The effects of tears in infraspinatus on other rotator cuff constituents.

The rotator cuff tear effects on glenohumeral joint tissues, such as superior labrum anterior-posterior (SLAP) lesions, have been studied experimentally or numerically in various cases. In relation to these studies, and as a novel feature of our study, infraspinatus (INF) muscle tear effects on other muscle force variations and stress and strain increases on glenoid labrum (GL), glenoid cartilage (GC) tissues, and a SLAP pathology were investigated. The ITK-SNAP Software (ISS) was used to segment the humerus and glenoid bone. The surface entities were segmented and exported to SolidWorks 2019, where the finite element model (FEM) was completed. Static optimizations of the muscle forces were calculated using a generic model in OpenSim 4.1 for the 0-3.88 s time interval to perform our finite element analyses (FEAs) in ANSYS 19.3 for the intact, partial torn, and fully torn INF muscle. The FEAs were also conducted for the specified time interval. The stress and strain increases on the GL, and GC tissues were determined to be critical when compared with yield strengths. In the case of fully torn INF, the GL and cartilage interfacial principal stress was calculated to be 3.3856 MPa. In the case of the fully torn INF, the principal stress that occurred on the GC tissue was calculated to be 42.465 MPa. In the case of the intact INF, the principal stress that occurred on the labrum was obtained as 4.257 MPa. These results showed that there was no detachment or disorder on the designated tissues caused by the INF muscle tear when the shoulder functioned at 60° of external rotation at 11° of abduction. Nonetheless, a minor amount of external force could cause severe pathological effects on the specified tissues.

Arthroscopic Bankart Repair with Remplissage Yields Similar Outcomes to Open Latarjet for Primary and Revision Stabilization in The Setting of Subcritical Glenoid Bone Loss.

BACKGROUND: Management of patients with recurrent anterior glenohumeral instability in the setting of subcritical glenoid bone loss (GBL), defined in this study as 20% GBL or less, remains controversial. This study aimed to compare arthroscopic Bankart with remplissage (ABR+R) to open Latarjet for subcritical GBL in primary or revision procedures. We hypothesized that ABR+R would yield higher rates of recurrent instability and reoperation compared to Latarjet in both primary and revision settings. METHODS: A retrospective study was conducted on patients undergoing either arthroscopic ABR+R or an open Latarjet procedure. Patients with connective tissue disorders, critical GBL (>20%), < 2 year follow-up, or insufficient data were excluded. Recurrent instability and revision were the primary outcomes of interest. Additional outcomes of interest included subjective shoulder value (SSV), strength and range of motion (ROM) RESULTS: 108 patients (70 ABR+R, 38 Latarjet) were included with an average follow-up of 4.3 ±2.1 years. In the primary and revision settings, similar rates of recurrent instability (Primary: p=0.60; Revision: p=0.28) and reoperation (Primary: p=0.06; Revision: p=1.00) were observed between Latarjet and ABR+R. Primary ABR+R exhibited better SSV, active ROM, and internal rotation strength compared to primary open Latarjet. However, no differences were observed in the revision setting. CONCLUSION: Similar rates of recurrent instability and reoperation in addition to comparable outcomes with no differences in ROM were found for ABR+R and Latarjet in patients with subcritical GBL in both the primary and revision settings. ABR+R can be a safe and effective procedure in appropriately selected patients with less than 20% GBL for both primary and revision stabilization.

Is Revision Arthroscopic Bankart Repair a Viable Option? A Systematic Review of Recurrent Instability following Bankart Repair.

Background/Objectives: Recurrent shoulder instability following Bankart lesion repair often necessitates surgical revision. This systematic review aims to understand the failure rates of arthroscopic revision Bankart repair. Methods: Following the PRISMA guidelines and registered on PROSPERO, this systematic review examined twenty-five articles written between 2000 and 2024. Two independent reviewers assessed eligibility across three databases, focusing on recurrent instability as the primary endpoint, while also noting functional measures, adverse events, revision operations, and return-to-sport rates when available. Results: The key surgical techniques for recurrent instability post-Bankart repair were identified, with revision arthroscopic Bankart being the most common (685/1032). A comparative analysis revealed a significantly lower recurrence for open coracoid transfer compared to arthroscopic revision Bankart repair (9.67% vs. 17.14%; p < 0.001), while no significant difference was observed between remplissage plus Bankart repair and Bankart repair alone (23.75% vs. 17.14%; p = 0.24). The majority of studies did not include supracritical glenoid bone loss or engaging Hill-Sachs lesions, and neither subcritical nor non-engaging lesions significantly influenced recurrence rates (p = 0.85 and p = 0.80, respectively). Conclusions: Revision arthroscopic Bankart repair remains a viable option in the absence of bipolar bone loss; however, open coracoid transfer appears to have lower recurrence rates than arthroscopic Bankart repair, consistent with prior evidence. Further studies should define cutoffs and investigate the roles of critical glenoid bone loss and off-track Hill-Sachs lesions. Preoperative measurements of GBL on three-dimensional computed tomography and characterizing lesions based on glenoid track will help surgeons to choose ideal candidates for arthroscopic revision Bankart repair.

