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Glenoid component loosening remains the most common reason for revision of anatomic total shoulder arthroplasty (aTSA). We assessed early clinical and radiographic outcomes following aTSA using a press-fit short stem and a peripherally enhanced fixation glenoid. 275 consecutive patients with end-stage glenohumeral arthritis and Walch A- or B-type glenoid morphology who underwent primary aTSA in 2017-2018 at two high-volume shoulder arthroplasty institutions were evaluated, and patient-reported outcomes (PROMs) and radiographic findings were studied in those with completed baseline and minimum 2-year follow-up, respectively. Patient demographics, glenoid morphology, body mass index (BMI), Charlson Comorbidity Index (CCI), range of motion, American Shoulder and Elbow Surgeons (ASES) score, and Simple Assessment Numeric Evaluation score were collected. Radiographic analysis of glenoid and humeral components was performed. Multivariable logistic, equal adjacent odds ordinal, and beta regression were respectively used to identify predictors of glenoid radiolucent lines, humeral calcar resorption, and total ASES score. Patients were 43% female, with a mean age of 66, a median BMI of 30, and median follow-up of 28.4 months. ASES and Simple Assessment Numeric Evaluation scores improved by respective medians of 54.4 and 55.0 points, forward elevation by median 35°, and external rotation by median 30° (all P <.001 for preoperative to postoperative change). Postoperative radiographs of 177 cases showed 10 (5.7%) glenoid osteolysis, 51 (28.8%) glenoid radiolucent lines, and 81 (45.8%) calcar resorptions. The follow-up duration (median 40.1 vs. 27.2 months; P <.001), BMI (median 27.5 vs. 30.7; P <.001), and Charlson Comorbidity Index (Q3 0 vs. 1; P =.02) were associated with glenoid osteolysis in bivariate analyses. In multiple logistic regression, surgeon (C vs. A/B) was the only statistically significant predictor of glenoid radiolucent lines [OR 0.27, 95% CI (0.1, 0.8)]. By descending importance, Surgeon C [OR 6.5 (2.0, 20.5)], humeral canal filling ratio [upper vs. lower quartile OR 2.3 (1.3, 4.0)], mediolateral humeral head deviation [upper vs. lower quartile OR 1.9 (1.0, 3.5)], and glenoid osteolysis [OR 13.5 (2.6, 71.6)] significantly predicted greater calcar resorption. Longer follow-up duration marginally statistically significantly predicted lower ASES score [upper vs. lower quartile OR 0.8 (0.6, 1.0)]. Following aTSA with a peripherally enhanced fixation glenoid, pain, range of motion, and patient-reported outcomes significantly improved at a minimum of 2 years with only 5.7% glenoid osteolysis despite heterogeneous preoperative glenoid pathologies. [ABSTRACT FROM AUTHOR]

Both anatomic total shoulder arthroplasty and reverse shoulder arthroplasty have seen increasing utilization over the last 20 years. Malpositioned components present a significant risk for loosening and failure in both total shoulder arthroplasty and reverse shoulder arthroplasty. Preoperative planning with three-dimensional computed tomography imaging and virtual implant templating can help surgeons determine optimal implant position and has been shown to provide superior accuracy over standard 2D computed tomography imaging without virtual templating. Surgeons can use preoperative planning software to evaluate complex cases of glenoid bone loss or deformity requiring bone grafts or augmented implants to determine what surgical correction and techniques are necessary to achieve the goals of implant placement. While the development of preoperative planning software represents a technological advancement, it is important for surgeons to understand that variations can exist between different commercially available software programs in their methods of bony segmentation and landmark placement, which can lead to some differences in the measurement of pathology. This article will review how this technology is utilized to better understand preoperative bony deformity and optimize implant positioning. [ABSTRACT FROM AUTHOR]

