Measurement and analysis of condylar morphology and thickness of the roof of the glenoid fossa in patients with unilateral second molar scissor bite.

Objective The objective of this study was to measure and analyze the joint space, condylar morphology, and thickness of the roof of the glenoid fossa (RGF) in patients with unilateral second molar scissor bite using cone beam CT (CBCT). Methods A total of 80 patients were included in this study. Forty patients with a normal posterior occlusal relationship, who attended the Department of Orthodontics at the First Hospital of Shanxi Medical University from December 2021 to August 2023, were selected as the control group. The experimental group consisted of 40 patients with unilateral second molar scissor bite during the same period. All patients underwent CBCT scanning, and the resulting images were analyzed using the NNT viewer software in multiplanar reconstruction (MPR). Axial, coronal, and sagittal adjustments were made for each patient. Results In the control group, the right and left joint spaces (PS, SS, AS), the height of the upper part of the condyle, and the depth of the glenoid fossa did not show statistically significant differences (P > 0.05). When comparing bilateral condylar morphology and joint space in the experimental group, it was found that the posterior joint space on the scissor bite side was greater than that on the normal occlusion side, while the anterior joint space on the scissor bite side was smaller than that on the normal occlusal side. Additionally, the height of the upper condyle and the depth of the glenoid fossa on the scissor bite side were greater than that on the normal occlusal side, with statistically significant differences (P < 0.05). However, there were no statistically significant differences in SS, internal and external joint diameter, as well as anterior and posterior diameters (P > 0.05). The comparison of the minimum thickness of the roof of the glenoid fossa in both the sagittal and coronal directions between the patients in the experimental group and the control group showed no statistically significant difference (P > 0.05). Furthermore, the asymmetry index of the supracondylar height in the control group was significantly smaller than that in the experimental group, displaying a statistically significant difference (P < 0.05). The differences in the asymmetry indices of the anterior and posterior diameters of the condyle, as well as the inner and outer diameters, were not statistically significant (P > 0.05). When analyzing the position of the condyle in the sagittal direction of the glenoid fossa in the patients of the control group, it was observed that the majority were in the anterior and medial positions, with only 10% and 5% being in the posterior position. However, the analysis of the condyle position in the sagittal direction of the glenoid fossa in the experimental group revealed statistically significant differences (P < 0.05), with the condyle position on the scissor bite side being more anterior. Conclusion Unilateral second molar scissor bite can result in anterior displacement of the condyle, greater height of the condyle superiorly as well as the depth of the glenoid fossa.

Posterior Glenoid Bone Grafting in the Setting of Excessive Glenoid Retroversion Does Not Provide Adequate Stability in a Cadaveric Posterior Instability Model.

BACKGROUND: Excessive glenoid retroversion is a known risk factor for posterior shoulder instability and failure after soft tissue stabilization procedures. Whether excessive glenoid retroversion is a risk factor for failure after posterior glenoid bone grafting is unknown. PURPOSE: To evaluate the biomechanical effectiveness of posterior iliac crest bone grafting (ICBG) for posterior shoulder instability with increasing glenoid retroversion. STUDY DESIGN: Controlled laboratory study. METHODS: Six fresh-frozen cadaveric shoulders had a posterior glenoid osteotomy allowing the glenoid retroversion to be set at 0°, 10°, and 20°. At these 3 preset angles, 4 conditions were simulated consecutively on the same specimen: (1) intact glenohumeral joint, (2) posterior Bankart lesion, (3) 20% posterior glenoid bone defect, and (4) posterior ICBG. Stability was evaluated in the jerk position (60° of glenohumeral anteflexion, 60° of internal rotation) by measuring (A) posterior humeral head (HH) translation (in mm) and (B) peak translational force (in N) necessary for translation of the HH over 25% of glenoid width. RESULTS: At 0° of retroversion, the ICBG restored posterior HH translation and peak translational force to values comparable with those of the intact condition (P = .649 and P = .979, respectively). At 10° of retroversion, the ICBG restored the peak translational force to a value comparable with that of the intact condition (22.3 vs 24.7 N, respectively; P = .418) but showed a significant difference in posterior HH translation in comparison to the intact condition (4.5 vs 2.0 mm, respectively; P = .026). There was a significant increase in posterior HH translation and significant decrease in peak translational force with the ICBG at 20° of glenoid retroversion compared with the intact condition (posterior HH translation: 7.9 vs 2.0 mm, respectively; P < .006; peak translational force: 15.3 vs 24.7 N, respectively; P = .014). CONCLUSION: In this cadaveric study, posterior ICBG was able to restore stability to a level comparable to that of the native condition at 0° and to some extent at 10° of retroversion. However, posterior ICBG was not able to provide adequate stability at 20° of glenoid retroversion. CLINICAL RELEVANCE: Posterior glenoid bone grafting with ICBG should be used with caution when performed in isolation in the setting of posterior instability associated with glenoid bone loss and combined glenoid retroversion of >10°.

