedures were reported. Mean operative times was 65 min. Intraoperative complications included 3 cases of glenoid loosening. Only one case of dislocation was reported as postoperative complication. At mean follow-up of 32.3 months post-revision, no glenoid loosening was reported, VAS score decreased from 7.7 to 1.5, Constant Score increased from 24.8 to 57.6., Conclusions: Revision to RSA after failed TSA using a convertible modular glenoid component was associated with a low rate of intraoperative and postoperative complications, low surgical time and led to good results in term of pain relieve and functional outcomes. Given the complexity and risk associated with revision of anatomic shoulder prosthesis having a convertible glenoid may help to simplify the procedure and improve clinical results., (© 2024. The Author(s) under exclusive licence to SICOT aisbl.)

Background: Clinical significance, as opposed to statistical significance, has increasingly been utilized to evaluate outcomes after total shoulder arthroplasty (TSA). The purpose of this study was to identify thresholds of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for TSA outcome metrics and determine if these thresholds are influenced by prosthesis type (anatomic or reverse TSA), sex, or preoperative diagnosis., Methods: A prospectively collected international multicenter database inclusive of 38 surgeons was queried for patients receiving a primary aTSA or rTSA between 2003 and 2021. Prospectively, outcome metrics including ASES, shoulder function score (SFS), SST, UCLA, Constant, VAS Pain, shoulder arthroplasty smart (SAS) score, forward flexion, abduction, external rotation, and internal rotation was recorded preoperatively and at each follow-up. A patient satisfaction question was administered at each follow-up. Anchor-based MCID, SCB, and PASS were calculated as defined previously overall and according to implant type, preoperative diagnosis, and sex. The percentage of patients achieving thresholds was also quantified., Results: A total of 5851 total shoulder arthroplasties (TSAs) including aTSA (n = 2236) and rTSA (n = 3615) were included in the study cohort. The following were identified as MCID thresholds for the overall (aTSA + rTSA irrespective of diagnosis or sex) cohort: VAS Pain (-1.5), SFS (1.2), SST (2.1), Constant (7.2), ASES (13.9), UCLA (8.2), SPADI (-21.5), and SAS (7.3), Abduction (13°), Forward elevation (16°), External rotation (4°), Internal rotation score (0.2). SCB thresholds for the overall cohort were: VAS Pain (-3.3), SFS (2.9), SST 3.8), Constant (18.9), ASES (33.1), UCLA (12.3), SPADI (-44.7), and SAS (18.2), Abduction (30°), Forward elevation (31°), External rotation (12°), Internal rotation score (0.9). PASS thresholds for the overall cohort were: VAS Pain (0.8), SFS (7.3), SST (9.2), Constant (64.2), ASES (79.5), UCLA (29.5), SPADI (24.7), and SAS (72.5), Abduction (104°), Forward elevation (130°), External rotation (30°), Internal rotation score (3.2). MCID, SCB, and PASS thresholds varied depending on preoperative diagnosis and sex., Conclusion: MCID, SCB, and PASS thresholds vary depending on implant type, preoperative diagnosis, and sex. A comprehensive understanding of these differences as well as identification of clinically relevant thresholds for legacy and novel metrics is essential to assist surgeons in evaluating their patient's outcomes, interpreting the literature, and counseling their patients preoperatively regarding expectations for improvement. Given that PASS thresholds are fragile and vary greatly depending on cohort variability, caution should be exercised in conflating them across different studies., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Introduction: Proximal humerus fractures are common in the older population. A consensus on the optimal management of complex fractures requiring surgery has yet to be reached. A systematic review and meta-analysis was performed to compare clinical outcomes between reverse total shoulder arthroplasty (RTSA) and open reduction and internal fixation (ORIF)., Methods: A systematic search of the literature was undertaken using the Medline ® , PubMed, Embase™ and Cochrane Central Register of Controlled Trials databases. Prospective and retrospective studies comparing clinical and patient reported results as primary outcome measures were included in this review, with secondary outcome measures including complications and revision surgery. A meta-analysis was conducted., Results: A total of 326 patients from 5 studies were eligible for inclusion in this review. Superior Constant-Murley scores (mean difference [MD]: 13.4, 95% confidence interval [CI]: 6.2-20.6; p <0.001), Oxford shoulder scores (MD: 4.3, 95% CI: 1.2-7.4; p =0.007), simple shoulder test scores (MD: 0.95, 95% CI: 0.01-1.89; p =0.05) and DASH (Disabilities of the Arm, Shoulder and Hand) scores (MD: 5.1 [1 study], 95% CI: 2.1-8.1; p =0.034) were noted in patients receiving RTSA. Range of motion and revision surgery rates were also superior in this group., Conclusions: This study suggests that RTSA affords more favourable outcomes and lower revision rates than ORIF following proximal humerus fractures. Definitive conclusions are precluded, however, owing to small sample sizes and risk of bias in retrospective studies.