Glenoid component loosening remains a common complication following anatomic total shoulder arthroplasty (TSA); however, plain radiographs are unable to accurately detect early implant migration. The purpose of this study was to validate the accuracy of a method of postoperative, three‐dimensional (3D) computed tomography (CT) imaging with metal artifact reduction (MAR) to detect glenoid component migration following anatomic TSA. Tantalum bead markers were inserted into polyethylene glenoid components for implant detection on 3D CT. In‐vitro validation was performed using a glenoid component placed into a scapula sawbone and incrementally translated and rotated, with MAR 3D CT acquired at each test position. Accuracy was evaluated by root mean square error (RMSE). In‐vivo validation was performed on six patients who underwent anatomic TSA, with two postoperative CT scans acquired in each patient and marker‐based radiostereometric analysis (RSA) performed on the same days. Glenoid component migration was calculated relative to a scapular coordinate system for both MAR 3D CT and RSA. Accuracy was evaluated by RMSE and paired Student's t‐tests. The largest RMSE on in‐vitro testing was 0.24 mm in translation and 0.11° in rotation, and on in‐vivo testing was 0.47 mm in translation and 1.04° in rotation. There were no significant differences between MAR 3D CT and RSA measurement methods. MAR 3D CT imaging is capable of quantifying glenoid component migration with a high level of accuracy. MAR 3D CT imaging is advantageous over RSA because it is readily available clinically and can also be used to evaluate the implant‐bone interface. [ABSTRACT FROM AUTHOR]

Background: Posterior glenoid bone loss is commonly associated with primary glenohumeral osteoarthritis. Surgical management of bone loss in anatomic total shoulder arthroplasty (aTSA) remains controversial. We studied the use of a stepped augmented glenoid component for management of Walch B2 and B3 glenoids and compared the radiographic and clinical outcomes at short-term follow-up with those achieved with a non-augmented component of the same design in Walch A1 glenoids.Methods: Ninety-two patients (42 A1, 29 B2, and 21 B3 glenoids) were prospectively followed after aTSA. Sequential 3-dimensional (3D) computed tomography (CT) imaging was performed preoperatively, within 3 months postoperatively with metal artifact reduction (MAR) to define implant position, and at a minimum of 2 years postoperatively with MAR. Scapular 3D registration with implant registration allowed 3D measurement of glenoid implant position, implant shift, and central peg osteolysis (CPO).Results: CPO with or without implant shift occurred in a higher percentage of B3 glenoids treated with the augmented glenoid component (29%) than A1 glenoids treated with a standard component (5%) (p = 0.028). There was no significant difference in the frequency of CPO between B2 glenoids with the augmented component (10%) and A1 glenoids with the standard component. There was no difference in postoperative glenoid component version and inclination between groups. B3 glenoids were associated with more component medialization relative to the premorbid joint line compared with A1 and B2 glenoids (p < 0.001).Conclusions: A stepped augmented glenoid component can restore premorbid glenoid anatomy in patients with asymmetric biconcave glenoid bone loss (Walch B2), with short-term clinical and radiographic results equivalent to those for patients without glenoid bone loss (Walch A1) treated with a non-augmented component. There is a greater risk of CPO in patients with moderate-to-severe B3 glenoid pathology with this stepped augmented glenoid component. Longer follow-up will help define the clinical implications of CPO over time.Level Of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

