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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]

Cases: Two patients presented to different surgeons complaining of persistent shoulder pain after reverse total shoulder arthroplasty. Workups for fracture, instability, and periprosthetic infection were negative. Advanced imaging, nerve conduction studies, and diagnostic injections localized symptoms to the suprascapular nerve. Revision arthroplasty with removal of the offending screws improved pain in both patients. Conclusion: Suprascapular nerve irritation because of the malposition of baseplate screws in reverse total shoulder arthroplasty can be a source of postoperative pain. Removal of the offending screw without formal nerve exploration may result in symptomatic improvement. [ABSTRACT FROM AUTHOR]

Background: Use of 3-dimensional (3D) computed tomography (CT) preoperative planning and patient-specific instrumentation has been demonstrated to improve the accuracy of glenoid implant placement in total shoulder arthroplasty (TSA). The purpose of this study was to compare the accuracy of glenoid implant placement in primary TSA among different types of instrumentation used with the 3D CT preoperative planning.Methods: One hundred and seventy-three patients with end-stage glenohumeral arthritis were enrolled in 3 prospective studies evaluating patient-specific instrumentation and 3D preoperative planning. All patients underwent preoperative 3D CT planning to determine optimal glenoid component and guide pin position based on surgeon preference. Patients were placed into 1 of 5 instrument groups used for intraoperative guide pin placement: (1) standard instrumentation, (2) standard instrumentation combined with use of a 3D glenoid bone model containing the guide pin, (3) use of the 3D glenoid bone model combined with single-use patient-specific instrumentation, (4) use of the 3D glenoid bone model combined with reusable patient-specific instrumentation, and (5) use of reusable patient-specific instrumentation with an adjustable, reusable base. Postoperatively, all patients underwent 3D CT to compare actual versus planned glenoid component position. Deviation from the plan (in terms of orientation and location) was compared across groups on the basis of absolute differences and outlier analysis. Univariable and multivariable comparisons were performed. As the initial analyses showed no significant differences in preoperative factors or in deviation from the plan between Groups 1 and 2 or between Groups 4 and 5 across studies, the final analysis was across 3 major treatment groups: standard instrumentation (Groups 1 and 2), single-use patient-specific instrumentation (Group 3), and reusable patient-specific instrumentation (Groups 4 and 5).Results: In nearly all comparisons, there were no significant differences in the deviation from the plan (absolute differences or outlier frequency) for glenoid implant orientation or location across the 3 major treatment groups.Conclusions: This study did not demonstrate that any type of patient-specific instrumentation resulted in consistent differences in accuracy of glenoid implant placement in primary TSA with 3D CT preoperative planning. Surgeons have multiple patient-specific instrumentation options available for improving accuracy of glenoid implant placement when compared with 2D imaging without patient-specific instrumentation.Level Of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Purpose: Clinical shoulder science lacks a benchmark against which the early clinical value of new glenoid components can be compared; such a benchmark may be derived from a multicenter study of patients receiving an established, internationally used design of glenoid component.Methods: We obtained data from 11 centers on 1270 patients having total shoulder arthroplasty using an all-polyethylene component with a fluted central peg. We analyzed individual patient outcomes at 1 and 2 years after surgery. We compared the improvement for each patient to the minimal clinically important difference (MCID) and calculated each patient's improvement as a percent of maximal possible improvement (MPI).Results: The preoperative scores improved from SST 3 ± 2, ASES 37 ± 15, Constant score 36 ± 16, and Penn score 30 ± 19 to SST 10 ± 2, ASES 90 ± 12, Constant 76 ± 13, and Penn 80 ± 24 (p < 0.001 for each). A high percentage of patients improved by more than the MCID (SST 96%, ASES 98%, Constant 94%, Penn 93%) and obtained improvement of at least 30% of the MPI (SST 95%, ASES 98%, Constant 91%, Penn 87%). The clinical outcomes realized with this glenoid design were not worse for the 41% of shoulders with preoperative type B glenoids or for the 30% of shoulders with more than 15 degrees of glenoid retroversion.Conclusions: Individual patients from 11 international practices having total shoulder arthroplasty using a basic glenoid component design obtained highly significant clinical outcomes, providing a benchmark against which the early outcomes of new designs can be compared to determine whether they provide increased clinical value. [ABSTRACT FROM AUTHOR]

Background: Osteoarthritis of the glenohumeral joint has typical patterns of deformity as described by Walch et al. However, more severe glenoid pathology may be difficult to classify. The purpose of this study was to use 3-dimensional computed tomography (3-D CT) imaging analysis to define common pathologic subtypes that can be differentiated from the current Walch classification.Methods: We performed quantitative measurements of premorbid and pathologic anatomy using preoperative 3-D CT scans from 155 cases of advanced glenohumeral osteoarthritis that underwent anatomic or reverse total shoulder arthroplasty. We defined premorbid glenohumeral anatomy on the basis of previously validated methods using 3-D glenoid vault and humeral best-fit circle models including the premorbid glenoid version, joint-line medialization, and humeral-glenoid alignment (HGA). We determined the anatomic features that differentiate new glenoid morphologic subtypes from the existing Walch classification both qualitatively and quantitatively.Results: We defined 2 new glenoid subtypes (B3 and C2) for which the glenoid pathology and humeral alignment were not defined in the original Walch classification. The B3 glenoid has high pathologic retroversion, normal premorbid version, and acquired central and posterior bone loss that, on average, is greater than that of the B2 glenoid. The C2 glenoid is dysplastic with high pathologic retroversion, high premorbid version, and acquired posterior bone loss, giving it the appearance of a biconcave glenoid with posterior translation of the humeral head. This C2 glenoid can be confused with the B2 glenoid.Conclusions: The B3 and C2 patterns have qualitative and quantitative differences that may result in different clinical outcomes than classic B2 or C types; therefore, our findings suggest that these new subtypes should be included in a new or modified classification system. [ABSTRACT FROM AUTHOR]

Background: Preoperative quantitative assessment of glenoid bone loss, selection of the glenoid component, and definition of its desired location can be challenging. Placement of the glenoid component in the desired location at the time of surgery is difficult, especially with severe glenoid pathological conditions. Methods: Forty-six patients were randomly assigned to three-dimensional computed tomographic preoperative templating with either standard instrumentation or with patient-specific instrumentation and were compared with a nonrandomized group of seventeen patients with two-dimensional imaging and standard instrumentation used as historical controls. All patients had postoperative three-dimensional computed tomographic metal artifact reduction imaging to measure and to compare implant position with the preoperative plan. Results: Using three-dimensional imaging and templating with or without patient-specific instrumentation, there was a significant improvement achieving the desired implant position within 5° of inclination or 10° of version when compared with two-dimensional imaging and standard instrumentation. Conclusion: Three-dimensional assessment of glenoid anatomy and implant templating and the use of these images at the time of surgery improve the surgeon's ability to place the glenoid implant in the desired location. [ABSTRACT FROM AUTHOR]

Background: We hypothesized that a novel surgical method, in which three-dimensional (3-D) preoperative planning software is generated to create a patient-specific surgical model that is used with a reusable and adjustable tool, could substantially improve the positioning accuracy of the glenoid guide pin used in total shoulder arthroplasty. We tested this method using bone models from patients with shoulder pathology and compared the results with those achieved using surgical methods representing the current standard of care. Methods: Three surgeons with a variety of surgical experience placed a guide pin in nine bone models from patients with a variety of glenohumeral arthritis severity using (1) standard instrumentation alone, (2) standard instrumentation and 3-D preoperative surgical planning, and (3) the reusable transfer device and 3-D preoperative surgical planning. A postoperative 3-D computed tomography scan of the bone model was made and registered to the preoperative plan, and the differences between the actual and planned pin locations and trajectories were measured. Results: Use of the standard instrumentation combined with 3-D preoperative planning software improved guide pin positioning compared with standard instrumentation and preoperative planning using 2-D imaging. The accuracy of pin positioning increased by 4.5° ± 1.0° in version (p < 0.001), 3.3° ± 1.3° in inclination (p = 0.013), and 0.4 ± 0.2 mm in location (p = 0.042). Use of the adjustable and reusable device and the 3-D software improved pin positioning by a further 3.7° ± 0.9° in version, 8.1° ± 1.2° in inclination, and 1.2 ± 0.2 mm in location (p < 0.001 for all) compared with standard instrumentation and the 3-D software; the improvement compared with use of standard instrumentation with 2-D imaging was 8.2° ± 0.9° in version, 11.4° ± 1.2° in inclination, and 1.7 ± 0.2 mm in location (p < 0.001 for all). Conclusions: Use of 3-D preoperative planning and use of the patient-specific bone model and transfer device both improved the positioning accuracy of the pin used to guide placement of the glenoid component in total shoulder arthroplasty. Clinical Relevance: Proper positioning of the glenoid component would be expected to improve the function and durability of the joint replacement. [ABSTRACT FROM AUTHOR]

