Glenoid Morphology Research Articles

Autografting for B2 Glenoids.

The Walch B2 glenoid is characterized by a biconcave glenoid deformity, acquired glenoid retroversion, and posterior subluxation of the humeral head. Surgical reconstruction of the B2 glenoid is often challenging due to the complexity of the deformity. Bone graft augmentation using humeral head autograft is a valuable adjunct to anatomic total shoulder arthroplasty in the B2 glenoid, particularly in the young, highly active patient with severe glenoid retroversion (>25°–30°). Although this technique affords the ability to correct glenoid version and simultaneously enhances glenoid bone stock, it is technically challenging. The potential for graft-related complications also exists, which may further impact glenoid implant longevity and functional outcome. This review article aims to describe the B2 glenoid morphology, discuss the challenges in managing the B2 deformity, and provide further insight specifically regarding autografting at the time of anatomic total shoulder arthroplasty for reconstruction of the B2 glenoid.

Intraobserver and interobserver reliability of the modified Walch classification using radiographs and computed tomography

The Walch classification was introduced to classify glenoid morphology in primary glenohumeral osteoarthritis. A modified Walch classification was recently proposed, with 2 additional categories, B3 (monoconcave glenoid with posterior bone loss leading to retroversion > 15° or subluxation > 70%) and D (excessive anterior subluxation), as well as a more precise definition of subtypes A2 and C. The purpose of this study was to evaluate the intraobserver and interobserver agreement of the modified Walch classification system using both plain radiographs and computed tomography (CT). Three fellowship-trained shoulder surgeons blindly and independently evaluated radiographs and CT scans of 100 consecutive shoulders (98 patients) with primary glenohumeral osteoarthritis and classified all shoulders according to the modified Walch classification in 4 separate sessions, each 4 weeks apart. Statistical analysis with the κ coefficient was used to evaluate reliability. The first reading by the most senior observer on the basis of CT scans was used as the gold standard (distribution: A1, 18; A2, 12; B1, 20; B2, 25; B3, 22; C, 1; and D, 2). The average intraobserver agreement for radiographs and CT scans was 0.73 (substantial; 0.72, 0.74, and 0.72) and 0.73 (substantial; 0.77, 0.69, and 0.72), respectively. The average interobserver agreement was 0.55 (moderate; 0.61, 0.51, and 0.53) for radiographs and 0.52 (moderate; 0.63, 0.50, and 0.43) for CT scans. Intraobserver agreement of the modified Walch classification was substantial both for axillary radiographs and for CT scans. Interobserver agreement was fair. Although the modified Walch classification represents an improvement over the original classification, automated computer-based analysis of CT scans may be needed to further improve the value of this classification.

Glenoid morphology is associated with the development of instability arthropathy

Instability arthropathy (IA) is a major long-term concern in patients with anterior shoulder instability. This study investigated the association of glenoid morphology with the development of IA. The study included 118 patients with unilateral anterior shoulder instability and available bilateral computed tomography scans. Instability-specific information was obtained from all patients. The glenoid morphology of the affected shoulder was compared with the nonaffected contralateral side resembling the constitutional preinjury glenoid shape. Both shoulders were evaluated independently by 3 observers to assess the grade of IA according to a Comprehensive Arthropathy Rating (CAR) system. Associations between IA and the glenoid morphology parameters were investigated. The average glenoid retroversion (P < .001), glenoid depth (P < .001), glenoid diameter (P < .001), and the bony shoulder stability ratio (P < .001) of the affected shoulder were significantly reduced compared with the contralateral side due to bony defects in 79.6% of the patients. The CAR of the affected side was significantly higher (P < .001), with more osteophytes (P = .001) and more sclerosis and cysts (P < .001). Differences in CAR (Δ-CAR) correlated positively with the age at the time of the computed tomography scan (P < .001), age at the initial dislocation (P = .001), size of the glenoid defect (P = .005), and the contralateral glenoid depth (P = .011), glenoid diameter (P = .016), and bony shoulder stability (P = .029), and negatively with glenoid retroversion of the affected side (P = .027). Development of IA arthropathy is associated not only with the age of the patients but also with morphologic parameters of the glenoid, including glenoid defect size and the constitutional glenoid concavity shape.

Clinical and Radiographic Outcomes of a Posteriorly Augmented Glenoid Component in Anatomic Total Shoulder Arthroplasty for Primary Osteoarthritis with Posterior Glenoid Bone Loss.

