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The primary purpose of this study was to compare 2-year anatomic total shoulder arthroplasty (TSA) functional and radiographic outcomes between Walch type A and B glenoids treated with an all-polyethylene glenoid designed for hybrid fixation with peripheral cement and central osseous integration. The secondary purpose was to evaluate outcomes based on central peg technique. The hypotheses were that there would be no difference in short-term radiographic or functional outcome scores based on preoperative glenoid morphology or central peg technique.We performed a multicenter retrospective review of patients who underwent TSA with the same hybrid all-polyethylene glenoid and had minimum 2-year follow-up. Patient-reported outcomes and radiographic outcomes were analyzed based on preoperative Walch morphology and central peg technique. Radiographic analysis included preoperative glenoid morphology; preoperative and postoperative glenoid version, glenoid inclination, and posterior humeral head subluxation; and postoperative glenoid radiolucencies according to the Wirth and Lazarus classifications.A total of 266 patients with a mean age of 64.9 ± 8.2 years were evaluated at a mean of 28 months postoperatively. Postoperatively, there were significant improvements in all functional outcome measures (P .001), range-of-motion measures (forward elevation, external rotation at 0°, external rotation at 90°, internal rotation by spinal level, and internal rotation at 90°; P .001), and strength measures (Constant, external rotation, and modified belly press; P .001). There were no clinically meaningful differences in functional outcomes or statistically significant differences in radiographic appearance between Walch type A and B glenoids. Subgroup analysis revealed that glenoids with a cemented central peg had the worst radiographic outcomes based on Lazarus scoring.Patients undergoing TSA with a hybrid in-line pegged glenoid have excellent clinical outcomes at short-term follow-up regardless of preoperative glenoid morphology. Different central peg techniques do not appear to play a significant role in the risk of glenoid component lucencies at 2 years postoperatively.

Background: Although posterior glenohumeral instability is becoming an increasingly recognized cause of shoulder pain, the role of posterior glenoid bone loss on outcomes remains incompletely understood. Purposes: To prospectively determine the amount of bone loss associated with posterior instability events and to determine predisposing factors based on preinstability imaging. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 1428 shoulders were evaluated prospectively for ≥4 years. At baseline, a subjective history of shoulder instability was ascertained for each patient, and bilateral noncontrast magnetic resonance imaging (MRI) scans of the shoulders were obtained regardless of any reported history of shoulder instability. The cohort was prospectively followed during the study period, and those who were diagnosed with posterior glenohumeral instability were identified. Postinjury MRI scans were obtained and compared with the screening MRI scans. Glenoid version, perfect-circle-based bone loss was measured for each patient's pre- and postinjury MRI scans using previously described methods. Results: Of the 1428 shoulders that were prospectively followed, 10 shoulders sustained a first-time posterior instability event and 3 shoulders sustained a recurrent posterior instability event. At baseline, 11 of 13 shoulders had some amount of glenoid dysplasia and/or bone loss. The change in glenoid bone loss was 5.4% along the axis of greatest loss (95% CI, 3.8%-7.0%; P = .009), 4.4% at the glenoid equator (95% CI, 2.7%-6.2%; P = .016), and 4.2% of total glenoid area (95% CI, 2.9%-5.3%; P = .002). Recurrent glenoid instability was associated with a greater amount of absolute bone loss along the axis of greatest loss compared with first-time instability (recurrent: 16.8% ± 1.1%; 95% CI, 14.6%-18.9%; first-time: 10.0% ± 1.5%; 95% CI, 7.0%-13.0%; P = .005). Baseline glenoid retroversion ≥10° was associated with a significantly greater percentage of bone loss along the axis of greatest loss (≥10° of retroversion: 13.5% ± 2.0%; 95% CI, 9.6%-17.4%; Conclusions: Posterior glenohumeral instability events were associated with glenoid bone loss of 5%. The amount of glenoid bone loss after a recurrent posterior glenohumeral instability event was greater than that after first-time instability. Glenoid retroversion ≥10° was associated with a greater amount of posterior glenoid bone loss after a posterior instability event.

In recent years, an appreciation for the dynamic relationship between glenoid and humeral-sided bone loss and its importance to the pathomechanics of glenohumeral instability has substantially affected modern treatment algorithms. However, comparatively less attention has been paid to the influence of glenoid version on glenohumeral instability. Limited biomechanical data suggest that alterations in glenoid version may affect the forces necessary to destabilize the glenohumeral joint. However, this phenomenon has not been consistently corroborated by the results of clinical studies. Although increased glenoid retroversion may represent an independent risk factor for posterior glenohumeral instability, this relationship has not been reliably observed in the setting of anterior glenohumeral instability. Similarly, the effect of glenoid version on the failure rates of surgical stabilization procedures remains poorly understood.

The rationale for advances in implant design is to improve performance in comparison to their predecessors. The purpose of this study was to compare a newer, self-pressurizing peripheral peg glenoid to a traditional polyethylene pegged glenoid through biomechanical evaluation and a retrospective radiographic and clinical review.Three testing conditions (uncemented, partially cemented, and fully cemented) were chosen to assess the 2 component designs in a foam block model. The number of hammer hits to seat the component, amount of time to seat the component, and resistance-to-seat were collected. The implants were then cyclically loaded following ASTM F2028-17 testing standard. Clinically, postoperative radiographs of patients with a self-pressurized glenoid component (n = 225 patients) and traditional glenoid component (n = 206 patients) were evaluated for radiolucent lines and glenoid seating at various timepoints. Clinical outcomes (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Simple Shoulder Test, and visual analog scale pain scores) and complications were recorded. The presence of radiolucent lines at the bone-cement interface was evaluated using the Modified Franklin Grade and the Lazarus grade.The self-pressurizing glenoid design required significantly more hammer hits than traditional glenoid designs in all groups tested (P .029). Moreover, the self-pressurizing design had significantly more resistance-to-seat than traditional components in both the uncemented and partially cemented group (P .002). No difference in resistance-to-seat was found between designs in the fully cemented group. The uncemented and partially cemented groups did not survive the full 50,000 cycles; however the self-pressurizing design had significantly less motion than the traditional design (P .001). No differences between component designs were found in the fully cemented group at 50,000 cycles. The self-pressurizing glenoid component had 0.005% radiographic radiolucent lines, and the traditional glenoid component had 45% radiographic radiolucent lines, with 38% of the radiolucencies in the traditional glenoid component group being defined as grade E. There were no progressive radiolucencies, differences in clinical outcomes, or complications at 2 years postoperatively.In the fully cemented condition, the 2 component designs had comparable performance; however, the differences in designs could be better observed in the uncemented group. The self-pressurizing all-polyethylene design studied has superior biomechanical stability. Clinically, the improved stability of the glenoid component correlated with a reduction of radiolucent lines and will likely lead to a reduction in glenoid component loosening.

Background: The scapula is a small irregular-shaped flat bone, which may suffer from a variety of tumors or tumor-like lesions. As the imaging manifestations are complex and changeable, correct imaging diagnosis is difficult. Introduction: At present, there are few related radiology literatures, and it is necessary to fully analyze the imaging signs of different types of benign and malignant tumors in scapula to guide clinical treatment. This study was to investigate clinical and imaging presentations of tumors and tumor- like lesions in the scapula so as to increase the diagnostic accuracy of diseases in the scapula. Methods: Patients with scapular tumors confirmed by pathology were enrolled. The imaging and clinical data were analyzed. Result: Among 108 patients, benign tumors were in 53 (49.1%) cases, intermediate in seven (6.5%), and malignant in 48 (44.4%) involving 16 diseases. Osteochondroma was the first benign tumors in 45 cases accounting for 84.9% of all benign scapular tumors, followed by chondroma in four cases (7.5%). The intermediate tumors were mainly eosinophilic granuloma in four cases. Metastatic tumors were the commonest malignant tumor (27 cases or 56.2% of all malignant tumors), followed by chondrosarcoma (in 13 cases). Except for the one case of chondroblastoma in which the lesion involved the glenoid cavity, all the other cartilaginous tumors were located in the scapular body and processes. The type of lesions in the bony processes is the same as in the scapular body, the common lesions in the central area of the body were malignant tumors, and the commonest lesions in the glenoid area were metastasis. Common imaging features of malignant scapular tumors were ill-defined margins, cortical destruction and soft tissue involvement. The imaging features of chondrosarcoma lack specificity except for calcification. Benign lesions usually had a clear boundary and marginal sclerosis. Conclusion: A wide variety of benign and malignant tumors may occur in the scapula with mostly cartilaginous and metastatic tumors, and the location and distribution of lesions are similar in the scapula to those in the long bones.

Glenoid fossa morphology may change following orthognathic surgery and may subsequently affect skeletal stability and functionality, however hardly documented. Hence, the purpose of this study was to evaluate the morphological change of the glenoid fossa 2 years after bimaxillary surgery.A case series was performed including subjects diagnosed with maxillary and/or mandibular growth disturbances, who underwent bimaxillary surgery between March 2012 and November 2017 at the Department of Oral and Maxillofacial Surgery, University Hospital of Southern Denmark, Esbjerg, Denmark. The study variables were gender, age, and postoperative condylar resorption. Subjects were sampled evenly within subgroups with and without postoperative condylar resorption. The outcome variable, three-dimensional morphological change of the glenoid fossa, was calculated as surface distance in mm between superimposed preoperative and postoperative (2 years) cone-beam computed tomography scans, and the glenoid fossa was spatially divided into 4 regions. Evaluation of glenoid fossa changes of more than one voxel (0.3 mm) and comparison of subjects with and without postoperative condylar resorption were performed by one-sample and unpaired t tests, respectively.Twenty subjects (16 women; 4 men; mean age = 27.6 years) with Class II malocclusion and maxillomandibular retrognathia were included. The glenoid fossa changes (0.36 mm) were significant (P = .021) and significantly larger in subjects with condylar resorption than in those without condylar resorption in the anterior-lateral (0.40 mm vs 0.27 mm, P = .021) and anterior-medial fossa region (0.48 mm vs 0.26 mm, P = .015).Significant morphological fossa changes were found 2 years after orthognathic surgery, and subjects with postoperative condylar resorption showed a significantly higher degree of morphological change in the anterior glenoid fossa than subjects without postoperative condylar resorption.