Background: Failure of tendon healing after a rotator cuff repair is demonstrated by magnetic resonance imaging (MRI) as a fluid-filled defect within the tendon. The frequency of, and factors associated with, failure of the tendon repair to heal have been the focus of many clinical studies. The timing of when these defects occur has not been previously studied in a large prospectively defined patient population, to our knowledge. It was our hypothesis that the majority of failures occur within twelve weeks after surgery.Methods: One hundred and thirteen patients were enrolled in a multi-institutional prospective study. All patients had a standardized arthroscopic repair of a full-thickness tear of 1 to 4 cm as well as sequential MRI studies at six intervals from two weeks to fifty-two weeks. MRIs were reviewed at the time of imaging by the treating surgeon. Standardized patient-oriented clinical data were collected, physical examination was performed, and strength measurements were made preoperatively and postoperatively.Results: The treating surgeons diagnosed a recurrent tear with MRI in nineteen (17%) of the 113 patients within one year after surgery. The mean time to the retear was 19.2 weeks. There was a linear increase in retears over the first twenty-six weeks after surgery, and one additional tear was diagnosed between twenty-six and fifty-two weeks after repair.Conclusions: Retears primarily occur between six and twenty-six weeks after arthroscopic rotator cuff repair, and few additional tears occur thereafter. A substantial number of retears occur between twelve and twenty-six weeks after repair.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

BACKGROUND: While there have been numerous reports concerning glenohumeral arthrodesis for many indications, there is little available information specific to glenohumeral arthrodesis performed after failed prosthetic shoulder arthroplasty. The purpose of this study was to report the outcomes of glenohumeral arthrodesis in the setting of severe glenohumeral bone loss and deltoid muscle and rotator cuff insufficiency following failed prosthetic shoulder arthroplasty. METHODS: We retrospectively reviewed clinical and radiographic data on seven consecutive patients treated with glenohumeral arthrodesis following a failed prosthetic shoulder arthroplasty between 1997 and 2004. The average duration of clinical follow-up was four years (range, 1.5 to eight years). RESULTS: Five of the seven patients demonstrated an intact fusion at the time of the latest follow-up. Four of the seven patients had undergone additional bone-grafting procedures in an effort to obtain union. Two of these patients ultimately had a persistent nonunion despite the additional procedures for bone-grafting and revision of the fixation hardware. Overall, the average subjective clinical outcome score (Penn Shoulder Score) improved significantly from 17 points (range, 8 to 33 points) to 58 points (range, 31 to 77 points) (p = 0.008). The most common complication was delayed union requiring additional procedures for bone-grafting and revision of the fixation hardware. CONCLUSIONS: Treatment of a failed prosthetic shoulder arthroplasty with concomitant extensive glenohumeral bone loss and soft-tissue deficiencies is extremely challenging. The results of this study suggest that glenohumeral arthrodesis can yield satisfactory clinical outcomes. However, both the patient and the surgeon should be aware of the complex nature of this surgery and the frequent need for additional surgical procedures to obtain fusion. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

La artrodesis del hombro es una opción de salvamento final para las articulaciones dolorosas en las que no pueda llevarse a cabo una cirugía reconstructiva o en las que esta haya fracasado. La fusión del hombro está indicada en las roturas masivas del manguito rotador irreversibles e imposibles de reconstruir, en las denervaciones del músculo deltoides y en las desinserciones del origen de dicho músculo. En raras ocasiones la artrodesis se realiza para estabilizar la articulación glenohumeral tras múltiples intentos fallidos de reconstrucción del hombro. La artrodesis tras artroplastias protésicas fallidas y tras resecciones tumorales supone un reto aún mayor, debido a la pérdida ósea asociada en el lado humeral y/o glenoideo de la articulación. La artrodesis primaria requiere una fijación interna con placa rígida y una fusión tanto extra como intraarticular. Dependiendo de la cantidad de hueso que exista y de la calidad del mismo, puede hacer falta utilizar una ortesis durante 8-10 semanas, un injerto óseo autólogo o un aloinjerto, o un injerto de peroné vascularizado para reconstruir las deficiencias óseas. Además, se necesita una inmovilización prolongada mediante espica de yeso. La posición óptima para una artrodesis de hombro es de 20° de flexión, 20° de abducción y 40° de rotación interna, con modificaciones según el tamaño corporal y otros factores específicos de cada paciente. La fusión ósea aasi siempre se logra, consiguiéndose una marcada disminución del dolor y una mejoría de la función. En el postoperatorio, los pacientes deben elevar el brazo casi a la altura del hombro y llegar a la parte más alta de la cabeza, a la boca, al bolsillo trasero homolateral y a la ingle. Entre las complicaciones de la artrodesis destacan la pseudoartrosis, la posición anómala del hombro, el dolor relacionado con el material de osteosíntesis y las fracturas periarticulares. [ABSTRACT FROM AUTHOR]

Background: Evidence to justify the use of porcine small intestine submucosa to augment repairs of large and massive rotator cuff tears is based on favorable results found in studies of Achilles tendon and infraspinatus tendon repairs in canines. The purpose of this study was to determine the effectiveness of a small intestine submucosal patch to augment the repair of chronic two-tendon rotator cuff tears in humans. Methods: Thirty shoulders with a chronic two-tendon rotator cuff tear that was completely repairable with open surgery were randomized to be treated with either augmentation with porcine small intestine mucosa or no augmentation. All patients completed a PENN shoulder-score questionnaire preoperatively and at the time of the latest follow-up (at an average of fourteen months). Magnetic resonance imaging showed that nine shoulders had a large tear and twenty-one had a massive tear. All patients underwent a magnetic resonance imaging scan with intra-articular gadolinium one year after the repair to assess the status of the rotator cuff. Results: The rotator cuff healed in four of the fifteen shoulders in the augmentation group compared with nine of the fifteen in the control group (p = 0.11). The median postoperative PENN total score was 83 points in the augmentation group compared with 91 points in the control group (p = 0.07). Healing of the defects in both groups demonstrated a strong correlation with the patients' clinical scores. The median postoperative PENN total score was 96 points in the group with a healed repair and 81 points in the group with a failed repair (p = 0.007). The percentage change between the preoperative and postoperative patient satisfaction scores was 400% in the group with a healed repair, and 50% in the group with a failed repair (p = 0.04). Conclusions: Augmentation of the surgical repair of large and massive chronic rotator cuff tears with porcine small intestine submucosa did not improve the rate of tendon-healing or the clinical outcome scores. On the basis of these data, we do not recommend using porcine small intestine submucosa to augment repairs of massive chronic rotator cuff tears done with the surgical and postoperative procedures described in this study. Level of Evidence: Therapeutic Level II. See Instructions to Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

La artrodesis del hombro es una opción de salvamento final para las articulaciones dolorosas en las que no pueda llevarse a cabo una cirugía reconstructiva o en las que esta haya fracasado. La fusión del hombro está indicada en las roturas masivas del manguito rotador irreversibles e imposibles de reconstruir, en las denervaciones del músculo deltoides y en las desinserciones del origen de dicho músculo. En raras ocasiones la artrodesis se realiza para estabilizar la articulación glenohumeral tras múltiples intentos fallidos de reconstrucción del hombro. La artrodesis tras artroplastias protésicas fallidas y tras resecciones tumorales supone un reto aún mayor, debido a la pérdida ósea asociada en el lado humeral y/o glenoideo de la articulación. La artrodesis primaria requiere una fijación interna con placa rígida y una fusión tanto extra como intraarticular. Dependiendo de la cantidad de hueso que exista y de la calidad del mismo, puede hacer falta utilizar una ortesis durante 8-10 semanas, un injerto óseo autólogo o un aloinjerto, o un injerto de peroné vascularizado para reconstruir las deficiencias óseas. Además, se necesita una inmovilización prolongada mediante espica de yeso. La posición óptima para una artrodesis de hombro es de 20° de flexión, 20° de abducción y 40° de rotación interna, con modificaciones según el tamaño corporal y otros factores específicos de cada paciente. La fusión ósea aasi siempre se logra, consiguiéndose una marcada disminución del dolor y una mejoría de la función. En el postoperatorio, los pacientes deben elevar el brazo casi a la altura del hombro y llegar a la parte más alta de la cabeza, a la boca, al bolsillo trasero homolateral y a la ingle. Entre las complicaciones de la artrodesis destacan la pseudoartrosis, la posición anómala del hombro, el dolor relacionado con el material de osteosíntesis y las fracturas periarticulares. [ABSTRACT FROM AUTHOR]