Glenoid Fracture Fixation Using an Acu-Loc Distal Radius Plate.

Displaced fractures of the glenoid require surgical fixation. This poses multiple problems, including a difficult approach and achieving adequate reduction with current implants. We provide a surgical technical tip for fixing scapula neck and glenoid rim fractures with an Acu-Loc distal radius plate (Acumed, Weyhill, UK), illustrated with two recent case reports. Here, we present two cases of a 58-year-old female and a 51-year-old male presenting to a hospital following a fall, both sustaining an isolated right glenoid intra-articular fracture evident on plain radiographs. CT scans revealed a displaced and fragmented glenoid surface. A reverse Judet posterior approach facilitated exposure to enable the reduction of the glenoid, an uncommon approach. Current plate designs provide surgeons with limited options to fix complex fractures of the scapula and were not suitable here. The lateral scapula border and inferior glenoid have a similar anatomical shape to the distal radius. An Acu-Loc locking distal radius plate with a radial styloid plate was trialled and provided a good reduction to the fragmented glenoid. A distal radius plate can be a useful option to consider in complex scapula neck and glenoid rim fractures. A better understanding of glenoid shape will facilitate the further development of orthopaedic implants. Familiarity with various surgical approaches is needed to operate on these complex fractures.

Anatomic total shoulder arthroplasty for posteriorly eccentric and concentric osteoarthritis: a comparison at minimum 5-year follow-up.

BACKGROUND: In patients with glenohumeral osteoarthritis and posteriorly eccentric wear patterns, the early to mid-term results of TSA using conservative glenoid reaming with no attempt at version correction have been favorable at early follow-up. The purpose of this study is to compare the clinical and radiographic outcomes of TSA using this technique for patients with and without eccentric wear patterns at a minimum 5-year follow-up. METHODS: Patients who underwent TSA with minimum 5-year follow-up were identified from an institutional registry. Preoperative and postoperative radiographs were used to determine humeroglenoid alignment (HGA-AP), humeroscapular alignment (HSA-AP), version, Walch classification and glenoid component seating. The outcome measures were the Simple Shoulder Test, glenoid component radiolucencies, and the occurrence of complications or revisions. RESULTS: Two hundred and ten patients were included in the study, of which 98 (47%) had posteriorly decentered humeral heads and 108 (51%) had centered humeral heads. There were 77 shoulders with Walch type A glenoids and 122 with Walch type B glenoids. At a mean 8-year follow-up, the final SST, change in SST and percentage of maximal improvement was not correlated with pre- and postoperative humeral head centering, Walch classification or glenoid version. There were no preoperative predictors of a low final SST. Two patients (1%) underwent open re-operations during the study period. In patients with Walch B1 and B2 glenoids (n=110), there were no differences in outcome measures between patients with postoperative retroversion of more and less than 15o. While 15 of 51 patients (29%) with minimum 5-year radiographs had glenoid radioluciences, these radiographic findings were not associated with inferior clinical outcomes. On multivariable analysis glenoid component radiolucencies were most strongly associated with incomplete component seating (OR 3.3, p = 0.082). CONCLUSION: The results of TSA with conservative glenoid reaming without attempt at version correction are favorable at minimum 5 year, mean 8-year follow-up. There were no differences in clinical and radiographic outcomes between patients with eccentric and concentric wear patterns. Incomplete glenoid component seating was the greatest predictor of glenoid component radiolucency, but these radiolucencies were not associated with inferior clinical outcomes.