In cases of severe osteoarthritis, posterior glenoid wear leads to acquired retroversion of the glenoid. Surgical treatment of glenoids with acquired retroversion and posterior humeral subluxation with anatomic total shoulder arthroplasty (aTSA) is controversial. The purpose of this study was to determine mid- to long-term outcomes and reoperation rates of augmented and nonaugmented aTSA for treatment of glenohumeral osteoarthritis with Walch B3 glenoid deformity.This observational cohort study reviewed patients with a Walch B3 glenoid undergoing aTSA at a single institution between 2007 and 2014. Patients were contacted to complete updated patient-reported outcome measures at a minimum of 6 years postoperatively. Outcome measures collected included the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score and Single Alpha Numeric Evaluation (SANE) score. Secondary outcomes included any additional surgery on the operative shoulder, patient satisfaction, and willingness to undergo aTSA again.Thirty-nine patients met inclusion criteria, and thirty-five (89.7%) were able to be contacted for final outcomes evaluation. Mean follow-up was 8.7 years (range 6-13) after surgery. Sixteen patients were treated with an augmented glenoid component, and 19 patients were treated with a standard glenoid component. Of those with standard components, all were partially corrected with asymmetric reaming. At final follow-up, there were no statistically significant differences between those with augmented and standard glenoid components for mean ASES score (93.3 vs. 85.7, P = .217), ASES pain score (47.2 vs. 41.6, P = .161), SANE score (87.8 vs. 86.0, P = .692), and percentage patient satisfaction (95.6% vs. 96.8%, P = .735), forward elevation (148° vs. 149°, P = .852), or external rotation (36° vs. 39°, P = .202). No patient in either group had undergone revision surgery of the operative shoulder over the study period and all patients stated that they would undergo the same surgery again.Both augmented and standard aTSA can provide satisfactory and sustained improvements in patient-reported outcomes in patients with acquired glenoid retroversion due to glenohumeral osteoarthritis. Despite a trend toward alternative treatment options, anatomic shoulder arthroplasty should remain a surgical consideration even in the setting of a Walch B3 glenoid deformity.

BACKGROUND Preoperative planning for total shoulder arthroplasty (TSA) may change according to the measured degree of glenoid version. Both 2-dimensional (2D) and 3-dimensional (3D) computed tomographic (CT) scans are used to measure glenoid version, with no consensus on which method is more accurate. However, it is generally accepted that 3D measurements are more reliable, yet most 3D reconstruction software currently in clinical use have never been directly compared to 2D. The purpose of this study is to directly compare 2D and 3D glenoid version measurements and determine the differences between the two. METHODS CT scans were performed preoperatively on 315 shoulders undergoing either anatomic or reverse TSA. 2D measurements of glenoid version were obtained manually using the Friedman method, whereas 3D measurements were obtained using the Equinoxe Planning Application (Exactech Inc.) 3D-reconstruction software. Negative version values indicate retroversion, whereas positive values indicate anteversion. Two observers collected the 2D measurements 2 separate times, and intra- and interobserver measurements were calculated. Groups were compared for variability using intraclass correlation coefficients (ICCs), and for differences in sample means using Student t tests. Additionally, samples were stratified by version value in order to better understand the potential sources of error between measurement techniques. RESULTS For the 2D measurements, intraobserver variability indicated excellent reproducibility for both observer 1 (ICC = 0.928, 95% confidence interval [CI] 0.911-0.942) and observer 2 (ICC = 0.964, 95% CI 0.955-0.971). Interobserver variability measurements also indicated excellent reproducibility (ICC = 0.915, 95% CI 0.778-0.956). The overall 2D version measurement average (-4.9° ± 10.3°) was significantly less retroverted than the 3D measurement average (-8.4° ± 9.1°) (P < .001), with 3D measurements yielding a more retroverted value 73% of the time. When stratified on the basis of version value with outliers excluded, there was no significant difference in the distribution of high-error samples within the data. DISCUSSION There was excellent reproducibility between the 2 observers in terms of both intra- and interobserver variability. The 3D measurement techniques were significantly more likely to return a more retroverted measurement, and high-error samples were evenly distributed throughout the data, indicating that there were no discernable trends in the degree of error observed. Shoulder surgeons should be aware that different glenoid version measurement strategies can yield different version measurements, as these can affect preoperative planning and surgeon decision making.

The purpose of this study is to evaluate whether the amount of measured posterior bone loss on 2- and 3-dimensional (2D and 3D) imaging of Walch B2 glenoids can reliably predict the plan for an augmented anatomic glenoid component.Patients with Walch B2 glenoids and preoperative computed tomography (CT) scans were retrospectively identified. 2D axial CT scans were reviewed and posterior bone loss was measured by 3 independent reviewers. Images were then formatted into BluePrint (Wright Medical) preoperative planning software. The same 3 reviewers again measured posterior bone loss on 3D imaging. Additionally, all cases were planned with BluePrint software. An augment was used when the following criteria were unable to be satisfied with standard implants:10° retroversion,10° superior inclination, ≥90% backside contact,2 mm medial reaming, and ≤1 peg perforation.Forty-two patients were included in the final analysis with a mean age of 63.1 ± 6.3 years. As measured by BluePrint, the mean retroversion was 23° ± 7° (range = 9°-40°), the mean superior inclination was 5° ± 6° (range = -9° to 22°), and the mean posterior subluxation was 80% ± 17% (range = 41%-95%). The mean 2D bone loss measurements (3.5 ± 1.6 mm) were significantly lower than the mean 3D bone loss (4.0 ± 1.8 mm) measurements (P = .03). There was substantial agreement between reviewers on both 2D and 3D measurements with an interclass correlation of 0.815 (95% confidence interval [CI] 0.714-0.889, P.001) and an interclass correlation of 0.802 (95% CI 0.683-0.884, P.001), respectively. Augments were used in 73.8%, 63.4%, and 63.4% of cases by reviewers 1, 2, and 3, respectively, with moderate agreement with a Fleiss kappa of 0.592 (95% CI 0.416-0.769, P.001). Augment size was moderately, positively correlated with the amount of bone loss on 3D imaging but not with 2D imaging. After multivariate logistic regression, both 3D bone loss and retroversion were found to be predictive for a plan to use an augment.Planning for a posterior augment in Walch B2 glenoids is better predicted with 3D imaging than with 2D imaging, as 2D imaging may underestimate posterior bone loss. Additionally, use of a larger augment size is moderately correlated with posterior bone loss on 3D imaging but not 2D imaging. Standard 2D imaging may be limited in cases of posterior bone loss, and 3D imaging may be beneficial for preoperative planning in Walch B2 glenoids.

Osteoarthritic shoulders with posterior glenoid erosion present a unique challenge to shoulder arthroplasty surgeons. Although numerous treatment options and techniques have been described, a consensus regarding the optimal surgical management strategy has not been reached. It is important to summarize the best available evidence regarding these different treatment options, with a particular focus on the young patient.

Summary Objectives Understanding the mechanism of mandibular asymmetry (MA) is important to provide suggestions for occlusal treatment and to know the developmental process of masticatory dysfunction. To investigate the morphological and functional effects on MA, we evaluated the three-dimensional position of the glenoid fossa and its relationship to asymmetrical condylar translational movement. Methods In this retrospective study, 50 subjects who previously underwent computed tomography for surgical purposes were divided into MA and control groups according to a menton deviation of at least 4 mm from the mid-sagittal plane. The glenoid fossae positions were evaluated using a three-dimensional analysis program. Condylar translational movements were recorded and measured by computerized axiography on protrusion. Side-to-side asymmetry was measured for each parameter. Asymmetry index value was calculated to assess the correlation between glenoid fossa position and condylar movement. Wilcoxon’s signed-ranked test, Mann–Whitney U-test, and Spearman’s rank correlation were used for the statistical analysis. Results In the MA group, glenoid fossa position on the shifted side was significantly inferior and posterior as compared to that on the non-shifted side and of the control group. Condylar path length and sagittal condylar inclination were significantly greater on the shifted side versus non-shifted side, while no significant difference was found in transverse condylar inclination. The asymmetry index of the anterior–posterior glenoid fossa position was significantly correlated with that of condylar path length and bilateral transverse condylar inclination. In the control group, there were no significant correlations among the morphological and functional parameters. Limitations This study did not consider muscle activity and disc position, which may affect condylar movement. Conclusions Functional asymmetry of condylar translational movements is closely related to asymmetry of glenoid fossa position in MA patients.

To demonstrate how reverse shoulder arthroplasty (RSA) planning software could be used to improve how the trainees position glenoid and humeral implants and obtain optimal simulated range of motion (ROM). We selected four groups of five various level participants: medical student (MS), junior resident (JR), senior resident (SR), and shoulder expert (SE). Thereafter, the 20 participants planned five cases of arthritic shoulders for a RSA on a validated planning software following three phases: (1) no guidelines and no ROM feedback, (2) guidelines but no ROM feedback, and (3) guidelines and ROM feedback. We evaluated the final simulated impingement-free ROM, the choice of the implant (baseplate size, graft, glenosphere), and the glenoid implant positioning. MS planning were significantly improved by the ROM feedback only. JR took the best advantage of both guidelines and ROM in final results. SR planning were less performant than SE into phase 1 regarding flexion, external rotation, and adduction (respectively − 10°, p = 0.03; − 11°, p = 0.003; and − 3°, p = 0,03), but reached similar results into phase 3 (respectively − 2°, p = 0.329; − 4°, p = 0.44; − 2°, p = 0.319). For MS, JR, and SR, we observed a systematic improvement in the agreement over the study course. The glenoid diameter remained highly variable even for SE. Comparing glenoid implant position to SE, the distance error decreased with advancing phases. Planning software can be used as a simulation training tool to improve implant positioning in shoulder arthroplasty procedures.