Background: This prospective multi-institutional study was designed to define the accuracy of ultrasonography, when performed in an orthopaedic surgeon's office, for the diagnosis of rotator cuff tears. Methods: An anatomic diagnosis and a treatment plan were made on the basis of office-based shoulder ultrasonography, physical examination, and radiographs for ninety-eight patients (ninety-nine shoulders) with a clinical diagnosis of a rotator-cuff-related problem. The results of the ultrasonographic studies were then compared with the results of magnetic resonance imaging and the operative findings. Results: Office-based ultrasonography led to the correct diagnosis for thirty-seven (88%) of forty-two shoulders with a full-thickness rotator cuff tear or both full and partial-thickness tears, twenty-six (70%) of thirty-seven shoulders with a partial-thickness rotator cuff tear only, and sixteen (80%) of twenty shoulders with normal tendons. In no case was the surgical approach (open or arthroscopic) that had been planned on the basis of the ultrasonography altered by the operative findings, but the operative finding of a full-thickness tear resulted in an arthroscopic cuff repair in four shoulders. Magnetic resonance imaging led to the correct diagnosis for forty (95%) of forty-two shoulders with a full-thickness rotator cuff tear or both full and partial-thickness rotator cuff tears, twenty-seven (73%) of thirty-seven shoulders with only a partial-thickness tear, and fifteen (75%) of twenty shoulders with normal tendons. There were no significant differences between magnetic resonance imaging and ultrasonography with regard to the correct identification of a full-thickness tear or its size. The sensitivity of ultrasonography for detecting tear size in the anteriorposterior dimension was 86% (95% confidence interval, 71% to 95%), and that of magnetic resonance imaging was 93% (95% confidence interval, 81% to 99%) (p = 0.26). The sensitivity of ultrasonography for detecting tear size in the medial-lateral dimension was 83% (95% confidence interval, 69% to 93%), and that of magnetic resonance imaging was 88% (95% confidence interval, 74% to 96%) (p = 0.41). Conclusions: A well-trained office staff and an experienced orthopaedic surgeon can effectively utilize ultrasonography, in conjunction with clinical examination and a review of shoulder radiographs, to accurately diagnose the extent of rotator cuff tears in patients suspected of having such tears. Errors in diagnosis made on the basis of ultrasonography most often consist of an inability to distinguish between partial and full-thickness tears that are approximately 1 cm in size. In this study, such errors did not significantly affect the planned surgical approach. Level of Evidence: Diagnostic Level I. See Instructions to Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

The article discusses nonprosthetic management of proximal humeral fractures. Indications for hemiarthroplasty; Isolated fracture of tuberosity; Approach towards surgical neck fractures; forces; Common patterns of three-part proximal humeral fractures and muscle forces that act on the fracture fragments.

Background: The technique of shoulder arthroplasty requires a method for securely and durably fixing the humeral component in the medullary canal of the proximal part of the humerus. As an alternative to fixation by cementing or tissue ingrowth, we explored the effectiveness of using a prosthesis with a metaphyseal taper from the anatomic neck to the diaphysis. This component is designed to obtain press-fit fixation in the cancellous bone of the metaphysis rather than in the cortical bone of the diaphysis. We tested the hypothesis that this press-fit humeral stem, designed to respect the taper of the proximal part of the humeral canal, would be associated with a low rate of loosening in patients managed with primary shoulder arthroplasty for osteoarthritis. Methods: A prospective study was conducted to evaluate the prevalence of radiolucent lines around press-fit humeral prostheses. One hundred and thirty-one patients with glenohumeral osteoarthritis were followed for a minimum of two years. A zonal method of evaluating radiolucent lines was established. Shift in position and subsidence were judged qualitatively. Results: No component showed subsidence or a shift in position. Fifty shoulders (39%) had no radiolucency. Two shoulders had radiolucency around the proximal part of the prosthesis, and seventy-five had radiolucency at the distal tip. Eleven radiolucencies were≥1 mm in width. A neutral stem orientation was significantly less likely to be associated with radiolucency (p = 0.026). The prevalence of radiolucent lines did not differ between patients managed with hemiarthro-plasty and those managed with total shoulder arthroplasty, and it did not increase with longer periods of follow-up. Results: In patients managed with shoulder arthroplasty, the fixation of a press-fit humeral component that has a tapered metaphyseal segment is comparable with that reported for cemented components and superior to that reported for press-fit cylindrical components.... [ABSTRACT FROM AUTHOR]

Background: The results of shoulder arthroplasty for osteoarthritis have been reported to be excellent or good for the majority of patients, but the value of using a glenoid component and the anatomic factors that affect outcome are still debated. The purpose of this study was to evaluate the influence of an operatively confirmed full-thickness tear of the rotator cuff, the severity of preoperative erosion of glenoid bone, preoperative radiographic evidence of subluxation of the humeral head, and the severity of preoperative loss of the passive range of motion on the outcome of total shoulder arthroplasty and hemiarthroplasty. Methods: In a multicenter clinical outcome study, we evaluated 128 shoulders in 118 patients with primary osteoarthritis who had been followed for a mean of forty-six months (range, twenty-four to eighty-seven months). Results: Patients with <10° of passive external rotation preoperatively had significantly less improvement in external rotation after hemiarthroplasty (p = 0.006). Thirteen (10%) of the 128 shoulders had a repairable full-thickness tear of the supraspinatus tendon, but these tears did not affect the overall American Shoulder and Elbow Surgeons score, the decrease in pain, or patient satisfaction. Severe or moderate eccentric glenoid erosion was seen in twenty-nine (23%) of the 128 shoulders, and total shoulder arthroplasty resulted in significantly better passive total elevation and active external rotation as well as a trend toward significantly better active forward flexion than did hemiarthroplasty in these shoulders. The humeral head was subluxated posteriorly in twenty-three shoulders (18%), and when they were compared with the other shoulders in the study, these shoulders were found to have lower final American Shoulder and Elbow Surgeons scores, more pain, and decreased active external rotation following either total shoulder arthroplasty or hemiarthroplasty. Conclusions: On the basis of our data, we recommend... [ABSTRACT FROM AUTHOR]

With the current development of the 5G infrastructure, there presents a unique opportunity for the deployment of battery-less mmWave reflect-array-based sensors. These fully-passive devices benefit from having a larger detectability than alternative battery-less solutions to create self-monitoring megastructures. The presented 'smart' skin sensor uses a Van-Atta array design enabling ubiquitous local strain monitoring for the structural health monitoring of composite materials featuring wide interrogation angles. Proof-of-concept prototypes of these 'smart' skin millimeter-wave identification tags, that can be mounted on or embedded within common materials used in wind turbine blades, present a highly-detectable radar cross-section of − 33.75 dBsm and − 35.00 dBsm for mounted and embedded sensors respectively. Both sensors display a minimum resolution of 202 μ -strain even at 40 ∘ off-axis enabling interrogation of the fully-passive sensor at oblique angles of incidence. When interrogated from a proof-of-concept reader, the fully-passive, sticker-like mmID enables local strain monitoring of both carbon fiber and glass fiber composite materials. The sensors display a repeatable and recoverable response over 0–3000 μ -strain and a sensitivity of 7.55 kHz/ μ -strain and 7.92 kHz/ μ -strain for mounted and embedded sensors, respectively. Thus, the presented 5G-enabled battery-less sensor presents massive potential for the development of ubiquitous Digital Twinning of composite materials in future smart cities architectures. [ABSTRACT FROM AUTHOR]