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 three 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) computer tomography (CT) scans were obtained from patients exhibiting glenoid erosion patterns according to the Walch and Favard classifications. Cases were planned using validated three-dimensional (3D) preoperative planning software. The CT data was then used to 3D print triplicate plastic models of each glenoid to evaluate the three guide pin insertion techniques. The first technique employed traditional software planning with freehand guide pin insertion. The second method used preoperatively planned PSI guides, while the third utilized a 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° versus 2±1°; P=0.056), version error (1±1° versus 1±1°; P=1.000), and Total Global Error (5±1 [mm+deg] versus 5±1 [mm+deg], P=1.000), respectively. The freehand technique produced significantly greater error than MR-NAV and PSI for inclination (5±3°, P≤0.017), version (4±3°, P≤0.032) and Total Global Error (8±3 [mm+deg], P<0.001). No statistically significant differences in the entry point error were observed between all guide pin insertion methods (P≥0.058). 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 intra-operatively, in addition to assessing a potential learning curve between surgeons of varying experience with the MR-NAV system.

Graft Position, Healing, and Resorption in Anterior Glenohumeral Instability: A Comparison of 4 Glenoid Augmentation Techniques.

Background: The success of glenoid augmentation procedures depends on accurate placement and healing of the graft to the glenoid. Different glenoid augmentation techniques have been described, but no comparative studies between them exist. Purpose: To assess the bone graft position, healing, and resorption in a group of patients treated with 1 of 4 procedures: arthroscopic anterior bone-block procedure using either (1) fresh-frozen iliac crest allograft or (2) iliac crest autograft, (3) open Latarjet, or (4) arthroscopic Latarjet. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 40 patients (87.5% men; mean age, 29.5 ± 7.9 years) were included, with 10 patients in each of the procedure groups. The graft position in the axial and sagittal planes was assessed on postoperative computed tomography (CT). Graft healing and resorption were assessed in a second CT scan performed 1 year postoperatively. Qualitative variables were compared between the 4 procedures using the chi-square test, and quantitative variables were compared with the Student t test or Mann-Whitney U test. Results: No differences were found between the procedures in the axial or sagittal position. The healing rate was significantly lower in the allograft bone-block group (20%) compared with the autograft bone-block (80%), open Latarjet (90%), and arthroscopic Latarjet (90%) groups (P < .001). Graft resorption developed in 17 of 40 (42.5%) cases overall. Osteolysis occurred in 100% of cases in the allograft bone-block group compared with 50% in the autograft group, 20% in the open Latarjet group, and 0% in the arthroscopic Latarjet group (P < .001). The glenoid surface area on 1-year CT scan was significantly lower in the allograft bone-block group compared with the autograft bone-block, open Latarjet, and arthroscopic Latarjet groups (P < .001). Conclusion: Arthroscopic bone-block, open Latarjet, and arthroscopic Latarjet procedures provided accurate bone graft positioning. However, very high rates of osteolysis and nonunion were observed in the iliac crest fresh-frozen allograft bone-block procedure when compared with the other procedures.

[Effectiveness analysis of double EndoButton suture fixation Latarjet procedure for treatment of anterior shoulder dislocation with glenoid bone defect caused by military training injuries].

Objective: To investigate the effectiveness of double EndoButton suture fixation Latarjet procedure in the treatment of shoulder anterior dislocation with glenoid bone defect caused by military training injuries. Methods: The clinical data of 14 patients with anterior shoulder dislocation with glenoid bone defect due to military training injuries who met the selection criteria and admitted between August 2021 and December 2022 were retrospectively analyzed. All patients were male, the age ranged from 21 to 38 years, with an average of 26.8 years. The time from initial dislocation to operation was 6-15 months, with an average of 10.2 months. Anterior shoulder dislocation occurred 5-12 times, with an average of 8.2 times. All glenoid bone defects were more than 10%, including 5 cases of 10%-15%, 8 cases of 15%-20%, and 1 case of 24%. All patients were treated by double EndoButton suture fixation Latarjet procedure. The operation time and complications were recorded. The shoulder function and pain were evaluated by the American Association for Shoulder and Elbow Surgery (ASES) score, Rowe score, Instability Severity Index Score (ISIS), and visual analogue scale (VAS) score before and after operation. The range of motion of the shoulder was recorded, including forward flexion, 0° external rotation, and abduction 90° external rotation. The position, healing, and resorption of the bone mass were evaluated by three-dimensional CT of shoulder joint after operation. Results: All patients successfully completed the operation, and the operation time was 100-150 minutes, with an average of 119.7 minutes. There was no complications such as infection, vascular and nerve injury. All patients were followed up 12-20 months, with an average of 15.6 months. During the follow-up, 4 patients had bone mass separation, absorption, and recurrent anterior dislocation, and the shoulder joint fear test was positive. Imaging of the remaining patients showed that the bone mass healed well, no anterior dislocation recurrence occurred, and the healing time was 3-7 months (mean, 4.7 months). At last follow-up, the range of motion, ASES score, Rowe score, ISIS score, and VAS score of the patients significantly improved when compared with those before operation ( P<0.05). Conclusion: The effectiveness of double EndoButton suture fixation Latarjet procedure for the treatment of anterior shoulder dislocation with glenoid bone defect caused by military training injury is satisfactory.