Introduction: Similar to the management of periprosthetic joint infections of the lower limb, one-stage revision in total shoulder arthroplasty (TSA) infections is an option that has been highlighted in scientific publications since the early 2010s. However, there are only a few studies which validate this treatment and determine its scope of application in relation to two-stage treatment., Hypothesis: Single-stage revision for infected TSA is a reliable treatment allowing good infection control and satisfactory functional results., Methods: This single-center retrospective series of 34 consecutive patients operated on between 2014 and 2020 for a one-stage prosthetic revision was evaluated at a minimum of 2 years of follow-up. All of the patients included underwent revision shoulder arthroplasty during this period with the diagnosis of infection confirmed by microbiological analysis of surgical samples. Patients who did not benefit from a bipolar revision were excluded. All patients were followed at least 2 years after the intervention. Clinically suspected recurrence of infection was confirmed by a periprosthetic sample under radiographic guidance. Functional clinical outcomes as well as mechanical complications were also reported., Results: The average follow-up was 40.4 months (24-102±21.6). A septic recurrence was observed in three patients (8.8%). A mechanical complication was present in four patients (14.7%), and three (11.8%) required at least one surgical revision. The mean Constant-Murley score at the last follow-up was 49 (42-57±21.83)., Discussion: Single-stage revision for shoulder periprosthetic joint infection results in a success rate of 91.2% with satisfactory functional results after more than 2 years of follow-up., Level of Evidence: IV; retrospective study., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Background: Reverse shoulder arthroplasty is an established procedure for patients with rotator cuff tear arthropathy. However, the repair of the subscapularis tendon remains a controversial and frequently discussed topic. This prospective randomized study was conducted to evaluate the clinical benefit of the subscapularis repair after reverse shoulder arthroplasty., Methods: Fifty patients (36 female and 14 male) were randomized and assigned to either the "repaired" (rep) or the "not repaired" (nrep) cohort. Intraoperatively, the subscapularis tendon was reattached in the rep cohort with 4 tendon-to-tendon sutures, whereas no repair was performed in the nrep cohort. The Constant-Murley Score (CS) and the range of motion were evaluated preoperatively as well as 12 and 36 months postoperatively. The Subjective Shoulder Value and the Lift-off test were performed 36 months postoperatively. The postoperative subscapularis integrity was assessed sonographically., Results: Twelve months postoperatively the rep cohort presented better results in the CS (rep: 71 vs. nrep: 66, P = .037). The normalized CS was 80% in the rep cohort and 75% in the nrep cohort (P = .114). At our last follow-up after 36 months, we did not find significant differences between the rep cohort and the nrep cohort in the CS (rep: 76 vs. nrep: 75, P = .285) and normalized CS (rep: 91% vs. nrep: 91%, P = .388). Concerning internal rotation (in points), the rep cohort achieved better results than the nrep cohort (rep: 7.3 vs. nrep: 6.6, P = .040). Flexion (rep: 145° vs. nrep: 151°, P = .826), abduction (rep: 135° vs. nrep: 137°, P = .816), external rotation (rep: 34° vs. nrep: 37°, P = .817), and the Subjective Shoulder Value (rep: 81% vs. nrep: 77%, P = .398) presented no significant differences between the cohorts. The ultrasound examination after 36 months displayed an intact tendon in 70%., Conclusions: Although the subscapularis repair affects the postoperative internal rotation positively, there were no differences in midterm follow-up concerning the overall results after reverse total shoulder arthroplasty. Further, the external rotation is not affected by the repair of the subscapularis tendon., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Purpose: Reverse shoulder arthroplasty has demonstrated excellent clinical efficacy for patients with shoulder joint diseases and is increasingly in demand. Traditional surgery faces challenges such as limited exposed surfaces and a narrow field of vision, leading to a shorter prosthesis lifespan and a higher risk of complications. In this study, an optical navigation system was proposed to assist surgeons in real-time tracking of the surgical scene., Methods: Our optical navigation system was developed using the NDI Polaris Spectra device and several open-source platforms. The first step involved using the preoperative medical image to plan screw implantation paths. Real-time tracking of the patient phantom or cadaver and the surgical instrument was achieved through registration and calibration algorithms. Surgeons were guided on drilling through visualization methods. Postoperative results were compared with the planned implantation paths, and an algorithm was introduced to correct errors caused by the incorrect beginning points., Results: Experiments involved three scapula cadavers and their corresponding phantoms with identical anatomy. For each experiment, three holes were completed with drills with diameters of 3.2 mm and 8.0 mm, respectively. Comparisons between the postoperative actual screw implantation paths and the preoperative planned implantation paths revealed an entry error of 1.05 ± 0.15 mm and an angle error of 2.47 ± 0.55° for phantom experiments. For cadaver experiments, the entry error was 1.53 ± 0.22 mm, and the angle error was 4.91 ± 0.78°., Conclusion: Our proposed optical navigation system successfully achieved real-time tracking of the surgical site, encompassing the patient phantom or cadaver and surgical instrument, thereby aiding surgeons in achieving precise surgical outcomes. Future study will explore the integration of robots to further enhance surgical efficiency and effectiveness., (© 2024. CARS.)