Purpose: The role of reverse total shoulder arthroplasty (RTSA) for three and four-part proximal humerus fractures is evolving. However, there does not appear to be a clear consensus amongst surgeons. The purpose of this study is to further define the standard of care, assessing surgeon preference and treatment considerations for management of such fractures.Methods: Orthopaedic surgeons were surveyed on their training, practice setting, and experience regarding management of four-part proximal humerus fractures. The survey also presented five representative cases to assess treatment preferences.Results: Two hundred five surgeons responded to the survey with fellowship training in shoulder and elbow surgery (114), orthopaedic trauma (35) or sports medicine/other training (56). There was no difference between respondents with years in practice and confidence with performing RTSA, however, surgeons in the academic setting were more confident in performing the surgery. Surgeons preferred RTSA for management of four-part fractures in patients over age 65. However, they also trended to favour hemiarthroplasty with higher co-morbidities. Physicians with more than 11 years of experience were more likely to choose hemiarthroplasty for older and high comorbidity patients. RTSA was not the preferred treatment method for younger, active patients. Patient age and fracture pattern had a greater influence on the surgeon's decision.Conclusions: There is a consensus in our study population that RTSA is the preferred treatment for four-part proximal humerus fractures for elderly patients with patient age and fracture pattern being the most important factors in making management decisions.Level Of Evidence: Level III - Case controlled study. [ABSTRACT FROM AUTHOR]

Presents a letter by the author apologizing for any apparent duplication of his article exploring the effect of humeral component anteversion on shoulder stability with glenoid component retroversion.

Background: Most orthopaedic journals currently require reporting outcomes of surgical interventions for at least 2 postoperative years, but there have been no rigorous studies on this matter. Various patient-reported outcome (PRO) measures (PROMs) have been used to assess the status of the shoulder after rotator cuff repair (RCR). Hypothesis: We hypothesized that the mean shoulder-specific PROMs at 1 year improve substantially over baseline but that there is no clinically meaningful difference between the mean 1- and 2-year PROMs after RCR. Study Design: Meta-analysis; Level of evidence, 2. Methods: We conducted a systematic review of published randomized controlled trials (RCTs) and prospective cohort studies (level of evidence 1 and 2) reporting the shoulder-specific American Shoulder and Elbow Surgeons (ASES), the Constant, or the Western Ontario Rotator Cuff (WORC) Index scores at baseline, 1 year, and 2 years after RCR. The methodologic quality of studies was assessed. Also, the random effects meta-analyses of changes in PROMs for each of the first and second postoperative years were conducted. Results: Fifteen studies (n = 11 RCTs; n = 4 cohort studies) with a total of 1371 patients were included. Studies were highly heterogeneous, but no visual evidence of major publication bias was observed. The weighted means of the baseline PROMs were 46.2 points for the ASES score, 46.4 points for the Constant score, and 38.8 points for the WORC Index. The first-year summary increments were 41.1 (95% CI, 36.0-46.2) points for the ASES score, 34.2 (95% CI, 28.8-39.6) points for the Constant score, and 42.9 (95% CI, 37.3-48.4) points for the WORC Index. In contrast, the second-year summary increments were 2.3 (95% CI, 1-3.6) points for the ASES score, 3.2 (95% CI, 1.9-4.4) points for the Constant score, and 2 (95% CI, -0.1 to 4) points for the WORC Index. Conclusion: All PROMs improved considerably from baseline to 1 year, but only very small gains that were below the minimal clinically important differences were observed between 1 year and 2 years after RCR. This study did not find any evidence for requiring a minimum of 2 years of follow-up for publication of PROs after RCR. Our results suggest that focusing on 1-year PROMs after RCR would foster more timely reporting, better control of selection bias, and better allocation of research resources. [ABSTRACT FROM AUTHOR]

Each year, 250,000 rotator cuff repairs are performed in the United States at a cost of $3 billion. Despite advancements in repair techniques and rehabilitation, 20%-70% of repairs continue to undergo structural failure; however, there is a poor correlation between clinical and structural outcomes, both before and after surgery. "Failure in continuity", or retraction of the repair site without a structural defect, is likely a common phenomenon after rotator cuff repair, and this retraction of the myotendinous unit and interposing scar tissue may be one explanation for the discordance between clinical and structural outcomes. Scaffolds, both synthetic and biologic, have shown promise in both augmentation of repairs and interposition of irreparable tears, but most studies are small retrospective case series without control groups. Future efforts will need to determine the ideal indications for use, methods of application, and comparative effectiveness between the devices. Platelet-rich plasma also has potential to improve rotator cuff healing, but current limitations include the significant variation in preparation methods, biologic makeup, and application methods. Future work may help us understand whether application of platelet-rich plasma and its growth factors should be done at the time of surgery or later during a more advanced stage of healing. Regardless of the device or technique, mechanical and/or biologic augmentation of rotator cuff repairs requires the surgeon to be technically proficient in its use and aware of its associated increased operative time and cost. In order to justify the use of these technologies and their associated incremental cost, we must demonstrate efficacy in improving both clinical and structural outcomes. [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]

The article provides an overview of generational issues addressed at the American Orthopedic Association (AOA) symposium. The factors to be considered when managing a new hire are outlined. The generational issues highlighted at the AOA symposium include the terms "Silent Generation," "Baby Boomers" and "Generation X."

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]

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]

Background: Replicating the normal anatomy of the shoulder is an important principle in the design of prosthetic devices and the development of surgical techniques. In this study, we used a three-dimensional surgical simulation to compare the abilities of an adjustable neck-shaft angle prosthesis and a fixed neck-shaft angle prosthesis to restore the normal geometry of the proximal part of the humerus. Methods: A total of 2058 cadaveric humeri were measured to define the normal distribution of neck-shaft angles. Thirty-six humeri were selected to represent a wide variation in neck-shaft angles, and computed tomographic scans with three-dimensional reconstruction were made of these specimens. With use of a three-dimensional computer surgical simulator, the humeral head was then cut at the anatomic neck to replicate a normal neck-shaft angle and version or it was cut at a fixed 135° angle with anatomic version. The anatomy of an adjustable-angle prosthesis and that of a fixed- angle prosthesis of the same design were both compared with native humeral anatomy in three dimensions. Results: The average neck-shaft angle of the 2058 humeri was 134. 7° (range, 115° to 148°), and the angle was between 130° and 140° in 77.84% of the humeri. In the setting of a high varus or valgus neck-shaft angle, an adjustable-angle prosthesis allowed optimal reconstruction when the humeral head was cut along the anatomic neck and allowed a standard and consistent surgical technique with use of anatomic landmarks. A fixed-angle prosthesis also replicated the anatomic center of rotation, tuberosity-head height, and head volume if the surgical procedure was altered to adapt to variations in humeral anatomy. There was no significant difference in anatomic parameters between the two types of prostheses, except that in all cases the head thickness was decreased when a fixed-135°-angle prosthesis was used in a humerus with a high valgus or high varus neck-shaft angle, resulting in a smaller articular arc and percent articular surface match. Conclusions: This study demonstrates the ability of both an adjustable and a fixed neck-shaft angle prosthesis to replicate humeral anatomy. However, the fixed-angle device requires specific modifications of the surgical technique to accommodate the specific prosthetic design and optimize the surgeon's ability to replicate normal anatomic parameters in humeri with an extreme neck-shaft angle. Clinical Relevance: This information can be used to optimize humeral component placement intraoperatively. [ABSTRACT FROM AUTHOR]