[Anatomical study of the limited osteotomy suture button fixation Latarjet procedure with coracoacromial ligament preservation].

Objective: To investigate the morphological characteristics of the glenohumeral joint (including the glenoid and coracoid) in the Chinese population and determine the feasibility of designing coracoid osteotomy based on the preoperative glenoid defect arc length by constructing glenoid defect models and simulating suture button fixation Latarjet procedure. Methods: Twelve shoulder joint specimens from 6 adult cadavers donated voluntarily were harvested. First, whether the coracoacromial ligament and conjoint tendon connected was anatomically observed and their intersection point was identified. The vertical distance from the intersection point to the coracoid, the maximum allowable osteotomy length starting from the intersection point, and the maximum osteotomy angle were measured. Next, the anteroinferior glenoid defect models of different degrees were randomly constructed. The arc length and area of the glenoid defect were measured. Based on the arc length of the glenoid defect of the model, the size of coracoid oblique osteotomy was designed and the actual length and angle of the coracoid osteotomy were measured. A limited osteotomy suture button fixation Latarjet procedure with the coracoacromial ligament and pectoralis minor preservation was performed and the position of coracoid block was observed. Results: All shoulder joint specimens exhibited crossing fibers between the coracoacromial ligament and the conjoint tendon. The vertical distance from the tip of the coracoid to the coracoid return point was 24.8-32.2 mm (mean, 28.5 mm). The maximum allowable osteotomy length starting from the intersection point was 26.7-36.9 mm (mean, 32.0 mm). The maximum osteotomy angle was 58.8°-71.9° (mean, 63.5°). Based on the anteroinferior glenoid defect model, the arc length of the glenoid defect was 22.6-29.4 mm (mean, 26.0 mm); the ratio of glenoid defect was 20.8%-26.2% (mean, 23.7%). Based on the coracoid block, the length of the coracoid osteotomy was 23.5-31.4 mm (mean, 26.4 mm); the osteotomy angle was 51.3°-69.2° (mean, 57.1°). There was no significant difference between the arc length of the glenoid defect and the length of the coracoid osteotomy ( P>0.05). After simulating the suture button fixation Latarjet procedure, the highest points of the coracoid block (suture loop fixation position) in all models located below the optimal center point, with the bone block concentrated in the anteroinferior glenoid defect position. Conclusion: The size of the coracoid is generally sufficient to meet the needs of repairing larger glenoid defects. The oblique osteotomy with preserving the coracoacromial ligament may potentially replace the traditional Latarjet osteotomy method.

[Application of LU-tarjet congruent-arc technique in treatment of recurrent shoulder dislocation with huge glenoid defect].

Objective: To investigate the early effectiveness of the limited unique coracoid osteotomy suture button fixation Latarjet (LU-tarjet)-congruent-arc (CA) technique (LU-tarjet-CA) in treating recurrent shoulder dislocations with huge glenoid defect. Methods: The clinical data of 12 patients with recurrent shoulder dislocation and huge glenoid defect who met the selection criteria and treated with arthroscopic LU-tarjet-CA between January 2021 and December 2023 were retrospectively analyzed. The cohort included 8 males and 4 females, aged 20-40 years with an average age of 30.4 years. The range of glenoid bone loss was 30%-40%, with an average of 35.5%. The time from symptom onset to hospital admission ranged from 1 to 36 months, with an average of 18.5 months. The University of California Los Angeles (UCLA) score, American Association for Shoulder and Elbow Surgery (ASES) score, Walch-Duplay score, and Rowe score were used to evaluate shoulder function preoperatively and at 3, 6, and 12 months postoperatively. CT three-dimensional (3D) reconstruction was used to assess coracoid healing and plasticity at 3, 6, and 12 months postoperatively. Subjective satisfaction of patient was recorded at last follow-up. Results: All incisions healed by first intention, with no incision infection or nerve injury. All 12 patients were followed up 12 months. One patient developed Propionibacterium acnes infection within the joint postoperatively and recovered after initial arthroscopic debridement and anti-inflammatory treatment. At 3 months after operation, CT 3D-reconstruction showed 1 case of complete coracoid absorption; neither of these two patients experienced redislocation. The remaining patients exhibited partial coracoid absorption but displayed local reshaping, filling the preoperative defect area, and bony fusion between the coracoid and the glenoid. At last follow-up, 9 patients (75%) were very satisfied with the outcome, and 3 patients (25%) were satisfied; the satisfied patients experienced postoperative shoulder stiffness caused by suboptimal functional exercise but did not have impaired daily life activities. The UCLA score, ASES score, Walch-Duplay score, and Rowe score at 3, 6, and 12 months postoperatively were significantly better than preoperative scores, and each score improved further over time postoperatively, with significant differences between different time points ( P<0.05). Conclusion: The arthroscopic LU-tarjet-CA technique for treating recurrent shoulder dislocations with huge glenoid defect can achieve the surgical objective of bony blockade and filling bone defects to prevent shoulder dislocation, thereby improving patients' quality of life and shoulder joint function and stability.