Gender-specific factors influencing the glenoid version and reference values for it.

BACKGROUND: Glenoid version is an important factor in the evaluation of shoulder stability and shoulder pathologies. However, there are neither established reference values nor known factors that influence the glenoid version, even though valid reference values are needed for diagnostic and orthopaedic surgery like corrective osteotomy and total or reverse shoulder arthroplasty (TSA/RSA). The aim of our population-based study was to identify factors influencing the glenoid version and to establish reference values from a large-scale population cohort. RESULTS: Our study explored the glenoid versions in a large sample representing the general adult population. We investigated 3004 participants in the population-based Study of Health in Pomerania (SHIP). Glenoid version was measured for both shoulders via magnetic resonance imaging (MRI). Associations with the glenoid version were calculated for sex, age, body height, body weight and BMI. The reference values for glenoid version in the central European population range between -9° and 7.5°, while multiple factors are associated with the glenoid version. CONCLUSION: To achieve a reliable interpretation prior to orthopaedic surgery, sex- and age-adjusted reference values are proposed.

Superior approach to the glenoid for treating acromion fractures combined with ideberg type III scapular glenoid fractures: a technical note.

PURPOSE: Scapular glenoid fractures, categorized based on the Ideberg classification, are commonly addressed surgically through approaches like the anterior deltoid-pectoral approach, posterior Judet approach, modified Judet approach, or posterior axillary approach. However, these methods present limitations in exposing the superior part of the glenoid. Therefore, we propose an approach for patients with concomitant acromion fractures, involving the anterior lateral flipping of the fractured acromion, allowing direct superior visualization of the superior and posterior superior parts of the glenoid. METHOD: Retrospective analysis was conducted on the data of five patients with shoulder fractures combined with scapular Ideberg III fractures between June 2018 and May 2023. All patients were treated using the shoulder approach above the scapular spine. There were four males and one female, aged 23-54 years with an average age of 36.6 years. One case involved the left shoulder, and four cases involved the right shoulder. X-rays and CT were taken before and after surgery to assess the location of the fractures and the healing status. Clinical evaluation included the assessment of efficacy using the Constant-Murley scoring criteria and analysis of surgical complications. RESULTS: All five patients were followed up for a duration of 14-36 months. All fractures healed completely, with an average healing time of 4.3 months (range: 3-6 months). There were no complications such as suprascapular nerve injury, nonunion, wound infection, or shoulder joint instability observed postoperatively. At the final follow-up, the Constant-Murley shoulder joint function score ranged from 84 to 98 points, with an average of 91.4 points. Three patients achieved an excellent rating in shoulder joint function score, while two patients achieved a good rating. CONCLUSION: The shoulder approach above the scapular spine exhibits advantages such as easy exposure and reduction, minimal intraoperative trauma, and clear visualization.

Clinical and Radiographic Outcomes and Graft Incorporation Rate Assessed by CT Scan After Reverse Shoulder Arthroplasty With Glenoid Structural Bone Graft Reconstruction.