The purpose of this study was to demonstrate the validity and efficiency of the Outcomes Management and Evaluation (OME) system, a prospectively designed electronic data collection tool, for collecting comprehensive and standardized surgical data in shoulder arthroplasty. Surgical data from the first 100 cases of shoulder arthroplasty that were collected into the OME database were analyzed. Surgeons completed a traditional narrative operative note and also an OME case report using an encrypted smartphone. A blinded reviewer extracted data from the operative notes and implant logs in the electronic medical records (EMR) by manual chart review. OME and EMR data were compared with regard to data counts and agreement between 39 variables related to preoperative pathology, including rotator cuff status and glenoid wear, and surgical procedures. Data counts were assessed using both raw percentages and with McNemar's test (with continuity correction). Agreement of nominal variables was analyzed using Cohen's unweighted kappa (κ) and of ordinal variables using the linearly weighted Cohen's test. Efficiency was assessed by calculating the median time needed to complete OME. Compared to the EMR, the OME database had significantly higher data counts for 56% (22 of 39) of the variables assessed. A high level of proportional and statistical agreement was demonstrated between the data in the 2 datasets. Ten of 39 variables had 100% agreement but could not be statistically compared because both datasets had the same single response under those variables. Among the 29 variables that were compared, 79% (23 of 29) of variables had >80% raw proportional agreement, and 69% (20 of 29) of variables showed at least substantial agreement (κ > 0.6). The median time for completing OME surgery data entry was 92 seconds (IQR 70-126). The prospectively designed, electronic data entry system (OME) is an efficient and valid tool for collecting comprehensive and standardized surgical data on shoulder arthroplasty. Level IV; Case series; Diagnostic study [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to evaluate glenoid component position and radiolucency following anatomic total shoulder arthroplasty (TSA) using sequential 3-dimensional computed tomography (3D CT) analysis.Methods: In a series of 152 patients (42 Walch A1, 16 A2, 7 B1, 49 B2, 29 B3, 3 C1, 3 C2, and 3 D glenoids) undergoing anatomic TSA with a polyethylene glenoid component, sequential 3D CT analysis was performed preoperatively (CT1), early postoperatively (CT2), and at a minimum 2-year follow-up (CT3). Glenoid component shift was defined as a change in component version or inclination of ≥3° from CT2 to CT3. Glenoid component central anchor peg osteolysis (CPO) was assessed at CT3. Factors associated with glenoid component shift and CPO were evaluated.Results: Glenoid component shift occurred from CT2 to CT3 in 78 (51%) of the 152 patients. CPO was seen at CT3 in 19 (13%) of the 152 patients, including 15 (19%) of the 78 with component shift. Walch B2 glenoids with a standard component and glenoids with higher preoperative retroversion were associated with a higher rate of shift, but not of CPO. B3 glenoids with an augmented component and glenoids with greater preoperative joint-line medialization were associated with CPO, but not with shift. More glenoid component joint-line medialization from CT2 to CT3 was associated with higher rates of shift and CPO. A greater absolute change in glenoid component inclination from CT2 to CT3 and a combined absolute glenoid component version and inclination change from CT2 to CT3 were associated with CPO. Neither glenoid component shift nor CPO was associated with worse clinical outcomes.Conclusions: Postoperative 3D CT analysis demonstrated that glenoid component shift commonly occurs following anatomic TSA, with increased inclination the most common direction. Most (81%) of the patients with glenoid component shift did not develop CPO. Longer follow-up is needed to determine the relationships of glenoid component shift and CPO with loosening over time.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Glenoid morphology and rotator cuff muscle quality are important anatomic factors that can impact longevity of the glenoid component following total shoulder arthroplasty (TSA). We hypothesized that rotator cuff muscle fatty infiltration is associated with increased pathologic glenoid bone loss in glenohumeral osteoarthritis (OA).Methods: We retrospectively reviewed 190 preoperative computed tomography (CT) scans of 175 patients (mean age, 66 years; range, 44 to 90 years) who underwent TSA for the treatment of primary glenohumeral OA. Two-dimensional orthogonal CT images were reformatted in the plane of the scapula from 3-dimensional images. Pathologic joint-line medialization was defined with use of the glenoid vault model. Pathologic glenoid version was measured directly. Glenoid morphology was graded according to a modified Walch classification (subtypes A1, A2, B1, B2, B3, C1, and C2). Rotator cuff muscle fatty infiltration was assessed and assigned a Goutallier score on the sagittal CT slice just medial to the spinoglenoid notch for each muscle.Results: There was a significant difference in the Goutallier score for the supraspinatus, infraspinatus, and teres minor muscles between Walch subtypes (p ≤ 0.05). High-grade posterior rotator cuff muscle fatty infiltration was present in 55% (21) of 38 B3 glenoids compared with 8% (3) of 39 A1 glenoids. Increasing joint-line medialization was associated with increasing fatty infiltration of all rotator cuff muscles (p ≤ 0.05). Higher fatty infiltration of the infraspinatus, teres minor, and combined posterior rotator cuff muscles was associated with increasing glenoid retroversion (p ≤ 0.05). After controlling for joint-line medialization and retroversion, B3 glenoids were more likely to have fatty infiltration of the supraspinatus and infraspinatus muscles than B2 glenoids were.Conclusions: High-grade rotator cuff muscle fatty infiltration is associated with B3 glenoids, increased pathologic glenoid retroversion, and increased joint-line medialization. Additional studies are needed to determine the causal relationship between these muscle changes and glenoid wear, whether these muscle changes independently affect clinical and radiographic outcomes in anatomic TSA, and whether fatty infiltration can improve postoperatively with correction of pathologic version and/or joint-line restoration.Clinical Relevance: This study investigates the association between different patterns of glenoid bone loss and rotator cuff muscle fatty infiltration. Both factors have been shown to affect clinical outcome following TSA. [ABSTRACT FROM AUTHOR]