The Use of Linear Formulas to Estimate Glenoid Bone Loss in the Lebanese Population: A 3-Dimensional Computed Tomography Study.

Background: Glenoid bone loss (GBL) is common in patients with shoulder instability and plays a major role in surgical decision-making. While a plethora of GBL estimation methods exist, all of which present specific challenges, recent studies have developed simple linear formulas estimating GBL based on glenoid height. Purpose: To assess the correlation between glenoid height and width, and to develop specific formulas based on age and sex to calculate the native glenoid width in the Lebanese population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Computed tomography scans for 202 normal shoulders were extracted from our database. The glenoids were reconstructed in 3 dimensions and their width and height were measured. Glenoid width and height were compared between male and female groups. Correlation analysis was also performed on the width, height, age, and body mass index. Formulas estimating glenoid width were developed using regression analysis including all variables significantly influencing the model. Results were then compared with the values calculated using previously published formulas to determine the external validity when using linear formulas to estimate GBL. Results: Significant differences were found between men and women. Regression analysis found that glenoid height and width strongly influenced the model, and that age showed a weak but significant correlation; therefore, the following 2 sex-specific formulas were developed: width (mm) = 6.1 + 0.51 ×height+ 0.03 ×age, and width (mm) = 4.55 + 0.51 ×height+ 0.03 ×age, in men and women, respectively. The values yielded from the formulas developed in this study and the true width significantly differed from those calculated from previous reports. Conclusion: A strong correlation was found between glenoid height and width in a the Lebanese population and demonstrated that glenoid width can be accurately calculated based on the glenoid height and patient's age and sex using the following simplified formulas: width (mm) = 6 + 0.5 ×height+ 0.03 ×age, and width (mm) = 4.5 + 0.5 ×height+ 0.03 ×age, in men and women, respectively.

Determining the Normal Glenoid Version in the Indian Population.

Background Glenoid version refers to the angle subtended by the glenoid with the scapula. On average, it is 0 ± 10 degrees with a slight propensity toward retroversion. Numerous factors such the dominance(handedness), gender, ethnicity, and pathology are known to affect version. Version has important consequences on the biomechanics of the shoulder joint and is altered in those with arthritis and shoulder joint instability. Aim Our study aimed to determine the normal range of glenoid version in the population. Further, we aim to assess the relationship between gender and version. Settings and Design We conducted a retrospective observational study in a tertiary referral hospital with a target sample size of 200 shoulders. Methods and Materials The computed tomography images were retrospectively reviewed to determine the scapular shape and the glenoid version angle. Statistical Analysis Statistical analysis was done using SPSS v.22 software with p -value less than 0.05 considered as significant. Results The mean age of the individuals in our study was 44 years. In our study, irrespective of gender, most individuals had some degree of anteversion and males had lower degree of anteversion. Previous studies have shown that most normal individuals usually have retroverted shoulder joints. The mean glenoid version was significantly lower in the right than in the left shoulder and males had significantly lower mean glenoid version than females in both shoulders. Most individuals in our study had a flat scapular spine. Conclusion This study shows that the Indian population may have a slight propensity toward anteversion and this has an important bearing on shoulder arthroplasty. Further, this study shows that significantly lower degrees of version are found on the right side and that the degree of version is significantly lower in males. Understanding the role of glenoid version in shoulder biomechanics will go a long way in the early identification of pathology, the preoperative planning of shoulder arthroplasty, and the operative restoration of a functional shoulder joint.