Muchos ensayos clínicos han valorado la terapia de ondas de choque extracorpóreas en las tendinosis crónicas del supraespinoso, en las epicondilitis y en las fascitis plantares. Aunque esta terapia parece haber sido eficaz en algunos estudios, en otros no ha sido más eficaz que los placebos. Las múltiples variables asociadas a la terapia de ondas de choque extracorpóreas (frecuencia, momento de su liberación y la utilización o no de anestesia) hacen difíciles las comparaciones entre diferentes estudios clínicos. Cuando el tratamiento conservador de las tendinosis calcificantes del supraespinoso y de las fascitis plantares fracase, las ondas de choque extracorpóreas podrían resolver con éxito estos problemas. Sin embargo, en las epicondilitis los resultados han sido contradictorios, y en las tendinosis no calcificantes del supraespinoso la terapia con ondas de choque extracorpóreas no ha sido eficaz. La terapia con ondas de choque extracorpóreas es más eficaz en pacientes colaboradores, puesto que en ellos resulta más fácil orientar las ondas de choque a las áreas más dolorosas. La orientación de las ondas puede guiarse también por la anatomía o por las imágenes, para de esta forma dirigir las ondas a una determinada estructura anatómica como punto de referencia. [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: The results of shoulder arthroplasty for osteoarthritis have been reported to be excellent or good for the majority of patients, but the value of using a glenoid component and the anatomic factors that affect outcome are still debated. The purpose of this study was to evaluate the influence of an operatively confirmed full-thickness tear of the rotator cuff, the severity of preoperative erosion of glenoid bone, preoperative radiographic evidence of subluxation of the humeral head, and the severity of preoperative loss of the passive range of motion on the outcome of total shoulder arthroplasty and hemiarthroplasty.Methods: In a multicenter clinical outcome study, we evaluated 128 shoulders in 118 patients with primary osteoarthritis who had been followed for a mean of forty-six months (range, twenty-four to eighty-seven months).Results: Patients with <10 degrees of passive external rotation preoperatively had significantly less improvement in external rotation after hemiarthroplasty (p = 0.006). Thirteen (10%) of the 128 shoulders had a repairable full-thickness tear of the supraspinatus tendon, but these tears did not affect the overall American Shoulder and Elbow Surgeons score, the decrease in pain, or patient satisfaction. Severe or moderate eccentric glenoid erosion was seen in twenty-nine (23%) of the 128 shoulders, and total shoulder arthroplasty resulted in significantly better passive total elevation and active external rotation as well as a trend toward significantly better active forward flexion than did hemiarthroplasty in these shoulders. The humeral head was subluxated posteriorly in twenty-three shoulders (18%), and when they were compared with the other shoulders in the study, these shoulders were found to have lower final American Shoulder and Elbow Surgeons scores, more pain, and decreased active external rotation following either total shoulder arthroplasty or hemiarthroplasty.Conclusions: On the basis of our data, we recommend the use of a glenoid component in shoulders with glenoid erosion. Humeral head subluxation was associated with a less favorable result regardless of the type of shoulder arthroplasty and must be considered in preoperative planning and counseling. Severe loss of the passive range of motion preoperatively was associated with a decreased passive range of motion postoperatively. A repairable tear of the supraspinatus tendon is not a contraindication to the use of a glenoid component. . [ABSTRACT FROM AUTHOR]

Objective: To determine whether a simulated low-dose metal artifact reduction (MAR) CT technique is comparable with a clinical dose MAR technique for shoulder arthroplasty evaluation. Materials and methods: Two shoulder arthroplasties in cadavers and 25 shoulder arthroplasties in patients were scanned using a clinical dose (140 kVp, 300 qrmAs); cadavers were also scanned at half dose (140 kVp, 150 qrmAs). Images were reconstructed using a MAR CT algorithm at full dose and a noise-insertion algorithm simulating 50% dose reduction. For the actual and simulated half-dose cadaver scans, differences in SD for regions of interest were assessed, and streak artifact near the arthroplasty was graded by 3 blinded readers. Simulated half-dose scans were compared with full-dose scans in patients by measuring differences in implant position and by comparing readers' grades of periprosthetic osteolysis and muscle atrophy. Results: The mean difference in SD between actual and simulated half-dose methods was 2.42 HU (95% CI [1.4, 3.4]). No differences in streak artifact grades were seen in 13/18 (72.2%) comparisons in cadavers. In patients, differences in implant position measurements were within 1° or 1 mm in 149/150 (99.3%) measurements. The inter-reader agreement rates were nearly identical when readers were using full-dose (77.3% [232/300] for osteolysis and 76.9% [173/225] for muscle atrophy) and simulated half-dose (76.7% [920/1200] for osteolysis and 74.0% [666/900] for muscle atrophy) scans. Conclusion: A simulated half-dose MAR CT technique is comparable both quantitatively and qualitatively with a standard-dose technique for shoulder arthroplasty evaluation, demonstrating that this technique could be used to reduce dose in arthroplasty imaging. [ABSTRACT FROM AUTHOR]

Background: Shoulder pain and dysfunction are common indications for rotator cuff repair surgery, yet the factors that are associated with these symptoms are not fully understood. Purpose/Hypothesis: This study aimed to investigate the associations of patient and disease-specific factors with baseline patient-reported outcome measures (PROMs) in patients undergoing rotator cuff repair. We hypothesized that tear size and mental health status, as assessed by the Veterans RAND 12-Item Health Survey mental component score (VR-12 MCS), would be associated with baseline total Penn Shoulder Score (PSS) and its pain, function, and satisfaction subscale scores. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We prospectively identified 12 patient factors and 12 disease-specific factors as possible statistical predictors for baseline PROMs in patients undergoing surgical repair of superior-posterior rotator cuff tears at a single institution over a 3-year period. Multivariable statistical modeling and Akaike information criterion comparisons were used to investigate the unique associations with, and relative importance of, these factors in accounting for variation in baseline PSS and its subscale scores. Results: A total of 1442 patients who had undergone surgery by 23 surgeons met inclusion criteria, with a baseline median total PSS of 38.5 (pain, 12; function, 24.2; satisfaction, 2). Adjusted R 2 in multivariable models demonstrated that the 24 general patient and disease-specific factors accounted for 22% to 24% of the variability in total PSS and its pain and function subscale scores. Large/massive tear size was significantly associated with worse PSS total score and function score but not pain or satisfaction scores. Lower VR-12 MCS was significantly associated with worse total PSS and all 3 subscale scores. Among other factors significantly associated with baseline PROMs were sex, race, preoperative opioid use, years of education, employment status, acromion status, and adhesive capsulitis. Lower VR-12 MCS, preoperative opioid use, female sex, and black race were the factors most strongly associated with baseline PROMs. Conclusion: Large/massive tear size, lower VR-12 MCS, and several additional patient and disease-specific factors are associated with baseline PROMs in patients undergoing rotator cuff repair. Further studies are needed to investigate whether these factors will also predict poor postoperative PROMs. [ABSTRACT FROM AUTHOR]

The purpose of the study was to describe the characteristics and demonstrate proof-of-concept and clinical use of a barium sulfate infused polypropylene radiopaque tissue marker for soft tissue localization and in vivo measurement of lengths and areas. Marker mechanical properties were evaluated by tensile tests. Biocompatibility was evaluated following 8–12 weeks' implantation in a pig model. Proof-of-concept of marker application was performed in a human cadaveric shoulder model, and methods for CT imaging and measurement of dimensions were established. Lastly, the method of clinical use of the markers was described in one patient undergoing arthroscopic rotator cuff repair (RCR). The radiopaque markers had a tensile strength of 28 ±4.7 N and were associated with minimal to mild inflammatory tissue reaction similar to polypropylene control. CT-based measurements showed relatively high precisions for lengths (0.66 mm), areas (6.97 mm2), and humeral orientation angles (2.1°) in the cadaveric model, and demonstrated 19 ±3 mm medio-lateral tendon retraction and 227 ±3 mm2 increase in tendon area in the patient during 26 weeks following RCR. No radiographic leaching, calcification or local adverse events were observed. The radiopaque tissue marker was biocompatible and had adequate strength for handling and affixation to soft tissues using standard suturing techniques. The marker could be used with low-dose, sequential CT imaging to quantitatively measure rotator cuff tendon retractions with clinically acceptable accuracy. We envision the radiopaque tissue marker to be useful for soft tissue localization and in vivo measurement of tissue and organ dimensions following surgery. [ABSTRACT FROM AUTHOR]