Background: The design of reverse shoulder arthroplasty (RSA) implants has evolved significantly over the past 50 years. Today there are many options available that differ in design of the glenoid and humeral components, fixation methods, sizes, and modularity. With respect to the humeral component, the literature has generally focused on the differences between inlay and onlay designs and the potential impact on outcomes. However, inlay and onlay design represents only one factor of many., Methods: It is our hypothesis that separating onlay and inlay designs into 2 distinct entities is an oversimplification as there can be a wide overlap of the 2 designs, depending on surgical technique and the implant selected. As such, the differences between inlay and onlay designs should be measured in absolute terms-meaning combined distalization and lateralization., Results: By reviewing the many factors that can contribute to the glenosphere-humerus relationship, the role of inlay and onlay humeral designs as an important distinguishing feature is shown to be limited. Preliminary studies suggest that the amount of distalization and lateralization of the construct may be the most accurate method of describing the differences in the constructs., Conclusions: Inlay and onlay humeral component design represents only one factor of many that may impact outcomes. A more accurate method of defining specific design and technique factors in RSA is the degree of lateralization and distalization., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The appropriate amount of cementation at the time of reverse total shoulder arthroplasty with significant proximal bone loss or resection is unknown. Extensive cementation of a humeral prosthesis makes eventual revision arthroplasty more challenging, increasing the risk of periprosthetic fracture. We analyzed the degree of subsidence and torque tolerance of humeral components undergoing standard cementation technique vs. our reduced polymethyl methacrylate (PMMA) protocol. Reduced cementation may provide sufficient biomechanical stability to resist physiologically relevant loads, while still permitting a clinically attainable torque for debonding the prosthesis., Methods: A total of 12 cadaveric humeri (6 matched pairs) underwent resection of 5 cm of bone distal to the greater tuberosity. Each pair of humeri underwent standard humeral arthroplasty preparation followed by either cementation using a 1.5-cm PMMA sphere at a location 3 cm inferior to the porous coating or standard full stem cementation. A 6-degree-of-freedom robot was used to perform all testing. Each humeral sample underwent 200 cycles of abduction, adduction, and forward elevation while being subjected to a physiologic compression force. Next, the samples were fixed in place and subjected to an increasing torque until implant-cement separation or failure occurred. Paired t tests were used to compare mean implant subsidence vs. a predetermined 5-mm threshold, as well as removal torque in matched samples., Results: Fully and partially cemented implants subsided 0.49 mm (95% CI 0.23-0.76 mm) and 1.85 mm (95% CI 0.41-3.29 mm), respectively, which were significantly less than the predetermined 5-mm threshold (P < .001 and P < .01, respectively). Removal torque between fully cemented stems was 45.22 Nm (95% CI 21.86-68.57 Nm), vs. 9.26 Nm (95% CI 2.59-15.93 Nm) for partially cemented samples (P = .021). Every fully cemented humerus fractured during implant removal vs. only 1 in the reduced-cementation group. The mean donor age in our study was 76 years (range, 65-80 years). Only 1 matched pair of humeri belonged to a female donor with comorbid osteoporosis. The fractured humerus in the partially cemented group belonged to that donor., Conclusion: Partially and fully cemented humeral prostheses had subsidence that was significantly less than 5 mm. Partially cemented stems required less removal torque for debonding of the component from the cement mantle. In all cases, removal of fully cemented stems resulted in humeral fracture. Reduced cementation of humeral prostheses may provide both sufficient biomechanical stability and ease of future component removal., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Hypothesis and Background: Recently, the indication of reverse total shoulder arthroplasty (RTSA) has expanded beyond