Complications and Revisions in Metal-Backed Anatomic Total Shoulder Arthroplasty: A Comparative Study of Revision Rates Between Stemless and Stemmed Humeral Components.

BACKGROUND: The primary objective of this study was to evaluate and compare the incidence of complications and revision surgeries between in two of convertible metal-back glenoid systems in total shoulder arthroplasty (aTSA) groups over a follow-up period of up to five years. METHODS: A retrospective analysis included 69 shoulders from 65 patients with primary aTSA. Patients were divided into Group 1 (n=31), receiving convertible cementless stemmed aTSA (Lima SMR) and Group 2 (n=38), receiving humeral head replacement aTSA (Arthrex, Eclipse) both with metal-back glenoid components. Clinical and radiological assessments were conducted at 2, 5, and 10 years postoperatively. Assessments included the following: Constant Score, DASH, SPADI, SSV, Glenohumeral Distance, Critical Shoulder Angle and Lateral Acromion Index. In addition, we compared complications, revision rates and survival rates between groups using Kaplan-Maier curves and Log-Rank-test. RESULTS: Baseline demographics and preoperative outcome scores showed no significant differences between groups (p≥0.05). The overall revision rate did not significantly differ between groups (Group 1:32% vs. Group 2:24%, p=0.60), nor did the mean time to revision (p=0.27). The mean follow-up was 71±41 months (Group 1: 94±48 months, Group 2: 53±23 months, p<0.001). Kaplan-Meier analysis showed similar mid-term survival probabilities (p=0.94). Revision reasons included rotator cuff insufficiency (n=4 in Group 1, n=2 in Group 2) and glenoid wear/loosening (n=5 in Group 1, n=7 in Group 2). Interestingly, Group 1 demonstrated no occurrence of glenoid metal baseplate or humeral loosening, while complex revisions were more common in the Group 2. At 2 and 5 years, non-revised patients in both groups had similar outcome scores. CONCLUSION: Metal-backed glenoid implants in combination with both stemless and stemmed humeral components in aTSA exhibit comparable revision rates and survival probabilities. Rotator cuff insufficiency and polyethylene wear are the two most common complications leading to revision. To facilitate ongoing monitoring and optimize patient safety, we implemented a modification in the follow-up protocol, transitioning to annual appointments or earlier when necessary. This study underscores the unsolved disadvantages in metal-back components and the importance of a mid- to long-term longitudinal assessment of those patients.

Glenoid Structural Bone Grafting in Reverse Total Shoulder Arthroplasty: Clinical and Radiographic Outcomes.

INTRODUCTION: Current options for reconstruction of large glenoid defects in reverse total shoulder arthroplasty (RTSA) include structural bone grafting, utilization of augmented components, or 3D printed custom implants. Given the paucity in the literature on structural bone grafts in RTSA, this study reflects our experience on clinical and radiographic outcomes of structural bone grafts utilized for glenoid defects in RTSA. METHODS: We identified 33 consecutive patients who underwent RTSA utilizing structural bone grafts for glenoid bone loss between 2008 and 2019. Twenty-six patients with mean clinical follow-up of 4.4 ± 3.9 years and mean radiographic follow-up of 2.7 ± 3.2 years were included. Patient demographic data, peri-operative functional outcomes, radiographic outcomes, complications, and re-operation rates were determined. RESULTS: Between 2008 and 2019, 26 RTSAs were performed utilizing structural autograft or allograft for glenoid defects. There were 20 females (77%) and 6 males (23%), with mean presenting age of 68 years (range 41-86), mean BMI of 29 (range 21-44) and mean Charlson Comorbidity Index of 3 (range 0-8). There were 19 cases of central glenoid defects, and 7 were combined central and peripheral defects. Structural grafts included humeral head autograft (7), proximal humerus autograft (7), iliac crest autograft (7), distal clavicle autograft (2), and femoral head allograft (3). All eighteen revision RTSA cases had simultaneous humeral-sided revision. There was significant postoperative improvement in ASES scores (27.0 ± 12.6 preop vs. 59.8 ± 24.1 postop; p<0.001) and VAS scores (8.1 ± 3.6 preop vs. 3.0 ± 3.2 postop; p<0.001). Range of motion improved significantly for active forward elevation (63 ± 36º preop vs. 104 ± 36º postop; p<0.001) and external rotation (21 ± 20º preop vs. 32 ± 23º postop, p=0.036). Eighty-eight percent (23/26) of cases had successful reconstruction of the glenoid, defined as no visible radiolucent lines nor glenoid component migration at final follow-up. Re-operation rate was 19% (5/26) Postoperative complications included 2 cases of acromial stress fractures that were treated non-operatively, for a total complication rate (including re-operation) of 27% (7/26 cases). CONCLUSIONS: The use of structural bone autografts and allografts in RTSA was associated with improved outcome scores and range of motion. A reoperation rate of 19% and total complication rate of 27% were reported for these challenging cases. However, 86% of these complications were not related to structural glenoid reconstruction failure. Structural grafts are a reasonable option for glenoid reconstruction in RTSA cases with glenoid bone loss.