Background Patient satisfaction is increasingly being tied to reimbursement rates, and patient satisfaction is often associated with improving functionality and decreasing disability postoperatively. This study sought to determine if a total shoulder arthroplasty patient's preoperative confidence in his or her ability to attain the level of activity desired would influence postoperative functional scores. Materials and methods Patients undergoing a primary total shoulder arthroplasty at a single institution were asked to complete a preoperative questionnaire with multiple items including baseline symptom severity measures and their confidence in reaching their level of desired functionality postoperatively (scored 0-10). Patients then completed an identical postoperative questionnaire at their follow-up visits. Associations between the patient's confidence in attaining treatment goals and functional outcomes was established by multiple linear regression models that were adjusted for gender, age, body mass index, baseline 12-Item Short Form Health Survey mental component scores, college education, smoking status, baseline functional scores, and length of follow-up. Results Patients had a high level of confidence that their outcome would match their expectations, with an average score of 7.8 (range, 0-10; 28.4% reported a full 10/10 confidence). For every 1-point increase in confidence, patients experienced an average increase in their function score of 2.7 points ( P = .039) and improvement in their pain score of 2.0 ( P = .033) according to the Penn Shoulder Score. There was no significant association with the patient's 12-Item Short Form Health Survey score postoperatively. Conclusions Patients with greater preoperative confidence actually have significantly better postoperative functional outcomes than their less confident peers even with adjustment for other known risk factors. [ABSTRACT FROM AUTHOR]

Background: The magnitude and anatomic consequences of pathologic acquired glenoid retroversion and posterior bone loss that can be surgically corrected with a standard versus an augmented glenoid component have not been studied extensively in a surgical patient population. Materials and methods: Twenty-nine patients with glenohumeral osteoarthritis, acquired posterior bone loss, and increased retroversion were studied by use of a three-dimensional computer surgical simulation. For each case, amount of medialization was measured as the linear distance from the lateral aspect of the glenoid vault model to the center of the articular implant surface. Simulation of implant placement at 0° or 6° was performed with use of a standard glenoid having a uniform thickness and an asymmetric thickness augmented component. Results: An increased amount of medialization was seen with the standard glenoid, 8.3 ± 4.1 mm, compared with 3.8 ± 3.3 mm with use of the augmented glenoid implant (P < .001). When glenoid retroversion was corrected to 0°, pathologic version was shown to have strong and significant relationship to the amount of medialization for both the standard (R 2 = 0.825) and augmented (R 2 = ?0.68) glenoid implant. There was an increased ability to correct greater amounts of pathologic version with less medialization by use of an augmented step glenoid compared with a standard anchor peg glenoid. Discussion: Correction of moderate to severe glenoid retroversion by asymmetric reaming cannot always be done with use of a standard component, and if it is done, it will result in greater medialization of the joint line. Use of an augmented component can allow complete correction of retroversion and minimize the effect of medialization. [Copyright &y& Elsevier]

Background: Glenohumeral osteoarthritis may be associated with severe posterior glenoid bone loss and glenoid retroversion. Treatment with total shoulder arthroplasty and autologous bone graft obtained from the humeral head has been infrequently reported in the peer-reviewed literature. Methods: The clinical and radiographic results of primary total shoulder replacement with an all-polyethylene glenoid component and autologous humeral head graft augmentation performed by a single surgeon in thirteen consecutive patients were evaluated. Results: Twelve of the thirteen patients were followed for a minimum of two years (average, fifty-three months; range, twenty-six to 110 months). The average glenoid retroversion on preoperative computed tomography (CT) scans was 44° (range, 20° to 65°). Based on the Walch classification of pathologic glenoid morphology, nine glenoids were B2 and three were type C. All patients had an intact cuff at the time of surgery. At the time of the last follow up, ten of the twelve patients had graft incorporation without any resorbtion and two had minor bone graft resorption. Broken screws occurred in two of these ten cases. Two patients, both of whom required revision surgery, had failure of fixation and of graft incorporation; one of these failures was due to early postoperative trauma and the other, to Propionibacterium acnes infection. Conclusions: The early and midterm results of total shoulder arthroplasty with autogenous bone graft demonstrated substantial clinical and radiographic improvement in most cases. Level of Evidence: Therapeutic Leve IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Glenoid component malposition for anatomic shoulder replacement may result in complications. The purpose of this study was to define the efficacy of a new surgical method to place the glenoid component. Methods: Thirty-one patients were randomized for glenoid component placement with use of either novel three-dimensional computed tomographic scan planning software combined with patient-specific instrumentation (the glenoid positioning system group), or conventional computed tomographic scan, preoperative planning, and surgical technique, utilizing instruments provided by the implant manufacturer (the standard surgical group). The desired position of the component was determined preoperatively. Postoperatively, a computed tomographic scan was used to define and compare the actual implant location with the preoperative plan. Results: In the standard surgical group, the average preoperative glenoid retroversion was - 11.3° (range, -39° to 17°). In the glenoid positioning system group, the average glenoid retroversion was -14.8° (range, -27° to 7°). When the standard surgical group was compared with the glenoid positioning system group, patient-specific instrumentation technology significantly decreased (p < 0.05) the average deviation of implant position for inclination and medial-lateral offset. Overall, the average deviation in version was 6.9° in the standard surgical group and 4.3° in the glenoid positioning system group. The average deviation in inclination was 11.6° in the standard surgical group and 2.9° in the glenoid positioning system group. The greatest benefit of patient-specific instrumentation was observed in patients with retroversion in excess of 16°; the average deviation was 10° in the standard surgical group and 1.2° in the glenoid positioning system group (p < 0.001). Preoperative planning and patient-specific instrumentation use resulted in a significant improvement in the selection and use of the optimal type of implant and a significant reduction in the frequency of malpositioned glenoid implants. Conclusions: Novel three-dimensional preoperative planning, coupled with patient and implant-specific instrumentation, allows the surgeon to better define the preoperative pathology, select the optimal implant design and location, and then accurately execute the plan at the time of surgery. [ABSTRACT FROM AUTHOR]