The success of the modified Latarjet procedure depends on proper sizing of the coracoid graft. There is no information available regarding the morphometric relationship between the glenoid cavity and the coracoid process for the South African population. This study aims at measuring the relationship between the glenoid and coracoid morphometries and investigates their gender-related differences.Glenohumeral computerized tomography scans of 100 consecutive patients were considered for this study. Morphometric measurements were performed after aligning the coracoid and glenoid in their optimum orientation. These measurements were performed by 2 independent observers. The ratio between glenoid and coracoid measurements was calculated and statistically compared using the Mann-Whitney U test. Intraclass correlation coefficients were calculated to analyze interobserver reliability. All the statistical tests were performed in SPSS v.26, and power calculations in G∗Power v.3.1.An average intraclass correlation coefficient value of 0.79 suggested that the interobserver reliability was good. Except for coracoid length, statistically significant (P.05) gender differences were observed for all the other morphometries. The coracoid width (16.5 ± 1.4 mm vs. 14.7 ± 1.4 mm) and height (13.6 ± 1.6 mm vs. 10.5 ± 1.5 mm) differed between genders by 1.8 and 3.1 mm, respectively. The glenoid anteroposterior (AP) (25.3 ± 2.9 mm vs. 23.2 ± 2.4 mm) and superioinferior (36.9 ± 1.9 mm vs. 33.7 ± 2.6 mm) measurements differed by 2.1 and 3.3 mm, respectively, between the males and the females. The ratio between the AP width of the glenoid and the coracoid height was also found to be significantly different (P.05) between the gender groups. These morphometric ratios for the coracoid width (0.66 ± 0.09 mm vs. 0.64 ± 0.08 mm) and the coracoid height (0.55 ± 0.09 mm vs. 0.46 ± 0.07 mm) differed between genders by 0.02 and 0.09, respectively.Measurements taken from computerized tomography scans showed significant differences between genders in absolute measurements and in the ratio of the coracoid height to the glenoid AP distance. This could have implications on the ability of the Latarjet procedure to compensate for bone loss in female patients.

BACKGROUND: The aim of this study was to describe the surgical technique and evaluate functional outcomes following open reduction and internal fixation in patients with scapular fractures. METHODS: In this study, ten patients with scapular fractures with Ideberg type four and five, who had undergone operatively with the Judet approach in three different orthopedic centers between March 2014 and October 2018, were evaluated retrospectively. By the end of at least a 2-year follow-up period, postoperative Disabilities of the Arm, Shoulder and Hand (DASH), Constant question-naires were evaluated by all participating patients.RESULTS: Three of these patients had fractures on the left; seven patients had fractures on the right side, and the average patient age was 35.1 +/- 9.75. Mean Constant and DASH scores were 87.9 +/- 13.68 and 5.57 +/- 5.21, respectively. In two patients, about 2 cm adjacent to the suprascapular notch, perioperative suprascapular nerve injury was stated and sutured using the epineural technique. By the end of the 2-year follow-up of these two patients, infraspinatus muscle atrophy had occurred. However, external rotation muscle strength was 4/5 in both patients.CONCLUSION: This study suggests that scapula fractures extending glenoid articular surface can be safely fixed through the Judet approach and had satisfactory results. In addition, two patients with traumatic suprascapular nerve injury were encountered during the surgery and repaired which may be hard to diagnose with modified or minimal incisional approaches.

Background: Glenoid restoration techniques to address glenohumeral instability–induced anterior and posterior glenoid bone loss (AGBL and PGBL) often require reconstruction, but best-fit bone block (BFBB) modeling has not been developed. Purpose: To provide glenoid bony reconstruction models for anterior and posterior instability of the shoulder using a bone loss instability cohort with high-fidelity 3-dimensional (3D) imaging. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We reviewed consecutive patients indicated for operative stabilization who had posterior glenohumeral instability and suspected GBL who underwent 2-dimensional (2D) computed tomography (CT). Patients were matched by sex, laterality, and age to patients who underwent operative stabilization of anterior glenohumeral instability. Mimics software was used to convert all 2D CT scans into 3D models of the scapula. A BFBB model was designed to digitally reconstruct GBL and was used to predict the amount, anatomic configuration, and fixation configuration of bony reconstruction required in AGBL and PGBL. Results: The study included 30 patients with posterior instability and 30 patients with anterior instability; the participants’ mean ± SD age was 28.8 ± 8.15 years (range, 16.0-51.0 years). Mean surface area of AGBL was 24.9% ± 7.7% (range, 14.7%-39.1%). Mean BFBB dimensions to reconstruct the anterior glenoid were determined to be a superior-inferior length of 23.9 ± 4.2 mm, anterior-posterior width of 6.4 ± 2.4 mm, and height of 1 cm. Mean angle of AGBL bone block interface relative to glenoid to reconstruct the native concavity was 79.4°± 5.9°. For PGBL, the mean surface area was 9.2% ± 5.6% (range, 3.0%-26.3%). Mean BFBB dimensions to reconstruct the posterior glenoid were a superior-inferior length of 21.9 ± 3.4 mm, width of 4.5 ± 2.3 mm, and height of 1 cm. The mean angle of PGBL bone block interface relative to the glenoid to reconstruct the native concavity was 38.6°± 14.3°. Orientation relative to the vertical glenoid axis was 77.2°± 13.8° in anterior reconstructions versus 105.9°± 10.9° in posterior reconstructions. Conclusion: Patients with anterior instability required a more rectangular BFBB with a bone block–glenoid interface angle of 79°, whereas patients with posterior instability required a more trapezoidal, obtusely oriented BFBB with a bone block–glenoid interface angle of 39°. BFBBs for either AGBL or PGBL can be effectively designed, and their size and/or shape can be predicted based on approximate percentage of GBL.

Bone loss of either the glenoid or the humerus is a challenging problem in reverse total shoulder arthroplasty. When left unaddressed, it can lead to early failure of the implant and poor outcomes. Humeral bone loss can be addressed with the use of an endoprosthesis or allograft prosthetic implant. Glenoid bone loss can be treated with a variety of grafting options, such as augmented implants, patient-specific navigation, and implantation systems.

Purpose Surgical treatment of shoulder instability caused by anterior glenoid bone loss is based on a critical threshold of the defect size. Recent studies indicate that the glenoid concavity is essential for glenohumeral stability. However, biomechanical proof of this principle is lacking. The aim of this study was to evaluate whether glenoid concavity allows a more precise assessment of glenohumeral stability than the defect size alone. Methods The stability ratio (SR) is a biomechanical estimate of glenohumeral stability. It is defined as the maximum dislocating force the joint can resist related to a medial compression force. This ratio was determined for 17 human cadaveric glenoids in a robotic test setup depending on osteochondral concavity and anterior defect size. Bony defects were created gradually, and a 3D measuring arm was used for morphometric measurements. The influence of defect size and concavity on the SR was examined using linear models. In addition, the morphometrical-based bony shoulder stability ratio (BSSR) was evaluated to prove its suitability for estimation of glenohumeral stability independent of defect size. Results Glenoid concavity is a significant predictor for the SR, while the defect size provides minor informative value. The linear model featured a high goodness of fit with a determination coefficient of R2 = 0.98, indicating that 98% of the SR is predictable by concavity and defect size. The low mean squared error (MSE) of 4.2% proved a precise estimation of the SR. Defect size as an exclusive predictor in the linear model reduced R2 to 0.9 and increased the MSE to 25.7%. Furthermore, the loss of SR with increasing defect size was shown to be significantly dependent on the initial concavity. The BSSR as a single predictor for glenohumeral stability led to highest precision with MSE = 3.4%. Conclusion Glenoid concavity is a crucial factor for the SR. Independent of the defect size, the computable BSSR is a precise biomechanical estimate of the measured SR. The inclusion of glenoid concavity has the potential to influence clinical decision-making for an improved and personalised treatment of glenohumeral instability with anterior glenoid bone loss.

Background Variations in glenoid morphology affect surgical treatment and outcome of advanced glenohumeral osteoarthritis (OA). The purpose of this study was to assess the inter- and intraobserver reliability of the modified Walch classification using 3-dimensional (3D) computed tomography (CT) imaging in a multicenter research group. Methods Deidentified preoperative CTs of patients with primary glenohumeral OA undergoing anatomic or reverse total shoulder arthroplasty (TSA) were reviewed with 3D imaging software by 23 experienced shoulder surgeons across 19 institutions. CTs were separated into 2 groups for review: group 1 (96 cases involving all modified Walch classification categories evaluated by 12 readers) and group 2 (98 cases involving posterior glenoid deformity categories [B2, B3, C1, C2] evaluated by 11 readers other than the first 12). Each case group was reviewed by the same set of readers 4 different times (with and without the glenoid vault model present), blindly and in random order. Inter- and intraobserver reliabilities were calculated to assess agreement (slight, fair, moderate, substantial, almost perfect) within groups and by modified Walch classification categories. Results Interobserver reliability showed fair to moderate agreement for both groups. Group 1 had a kappa of 0.43 (95% confidence interval [CI]: 0.38, 0.48) with the glenoid vault model absent and 0.41 (95% CI: 0.37, 0.46) with it present. Group 2 had a kappa of 0.38 (95% CI: 0.33, 0.43) with the glenoid vault model absent and 0.37 (95% CI: 0.32, 0.43) with it present. Intraobserver reliability showed substantial agreement for group 1 with (0.63, range 0.47-0.71) and without (0.61, range 0.52-0.69) the glenoid vault model present. For group 2, intraobserver reliability showed moderate agreement with the glenoid vault model absent (0.51, range 0.30-0.72), which improved to substantial agreement with the glenoid vault model present (0.61, range 0.34-0.87). Discussion Inter- and intraobserver reliability of the modified Walch classification were fair to moderate and moderate to substantial, respectively, using standardized 3D CT imaging analysis in a large multicenter study. The findings potentially suggest that cases with a spectrum of posterior glenoid bone loss and/or dysplasia can be harder to distinguish by modified Walch type because of a lack of defined thresholds, and the glenoid vault model may be beneficial in determining Walch type in certain scenarios. The ability to reproducibly separate patients into groups based on preoperative pathology, including Walch type, is important for future studies to accurately evaluate postoperative outcomes in TSA patient cohorts.