rotator cuff arthropathy to include treatment of complex acute proximal humeral fracture (PHF). Limited previous studies have compared the long-term clinical and functional outcomes of patients undergoing RTSA for PHF vs. elective indications for degenerative conditions. The purpose of this study was to compare implant survivorship, reasons for revision and functional outcomes in patients undergoing RTSA for acute PHF with those undergoing elective RTSA in a population-based cohort study., Methods: Prospectively collected data from the New Zealand Joint Registry from 1999 to 2021 and identified 6862 patients who underwent RTSA. Patients were categorized by preoperative indication, including PHF (10.8%), rotator cuff arthropathy (RCA) (44.5%), osteoarthritis (OA) (34.1%), rheumatoid arthritis (RA) (5.5%), and old traumatic sequelae (5.1%). Revision-free implant survival and functional outcomes (Oxford Shoulder Scores [OSSs] at the 6-month, 5-year, and 10-year follow-ups) were adjusted by age, sex, American Society of Anesthesiologists class, and surgeon experience and compared., Results: Revision-free implant survival at 10 years for RTSA for PHF was 97.3%, compared with 96.1%, 93.7%, 92.8%, and 91.3% for OA, RCA, RA and traumatic sequelae, respectively. When compared with RTSA for PHF, the adjusted risk of revision was significantly higher for traumatic sequelae (hazard ratio = 2.3, P = .023) but not for other elective indications. The most common reason for revision in the PHF group was dislocation or instability (42.9%), which was similar to the OA (47.6%) and traumatic sequelae (33.3%) groups. At 6 months post-surgery, OSSs were significantly lower for the PHF group compared with the RCA, OA, and RA groups (31.1 vs. 35.6, 37.7, and 36.5, respectively, P < .001), and similar to traumatic sequelae (31.7, P = .431). At 5 years, OSSs were only significantly lower for PHF compared with OA (37.4 vs. 41.0, P < .001) and there was no difference between the PHF and other groups. At 10 years, there were no significant differences between groups., Conclusions: RTSA for PHF demonstrated reliable long-term survivorship and functional outcomes compared with elective indications. Despite lower functional outcomes in the early postoperative period for the PHF group, implant survivorship was similar in patients undergoing RTSA for the primary indication of acute PHF compared with RCA, OA, and RA and superior compared to the primary indication of traumatic sequelae., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Introduction: This study aimed to assess cost-effectiveness of shoulder arthroplasty for osteoarthritis (OA) and rotator cuff tear arthropathy (CTA) from the perspective of a publicly funded health care system using patient data, health utilities and costs from a real-world situation., Hypothesis: Our hypothesis was that arthroplasty for OA is more cost-effective than for CTA., Material and Methods: We gathered a cohort of patients with 153 anatomic total shoulder arthroplasty (TSA) for OA and 107 reverse shoulder arthroplasty (RSA) for CTA between years 2016-2020 at a university hospital. Short-term (mean 2.8years) shoulder function, health utilities and costs were obtained from prospectively collected data, and a Markov cohort simulation was carried out to assess lifetime cost-utility. The primary outcome measures were change in 15D score to calculate gain in quality-adjusted life years (QALYs) and change in Western Ontario osteoarthritis score of the shoulder (WOOS)., Results: Both TSA and RSA restored shoulder function well, WOOS improvement was 59.7 (95% CI: 56.2-63.2) and 55.8 (95% CI: 50.4-61.2), respectively. The cost/QALY gained was 20,846.82 € for TSA and 38,711.90 € for RSA. The cost-utility was not remarkable sensitive to costs, discounting of future costs or estimated revision rates. However, the cost-effectiveness was very sensitive to change in 15D health utility scores and thus QALY gain, especially for RSA patients., Discussion: Shoulder arthroplasty restores shoulder function well in both OA and CTA. In health economic terms, RSA is less cost-effective than TSA in an everyday setting, mainly due to inferior improvement of health-related quality-of-life and reduced life expectancy of CTA patients., Level of Evidence: III; case series., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)