INTRODUCTION: Reverse total shoulder arthroplasty (RTSA) with structural bone graft has been described as a technique in addressing glenoid bony defects. Studies have demonstrated acceptable outcomes with structural autograft or allograft. However, most of these studies are relatively small and rarely evaluate bone graft incorporation with CT scan. The aim of this study was to assess clinical and radiographic outcomes and report graft incorporation assessed on CT scan after RTSA where structural bone autograft or allograft was used to reconstruct the glenoid. METHODS: From May 2011 through June 2016, 38 patients underwent RTSA with structural bone graft. Of these, 35 were available for a minimum 2-year follow-up and retrospectively enrolled. From July 2016 through February 2019, 32 patients undergoing RTSA with structural bone graft were prospectively enrolled. Preoperative and postoperative American Shoulder and Elbow Surgeons and visual analog scale (for pain) scores and radiographs were obtained. CT scan was obtained at least 1 year postoperatively. RESULTS: Thirty-five patients were enrolled retrospectively (52.2%) and 32 prospectively (47.8%). Autograft was used in 46 cases (68.7%) and allograft in 21 cases. The mean American Shoulder and Elbow Surgeons score improved from 33.1 (SD 18.5) to 78.2 (SD 22.4), with P < 0.0001. On postoperative radiographs, 63 cases (94.0%) showed stable RTSA constructs while four cases (6.0%) developed glenoid baseplate subsidence. Postoperative CT scan demonstrated complete graft incorporation in 45 cases (90.0%) while partial incorporation was noted in 4 cases (8.0%), and in 1 case (2.0%), there was no graft incorporation. No correlation was observed between baseplate subsidence and graft type (autograft versus allograft) or primary versus revision surgery. DISCUSSION: Reverse shoulder arthroplasty with structural bone autograft and allograft is reliable for glenoid augmentation in patients undergoing RTSA in both primary and revision settings. Bony incorporation of autograft and allograft as evaluated on CT scan is predictably high.

Automatic quantification of scapular and glenoid morphology from CT scans using deep learning.

OBJECTIVES: To develop and validate an open-source deep learning model for automatically quantifying scapular and glenoid morphology using CT images of normal subjects and patients with glenohumeral osteoarthritis. MATERIALS AND METHODS: First, we used deep learning to segment the scapula from CT images and then to identify the location of 13 landmarks on the scapula, 9 of them to establish a coordinate system unaffected by osteoarthritis-related changes, and the remaining 4 landmarks on the glenoid cavity to determine the glenoid size and orientation in this scapular coordinate system. The glenoid version, glenoid inclination, critical shoulder angle, glenopolar angle, glenoid height, and glenoid width were subsequently measured in this coordinate system. A 5-fold cross-validation was performed to evaluate the performance of this approach on 60 normal/non-osteoarthritic and 56 pathological/osteoarthritic scapulae. RESULTS: The Dice similarity coefficient between manual and automatic scapular segmentations exceeded 0.97 in both normal and pathological cases. The average error in automatic scapular and glenoid landmark positioning ranged between 1 and 2.5 mm and was comparable between the automatic method and human raters. The automatic method provided acceptable estimates of glenoid version (R2 = 0.95), glenoid inclination (R2 = 0.93), critical shoulder angle (R2 = 0.95), glenopolar angle (R2 = 0.90), glenoid height (R2 = 0.88) and width (R2 = 0.94). However, a significant difference was found for glenoid inclination between manual and automatic measurements (p < 0.001). CONCLUSIONS: This open-source deep learning model enables the automatic quantification of scapular and glenoid morphology from CT scans of patients with glenohumeral osteoarthritis, with sufficient accuracy for clinical use.

The Scapular Skiver Screw: A Useful Fixation Technique for Inferior Glenoid and Scapular Neck Fractures.

SUMMARY: The inferior glenoid and scapular neck are common locations for scapular fractures. Operative exposures for reduction and fixation can be challenging, and frequently, the proximal fracture planes are not conducive to optimal fixation with a plate alone. The purpose of this article was to describe a new technique for enhancing fixation in specific inferior glenoid fractures using a single cortical lag screw.

Experimental guide wire placement for total shoulder arthroplasty in glenoid models: higher precision for patient-specific aiming guides compared to standard technique without learning curve.