Static posterior subluxation of the humeral head is a pre-osteoarthritic deformity preceding posterior erosion in young patients. Its etiology remains unknown. The aim of this study was to analyze the differences in scapular morphology between young patients with pre-osteoarthritic static posterior subluxation of the humeral head and healthy controls with a centered humeral head.We performed a retrospective analysis of all patients with pre-osteoarthritic static posterior subluxation of the humeral head who were treated in our institution between January 2018 and November 2019. Fourteen shoulders in 12 patients were included in this study and then matched according their age, sex, and affected side with controls. Computed tomography images of both groups were compared in the standardized axial imaging plane for differences in scapular morphology. The following parameters were measured: glenoid version relative to the Friedman line and scapular blade axis, scapulohumeral and glenohumeral subluxation index, and neck angle, as well as glenoid and humeral offset.The patients in the subluxation group showed significantly higher scapulohumeral and glenohumeral subluxation indexes than controls (0.76 vs. 0.55 [P.0001] and 0.58 vs. 0.51 [P = .016], respectively). The mean measurements of glenoid version according to the Friedman line and relative to the scapular blade axis were significantly higher in the subluxation group than in controls (19° vs. 4° [P.0001]and 14° vs. 2° [P = .0002], respectively). The glenoid vault was significantly more anteriorly positioned with respect to the scapular blade axis in the subluxation group than in controls (neck angle, 166° vs. 173° [P = .0003]; glenoid offset, 9.2 mm vs. 4.6 mm [P = .0005]). The midpoint of the humeral head showed a posterior offset with respect to the scapular blade axis in the subluxation group, whereas controls had an anteriorly placed midpoint of the humeral head (-2 mm vs. 3.1 mm, P = .01). A higher scapulohumeral subluxation index showed significant correlations with an increased anterior offset of the glenoid vault (increased glenoid offset: r = 0.493, P = .008 and decreased neck angle: r = -0.554, P = .002), a posterior humeral offset (r = -0.775, P.0001), and excessive glenoid retroversion measured by both methods (Friedman line: r = 0.852, P.0001; scapular blade axis: r = 0.803, P.0001). A higher glenohumeral subluxation index also correlated significantly with an increased anterior offset of the glenoid vault (increased glenoid offset: r = 0.403, P = .034; decreased neck angle: r = -0.406, P = .032) and posterior humeral offset (r = -0.502, P = .006).Young patients with pre-osteoarthritic static posterior subluxation of the humeral head have significant constitutional differences in scapular morphology in terms of an increased anterior glenoid offset, excessive glenoid retroversion, and increased posterior humeral offset in relation to the scapular blade compared with healthy matched controls.

Introduction Progressive glenoid bone loss and humeral head subluxation occur in primary glenohumeral osteoarthritis (GHOA), but less is known about the rate and pattern by which this occurs. The purpose of this study was to determine how glenohumeral subluxation and glenoid bone loss changed over time in shoulders that underwent arthroplasty and had been evaluated with radiographs at 1 or more time points over the 5-15 years before arthroplasty. Methods We retrospectively identified 48 shoulders that had been evaluated with high-quality radiographs both before arthroplasty and at least once 5-15 years earlier. Axillary radiographs were used to classify glenoid morphology using the modified Walch classification on the oldest, most recent, and all intervening radiographs. The mean interval time between the oldest and most recent radiographs was 8.9 years (range 5-15 years). Nineteen patients had a single intervening radiograph (mean, 6.7 years from most recent radiograph; range 4.4-8.9 years), 6 patients had 2 (mean, 5.6 years; range 0.2-13.9 years), 3 had 3 (mean, 5 years; range 2.4-8.3 years), 2 had 5 (mean, 3.4 years; range 1.1-5.7 years), and 1 had 6 (0.5 years). Results Glenoid morphology on the earliest radiograph was classified as A1 in 22, A2 in 13, B1 in 1, B2 in 9, B3 in 1, and D in 2 shoulders. Walch A patterns identified on early radiographs most commonly maintained an A pattern over time, but 20% developed eccentric wear with 5 of 35 becoming B type and 2 of 35 becoming a D type before arthroplasty. All B-type glenoids remained B type. Classic progression of bone loss along the same concentric or eccentric “track” occurred 41% of the time, with 9 of 22 A1 glenoids becoming A2 glenoids, the only B1 glenoid becoming a B2 glenoid, and 56% (5/9) of B2 glenoids becoming B3 glenoids before arthroplasty. Only 15% (2/13) of A2 glenoids developed eccentric wear compared with 32% (7/22) of A1 glenoids. Conclusion In primary GHOA, humeral head subluxation and glenoid bone loss do progress over time, but not universally and not always through the same pathway. Shoulders presenting with posterior subluxation (B types) remained posteriorly subluxed. Shoulders presenting with concentric arthritis developed an eccentric pattern 20% of the time. For concentric arthritis, progression of bone loss from A1 to A2 occurred 41% of the time. For eccentric arthritis, progression of bone loss from B2 to B3 occurred 56% of the time.

The purpose was to evaluate short-term changes in condylar and glenoid fossa morphology in infants with Pierre Robin sequence (PRS) undergoing early (age

Background Bone grafting during primary reverse shoulder arthroplasty (RSA) is a technique used to restore poor glenoid bone, increase lateralization, and restore abnormal inclination or version. The purpose of this article is to analyze early outcomes of bone grafting during RSA, assessing the influence of technical and patient considerations. Methods In a 4.5-year time period, 137 RSAs with glenoid bone grafting were performed with a minimum 3 months' follow-up. The mean follow-up was 17 months (range, 3-38). The mean age was 71 years (range, 45-89), and body mass index was 28 (range, 19-44). The source of the autografts were humeral head (n = 113) and iliac crest autograft (ICBG; n = 24). The humeral components included 84 onlay and 53 inlay designs. Results Overall, there were 16 complications (12%), of which 6 were major (5%) (3 graft nonunions and 3 infections) and 10 minor (8%) (1 carpal tunnel syndrome and 9 transient axillary neuropraxias). Of the 9 axillary neuropraxias, 8 resolved by the most recent follow-up, whereas 1 patient was lost to follow-up. There were 4 reoperations (3%): 2 for glenoid baseplate loosening, 1 for severe notching associated with severe glenoid bone loss, and 1 for deep periprosthetic infection. One additional patient had a baseplate failure and is undergoing further treatment. There was no difference in the occurrence of graft nonunions, revision surgery, or glenoid component loosening when comparing type of graft or humeral component used. There was an association of revision surgery (P = .02) with ICBG and older age at the time of surgery (P = .02) and an association of transient neuroapraxia with onlay humeral components (P = .01) and workers' compensation cases (P = .04). Conclusions There is a high union rate and low complication rate after bone grafting of the glenoid performed with RSA. Transient neuropraxias are the most frequent complication, but the majority resolve within the first postoperative year. These early findings can serve as the basis for future long-term, comprehensive analysis of complications and outcomes after bone grafting during RSA.

The Samilson-Prieto classification (SPC) depending on the humeral osteophyte length on a-pX-rays today is widely used to classify glenohumeral osteoarthritis in general. For treatment planning and prognosis, the patho-morphology of the glenoid and static posterior subluxation of the humeral head classified according to Walch is of much higher importance. Here, usually a CT or MRI scan is required for a correct classification. A possible correlation between both classifications is poorly explored. Without it, the complexity of the case might be mis-interpreted using the SPC. The aim of this study was to investigate such a correlation, i.e. whether it correlates with the glenoid deformity and degree of humeral head subluxation. Radiological datasets (X-ray and CT or MRI) of 352 patients with primary OA of the shoulder were evaluated by two observers experienced in shoulder surgery. For the Samilson-Prieto classification, true a-p shoulder radiographs and for the modified Walch classification CT or MRI scans in the axial plane were interpreted using a validated method. To investigate a correlation between both classifications, the Fisher’s exact test was used. For the interobserver reliability, the weighted kappa coefficient κ was determined. For the Walch classification, both observers found a similar percentage for the different types, with decreasing numbers from normal (type A1) to severely altered glenoids In the Samilson-Prieto classification, OA grade I was predominant, while grade II and III showed a relatively equal distribution. Interobserver reliability was high both for the Walch classification with a κ 0.923 (95% confidence interval 0.892; 0.954) and) for the SPC with a κ 0.88 (95% confidence interval 0.843; 0.916). A correlation between the two classifications in Fischer’s exact test could not be shown (p = 0.584). Since there is no correlation between both, using the Samilson-Prieto classification alone might miss relevant prognostic factors in gleno-humeral OA. Adequate imaging of the glenoid morphology also in the axial plane is absolutely mandatory to understand the complexity and chose the right treatment for each patient. Study of Diagnostic Test—Level II.