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

Multilevel glenoid morphology and retroversion assessment in Walch B2 and B3 types.

A major factor that impacts the long-term outcome and complication rates of total shoulder arthroplasty is the preoperative posterior glenoid bone loss quantified by glenoid retroversion. The purpose of this study was to assess if glenoid retroversion varies significantly at different glenoid heights in Walch B2 and B3 glenoids. Patients with B2 and B3 glenoid types were included following retrospective review of 386 consecutive CT shoulder studies performed for arthroplasty preoperative planning. True axial CT reconstructions were created using a validated technique. Two readers independently measured the glenoid retroversion angles according to the Friedman method using the "intermediate" glenoid at three glenoid heights: 75% (upper), 50% (equator), and 25% (lower). The variances between the three levels for a given patient were calculated. Twenty-nine B2 and 8 B3 glenoid types were included. There was no significant difference in variance of glenoid version among the three levels in B2 or B3 groups. The mean variance in retroversion degree between equator-lower, upper-equator, and upper-lower glenoid was -0.4, 0.3, and - 0.2 for B2; and - 0.2, 1.9, and 1.9 for B3 glenoid, respectively. The level of inter-reader agreement was fair to good for variance at equator-lower, and good to excellent for upper-equator and upper-lower glenoid. Glenoid version can be accurately measured at any level between 25 and 75% of glenoid height for Walch B2 and B3. We recommend that the glenoid equator be used as the reference to assure consistent and reliable version measurements in this group of patients.

Version and inclination obtained with 3-dimensional planning in total shoulder arthroplasty: do different programs produce the same results?

BackgroundOur purpose was to compare the output of glenoid measurements with 2 commercially available preoperative 3-dimensional (3D) total shoulder arthroplasty planning systems. The hypothesis was that there would be no difference in product-derived measurements between the systems. MethodsPreoperative 3D computed tomography scans of 63 consecutive patients undergoing primary arthroplasty were analyzed using 2 product-derived techniques: Blueprint and VIP. Glenoid version and inclination measurements with each system were blinded and statistically compared, and the amount of variance was recorded. ResultsGlenoid version based on Blueprint was –10.9° ± 9.0° (range, –41° to 14°) compared with –9.3° ± 8.2° (range, –36° to 8°) for VIP (P = .04). Inclination was 9.0° ± 8.8° (range, –12° to 29°) with Blueprint compared with 9.7° ± 6.1° (range, –6° to 22°) for VIP (P = .463). For version, the difference between the 2 systems was less than 5° in 44 cases (69.8%), 5°-10° in 12 cases (19.0%), and greater than 10° in 7 cases (11.1%). For inclination, the difference was less than 5° in 34 cases (54.0%), 5°-10° in 17 cases (27.0%), and greater than 10° in 12 cases (19.0%). We found no differences in glenoid version or inclination based on glenoid morphology between the 2 systems (P = .908) and no differences between patients with the most severe arthritis and posterior wear (P = .202). ConclusionsThere is considerable variability between preoperative measurements obtained for 3D planning of shoulder arthroplasty with the use of Blueprint and VIP. Given that implant choice and desired component positioning are based on preoperative measurements, further study is needed to evaluate the differences between the measurements obtained with different techniques.

Three dimensional scapular prints for evaluating glenoid morphology: An exploratory study

BackgroundComputerised Tomography (CT) scans are conventionally employed to assess the glenoid morphology prior to total shoulder arthroplasty (TSA). This study explores the role of three-dimensional (3D) models for assessing glenoid morphology. MethodsCT scans of 32 patients scheduled for TSA were reconstructed to scapular models using customised software and a desktop 3D printer. The size and aspect ratios were maintained. Glenoid version, glenoid maximum height and width, and the maximum acromion antero-posterior (AP) length were compared between the models and CT scans. ResultsThe models were an accurate qualitative reflection of scapular anatomy. The average retroversion in 3D models was 8.19°±30.8° compared to 10.26°±42.5° in scan images. The mean difference was 2.07°±24.6° (p=0.408). However, the mean absolute error was 5.02°±12.3°. The mean difference of the glenoid maximum width and the acromion maximum AP length was 0.22±3.33mm (p=0.862) and 0.32±14.12mm (p=0.213) respectively. However, the mean difference was significant for the glenoid maximum height measuring 3.67±12.04mm with p=0.004. The correlation between the examiners was high for all parameters, with intraclass correlation ranging between 0.94 and 0.99. Conclusion3D printing technology promises to be a useful tool for preoperative planning with accurate reproduction of transverse plane anatomy. 3D prints represent superior definition of reconstructed anatomical measures such as glenoid height as compared to conventional CT Scans.