Background: Loosening of the glenoid component continues to be the foremost cause of medium and long-term failure of shoulder replacements. The purpose of this study was to evaluate the clinical and radiographic results of a minimally cemented all-polyethylene pegged glenoid component designed for biologic fixation. Methods: Forty-four shoulders in forty-one patients with a mean age of sixty-six years underwent total shoulder arthroplasty with a pegged bone-ingrowth glenoid component. Outcome data included the American Shoulder and Elbow Surgeons questionnaire, the Simple Shoulder Test, and visual analog scales. A detailed radiographic analysis was performed by two board-certified musculoskeletal radiologists who were blinded to clinical and patient-reported outcomes. The radiographs were evaluated with regard to the presence of radiolucent lines at the bone-cement interface, implant seating, and the radiodensity between the flanges of the central peg. Results: The mean duration of clinical follow-up was four years and the mean duration of radiographic follow-up was three years. Twenty shoulders had perfect seating and radiolucency grades, thirty had increased radiodensity between the flanges of the central peg, and three demonstrated osteolysis. Radiodensity about the uncemented central peg at the time of the latest follow-up was positively associated with perfect seating and radiolucency grades on the initial postoperative radiographs (p = 0.03, Fisher exact test). The Simple Shoulder Test score, the American Shoulder and Elbow Surgeons score, and all visual analog scale scores had improved significantly (p < 0.01) at the time of the latest follow-up. Conclusions: Total shoulder arthroplasty with a minimally cemented, all-polyethylene, pegged glenoid implant can yield stable and durable fixation at short to medium-term follow-up (mean, four years). [ABSTRACT FROM AUTHOR]