Background: While the glenoid track concept presents a useful prediction for recurrent glenohumeral instability, little is known about the humeral head bony architecture as it relates to glenoid erosion in the setting of bipolar bone loss. Purpose: To (1) qualitatively and quantitatively analyze the interplay between glenoid bone loss (GBL) and Hill-Sachs lesions (HSLs) in a cohort of patients with anterior instability using 3-dimensional imaging software and (2) assess the relationships between GBL and HSL characteristics. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients were identified who had anterior shoulder instability with a minimum 5% GBL and evidence of HSL confirmed on computed tomography. Unilateral 3-dimensional models of the ipsilateral proximal humeral head and en face sagittal oblique view of the glenoid were reconstructed using MIMICS software (Materialise NV). GBL surface area, width, defect length, and glenoid track width were quantified. The volume, surface area, width, and depth of identified HSLs were quantified with their location (medial, superior, and inferior extent) on the humeral head. Severity of GBL was defined as percentage glenoid bone surface area loss and categorized as low grade (5%-10%), moderate grade (>10% to 20%), high grade (>20% to 30%), and extensive (>30%). Analysis of variance was then computed to determine significance ( P < .05) between severity of GBL and associated HSL parameters. Results: In total, 100 patients met inclusion criteria (mean age, 27.9 years; range, 18-43 years), which included 58 right shoulders and 42 left shoulders (84 male, 16 female). Among groups, there were 32 patients with low-grade GBL (mean GBL = 6.1%), 38 with moderate grade (mean GBL = 16.2%), 17 with high grade (mean GBL = 23.7%), and 13 with extensive (mean GBL = 34.0%), with an overall mean GBL of 18.1% (range, 5%-39%). Patients with 5%-10% GBL had significantly narrower HSLs (average and maximum width; P < .03) and deeper HSLs (average depth; P = .002) as compared with all other GBL groups, while greater GBL was associated with wider and shallower HSLs. GBL width, percentage width loss, defect length, and glenoid track width all significantly differed across the 4 GBL groups ( P < .05). Conclusion: HSLs had significantly different morphological characteristics depending on the severity of GBL, indicating that GBL was directly related to the characteristics of HSLs. Patients presenting with smaller glenoid defects had significantly narrower and deeper HSLs with less humeral head surface area loss, while greater GBL was associated with wider and shallower HSLs.

Glenoid component positioning affects implant survival after total shoulder arthroplasty, and accurate glenoid-component positioning is an important technical aspect.The use of virtual planning and patient-specific instrumentation has been shown to produce reliable implant placement in the laboratory and in some clinical studies.Currently available preoperative planning software programs employ different techniques to generate 3-dimensional models and produce anatomic measurements potentially affecting clinical decisions.There are no published data, to our knowledge, on the effect of preoperative computer planning and patient-specific instrumentation on long-term clinical outcomes.

Glenoid component malpositioning and glenoid component retroversion have been associated with higher rates of radiolucencies, raising concerns about its implications on glenoid loosening and ultimate failure of anatomic total shoulder arthroplasty (TSA). Although there is literature regarding the relative advantages of techniques to address posterior glenoid bone loss, we are not aware of studies comparing outcomes of TSA on these challenging Walch type B2 glenoids vs. more common A1 glenoids. The purpose of this study is to compare outcomes of TSA performed on A1 glenoids and B2 glenoids treated with asymmetric glenoid reaming.We identified 1045 shoulders that had primary TSAs performed for osteoarthritis in a prospective shoulder arthroplasty registry. Two hundred eighty-nine shoulders met inclusion criteria of a preoperative Walch type A1 (178) or B2 (111) glenoid morphology, treatment with TSA, asymmetric reaming in the B2 group, and a minimum of 2-year clinical and radiographic follow-up. Postoperative radiographs were assessed for lucencies, and patient-reported outcome measures were collected at all follow-up visits.Follow-up averaged 40 ± 15 months for all patients, and more men presented with a B2 glenoid (80 of 111; 72%) compared with A1 (101 of 178; 57%) (P = .009). Age at surgery (P = .166), dominant-sided surgery (P = .281), body mass index (P = .501), smoking (P = .155), preoperative opioid use (P = .154), and diabetes (P = .331) were not significantly different between groups. Both groups had similar Constant Strength scores preoperatively (A1: 4.7 ± 7.1, and B2: 4.3 ± 7.3) but the B2 group improved significantly more at final follow-up (A1: 10.3 ± 6.2 vs. B2: 12.7 ± 6.7, P = .005). The Total Constant score was also significantly better at follow-up in the B2 glenoid group (P = .039). All other Constant subscales, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and Single Assessment Numerical Evaluation (SANE) measures showed significant improvement preoperatively to final follow-up (all P.001) but there were no significant differences between the A1 and B2 glenoid groups (all P.05). A similar proportion of patients rated their satisfaction as either very satisfied or satisfied between the A1 (160; 90%) and B2 (100; 90%) (P = .613). Lazarus scores were also similar between the A1 and B2 groups (P = .952) as were the rates of humeral radiolucent lines (P = .749) and humeral osteolysis (P = .507).Although patients with B2 glenoids may present a more technically challenging anatomic total shoulder arthroplasty, treatment with concurrent asymmetric glenoid reaming produced similar, successful clinical and radiographic early to midterm outcomes for patients undergoing TSA compared with A1 glenoids. Additional follow-up on this cohort will be important to confirm the durability of these early results.

Background This study aimed to investigate the three-dimensional (3D) anatomical relationship between the suprascapular nerve and scapula, and the method of protecting the suprascapular nerve in reverse total shoulder arthroplasty (RTSA) Methods In the present study, 12 fresh adult cadaver shoulder specimens were dissected. X-ray and computed tomography (CT) were used to investigate the 3D scapular and suprascapular nerve images. Results The results revealed that the best fitting baseplate diameter was 24.73 ± 1.56 mm. Furthermore, the baseplate diameter correlated with the glenoid cavity width. After the osteotomy, a simulated screw placement on the baseplate was performed. The dangerous area for the posterior screw placement was at the angle between the upper edge and transverse axis exceeding 38° and between the lower edge and transverse axis exceeding 76°. The distance between the nearest point of the nerve and osteotomy plane was 15.38 ± 2.02 mm, and the angle between the projection point of the nearest point and transverse axis was 27.33 ± 7.96°, which was the dangerous area for retractor placement. The suitable angle between the superior screw and longitudinal axis was 21.67 ± 13.27°, and the suitable superior screw length was 34.66 ± 2.41 mm. Conclusion In RTSA, the baseplate size correlates with the glenoid cavity width. The relationship between the screw and suprascapular nerve and retractor placement position should be carefully considered to avoid damaging the suprascapular nerve.

Joint replacement surgery as a treatment for glenohumeral arthritis with glenoid bone loss is challenging. The aim of this study is to offer an anatomical orientation for glenoid reconstruction. In this study, we measured size, inclination and version of the glenoid surface, as well as the distance between the articular line of the glenoid, base of the coracoid process, and acromion using computer tomographic (CT) imaging of 131 study participants aged 19–88 years in the period of 2010–2013. We measured a mean distance of 6.5 ± 0.2 mm from the glenoid articular line to the base of the coracoid process in the transverse CT plane. Body height has shown no significant impact on the glenoid morphology. We observed significant differences between males and females: The glenoid appeared to be located 5.2 ± 0.9 mm higher and the humeral head was 4.5 ± 0.7 mm larger in male subjects compared with females (r = .699; p

Introduction Anatomic total shoulder arthroplasty (TSA) is a proven treatment for glenohumeral joint osteoarthritis, with superior results compared with hemiarthroplasty. However, glenoid component loosening remains a problem and is one of the most common causes of failure in TSA. Multiple component designs have been developed in an attempt to reduce loosening rates. The purpose of this study was to evaluate risk of revision after anatomic TSA according to the glenoid component design. Methods We conducted a cohort study including patients aged ≥18 years who underwent primary elective TSA for the diagnosis of osteoarthritis between 2010 and 2017. Patients with missing implant information, who received stemless humeral implants, or who received augmented glenoid implants, were excluded. Glenoid component designs used were categorized into 4 mutually exclusive treatment groups: polyethylene central-pegged ingrowth, polyethylene-metal hybrid, polyethylene all-cemented pegged, and polyethylene cemented keeled. Multivariable competing risk regression was used to evaluate the risk of glenoid loosening as a cause-specific revision by the glenoid component design. Results Of the 5566 TSA included in the final cohort, 39.2% of glenoid implants were polyethylene central-pegged ingrowth, 31.1% were polyethylene-metal hybrid, 26.0% were polyethylene all-cemented pegged, and 3.6% were polyethylene cemented keeled. At 6-year final follow-up, 4.1% of TSA were revised for any cause, and 1.4% for glenoid loosening. Compared with the polyethylene central-pegged ingrowth design, no difference in glenoid loosening revision risk was observed for the polyethylene-metal hybrid design (hazard ratio [HR] = 1.15, 95% confidence interval [CI] = 0.42-3.20). However, both the polyethylene all-cemented pegged (HR = 2.48, 95% CI = 1.08-5.66) and polyethylene cemented keeled (HR = 3.84, 95% CI = 1.13-13.00) designs had higher risks for revision due to glenoid loosening. Conclusions We observed glenoid component designs to be associated with differential risks in revision due to glenoid loosening with polyethylene all-cemented pegged glenoids and polyethylene cemented keeled glenoids having higher risks when compared with polyethylene central-pegged ingrowth glenoids. Surgeons may want to consider the glenoid component design when performing anatomic TSA.

Background Bony defects are common injuries associated with anterior shoulder dislocation. It is generally thought that these bony defects are created at the time of dislocation. However, there have been no biomechanical reports demonstrating the exact time point when these lesions occur. The purpose of this study was to clarify when, how, and which types of bony defects were created during experimental dislocation in cadaveric shoulders. Methods Fifteen fresh-frozen cadaveric shoulders (mean age at the time of death, 79 years) were fixed in a custom testing machine. First, the glenohumeral joint was inspected by arthroscopy. Then, the arm was held at 60° of abduction and maximum external rotation and was manually extended horizontally under fluoroscopy until an anterior dislocation occurred. Next, a force of 800 N was applied to a Kirschner wire inserted in the humeral head in the direction of the pectoralis major with use of an air cylinder. We waited until the arm came to equilibrium under this condition. Finally, the glenohumeral joint was arthroscopically examined. We further performed x-ray micro–computed tomography and histologic examination in 1 shoulder with a bipolar lesion. Results After the anterior dislocation, a Bankart lesion was created in 9 of 15 shoulders and a fragment-type glenoid defect (avulsion fracture) was created in 4. A Hill-Sachs lesion, on the other hand, was not observed after the dislocation. The equilibrium arm position was 40° ± 17° in flexion, 45° ± 22° in abduction, and 27° ± 19° in external rotation. In this arm position, newly created lesions were Hill-Sachs lesions in 6 shoulders and erosion-type glenoid defects (compression fracture) in 7. Micro–computed tomography, performed in a single specimen, showed a flattened anterior glenoid rim with collapse of trabecular bone. Histologic analysis of nondecalcified sections using hematoxylin-eosin staining indicated that the anterior rim of the glenoid was compressed and flattened. The cortex of the anterior glenoid rim could be clearly observed. Conclusion The fragment-type glenoid defect (avulsion fracture) was observed at the time of dislocation, whereas the erosion-type defect (compression fracture) was observed when the arm came to equilibrium in the midrange of motion. Hill-Sachs lesions were created not at the time of dislocation but after the arm came to equilibrium.