BACKGROUND: Patient-specific aiming devices (PSAD) may improve precision and accuracy of glenoid component positioning in total shoulder arthroplasty, especially in degenerative glenoids. The aim of this study was to compare precision and accuracy of guide wire positioning into different glenoid models using a PSAD versus a standard guide. METHODS: Three experienced shoulder surgeons inserted 2.5 mm K-wires into polyurethane cast glenoid models of type Walch A, B and C (in total 180 models). Every surgeon placed guide wires into 10 glenoids of each type with a standard guide by DePuy Synthes in group (I) and with a PSAD in group (II). Deviation from planned version, inclination and entry point was measured, as well as investigation of a possible learning curve. RESULTS: Maximal deviation in version in B- and C-glenoids in (I) was 20.3° versus 4.8° in (II) (p < 0.001) and in inclination was 20.0° in (I) versus 3.7° in (II) (p < 0.001). For B-glenoid, more than 50% of the guide wires in (I) had a version deviation between 11.9° and 20.3° compared to ≤ 2.2° in (II) (p < 0.001). 50% of B- and C-glenoids in (I) showed a median inclination deviation of 4.6° (0.0°-20.0°; p < 0.001) versus 1.8° (0.0°-4.0°; p < 0.001) in (II). Deviation from the entry point was always less than 5.0 mm when using PSAD compared to a maximum of 7.7 mm with the standard guide and was most pronounced in type C (p < 0.001). CONCLUSION: PSAD enhance precision and accuracy of guide wire placement particularly for deformed B and C type glenoids compared to a standard guide in vitro. There was no learning curve for PSAD. However, findings of this study cannot be directly translated to the clinical reality and require further corroboration.

An in vitro comparison of mixed-reality navigation to traditional freehand and patient-specific instrumentation techniques for glenoid guide pin insertion during shoulder arthroplasty.

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

Reliability of glenoid measurements performed using Multiplanar Reconstruction (MPR) of Magnetic Resonance (MRI) in patients with shoulder instability.

PURPOSE: Measurement of glenoid bone loss in the shoulder instability can be assessed by CT or MRI multiplanar imaging and is crucial for pre-operative planning. The aim of this study is to determine the intra and interobserver reliability of glenoid deficiency measurement using MRI multiplanar reconstruction with 2D assessment in the sagittal plane (MPR MRI). METHODS: We reviewed MRI images of 80 patients with anterior shoulder instability with Osirix software using MPR. Six observers with basic experience measured the glenoid, erosion edge length, and bone loss twice, with at least one-week interval between measurements. We calculated reliability and repeatability using the intra-class correlation coefficient (ICC) and minimal detectable change with 95% confidence (MDC95%). RESULTS: Intra and Inter-observer ICC and MDC95% for glenoid width and height were excellent (ICC 0,89-0,96). For erosion edge length and area of the glenoid were acceptable/good (ICC 0,61-0,89). Bone loss and Pico Index were associated with acceptable/good ICC (0,63 -0,86)) but poor MDC95% (45 - 84 %). Intra-observer reliability improved with time, while inter-observer remained unchanged. CONCLUSION: The MPR MRI measurement of the anterior glenoid lesion is very good tool for linear parameters. This method is not valid for Pico index measurement, as the area of bone loss is variable. The pace of learning is individual, therefore complex calculations based on MPR MRI are not resistant to low experience as opposed to true 3D CT.

Biomechanical study of 3D-printed titanium alloy pad for repairing glenoid bone defect.

Background: The purpose of this study was to investigate the effect of 3D-printed technology to repair glenoid bone defect on shoulder joint stability. Methods: The shoulder joints of 25 male cadavers were tested. The 3D-printed glenoid pad was designed and fabricated. The specimens were divided into 5 groups. Group A: no bone defect and the structure of the glenoid labrum and joint capsule was intact; Group B: Anterior inferior bone defect of the shoulder glenoid; Group C: a pad with a width of 2 mm was installed; Group D: a pad with a width of 4 mm was installed; Group E: a pad with a width of 6 mm was installed. This study measured the distance the humeral head moved forward at the time of glenohumeral dislocation and the maximum load required to dislocate the shoulder. Results: The shoulder joint stability and humerus displacement was significantly lower in groups B and C compared with group A (p < .05). Compared with group A, the stability of the shoulder joint of group D was significantly improved (p < .05). However, there was no significant difference in humerus displacement between groups D and A (p > .05). In addition, compared with group A, shoulder joint stability was significantly increased and humerus displacement was significantly decreased in group E (p < .05). Conclusion: The 3D-printed technology can be used to make the shoulder glenoid pad to perfectly restore the geometric shape of the shoulder glenoid articular surface. Moreover, the 3D-printed pad is 2 mm larger than the normal glenoid width to restore the initial stability of the shoulder joint.

A scapular statistical shape model can reliably predict premorbid glenoid morphology in conditions of severe glenoid bone loss.