Background: Improving outcomes after surgical procedures and determining the value of health care can be facilitated by a scientifically valid, cost-effective, and scalable data outcome collection system. We hypothesized that such a system could be constructed in orthopaedic surgery to (1) capture >95% of baseline validated patient-reported outcome measures (PROMs) for patients undergoing elective surgery, (2) capture >95% of surgeon-entered data on disease severity and treatment, and (3) be implemented as standard clinical care in daily practice.Methods: A modified Research Electronic Data Capture (REDCap) system was developed and was implemented at the time of surgery in a prospective cohort to collect demographic data, general health PROMs, joint-specific PROMs, and disease severity and treatments from patients and surgeons. All elective knee, hip, and shoulder orthopaedic surgical procedures performed in the Cleveland Clinic system at 7 hospitals were included.Results: Of 16,021 consecutive eligible patients (February 18, 2015, to July 31, 2017), 2% (320) were excluded because of language or physical barriers, and 0.6% (91) of the remaining 15,701 patients refused to participate. Of the remaining 15,610 patients, 97.4% (15,202) completed PROMs, and surgeons provided details on the disease severity and treatment for 99.9% (15,592) of the 15,610 patients. Overall, 97.3% (15,185) of the 15,610 patients had complete patient-reported and surgeon-reported baseline enrollment. The median completion time was 11.5 minutes for the patients and 1.6 minutes for the surgeons. The overall complete 1-year follow-up rate was 72.5% (9,354 of 12,896).Conclusions: A data collection system with validated measures with >97% baseline completion of PROMs and surgeon forms regarding disease severity and treatments, across elective knee, hip, and shoulder orthopaedic surgical procedures, was successfully implemented at 7 hospitals. The system is potentially scalable to the entire orthopaedic community and could serve as a template for all procedural-based specialties during routine patient care. [ABSTRACT FROM AUTHOR]

Background: The primary objectives of this study were to evaluate the ability of a posteriorly stepped augmented glenoid component, used in patients with primary glenohumeral osteoarthritis with B2 or B3 glenoid morphology, to correct preoperative retroversion and humeral head subluxation and to identify factors associated with radiographic radiolucency and patient-reported clinical outcomes.Methods: We identified 71 shoulders with B2 or B3 glenoid morphology that underwent anatomic total shoulder arthroplasty with use of a posteriorly stepped augmented glenoid component and with a preoperative 3-dimensional computed tomography (3D-CT) scan and a minimum of 2 years of clinical and radiographic follow-up. The Penn Shoulder Score (PSS), shoulder range of motion, glenoid center-peg osteolysis, and postoperative version and humeral head subluxation were the main outcome variables of interest.Results: Follow-up was a median of 2.4 years (range, 1.9 to 5.7 years); the mean patient age at treatment was 65 ± 7 years (range, 51 to 80 years). PSS, range of motion, humeral head centering, and glenoid version were significantly improved among all patients (p < 0.0001). Patients with persistent posterior subluxation of the humeral head postoperatively had worse preoperative fatty infiltration of the teres minor and greater postoperative component retroversion (p < 0.05). Patients with center-peg osteolysis had more preoperative joint-line medialization and posterior glenoid bone loss (p < 0.05). Patients with more preoperative humeral head posterior subluxation had a lower PSS, adjusting for confounders (p < 0.05).Conclusions: Posteriorly stepped augmented glenoid components can improve pathologic retroversion and posterior subluxation of the humeral head in B2 and B3 glenoids, with significant improvements found in clinical outcome scores at a minimum of 2 years of follow-up in the vast majority of patients.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Scapular notching is frequently observed following reverse total shoulder arthroplasty (rTSA), although the etiology is not well understood.Methods: Twenty-nine patients with preoperative computed tomography (CT) scans who underwent rTSA with a Grammont design were evaluated after a minimum of 2 years of follow-up with video motion analysis (VMA), postoperative three-dimensional (3D) CT, and standard radiographs. The glenohumeral range of motion demonstrated by the VMA and the postoperative implant location on the CT were used in custom simulation software to determine areas of osseous impingement between the humeral implant and the scapula and their relationship to scapular notching on postoperative CT. Patients with and without notching were compared with one another by univariable and multivariable analyses to determine factors associated with notching.Results: Seventeen patients (59%) had scapular notching, which was along the posteroinferior aspect of the scapular neck in all of them and along the anteroinferior aspect of the neck in 3 of them. Osseous impingement occurred in external rotation with the arm at the side in 16 of the 17 patients, in internal rotation with the arm at the side in 3, and in adduction in 12. The remaining 12 patients did not have notching or osseous impingement. Placing the glenosphere in a position that was more inferior (by a mean of 3.4 ± 2.3 mm) or lateral (by a mean of 6.2 ± 1.4 mm) would have avoided most impingement in the patients' given range of motion. Notching was associated with glenosphere placement that was insufficiently inferior (mean inferior translation, -0.3 ± 3.4 mm in the notching group versus 3.0 ± 2.9 mm in the no-notching group; p = 0.01) or posterior (mean, -0.3 ± 3.5 mm versus 4.2 ± 2.2 mm; p < 0.001). Two-variable models showed inferior and posterior (area under the curve [AUC], 0.887; p < 0.001), inferior and lateral (AUC, 0.892; p < 0.001), and posterior and lateral (AUC, 0.892; p < 0.001) glenosphere positions to be significant predictors of the ability to avoid scapular notching.Conclusions: Osseous impingement identified using patients' actual postoperative range of motion and implant position matched the location of scapular notching seen radiographically. Inferior, lateral, and posterior glenosphere positions are all important factors in the ability to avoid notching. Only small changes in implant position were needed to avoid impingement, suggesting that preoperative determination of the ideal implant position may be a helpful surgical planning tool to avoid notching when using this implant design.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Social media provide a unique method of analyzing outcomes and quality in medicine. The purpose of this observational study was to investigate the nature of social media content related to shoulder and elbow (S&E) surgery posted by patients, surgeons, and hospitals. A public search of Instagram for a twoyear period yielded 1,177 patient-related posts. A categorical system assessed the perspective, timing, tone, and content of each post. Twitter accounts of 77 S&E specialists from the top five ranked U.S. News & World Report institutions were analyzed for activity and content. 5,246 Twitter and Instagram posts for the institutions were analyzed for frequency and content. Most patient-related posts were by patients (68 %), postoperative (82 %), positive (87 %), and centered on return-toplay for Tommy John (34 %), surgical site for shoulder arthroplasty (52 %), and activities of daily living for rotator cuff repair (22 %). 37 % of surgeons had active accounts averaging 46 posts, 87 % of which were practice advertisements. Hospitals averaged 273 posts over the 2-year period, focusing on education (38 %) and community (18 %). S&E patients share outcomes on social media in a positive tone with proceduredependent emphases. Surgeons on social media use sites for practice augmentation. Hospitals often focused posts towards educating the community. [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: Walch defined the pathologic characteristics of glenohumeral osteoarthritis on the basis of patterns of glenoid morphology and humeral head subluxation. However, it is unclear how pathologic changes evolve over time. The purpose of this study was to determine whether there are common patterns of pathologic progression based on the Walch classification in primary glenohumeral osteoarthritis and if glenoid bone-loss patterns correlate with rotator cuff fatty infiltration.Methods: A retrospective chart review identified 65 shoulders with glenohumeral osteoarthritis for which at least 2 computed tomography (CT) scans had been performed at least 24 months apart. The CT scans were classified using a modification of the Walch classification. The amount and location of glenoid bone loss were measured using a vault model, and rotator cuff fatty infiltration was calculated as a percentage of cross-sectional muscle area.Results: The initial CT scans showed 42 A-type glenoids and 23 B-type glenoids. CT scans made at an average (and standard deviation) of 74 ± 32 months after the initial scans showed that only 8 of the 42 A1 glenoids had evidence of pathologic progression (5 to A2 type and 3 to B type) whereas 17 of 19 B1 glenoids had progressed (15 to B2 and 2 to B3); this difference was significant on univariate and multivariate analysis (p < 0.001). The odds of joint line medialization occurring were 8.1 times higher (95% confidence interval [CI]: 2.1 to 31.4) for B-type glenoids than for A-type glenoids. Among the glenoids that underwent medialization, those classified as B-type showed more medialization over time (estimated change, 0.70 mm/year; p = 0.036), whereas no significant relationship between medialization and time was observed for A-type glenoids (estimated change, 0.013 mm/year; p = 0.95). The median percent fatty infiltration in the infraspinatus muscle was higher in association with B-type glenoids than in association with A-type glenoids on both the initial (14% versus 7%; p < 0.001) and the final follow-up (16% versus 10%; p = 0.003) CT scans.Conclusions: Asymmetric bone loss rarely develops in A1 glenoids, whereas initial posterior translation of the humeral head (B1 glenoids) may be associated with subsequent development and progression of posterior glenoid bone loss over time. Differences in fatty infiltration of the posterior aspect of the rotator cuff were seen between A-type and B-type glenoids, but the clinical relevance of this finding is currently unknown.Level Of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