Shoulder osteoarthritis (OA) is a common and debilitating condition and a source of high morbidity and medical expenditures across the world among individuals older than 60 years. Shoulder OA results in the gradual destruction of articular cartilage of the humeral head and glenoid component, causing inflammation, pain, and a restricted range of motion. Most patients are diagnosed with shoulder OA after experiencing shoulder pain and stiffness, and the diagnosis is often made after medical and physical histories are obtained and physical and imaging examinations are performed. Use of various surgical techniques such as total anatomic or reverse shoulder arthroplasty and hemiarthroplasty has increased in recent years, resulting in reduced morbidity and improved functional status of patients. However, the rate of surgical complications such as premature loosening of components is significant, reducing the effectiveness of such procedures. Data in the literature indicate that high-grade fatty infiltration of the rotator cuff muscle before surgery is associated with postoperative glenoid component loosening. High-grade rotator cuff fatty infiltration and atrophy have been found to be associated with more severe Walch classification-based glenoid morphology subtypes, increased joint line medialization, glenoid bone loss, and increased pathologic glenoid version. The authors describe how advanced imaging techniques are used for preoperative evaluation of the shoulder and discuss how to measure glenoid version and bone stock and classify glenoid morphology types on the basis of Walch classification, as these parameters are commonly used in surgical planning. Methods involving the use of Friedman and paleoglenoid lines for respective measurements are illustrated by using three-dimensional CT and MRI case examples. ©RSNA, 2020.

Total shoulder arthroplasty (TSA) is commonly performed for shoulder osteoarthritis (OA). Uncemented metal-backed (MB) glenoid components were introduced in an attempt to avoid glenoid loosening. New Zealand and Australian Joint Registry studies have shown significantly higher revision rates when uncemented MB glenoids are used. We used the New Zealand Joint Registry (NZJR) to compare all-cause revision rates and functional scores for TSA and investigated the trends of glenoid fixation used in New Zealand.The NZJR was accessed for all primary TSA undertaken for OA from January 2000 to December 2017. Patient demographics were collated. All-cause revision rates were reported as rate per 100 component-years. Analysis was repeated excluding the uncemented SMR L2 glenoid (LimaCorporate), as it was a potential confounder. Kaplan-Meier survival analysis was performed. Oxford Shoulder Scores at both 6 months and 5 years were analyzed.A total of 2613 TSAs were performed for OA during the study period, representing 85.0% of all TSAs in New Zealand. Overall, 62.1% of the patients were female. In addition, 69.6% of glenoids were cemented and 30.4% uncemented. The most common uncemented MB glenoid was SMR 86.6% (LimaCorporate), and cemented was Global (DePuy) 49.8%. The revision rate for TSA with uncemented glenoids was significantly higher at 2.03 compared with cemented at 0.41 per 100 component-years (P.001). Hazard ratio 5.0 for revision of uncemented glenoids. No significant difference was found in Oxford Scores at 6 months (39.7 vs. 40.3, P = .13) or 5 years (42.1 vs. 42.8, P = .22). The most common mode of failure was glenoid loosening in cemented glenoids (44.4%), and component failure in uncemented (34.8%). Revision for rotator cuff, deep infection, and instability were comparable between groups. When excluding SMR L2, uncemented MB glenoid all-cause revision rates remained significantly higher than cemented (1.42 vs. 0.41 per 100 component-years, P.001). SMR L1 uncemented MB glenoids had a higher revision rate than the non-SMR uncemented glenoids (1.61 vs. 0.18 per 100 component-years, P = .009). Uncemented glenoid use peaked in New Zealand in 2011 at 46.7% of TSAs but declined to 20.1% in 2017.In the NZJR, primary TSAs undertaken for OA have a significantly higher all-cause revision rate when the glenoid component is uncemented. Uncemented glenoids have a 5.0 times higher revision rate. Excluding SMR L2 glenoids from the analysis, the significantly higher revision rate remained for uncemented glenoids. These data reaffirm that uncemented MB glenoids are associated with higher revision rates.

Objective: To assess whether Bare Spot is previously displaced by proportion (MEASURE BP-A × 1.25/MEASURE BP-P = 1). Methods: 35 patients with surgical indication for rotator cuff injury repair were evaluated. The distances from the Bare Spot to the anterior edge of the glenoid cavity (BS-A) and to the posterior edge (BS-P) were measured by arthroscopy and computed tomography with three-dimensional reconstruction of the scapula. Results: The distance from the Bare Spot to the anterior border (BS-A tc) was 11.6 mm with a median 12 mm; The distance to the posterior border (BS-P tc) was on average 15.5 mm with a median 15 mm. The distances from BS to anterior cavity edge measured by arthroscopy were on average (BS-A video) 12.25 mm with a median of 12 mm, and from BS to posterior edge (BS-P video) 16.25 mm on average with median 16 mm (p < 0.005). Conclusion: Bare Spot is displaced anteriorly at a proportion of 40% of the anterior margin and 60% of the posterior margin. Level of Evidence II - Development of diagnostic criteria on consecutive patients (with universally applied reference “gold standard”). RESUMO Objetivo: Avaliar in vivo se o Bare Spot (BS) se encontra deslocado anteriormente conforme a proporção (MEDIDA BP-A × 1,25/MEDIDA BP-P = 1). Métodos: 35 pacientes com indicação cirúrgica de reparo de lesão do manguito rotador foram avaliados. As distâncias do Bare Spot à borda anterior da cavidade glenoidal (BS-A) e à borda posterior (BS-P) foram mensuradas na artroscopia e na tomografia computadorizada com reconstrução tridimensional da escápula. Resultados: A distância do BS à borda anterior (BS-A tc) foi de 11,6 mm com mediana de 12 mm; a distância à borda posterior (BS-P tc) foi, em média, 15,5 mm com mediana de 15 mm. As distâncias do BS à borda anterior da cavidade medidas na artroscopia foram, em média (BS-A vídeo), 12,25 mm com mediana de 12 mm e do BS à borda posterior (BS-P vídeo) de 16,25 mm, em média, com mediana de 16 mm (p < 0,005). Conclusão: O BS se encontra deslocado anteriormente a uma proporção de 40% da margem anterior e 60% da margem posterior. Nível de Evidência II - Desenvolvimento de critérios diagnósticos em pacientes consecutivos (com padrão de referência “ouro” aplicado).

Anatomic total shoulder arthroplasty is the gold standard shoulder replacement procedure for patients with an intact rotator cuff and sufficient glenoid bone to accommodate prosthetic glenoid implant and offers reliable patient satisfaction, excellent implant longevity, and a low incidence of complications. Disparity exists in the literature regarding rehabilitation strategies following anatomic total shoulder arthroplasty. This article presents a consensus statement from experts in the field on rehabilitation following anatomic total shoulder arthroplasty. The goal of this consensus statement is to provide a current evidence–based foundation to inform the rehabilitation process after anatomic total shoulder arthroplasty. These guidelines apply to anatomic total shoulder arthroplasty (replacement of the humeral head and glenoid), hemiarthroplasty (replacing only the humeral head), and hemiarthroplasty with glenoid reaming or resurfacing. The consensus statement integrates an extensive literature review, as well as survey results of the practice patterns of members of the American Society of Shoulder and Elbow Therapists and the American Shoulder and Elbow Surgeons. Three stages of recovery are proposed, which initially protect and then gradually load soft tissue affected by the surgical procedure, such as the subscapularis, for optimal patient outcomes. The proposed guidelines should be used in collaboration with surgeon preferences and patient-specific factors. LEVEL OF EVIDENCE: Level IV; Expert Opinion

Background Structural bone graft for reconstruction of glenoid bone stock is often necessary in the setting of revision shoulder arthroplasty. This study introduces a new structural autograft technique using the distal clavicle for treatment of glenoid bone loss in the setting of revision shoulder arthroplasty. Methods This is a retrospective, single-surgeon study of patients with significant glenoid bone loss requiring revision shoulder arthroplasty with autologous distal clavicle bone grafting to the glenoid. Twenty patients with failed shoulder arthroplasty who underwent revisions of their glenoid components between 2015 and 2019 were retrospectively identified. Sixteen patients were available with follow-up of greater than 1 year. Patient records and radiographs were reviewed for intraoperative and postoperative complications. Preoperative and postoperative function were evaluated by physical examination and patient-reported outcome surveys. Results There were no observed intraoperative complications relating to the distal clavicle autograft harvest or placement. There were no iatrogenic nerve injuries or intraoperative instability. One of the 16 patients developed postoperative loosening and subsequent failure of the glenoid baseplate, requiring revision. One additional patient demonstrated increased elevation of the coracoclavicular interval postoperatively, likely related to the distal clavicle autograft harvest. At a mean follow-up of 25 months, 15 of 16 glenoid implants remained well fixed (93.4%), with no evidence of infection, or impingement demonstrated radiographically or clinically. Average patient age was 69 years at the time of surgery. Forward elevation improved from 76° to 123° at final follow-up (P = .0002). The American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score improved from an average of 35.8 to 67.8 at mean follow-up (P = .001). The visual analog scale score improved from an average of 5.9 to 2 at mean follow-up, though not statistically significant (P = .068). There was no significant change in external rotation following surgery (P = .319). Conclusion Osteolysis and bone loss of the glenoid poses a challenging problem in revision shoulder arthroplasty. Distal clavicle autograft augmentation is a viable and reproducible technique to manage structural glenoid defects.