Location of Shoulder Glenoid Labral Tears: A Study of 1763 Consecutive Patients.

BACKGROUND: Anterior shoulder labral tearing has historically been considered the most common location of shoulder labral pathology. Recently, smaller studies have reported that posterior labral involvement may be more common than previously recognized. PURPOSE: To examine the location of surgically repaired labral tears by a single surgeon over a consecutive 23-year period. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 1763 consecutive patients who underwent arthroscopic or open shoulder labral repair by a single seniorsports medicine fellowship-trained orthopaedic surgeon between April 2000 and April 2023 were retrospectively reviewed. Current Procedural Terminology codes were used to identify patients, which included 29806, 29807, 29822, and 29823. Exclusion criteria included isolated shoulder manipulation or glenohumeral joint or labral debridement that did not include repair. Intraoperative glenoid labral tears observed were categorized into 7 broad categories: (1) anterior labral tears, (2) posterior labral tears, (3) superior labral anterior posterior (SLAP) type II tears (A, B, or C), (4) SLAP type V tears, (5) SLAP type VIII tears, or (6) circumferential labral tears (combined SLAP, anterior, and posterior labral tear). Shoulders diagnosed with multiple tear patterns (ie, anterior and posterior) were also noted. RESULTS: During the 23-year period, 1763 patients underwent arthroscopic or open labral repair; they included 1295 male and 468 female patients, ranging in age from 12 to 70 years, with a mean age of 23.2 years and median age of 19 years. Overall, 28.4% of tears involved the anterior labrum, 64.9% involved the posterior labrum, and 59.6% involved the superior labrum. Regarding isolated tears, 9.3% were isolated anterior labral tears, 19.7% were isolated posterior labral tears, 11.5% involved the anterior and posterior labrum, 22.2% were isolated superior (SLAP type II-IV) tears, 3.63% were isolated SLAP type V tears, 29.8% were isolated SLAP type VIII tears, and 4.1% were circumferential tears. CONCLUSION: Posterior shoulder labral tearing was more common than anterior tearing in a large consecutive series of 1763 patients who underwent surgical repair. This highlights the importance of posterior labral pathology, which sometimes may be overlooked because of more vague complaints, with pain and loss of function being the most common.

Risk Factors for Recurrence Following Arthroscopic Bankart Repair - A Systematic.

BACKGROUND: Recurrent instability remains a major source of morbidity following arthroscopic Bankart repair. Many risk factors and predictive tools have been described, but there remains a lack of consensus surrounding individual risk factors and their contribution to outcomes. PURPOSE: To systematically review the literature to identify and quantify risk factors for recurrence following arthroscopic Bankart repair. METHODS: A literature search was performed using the PubMed/Medline databases based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Studies were included if they evaluated risk factors for recurrent instability following arthroscopic Bankart repair. RESULTS: Overall, 111 studies were included in the analysis, including a total of 19,307 patients and 2,750 episodes of recurrent instability with 45 risk factors described. Age at operation was reported by 60 studies, with 35 finding increased risk at younger ages. Meta-analysis showed a two-fold recurrence rate of 27.0% (171/634) for patients under 20 years old compared to 13.3% (197/1485) for older patients (p<0.001). Seventeen studies completed multivariable analysis, 13 of which were significant (Odds Ratio 1.3-14.0). Glenoid bone loss was evaluated by 39 studies, with 20 finding an increased risk. Multivariable analysis in 9 studies found OR ranging from 0.7-35.1; 6 were significant. Off-track Hill-Sachs lesions were evaluated in 21 studies (13 significant), with 3 of 4 studies that conducted multivariable analysis finding a significant association with odds ratio of 2.9-8.9 of recurrence. The number of anchors used in repair was reported by 25 studies, with 4 finding increased risk with fewer anchors. Pooled analysis demonstrated a 25.0% (29/156) risk of recurrence with 2 anchors compared to 18.1% (89/491) with 3 or more anchors (p=0.06). Other frequently described risk factors included glenohumeral joint hyperlaxity (46% of studies reporting a significant association), number of preoperative dislocations (31%), contact sport participation (20%), competitive sport participation (46%), patient sex (7%), and concomitant SLAP tear (0%). CONCLUSION: Younger age, glenoid bone loss, and off-track Hill-Sachs lesions, are established risk factors for recurrence following arthroscopic Bankart repair. Other commonly reported risk factors included contact and competitive sports participation, number of fixation devices, and patient sex.