ABSTRACT: The purpose of this study was to demonstrate feasibility of a clinical CT imaging and analysis technique to quantify regional variations in trabecular bone architecture and mineralization of glenoid bones. Specifically, our objective was to determine to what extent clinical CT imaging of intact upper extremities can describe variations of trabecular bone architectures at anatomic and peri‐implant regions by comparing trabecular bone architectures as measured by high‐resolution, micro CT imaging of same excised glenoid bones. Bone volume fraction (BVF), trabecular bone thickness (TbTh), number of trabecular bone (TbN), spacing (TbS), pattern factor (TbPf), bone surface area (BSA), and skeletal connectivity (Conn.), in addition to bone mineral content (BMC) and bone mineral density (BMD), were quantified from both clinical and micro CT images using whole bone, anatomic, and peri‐implant bone masks. Strong correlations of BVF, TbTh, TbSp, BMC, and BMD were found between clinical CT and micro CT imaging methods. The variations in BVF, TbTh, TbSp, TbN, BMC, and BMD at anatomical and peri‐implant regions were larger than those at whole bone regions. In this study, we have demonstrated that this clinical CT imaging methodology can be used to quantify variations of a patient's glenoid bone at anatomic and peri‐implant levels. Statement of Clinical Significance. An in vivo quantitative assessment of glenoid trabecular bone architecture in the anatomic and peri‐implant regions may improve our understanding on the role of bone quality on glenoid component loosening following total shoulder arthroplasty. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:85–96, 2018. [ABSTRACT FROM AUTHOR]

Background: Propionibacterium acnes is recognized as a pathogenic organism associated with periprosthetic joint infection following shoulder arthroplasty. The goal of our study was to determine the relationship between the time to P. acnes growth in culture and the likelihood of a culture result being a true positive versus a false positive based on the proportion of positive cultures and other perioperative findings in cases of revision shoulder arthroplasty. Methods: We retrospectively reviewed forty-six cases with P. acnes-positive cultures among patients who underwent revision shoulder arthroplasty between May 2010 and October 2014. Tissue and fluid was cultured anaerobically for a mean (and standard deviation) of 13.1 ± 3 days. Cases were categorized into one of two groups for analysis: probable true positive or probable contaminant (false-positive) on the basis of culture results and perioperative findings. Results: The time to P. acnes culture growth was significantly shorter (p = 0.002) in the probable true-positive culture group compared with the probable contaminant group (median of five days [interquartile range, four to seven days]) compared with nine days [interquartile range, six to twelve days]). Among the thirty-seven cases in the probable true-positive group, no culture result turned positive after eleven days, whereas in the probable contaminant group, cultures turned positive after this time point in 44% (four of nine) of the cases. There were also significantly fewer days to P. acnes culture growth among cases with a higher number of positive cultures (p = 0.001) and a higher proportion of positive cultures (p < 0.001), regardless of group classification. Conclusions: P. acnes is the most commonly identified organism following revision shoulder arthroplasty. The proportion of positive cultures and the timing of culture growth may help to distinguish a true-positive from a false-positive culture result. [ABSTRACT FROM AUTHOR]

BACKGROUND: Propionibacterium acnes is recognized as a pathogenic organism associated with periprosthetic joint infection following shoulder arthroplasty. The goal of our study was to determine the relationship between the time to P. acnes growth in culture and the likelihood of a culture result being a true positive versus a false positive based on the proportion of positive cultures and other perioperative findings in cases of revision shoulder arthroplasty. METHODS: We retrospectively reviewed forty-six cases with P. acnes-positive cultures among patients who underwent revision shoulder arthroplasty between May 2010 and October 2014. Tissue and fluid was cultured anaerobically for a mean (and standard deviation) of 13.1 ± 3 days. Cases were categorized into one of two groups for analysis: probable true positive or probable contaminant (false-positive) on the basis of culture results and perioperative findings. RESULTS: The time to P. acnes culture growth was significantly shorter (p = 0.002) in the probable true-positive culture group compared with the probable contaminant group (median of five days [interquartile range, four to seven days]) compared with nine days [interquartile range, six to twelve days]). Among the thirty-seven cases in the probable true-positive group, no culture result turned positive after eleven days, whereas in the probable contaminant group, cultures turned positive after this time point in 44% (four of nine) of the cases. There were also significantly fewer days to P. acnes culture growth among cases with a higher number of positive cultures (p = 0.001) and a higher proportion of positive cultures (p < 0.001), regardless of group classification. CONCLUSIONS: P. acnes is the most commonly identified organism following revision shoulder arthroplasty. The proportion of positive cultures and the timing of culture growth may help to distinguish a true-positive from a false-positive culture result. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Measurement of clinical outcomes is necessary to define best practice. It requires a validated tool that can be easily applied as part of clinical practice. We present the preliminary validation of a brief self-reported Review of Musculoskeletal System (ROMS) questionnaire that captures functional limitations due to musculoskeletal problems and other medical and emotional conditions. Methods: Data were derived from a clinical outcomes database (Orthopaedic Minimal Data Set [OrthoMiDaS]) that combines patient-reported data collected as part of routine care and secondary data extracted from electronic medical records. The study utilized 82,873 encounters collected from 24,116 consecutive patients with problems in the upper and lower extremities. In addition to the ROMS, the study used version 2 of the Short Form-12 (SF-12v2), the Penn Shoulder Score (PSS), the Hip disability and Osteoarthritis Outcome Score (HOOS), and the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaires. Fifteen cross-sectional samples were used to evaluate the floor and ceiling effects as well as the construct and content validity. Five longitudinal cohorts were used to measure test-retest reliability and responsiveness. Standard statistical tests were applied. Results: The floor and ceiling effects of the ROMS questionnaire in patients with shoulder, hip, and knee problems ranged from 1.3% to 8.5%. Construct-validity tests confirmed convergent and divergent validity of the ROMS. The tests also justified its additional value when the ROMS was used with joint-specific tools. When measuring test-retest reliability of the ROMS scales, intraclass correlation ranged from 0.80 to 0.90 at approximately one week and from 0.71 to 0.87 at approximately four weeks. Responsiveness of the ROMS was greater than that of the SF-12 and less than that of the jointspecific questionnaires. Conclusions: The ROMS is compatible with routine clinical process and has good psychometric properties in patients with shoulder, hip, and knee disorders. It can be used as a primary outcome tool for large observational studies and can supplement more specific tools in controlled studies. Clinical Relevance: The ROMS was developed as a tool to measure and monitor the clinical status of the musculoskeletal system in a population of patients during and after treatment as well as over time. [ABSTRACT FROM AUTHOR]