Interobserver and intraobserver comparison of imaging glenoid morphology, glenoid version and humeral head subluxation.

Glenoid morphology, glenoid version and humeral head subluxation represent important parameters for the treating physician. The most common method of assessing glenoid morphology is the Walch classification which has only been validated with computed tomography (CT). CT images and magnetic resonance imaging (MRI) images of 25 patients were de-identified and randomized. Three reviewers assessed the images for each parameter twice. The Walch classification was assessed with a weighted kappa value. Glenoid version and humeral head subluxation were comparted with a reproducibility coefficient. The Walch classification demonstrated almost perfect intraobserver agreement for MRI and CT images (k = 0.87). Weighted interobserver agreement values for the Walch classification were fair for CT and MRI (k = 0.34). The weighted reproducibility coefficient for glenoid version measured 9.13 (CI 7.16-12.60) degrees for CT and 13.44 (CI 10.54-18.55) degrees for MRI images. The weighted reproducibility coefficient for percentage of humeral head subluxation was 17.43% (CI 13.67-24.06) for CT and 18.49% (CI 14.5-25.52) for MRI images. CT and MRI images demonstrated similar efficacy in classifying glenoid morphology, measuring glenoid version and measuring posterior humeral head subluxation. MRI can be used as an alternative to CT for measuring these parameters.

Outcomes of Anatomic Total Shoulder Arthroplasty with B2 Glenoids: A Systematic Review.

Total shoulder arthroplasty remains an effective procedure for shoulder pain relief. Despite the negative effect of abnormal glenoid morphology and specifically retroverted and posteriorly subluxated glenoids, there is no consensus for management of B2 glenoids in total shoulder arthroplasty. The purpose of this study was to compare the outcomes and complication rates for B2 glenoid techniques so as to provide a baseline understanding of the current state of treatment of this pathology. A systematic review evaluating outcomes of total shoulder arthroplasty with biconcave glenoids using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology included searches up to December 31, 2015, of PubMed, Embase, MEDLINE, Cochrane Reviews, and Google Scholar. Nine articles met inclusion and exclusion criteria. In this study, 239 total shoulder arthroplasties with B2 glenoids with a mean follow-up of 55.5 months (range, 24 to 91 months) were included. The mean patient age was 63.3 years (range, 55.8 to 68.7 years). Asymmetric reaming was performed in 127 glenoids, posterior bone-grafting was included in 53 glenoids, and 34 received an augmented glenoid component to correct glenoid retroversion and bone loss. Overall, the mean Constant and Neer scores improved from preoperative measures. Fifty-eight percent of patients had no loosening, and 42% had some loosening, although not all of these patients were symptomatic. Despite variation in outcome measures hindering treatment approach comparison, the posteriorly augmented glenoid was generally reported to provide better outcomes with few complications. Although posterior glenoid bone-grafting results in acceptable outcomes, it also represents the highest rate of complications. The revision rate was 15.6% for asymmetric reaming, 9.5% for posterior glenoid bone-grafting, and 0% for posteriorly augmented glenoids. Surgical treatment of the B2 glenoid remains a challenge to the shoulder surgeon, with worse outcomes and higher complication rates. Longer follow-up, consistent outcome measures, and result stratification based on glenoid type may allow for direct comparison in the future. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Shoulder Arthroplasty for Sequelae of Obstetrical Brachial Plexus Injury.

Shoulder arthroplasty following obstetrical brachial plexus injury (OBPI) is technically challenging because glenoid morphology, muscle balance, and humeral version are substantially altered compared with the neurologically intact shoulder. The purpose of this study is to report the outcome of shoulder arthroplasty in a group of patients with end-stage arthritis secondary to OBPI. Seven patients with OBPI and secondary glenohumeral arthritis were treated with shoulder arthroplasty between 1976 and 2014. Two underwent hemiarthroplasty (HA), 2 underwent total shoulder arthroplasty (TSA), and 3 underwent reverse shoulder arthroplasty (RSA). One HA was lost to follow-up and was excluded. The remaining 6 patients (mean age, 62.5 years old at the time of surgery) were followed for a minimum of 2 years (mean, 7.5 years; range, 2-13 years) Outcome measures included pain, range of motion, and postoperative modified Neer ratings. Pain improved in all shoulders. Mean forward flexion was unchanged. No shoulders treated with HA/TSA regained forward elevation above 90°, compared with 1 out of the 3 RSAs. External rotation improved from a mean of -10° to 20°. Active internal rotation decreased from L1 to L5. Immediate postoperative radiographs showed either severe posterior or posterosuperior subluxation in all 3 patients treated with nonconstrained implants. Shoulder arthroplasty is an acceptable option to relieve pain in patients with symptomatic shoulder arthritis as a sequel of OBPI. However, range of motion improvements are not expected. Therapeutic V.