BACKGROUND: Knowledge of premorbid glenoid parameters at the time of shoulder arthroplasty, such as inclination, version, joint line position, height, and width, can assist with implant selection, implant positioning, metal augment sizing, and/or bone graft dimensions. The objective of this study was to validate a scapular statistical shape model (SSM) in predicting patient-specific glenoid morphology in scapulae with clinically relevant glenoid erosion patterns. METHODS: Computed tomography scans of 30 healthy scapulae were obtained and used as the control group. Each scapula was then virtually eroded to create 7 erosion patterns (Walch A1, A2, B2, B3, D, Favard E2, and E3). This resulted in 210 uniquely eroded glenoid models, forming the eroded glenoid group. A scapular SSM, created from a different database of 85 healthy scapulae, was then applied to each eroded scapula to predict the premorbid glenoid morphology. The premorbid glenoid inclination, version, height, width, radius of best-fit sphere, and glenoid joint line position were automatically calculated for each of the 210 eroded glenoids. The mean values for all outcome variables were compared across all erosion types between the healthy, eroded, and SSM-predicted groups using a 2-way repeated measures analysis of variance. RESULTS: The SSM was able to predict the mean premorbid glenoid parameters of the eroded glenoids with a mean absolute difference of 3° ± 2° for inclination, 3° ± 2° for version, 2 ± 1 mm for glenoid height, 2 ± 1 mm for glenoid width, 5 ± 4 mm for radius of best-fit sphere, and 1 ± 1 mm for glenoid joint line. The mean SSM-predicted values for inclination, version, height, width, and radius were not significantly different than the control group (P > .05). DISCUSSION: An SSM has been developed that can reliably predict premorbid glenoid morphology and glenoid indices in patients with common glenoid erosion patterns. This technology can serve as a useful template to visually represent the premorbid healthy glenoid in patients with severe glenoid bony erosions. Knowledge of the premorbid glenoid preoperatively can assist with implant selection, positioning, and sizing.

Double-pulley, V-shaped fixation technique for arthroscopic repair of ideberg type IA glenoid fracture.

Different techniques have been described for glenoid fractures, there is still a need for safe and effective agents to promote outcomes. From January 2016 to April 2021, the clinical data of 17 patients with pulley type IA fractures treated by the V-shaped fixation technique under shoulder arthroscopy were retrospectively analyzed. Preoperative X-ray, CT, and MRI examinations were completed. The functional score of the shoulder joint, such as the visual analog scale (VAS), Constant score, and Modified Rowe score, was used to evaluate the preoperative and final follow-up clinical outcomes. The active shoulder range of motion (ROM) was also collected preoperatively and at the final postoperative follow-up. Accordingly, intraoperative and postoperative complications were also observed. The mean follow-up was 49.52 months (16-79 months). The patients' follow-up exams showed that shoulder joint flexion, abduction, external rotation, internal rotation, and pain were not significantly different from those of the contralateral side (p > .05). The mean Constant score was 83.52 (58-98), and the average Modified Rowe score was 94.29 (70-100). X-ray and CT films of all cases showed good healing without articular depression or steps. Three patients had traumatic arthritis, with VAS <3 pain. No postoperative complications, such as infections, nerve or vessel damage, or suture anchor problems occurred during the follow-up period. Using the Double-pull, V-shaped fixation technique can stabilize the reduction of glenoid fractures while reducing the possibility of bone destruction. It is a good solution and provides an opportunity to treat rotator cuff tears associated with the procedure.

Does glenoid inclination affect the anterior stability of reverse total shoulder arthroplasty? A biomechanical study.

PURPOSE: The anterior stability of reverse total shoulder arthroplasty is affected by multiple factors. However, the effect of glenosphere inclination on stability has rarely been investigated, which is what this study aims to look into. METHODS: Reverse shoulder arthroplasty was performed on 15 cadaveric human shoulders. The anterior dislocation forces and range of motion in internal rotation in the glenohumeral joint (primary measured parameters) were tested in a shoulder simulator in different arm positions and implant configurations, as well as with a custom-made 10° inferiorly inclined glenosphere. The inclination and retroversion of the baseplate as well as the distance between the glenoid and coracoid tip in two planes (secondary measured parameters) were evaluated on CT scans. RESULTS: In biomechanical testing, the custom-made inclined glenosphere showed no significant influence on anterior stability other than glenoid lateralisation over all arm positions as well as the neck-shaft angle in two arm positions. The 6 mm lateralised glenosphere reduced internal rotation at 30° and 60° of glenohumeral abduction. In 30° of glenohumeral abduction, joint stability was increased using the 155° epiphysis compared with the 145° epiphysis. The mean inclination was 16.1°. The inclination was positively, and the distance between the glenoid and coracoid tip in the anterior-to-posterior direction was negatively correlated with anterior dislocation forces. CONCLUSIONS: The custom-made inferiorly inclined glenosphere did not influence anterior stability, but baseplate inclination itself had a significant effect on stability.