Background: Two-stage reimplantation for prosthetic joint infection reportedly has the lowest risk for recurrent infection. Most studies to date have evaluated revision surgery for infection using an anatomic prosthetic. As compared with anatomic prostheses, reverse total shoulder arthroplasty is reported to have a higher rate of infection. Questions/purposes: We determined reinfection rates, functional improvement, types and rates of complications, and influence of rotator cuff tissue on function for two-stage reimplantation for prosthetic joint infection treated with reverse shoulder arthroplasty. Patients and Methods: We retrospectively reviewed 27 patients treated with a two-stage reimplantation for prosthetic shoulder infection using a uniform protocol for management of infection; of these, 17 had reverse shoulder arthroplasty at second-stage surgery. Types of organisms cultured, recurrence rates, complications, function, and radiographic followup were reviewed for all patients. Results: One of the 17 patients had recurrence of infection. The mean (± SD) Penn shoulder scores for patients treated with reverse shoulder arthroplasty improved from 24.9 ± 22.3 to 66.4 ± 20.8. The average motion at last followup was 123° ± 33° of forward flexion and 26° ± 8° of external rotation in patients treated with a reverse shoulder arthroplasty. The major complication rate was 35% in reverse shoulder arthroplasty, with five dislocations and one reinfection. There was no difference in final Penn score between patients with and without external rotation weakness. Conclusions: Shoulder function and pain improved in patients treated with a second-stage reimplantation of a reverse prosthesis and the reinfection rate was low. Level of Evidence: Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Correction of pathologic glenoid retroversion improves gleonhumeral mechanics and reduces glenoid component wear after total shoulder arthroplasty. Determining the amount of correction necessary can be difficult because of the wide range of normal glenoid version. We hypothesize that normal glenoid version can be predicted in a pathologic shoulder based on conserved relationships between the anterior glenoid wall, Resch angle, and the internal structures of the glenoid vault. Materials and methods: Three-dimensional (3-D) computer tomography (CT) scan-based measurements of the anterior glenoid wall angle (AGWA), Resch angle (RA), and glenoid version were made in 58 scapulae from the Haeman-Todd Osteological Collection (Museum of Natural History in Cleveland, OH) and 19 paired scapulae from patients with unilateral osteoarthritis. Linear regression equations derived from the AGWA and RA and from a computer-generated vault model were used to predict native (nonpathologic) glenoid version as defined by the 19 nonpathologic scapula. Results: Linear regression equations based on the measured AGWA or RA, as well as the glenoid vault model in the 19 pathologic scapulae, were able to accurately predict native glenoid version in the contralateral nonpathologic shoulder. Discussion: This study demonstrates the ability to take 3-D CT scan-based measurements in a scapula with pathologic glenoid retroversion and predict the native (nonpathologic) glenoid version in the contralateral shoulder by using linear regression equations or a computer generated vault model. Such tools might assist in preoperative planning and intraoperative decision making to allow correction of pathologic glenoid retroversion. [Copyright &y& Elsevier]

Background: Recently, a lesser tuberosity osteotomy has been promoted as an alternative to tenotomy for release of the subscapularis during shoulder arthroplasty. To our knowledge, no direct comparison of the clinical results of the two techniques has been presented. Methods: Thirty-five shoulders in thirty-four consecutive patients with osteoarthritis who had a primary total shoulder arthroplasty, performed with use of a standard subscapularis tenotomy (Group 1) or lesser tuberosity osteotomy (Group 2) to release the subscapularis, were evaluated retrospectively at an average of thirty-three months. Group 1 consisted of fifteen shoulders in fourteen patients (seven in males and eight in females, with an average age of sixty-seven years). Group 2 consisted of twenty shoulders in twenty patients (fourteen males and six females, with an average age of sixty-nine years). Assessment included a physical examination, clinical outcome questionnaires, conventional radiography, ultrasound examination of the subscapularis, and measurement of internal rotation strength. Results: The postoperative total Penn Shoulder Scores improved significantly from the preoperative levels in both groups (mean and standard deviation, 29 ± 15 points to 81 ± 20 points [p < 0.00001] in Group 1 and 29 ± 16 points to 92 ± 11 points [p < 0.00001] in Group 2). However, the postoperative mean total Penn Shoulder Score was higher in Group 2 (92 ± 11 points) than in Group 1 (81 ± 20 points) (p = 0.04). At one year, an abnormal subscapularis on ultrasound was associated with a lower mean Penn Shoulder Score in Group 1 (73 ± 19 points compared with 92 ± 3 points; p = 0.01). However, at a minimum two-year follow-up, this difference was not significant (mean, 74 ± 24 points and 86 ± 15 points, respectively; p = 0.25). There were more abnormal subscapularis tendons in Group 1 (six attenuated tendons and one full-thickness tear) than in Group 2 (two attenuated tendons). Internal rotation strength did not differ between the groups when controlled for sex (mean, 117 ± 8 N and 127 ± 21 N for males in Group 1 and Group 2, respectively [p = 0.22] and 77 ± 27 N and 101 ± 26 N, respectively, for females [p = 0.1]). Conclusions: Both techniques resulted in improved clinical outcome scores. The lesser tuberosity osteotomy resulted in higher clinical outcome scores, a lower rate of subscapularis tendon tears, and universal healing of the osteotomy. This technique offers a means by which the rate of postoperative subscapularis tears may be reduced in patients undergoing total shoulder arthroplasty. Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

The article discusses the study in which eccentric loading and glenoid component retroversion shows as a significant mechanism that leads to glenoid component loosening. The study uses 66 shoulders as subjects that underwent total shoulder displacement with an all-polyethylene press-fit pegged glenoid component that was designed for osseous ingrowth for osteoarthritis treatment. Results shows that 30 percent of the 66 shoulders had osteolysis around the center peg.