Background A large engaging Hill-Sachs lesion (HSL) with subcritical glenoid bone loss (GBL) is approached through either increasing the glenoid arc by the Latarjet procedure or converting the HSL to an extra-articular defect by arthroscopic Bankart repair with remplissage (BRR). Until now, there has been no evidence-based consensus about which of these 2 most appropriate procedures is the better surgical choice. The purpose of this study was to analyze the current literature comparing results of BRR vs. the Latarjet procedure in the treatment of engaging HSLs with subcritical GBL. Methods A comprehensive review of the PubMed and Cochrane databases was completed for studies that compared the clinical outcomes and complications of BRR vs. the Latarjet procedure with minimum follow-up of 2 years. The outcome measures analyzed included postoperative Rowe score, visual analog scale pain score, postoperative range of motion (ROM), and rates of recurrent instability and other complications. Results Overall, 4 articles (level III evidence in 3 and level II in 1) were included from an initial 804 abstracts. The study population consisted of a total of 379 patients, of whom 194 underwent BRR and 185 underwent the Latarjet procedure. There were no unacceptable differences in baseline characteristics between the 2 groups. For the rate of recurrent instability, both groups had comparable risk ratios (RRs) (N = 379; RR, 0.72; 95% confidence interval [CI], 0.37-1.41). The risk of other complications was significantly increased with the Latarjet procedure (by about 7 times) relative to the the BRR procedure (N = 379; RR, 7.37; 95% CI, 2-27). Both groups had comparable postoperative Rowe scores (n = 190; mean difference [MD], –0.9; 95% CI, –3.45 to 1.7) and visual analog scale pain scores (n = 347; MD, –0.2; 95% CI, –0.6 to 0.2). Moreover, both groups had comparable postoperative external rotation ROM (MD, –1.7°; 95% CI, –9.4° to 6°) and internal rotation ROM (MD, 1.95°; 95% CI, –5.35° to 9.25°). There was substantial heterogeneity in the effect of both procedures on postoperative pain and ROM (external rotation and internal rotation). Conclusion Both the BRR and Latarjet procedures are effective for the management of engaging HSLs with subcritical GBL and give comparable clinical outcomes. However, given the fewer overall postoperative complications, remplissage may be safer. The results of the included studies were adequately consistent for most analyzed outcomes. However, for the intervention effect on postoperative pain and ROM, there was a small body of evidence, limiting the strength of the reported conclusions.

Background Recent studies have shown variations in glenoid bone density in asymmetric wear patterns but have yet to analyze non-arthritic or concentrically worn glenoids. Questions/Purposes The purpose of this study is to characterize and compare subchondral glenoid bone densities in both non-arthritic and A1, A2, B1, B2 and B3 osteoarthritic glenoids, as well as to assess uniformity in symmetric and asymmetric erosion wear patterns. Methods In all, 150 computerized tomography (CT) scans containing equal numbers of non-arthritic (N), A1, A2, B1, B2 and B3 glenoids were segmented semi-automatically. Each reconstructed glenoid was divided first into anterior and posterior quadrants, and then further subdivided into four quadrants. Volumes of interest (VOI) were defined at depths of 0–2.5 mm (Zone A), 2.5–5 mm (Zone B) and 5–7.5 mm (Zone C). Average bone densities were measured at each VOI depth and in each quadrant. Results Osteoarthritic glenoids had higher mean bone densities than N glenoids. Mean bone densities were uniform amongst all quadrants for N glenoids, but not for osteoarthritic glenoids. In A1 glenoids, the antero-superior quadrant was less dense in Zone C. A2 glenoids had increased bone density measured posteriorly in Zones B and C. In B1 and B2 glenoids, Zones B and C demonstrated increased bone densities of posterior quadrants compared to anterior quadrants. B3 glenoids presented similar results as A1 and A2 glenoids. Cystic changes were more pronounced in anterior quadrants of A2, B1, B2 and B3 glenoids. Conclusion This study demonstrates that osteoarthritic glenoids have greater bone density than non-arthritic glenoids, independent of depth of interest. It also confirms that N glenoids have uniform erosion wear patterns and that B1 and B2 glenoids have irregular wear patterns. It is the first study to reveal that A1, A2 and B3 glenoids, though geometrically symmetrical, have irregular bony densities similar to B2 glenoids. These findings have clinical implications for reaming the glenoid and implant fixation. Level of evidence Basic Science, Anatomy, Imaging.

Background Wedge-shaped porous metal augments were used to address bone deficiency in shoulder arthroplasty as part of a hybrid combination of high-density polyethylene, polymethyl methacrylate bone cement, and porous metal implant. This article presents an ongoing review of the use of the generically designed augments in the shoulder to address glenoid retroversion as part of anatomic total shoulder arthroplasty (aTSA). Materials Seventy-five shoulders in 66 patients (23 women and 43 men, aged 42-85 years) with Walch grade B2 or C glenoids underwent porous metal glenoid augment (PMGA) insertion as part of aTSA. Patients underwent preoperative 3-dimensional (3D) templating; based on that planning, patients received either a 15° or 30° PMGA wedge (secured by screws to the native glenoid) to correct excessive glenoid retroversion before a standard glenoid component was implanted using bone cement. Neither patient-specific guides nor navigation were used. Intraoperative glenoid alignment was assessed using a reusable guide that referenced the anterior scapular neck. Patients were prospectively assessed using shoulder functional assessments (Oxford Shoulder Score [OSS], American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES], visual analog scale [VAS] pain scores, and forward elevation [FE]) preoperatively; at 3, 6, and 12 months postoperation; and yearly thereafter, with similar radiologic surveillance. Results Of the total consecutive series, 49 shoulders had a follow-up of greater than 24 months, with a median follow-up of 48 months (range: 24-87 months). For this cohort, median outcome scores improved for OSS (21 to 44), ASES (24 to 92), VAS (7 to 0), and FE (90° to 140°) from preoperative outcomes to the most recent review, respectively. Four patients died, but no others were lost to follow-up. Apart from 1 infection at 18 months postoperatively and 1 minor peg perforation, there were no complications, hardware failures, implant displacements, significant lucency, or posterior resubluxations. Radiographs showed good incorporation of the wedge augment, with correction of glenoid retroversion from median 22° (13° to 46°) to 4° (17° to anteversion 16°). All but 4 glenoids were corrected to within the target range (less than 10° retroversion), and only 2 glenoid components were implanted outside 15° of neutral glenoid version. Conclusions The porous metal wedge–shaped augments effectively addressed posterior glenoid deficiency as part of aTSA for rotator cuff intact osteoarthritis, producing satisfactory clinical outcomes with no signs of impending future failure.

Background: Posterior glenohumeral instability is an increasingly recognized cause of shoulder instability, but little is known about the incidence or effect of posterior glenoid bone loss. Purpose: To determine the incidence, characteristics, and failure rate of posterior glenoid deficiency in shoulders undergoing isolated arthroscopic posterior shoulder stabilization. Study Design: Cohort study; Level of evidence, 3. Methods: All patients undergoing isolated posterior labral repair and glenoid-based capsulorrhaphy with suture anchors between 2008 and 2016 at a single institution were identified. Posterior bone deficiency was calculated per the best-fit circle method along the inferior two-thirds of the glenoid by 2 independent observers. Patients were divided into 2 groups: minimal (0%-13.5%) and moderate (>13.5%) posterior bone loss. The primary outcome was reoperation for any reason. The secondary outcomes were military separation and placement on permanent restricted duty attributed to the operative shoulder. Results: A total of 66 shoulders met the inclusion criteria, with 10 going on to reoperation after a median follow-up of 16 months (range, 14-144 months). Of the total shoulders, 86% (57/66) had ≤13.5% bone loss and 14% (9/66) had >13.5%. Patients with moderate posterior glenoid bone loss had significantly greater retroversion (−11.5° vs −4.3°; P = .01). Clinical failure requiring reoperation was seen in 10.5% of patients in the minimal bone deficiency group and 44.4% in the moderate group ( P = .024). There was no difference between groups in rate of military separation or restricted duty. Patients with moderate posterior glenoid bone deficiency were more likely to be experiencing instability instead of pain on initial presentation ( P < .001), were more likely to have a positive Jerk test result ( P = .05), and had increased glenoid retroversion ( P = .01). Conclusion: In shoulders with moderate glenoid bone deficiency (>13.5%) and increased glenoid retroversion, posterior capsulolabral repair alone may result in higher reoperation rates than in shoulders without bone deficiency.

Morphology of glenoid fossa might help the clinician in the diagnosis, establishing more biological treatment modalities and treatment response between patients with different skeletal malocclusions. This study aimed to assess the glenoid fossa morphology in different sagittal facial types using CBCT. The CBCT images of 64 patients with normal vertical growth patterns were classified into class I, class II, and class III based on the skeletal sagittal analysis. Depth, width, and angle of glenoid fossa were measured and assessed on CBCT images. One-way analysis of variance (ANOVA) and Tukey post-hoc test were used to compare mean values among the groups. There was a significant statistical difference in means of glenoid fossa' width between groups with skeletal class III and skeletal class I (P value: 0.038). However, no significant statistical differences were found in angle(P value = 0.18) and depth (P value = 0.40) of glenoid fossa among 3 groups. This study showed the glenoid fossa in class I patients was wider than class III patients. There were no statistically significant differences in the angle and depth of glenoid fossa in patients with a different sagittal skeletal pattern.