Anatomic total shoulder arthroplasty for B2 glenoids treated with asymmetric reaming has equivalent survivorship and patient outcomes compared with type A glenoids at a mean 9-year follow-up.

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

A Morphometric Study of Glenoid Cavity of Scapula in Bangladeshi Population.

This cross-sectional descriptive purposive study was conducted among 150 (70 right and 80 left) fully ossified dry human scapulae of Bangladeshi people from January 2019 to December 2019 in the Department of Anatomy, Mymensingh Medical College, Mymensingh. Shape of the glenoid cavity was observed as pear, oval or inverted comma shape. Morphometric parameters such as length and breadth of glenoid cavity were measured by digital Vernier slide calipers. In this study, 19.13% cases were found inverted comma shaped, 35.65% cases were oval and 45.22% cases were pear shaped. The mean±SD length of glenoid cavity was 37.5±3.61 mm and 36.19±3.68 mm on right and left sided scapulae respectively and mean±SD breadth was 23.6±2.73 mm on right and 23.42±2.75 mm on left side respectively. Mean±SD glenoid cavity index was 62.89±4.39 on right and 64.61±4.74 on left sided scapulae. Morphometric analysis of glenoid fossa of scapula might help clinicians in shoulder and its associated diseases.

Statistical shape models that predict native glenoid width based on glenoid height are inaccurate in their current form: a cross-sectional study.

BACKGROUND: The extent of measurement errors of statistical shape models that predict native glenoid width based on glenoid height to subsequently determine the amount of anterior glenoid bone loss is unclear. Therefore, the aim of this study was to (1) create a statistical shape model based on glenoid height and width measured on 3-dimensional computed tomography (3D-CT) and determine the accuracy through measurement errors and (2) determine measurement errors of existing 3D-CT statistical shape models. MATERIALS AND METHODS: A retrospective cross-sectional study included all consecutive patients who underwent CT imaging before undergoing primary surgical treatment of traumatic anterior shoulder dislocation between 2007 and 2022 at the Tohoku University Hospital and affiliated hospitals. Patients were included when instability was unilateral and CT scans of both the injured and contralateral uninjured shoulder were available. 3D segmentations were created and glenoid height and width of the injured and contralateral uninjured side (gold standard) were measured. Accuracy was determined through measurement errors, which were defined as a percentage error deviation from native glenoid width (contralateral uninjured glenoid), calculated as follows: measurement error = [(estimated glenoid width with a statistical shape model - native glenoid width) / native glenoid width] × 100%. A linear regression analysis was performed to create a statistical shape model based on glenoid height according to the formula: native glenoid width = a × glenoid height + b. RESULTS: The diagnosis and procedure codes identified 105 patients, of which 69 (66%) were eligible for inclusion. Glenoid height demonstrated a very strong correlation (r = 0.80) with native glenoid width. The linear regression formula based on this cohort was as follows: native glenoid width = 0.75 × glenoid height - 0.61, and it demonstrated an absolute average measurement error of 5% ± 4%. The formulas by Giles et al, Chen et al and Rayes et al demonstrated absolute average measurement errors of 10% ± 7%, 6% ± 5%, and 9% ± 6%, respectively. CONCLUSION: Statistical shape models that estimate native glenoid width based on glenoid height demonstrate unacceptable measurement errors, despite a high correlation. Therefore, great caution is advised when using these models to determine glenoid bone loss percentage. To minimize errors caused by morphologic differences, preference goes to methods that use the contralateral side as reference.

Posterior deltoid-sparing approach for displaced inferior or posterior glenoid fossa fractures: technical note and case series.

Scapular surgery has usually been performed through the posterior Judet approach. This approach allows access to the entire posterior scapular body, but causes significant soft tissue damage and detaches the deltoid muscle. To date, there has been no clinical study of a deltoid-preserving approach to access the joint for displaced postero-inferior glenoid fractures (Ideberg type II or Ib). We describe an easy and less invasive approach to the postero-inferior glenoid fossa.