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.

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.

Clinical and Radiographic Outcomes Of Primary Versus Revision Arthroscopic Anatomic Glenoid Reconstruction with Distal Tibial Allograft For Anterior Shoulder Instability With Bone Loss.

PURPOSE: The purpose of this study was to assess the clinical and radiographic outcomes of arthroscopic anatomic glenoid reconstruction (AAGR) used for primary versus revision surgery for addressing anterior shoulder instability with bone loss. METHODS: We performed a retrospective review on consecutive patients who underwent AAGR from 2012 to 2020. Patients who received AAGR for anterior shoulder instability with bone loss and had a minimum follow-up of two-years were included. Exclusion criteria included patients with incomplete primary patient reported outcome scores (PROs), multi-directional instability, glenoid fracture, non-rigid fixation and concomitant HAGL, or rotator cuff repair. Our primary outcome was measured using the Western Ontario Shoulder Instability Index (WOSI) scores. Secondary outcomes included postoperative Disabilities of Arm, Shoulder, Hand (DASH) scores, complications, recurrence of instability and CT evaluation of graft position, resorption, and healing. RESULTS: There were 73 patients (52 primary and 21 revision) finally included. Both groups had comparable demographics and preoperative WOSI and DASH scores. The primary group had significantly better postoperative WOSI and DASH scores at final follow-up when compared to the revision group (WOSI: 21.0 vs 33.8, p=0.019; DASH: 7.3 vs 17.2, p=0.001). The primary group also showed significantly better WOSI scores than the revision group at 6-month, 1-year and 2-year time points (p=0.029, 0.022 and 0.003; respectively). The overall complication rate was 9.6% (5/52) in the primary group and 23.8% (5/21) in the revision group. Both groups showed good graft healing and placement in the A to P and ML orientation and had a similar rate of graft resorption/remodeling. There was no difference between the groups in the remainder of the CT measurements. CONCLUSION: Functional outcome scores and stiffness were significantly worse in patients undergoing an AAGR procedure after a failed instability surgery when compared with patients undergoing primary AAGR. There were no differences in postoperative recurrence of instability or radiographic outcomes. As a result, AAGR should be considered as a primary treatment option within current treatment algorithms for shoulder instability.

The Buford Complex Redefined: A Pathologic Morphology in Sheep's Clothing.

Background: Considered a normal anatomic variant, the Buford complex has not been studied in children. Hypothesis: A Buford complex is not a normal anatomic variant and would, therefore, be present at a lower rate than that seen in the adult population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Measurements were recorded from magnetic resonance imaging performed over 13 years in children aged ≤11 years for various pathologies unrelated to glenohumeral instability. Interrater reliability was determined to identify Buford complexes, sublabral foramens and tears, and normal shoulders via 16 preadolescent and adolescent patients with confirmed arthroscopic correlation. The Buford complex and labral foramen rates were then compared with a published rate in adults using a binomial probability test. Results: A total of 122 children (62 girls; mean age, 6.4 years [age range, 2 months-10.9 years]) were evaluated. Interrater reliability was 0.846 (95% CI, 0.56-1) to identify anterosuperior labral variants. The expected sublabral foramen count was 23 children, but only 1 was identified (P < .001). The expected Buford complex count was 8 children, but none could be identified (P < .001). Conclusion: The absence of Buford complexes and the significant reduction in sublabral foramen abundance in younger children suggest that these anatomic variants are more likely to be developmental than congenital. The distinct possibility that these previously considered normal variants are truly pathologic findings cannot be ignored. Evidence of a Buford complex could potentially signify an underlying, long-term shoulder instability issue to the treating provider that warrants further investigation or management.