Background The purpose of this study was to compare long-term outcomes, complications, and reoperation rates of primary reverse total shoulder arthroplasty (RTSA) performed at a single institution using 2 implant designs: a Grammont medialized prosthesis (medialized [M] group) and a Frankle glenoid-based lateralized prosthesis (glenoid-lateralized [GL] group). Methods Between 2004 and 2008, 100 consecutive single-institution primary RTSAs were performed by reconstructive shoulder surgeons who were not design consultants, with the aim of obtaining 10-year follow-up: 56 in the M group and 44 in the GL group. Patients were followed up until death, until revision surgery, or for a minimum of 10 years. Results Of 100 patients, 87 had more than 2 years' follow-up (mean, 77 months). A subset analysis of 41 patients with an average of 10.2 years' follow-up showed sustained long-term outcomes. RTSA provided clinical improvements without significant differences between the M and GL groups, except for improved active forward elevation in the M group (144° in M group vs. 115° in GL group, P = .002). Reoperation was required in 6 shoulders (10-year cumulative incidence of 3 [5%] in M group vs. 3 [8%] in GL group) for a total of 16 complications (10-year cumulative incidence of 8 [14%] in M group vs. 8 [20%] in GL group). Notching rates were significantly higher in the M group (77% in M group vs. 47% in GL group, P = .013); differences in severe notching (grade 3 or 4) were clinically relevant but did not reach statistical significance (23% in M group vs. 9% in GL group, P = .22). Conclusion Primary RTSA using these first 2 prosthesis designs was associated with good outcomes and low reoperation (5%-8%) and complication (14%-20%) rates at 10 years. The M group had higher rates of notching. These results may provide a benchmark for comparison with newer implants, especially considering that these results include the early RTSA implantation learning curve.

© 2019 Journal of Shoulder and Elbow Surgery Board of Trustees Background: The purpose of this study was 2-fold: (1) to quantify type E2 bone loss orientation and its association with rotator cuff fatty infiltration and (2) to examine reverse baseplate designs used to manage type E2 glenoids. Methods: Computed tomography scans of 40 patients with type E2 glenoids were examined for pathoanatomic features and erosion orientation. The rotator cuff fatty infiltration grade was compared with the erosion orientation angle. To compare reconstructive options in light of the pathoanatomic findings, virtual implantation of 4 glenoid baseplate designs (standard, half wedge, full wedge, and patient-matched) was conducted to determine the volume of bone removal for seating and impingement-free range of motion. Results: The mean type E2 erosion orientation angle was 47° ± 17° from the 0° superoinferior glenoid axis, resulting in the average erosion being located in the posterosuperior quadrant directed toward the 10:30 clock-face position. The type E2 neoglenoid, on average, involved 67% of the total glenoid surface (total surface area, 946 ± 209 mm2; neoglenoid surface area, 636 ± 247 mm2). The patient-matched baseplate design resulted in significantly (P ≤.01) less bone removal (200 ± 297 mm3) for implantation, followed by the full-wedge design (1228 ± 753 mm3), half-wedge design (1763 ± 969 mm3), and standard (non-augmented) design (4009 ± 1210 mm3). We noted a marked difference in erosion orientation toward a more superior direction as the subscapularis fatty infiltration grade increased from grade 3 to grade 4 (P

Introduction Axillary nerve injury is a major complication of shoulder surgery during glenoid exposure. The aim of this study was to measure the mean distance between the inferior glenoid and the axillary nerve in healthy shoulders and then to compare this distance between osteoarthritic and rotator cuff deficient glenohumeral joints. Methods The magnetic resonance images of 50 patients with normal glenohumeral joints were reviewed. The infra-glenoid tubercle was determined as a fixed point and the distance to the axillary nerve was measured. Two separate assessors measured on the same sagittal sections. With a study power of 80%, the sample needed in each comparison group was 28 patients. Measurements were then performed on scans in patients with osteoarthritis and cuff tear arthropathy. The mean distance was compared between groups. Results The mean distance between the infra-glenoid tubercle and axillary nerve was 12mm (standard deviation, SD, 5.6mm) in normal shoulders, 10.6mm (SD 5.4mm) in shoulders with osteoarthritis and 9.7mm (SD 3.7mm) in those with cuff tear arthropathy. For this sample size of 50 patients with a confidence interval of 95%, the mean range is 12mm (95% CI 10.4–13.6). A comparison between normal shoulder and osteoarthritis showed a p-value of 0.3, and between normal and cuff tear arthropathy a p-value of 0.06. This was not statistically significant. Conclusions The axillary nerve lies on average 12mm from the infra-glenoid tubercle. The presence of inferior osteophytes in glenohumeral osteoarthritis and the proximal migration of humeral head in cuff tear arthropathy does not seem to alter the course of the nerve significantly in relation to the inferior glenoid tubercle.

Purpose This study sought to assess the relationships between a morphological characteristic of the superior semicircular canal (SSC) and both the roof thickness of the glenoid fossa (GF) and bone changes of the temporomandibular joint (TMJ) on three-dimensional images. Methods Cone-beam computed tomography (CBCT) images of 200 individuals (105 females and 95 males; 400 temporal bone regions) were examined by two different observers. The correlations between the bone thickness overlying the SSC and the thickness of the roof of the GF with TMJ's bone pathologies were analyzed. Results The superior semicircular canal dehiscence (SSCD) was significantly associated with dehiscence of the roof of the GF. The relationship between the dehiscence of the SSC and the roof thickness of the GF was found to be strongly correlated (p < 0.05). There were no statistically significant differences between the bone changes of TMJ and the presence or absence of the SSCD. Conclusions A correlation between the bone thickness overlying the SSC and the roof thickness of the GF was found. However, there was no relationship between the bone thickness overlying the SSC and bone changes of TMJ.

The aim of this study was to evaluate temporomandibular joint (TMJ) condyle and glenoid fossa morphology with measurements on Computed Tomography (CT) and volumetric analysis using InVesalius software program. 250 condyles in 125 patients (mean age: 40.64) was evaluated on CT. Length, width, and height of the condyle, condylar volume, the thickness of glenoid fossa (TGF), condyle surface area, anterior space (AS), superior space (SS), and posterior space (PS) were measured in this study. Two left and right sides of the jaw have been measured. Linear measurements were performed with the image analysis program (Image J, 1.4 v version, National Institutes of Health, Bethesda, MD). Volume and surface area measurements were performed with InVesalius software (CTI, Campinas, SaoPaulo, Brazil). To compare the dimensions of the condyle between males and females, there was only a significant difference in left AS and SS and no significant difference was found between males and females in other measured factors. There was a significant difference between the age groups and left SS. A significant difference was also found between the age groups and condylar height, condyle surface area, and condylar volume on both right and left sides. Evaluation of condylar morphology is important to assess the TMJ anomalies and bony changes. This study showed no significant differences between gender and all measured factors except in the left AS and SS. However, age factor had a major effect on the morphology.

Glenoid bony lesions play a role in approximately half of anterior shoulder instability cases. The purpose of this study is to see if the anatomy of the coracoid affects the location of glenoid rim defects. We hypothesized that a prominent coracoid (lower and lateral) would be more likely to cause an anterior–inferior glenoid lesion, and a less prominent coracoid more prone to cause an anterior lesion. The null hypothesis being the absence of correlation. Fifty-one shoulder CT-scans from a prospective database, with 3D reconstruction, were analyzed. The position of glenoid lesions was identified using the validated clock method, identifying the beginning and end time. The size of bony glenoid defects was calculated using the validated glenoid ratio method. The position of the coracoid tip was measured in three orthogonal planes. Analysis included 25 right shoulders and 26 left shoulders in seven females and 41 males. The vertical position of the coracoid tip relative to the top of the glenoid was highly correlated to the location of the glenoid defect on the profile view (r = −0.625; 95% CI 0.423–0.768; p = 0.001). Thus, higher coracoids were associated with anterior lesions, while lower coracoids were associated with anterior–inferior lesions. A more laterally prominent coracoid was also correlated with anterior–inferior lesions (r = 0.433; 95% CI 0.179–0.633; p = 0.002). This study shows that coracoid anatomy affects the location of bony Bankart defects in anterior shoulder instability. Lower and laterally prominent coracoids are associated with anterior–inferior lesions. This variation in anatomy should be considered during pre-op planning for surgeries involving bone graft. Level 4 basic science.

The segment of the axillary nerve (AxN) near the glenoid rim is at risk of iatrogenic lesion during arthroscopic procedures. We hypothesize that the distance between the AxN and the glenoid rim is not modified by the patient’s positioning. The primary objective was to compare the position of the AxN with the inferior glenoid rim in lateral decubitus or in beach chair and positions of the upper limb. Sixteen shoulders were dissected in beach chair position with the shoulder in neutral rotation. Needle one was placed in the axillary nerve where it was the closest with the inferior glenoid rim. In lateral decubitus with traction and 70° of abduction needle two was placed in the AxN at the closest with the inferior glenoid rim. The glenoid rim was marked with a needle at 6 o’clock. In beach chair position, the distance between needle one and the glenoid needle was measured for six positions. In lateral decubitus, measures were done for two positions of abduction. In lateral decubitus with 70° of abduction, the distance between needle two and the glenoid needle was also measured. The mean distance between AxN and the inferior glenoid rim was 14.4 mm in reference position in beach chair. The results showed the absence of difference between the positions during surgery except for lateral decubitus with 70° of abduction. Our study showed that the position of the shoulder during arthroscopic procedures cannot take away the AxN from the inferior glenoid rim. Level IV—basic science study

For proper treatment of recurrent anterior instability of the shoulder with a bone defect, the defect size should be assessed preoperatively with three-dimensional computed tomography or magnetic resonance imaging. In general, the risk of postoperative recurrence of instability is estimated on the basis of preoperative imaging of bipolar bone defects: more than 20%-25% glenoid bone loss and off-track Hill-Sachs lesions have been considered risk factors for recurrence. In patients with a glenoid bone defect more than 20%-25%, a bone graft procedure, such as the Latarjet procedure, is preferred regardless of the glenoid track concept, because compared with arthroscopic stabilization procedure, it provides greater postoperative stability. For patients with a borderline glenoid bone defect (around 20%), surgeons should discuss surgical options with the patients, considering their demand and physical activity level. In addition, the surgeon should take care to prevent postoperative instability and long-term complications. Arthroscopic soft-tissue reconstruction including labral repair and capsular plication combined with the additional remplissage procedure is an anatomical procedure and could be considered as one of the primary treatment methods for patients with glenoid bone defects around 20%. Therefore, treatment strategies for recurrent anterior shoulder instability combined with bone defects should be determined more flexibly on the basis of the patient's individual condition.