Background: Diagnosis of periprosthetic joint infection (PJI) in patients undergoing revision shoulder arthroplasty is challenging because of the low virulence of the most common infecting organisms. The goal of this study was to evaluate the diagnostic utility of measuring synovial fluid interleukin-6 (IL-6) levels for identifying PJI of the shoulder. Methods: Thirty-two consecutive patients evaluated for pain at the site of a shoulder arthroplasty were prospectively enrolled from November 2012 to September 2013 and underwent revision surgery (thirty-five procedures during which samples were obtained for synovial fluid IL-6 analysis). Cases were categorized into infection (n = 15) and no-infection (n = 20) groups on the basis of objective preoperative and intraoperative findings. Twenty patients treated with arthroscopic rotator cuff repair were also enrolled to serve as a non-infected control group. Synovial fluid was obtained through aspiration intraoperatively for all patients, as well as preoperatively for some. Synovial fluid IL-6 levels were measured with use of a cytokine immunoassay that utilizes electrochemiluminescent detection. A receiver operating characteristic curve was used to determine the diagnostic utility of synovial fluid IL-6 analysis. Results: Based on receiver operating characteristic curve analysis, synovial fluid IL-6 measurement had an area under the curve of 0.891 with an ideal cutoff value of 359.3 pg/mL. The sensitivity, specificity, and positive and negative likelihood ratios were 87%, 90%, 8.45, and 0.15, respectively. Seven patients who underwent a single-stage revision had negative results on standard perioperative testing, including the erythrocyte sedimentation rate and C-reactive protein levels, but multiple positive intraoperative tissue cultures. The level of synovial fluid IL-6 was elevated in five of these seven patients, with a median value of 1400 pg/mL. Intraoperative synovial fluid IL-6 values correlated well with preoperative IL-6 synovial fluid values (correlation = 0.61; p = 0.025) and frozen-section histologic findings (p < 0.001). Synovial fluid IL-6 levels were also significantly elevated in patients with Propionibacterium acnes infection (p = 0.01). Conclusions: Measurement of synovial fluid IL-6 levels is more sensitive and specific than current preoperative testing for predicting positive cultures for patients undergoing revision shoulder arthroplasty. This diagnostic accuracy can lead to improved decision-making in the management of PJI. Level of Evidence: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Objective: Iterative metal artifact reduction (IMAR) is a sinogram inpainting technique that incorporates high-frequency data from standard weighted filtered back projection (WFBP) reconstructions to reduce metal artifact on computed tomography (CT). This study was designed to compare the image quality of IMAR and WFBP in total shoulder arthroplasties (TSA); determine the optimal amount of WFBP high-frequency data needed for IMAR; and compare image quality of the standard 3D technique with that of a faster 2D technique. Materials and methods: Eight patients with nine TSA underwent CT with standardized parameters: 140 kVp, 300 mAs, 0.6 mm collimation and slice thickness, and B30 kernel. WFBP, three 3D IMAR algorithms with different amounts of WFBP high-frequency data (IMARlo, lowest; IMARmod, moderate; IMARhi, highest), and one 2D IMAR algorithm were reconstructed. Differences in attenuation near hardware and away from hardware were measured and compared using repeated measures ANOVA. Five readers independently graded image quality; scores were compared using Friedman's test. Results: Attenuation differences were smaller with all 3D IMAR techniques than with WFBP ( p < 0.0063). With increasing high-frequency data, the attenuation difference increased slightly (differences not statistically significant). All readers ranked IMARmod and IMARhi more favorably than WFBP ( p < 0.05), with IMARmod ranked highest for most structures. The attenuation difference was slightly higher with 2D than with 3D IMAR, with no significant reader preference for 3D over 2D. Conclusions: IMAR significantly decreases metal artifact compared to WFBP both objectively and subjectively in TSA. The incorporation of a moderate amount of WFBP high-frequency data and use of a 2D reconstruction technique optimize image quality and allow for relatively short reconstruction times. [ABSTRACT FROM AUTHOR]

The article offers step-by-step instructions for the bone-graft technique for shoulder arthroplasty in patients having severe glenoid bone loss which uses a step cut and graft fixation.

Background: Glenoid bone loss associated with advanced glenohumeral arthritis is frequently accompanied by subluxation of the humeral head with subsequent inferior outcomes of shoulder arthroplasty. We hypothesized that the relationship between the center of the humeral head and the perpendicular to the glenoid fossa plane differs from, and is independent of, the relationship between the center of the humeral head and the plane of the scapula. Methods: Three-dimensional computed tomography (3D CT) imaging was performed on sixty patients with advanced osteoarthritis and fifteen controls with no osteoarthritis to define the baseline relationship between the center of the humeral head and the perpendicular to the glenoid fossa plane and the plane of the scapula. Correlations between these variables and the amount of bone loss and glenoid version were assessed. Results: There was a strong linear relationship (p < 0.001) between glenoid retroversion and the center of the humeral head in relation to the center line of the scapula (humeral-scapular alignment). Humeral head alignment in relation to the glenoid plane (humeral-glenoid alignment) was variable and not strongly correlated with the amount of glenoid retroversion. The average glenoid retroversion for the normal shoulders was -3.5°, and the average humeral-scapular alignment offset percentage was -2.3%. The average humeral-glenoid alignment offset for the normal shoulders was 0.5 mm with an average humeral-glenoid alignment offset percentage of 0.9%. Conclusions: The location of the humeral head in relation to the glenoid can be defined as displacement from the plane of the scapula and from the perpendicular of the glenoid plane. These two measures are independent of one another. The data suggest that each measurement may represent a different effect on glenoid loading. [ABSTRACT FROM AUTHOR]

Background: Propionibacterium acnes is a clinically relevant pathogen with total shoulder arthroplasty. The purpose of this study was to determine the sensitivity of frozen section histology in identifying patients with Propionibacterium acnes infection during revision total shoulder arthroplasty and investigate various diagnostic thresholds of acute inflammation that may improve frozen section performance. Methods: We reviewed the results of forty-five patients who underwent revision total shoulder arthroplasty. Patients were divided into the non-infection group (n = 15), the Propionibacterium acnes infection group (n = 18), and the other infection group (n = 12). Routine preoperative testing was performed and intraoperative tissue culture and frozen section histology were collected for each patient. The histologic diagnosis was determined by one pathologist for each of the four different thresholds. The absolute maximum polymorphonuclear leukocyte concentration was used to construct a receiver operating characteristics curve to determine a new potential optimal threshold. Results: Using the current thresholds for grading frozen section histology, the sensitivity was lower for the Propionibacterium acnes infection group (50%) compared with the other infection group (67%). The specificity of frozen section was 100%. Using a receiver operating characteristics curve, an optimized threshold was found at a total of ten polymorphonuclear leukocytes in five high-power fields (400·). Using this threshold, the sensitivity of frozen section for Propionibacterium acnes was increased to 72%, and the specificity remained at 100%. Conclusions: Using current histopathology grading systems, frozen sections were specific but showed low sensitivity with respect to the Propionibacterium acnes infection. A new threshold value of a total of ten or more polymorphonuclear leukocytes in five high-power fields may increase the sensitivity of frozen section, with minimal impact on specificity. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Restoration of native, premorbid glenoid anatomy may be a goal in component placement during total shoulder arthroplasty. However, if patients with unilateral glenohumeral osteoarthritis are predisposed to the development of arthritis owing to abnormal native glenoid anatomy, this recommendation may be inappropriate. Questions/purposes: The purpose of this study was to determine if patients with glenohumeral osteoarthritis have abnormal premorbid glenoid version or inclination, thereby predisposing them to subsequent glenoid disorders. We specifically tested whether: (1) premorbid glenoid version or inclination in the pathologic shoulder of patients with unilateral osteoarthritis, as determined by the glenoid vault model, is different from glenoid version or inclination in the contralateral nonpathologic shoulder of these patients; (2) there are differences between glenoid version or inclination in normal cadaver shoulders and the nonpathologic side of patients with unilateral osteoarthritis; and (3) there are differences between glenoid version or inclination in normal cadaver shoulders and the premorbid glenoid version and inclination in the pathologic shoulder of patients with unilateral osteoarthritis, as determined by the glenoid vault model. Methods: Bilateral CT scans were obtained in 27 patients with unilateral glenohumeral osteoarthritis. Thirty normal cadaver control shoulders also underwent CT scans. Premorbid glenoid version and inclination in the pathologic shoulder, as measured by the glenoid vault model, were compared with the contralateral nonpathologic shoulder and the normal cadaver control shoulders. Glenoid version and inclination of the normal shoulders were compared with the nonpathologic side from patients with unilateral osteoarthritis. Measurements were made by two different methods using three-dimensional surgical simulation software: (1) a direct measurement technique and (2) measurements derived from placement of a glenoid vault model. Mean differences in these parameters were compared between shoulder groups using paired and unpaired Student's t-tests. Results: Premorbid glenoid version and inclination in the pathologic shoulder as measured by the vault model averaged −7° (SD, 5) and 10° (SD, 6), respectively, compared with −7° (SD, 5) and 12° (SD, 6) as directly measured on the nonpathologic side, and −7° (SD, 4) and 12° (SD, 5) as directly measured in the normal cadaver control shoulders. There were no differences in glenoid version or inclination between the normal shoulders and the nonpathologic side of patients with unilateral osteoarthritis or between these shoulders and the premorbid version and inclination of the arthritic shoulder as measured by the vault model. Conclusions: Patients with glenohumeral osteoarthritis do not appear to have abnormal premorbid glenoid retroversion or inclination. The glenoid vault model can be used to determine premorbid glenoid version and inclination. Clinical Relevance: The glenoid vault model may be a clinically useful tool to estimate patient-specific premorbid glenoid anatomy, which may help in preoperative or intraoperative surgical planning for total shoulder arthroplasty. Level of Evidence: Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]