Computed tomography underestimates rotator cuff pathology in patients with glenohumeral osteoarthritis

Computed tomography (CT) is the standard assessment of glenoid morphology before shoulder arthroplasty and is commonly used to evaluate rotator cuff pathology in patients with glenohumeral osteoarthritis (GHOA). Magnetic resonance imaging (MRI) is not routinely used in this setting but has higher sensitivity in diagnosing full-thickness rotator cuff tears (RCT) and is considered the gold standard. The purpose of this study was to determine the sensitivity and specificity of CT in diagnosing full-thickness RCTs and compare the evaluation of fatty infiltration and muscle atrophy on CT vs. MRI in the setting of GHOA. In this retrospective case-controlled study, we identified 49 patients from a prospectively maintained 2-surgeon registry who received preoperative CT and MRI scans for the evaluation of GHOA between 2011 and 2016. Three fellowship-trained shoulder surgeons assessed rotator cuff integrity, fatty infiltration, and muscle atrophy in the CT and MRI scans. CT sensitivity and specificity were 20% and 95.5%, respectively. Fatty infiltration was significantly lower on CT for the supraspinatus (P = .003), infraspinatus (P < .001), and subscapularis (P = .0182), whereas muscle atrophy was significantly lower on CT for only the supraspinatus (P = .0023). Our results suggest that CT underestimates the frequency of full-thickness RCTs and the severity of fatty infiltration and muscle atrophy in the setting of GHOA before total shoulder arthroplasty.

The Association Between Rotator Cuff Muscle Fatty Infiltration and Glenoid Morphology in Glenohumeral Osteoarthritis

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

Progression of Glenoid Morphology in Glenohumeral Osteoarthritis.

Walch defined the pathologic characteristics of glenohumeral osteoarthritis on the basis of patterns of glenoid morphology and humeral head subluxation. However, it is unclear how pathologic changes evolve over time. The purpose of this study was to determine whether there are common patterns of pathologic progression based on the Walch classification in primary glenohumeral osteoarthritis and if glenoid bone-loss patterns correlate with rotator cuff fatty infiltration. A retrospective chart review identified 65 shoulders with glenohumeral osteoarthritis for which at least 2 computed tomography (CT) scans had been performed at least 24 months apart. The CT scans were classified using a modification of the Walch classification. The amount and location of glenoid bone loss were measured using a vault model, and rotator cuff fatty infiltration was calculated as a percentage of cross-sectional muscle area. The initial CT scans showed 42 A-type glenoids and 23 B-type glenoids. CT scans made at an average (and standard deviation) of 74 ± 32 months after the initial scans showed that only 8 of the 42 A1 glenoids had evidence of pathologic progression (5 to A2 type and 3 to B type) whereas 17 of 19 B1 glenoids had progressed (15 to B2 and 2 to B3); this difference was significant on univariate and multivariate analysis (p < 0.001). The odds of joint line medialization occurring were 8.1 times higher (95% confidence interval [CI]: 2.1 to 31.4) for B-type glenoids than for A-type glenoids. Among the glenoids that underwent medialization, those classified as B-type showed more medialization over time (estimated change, 0.70 mm/year; p = 0.036), whereas no significant relationship between medialization and time was observed for A-type glenoids (estimated change, 0.013 mm/year; p = 0.95). The median percent fatty infiltration in the infraspinatus muscle was higher in association with B-type glenoids than in association with A-type glenoids on both the initial (14% versus 7%; p < 0.001) and the final follow-up (16% versus 10%; p = 0.003) CT scans. Asymmetric bone loss rarely develops in A1 glenoids, whereas initial posterior translation of the humeral head (B1 glenoids) may be associated with subsequent development and progression of posterior glenoid bone loss over time. Differences in fatty infiltration of the posterior aspect of the rotator cuff were seen between A-type and B-type glenoids, but the clinical relevance of this finding is currently unknown. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Reverse shoulder arthroplasty: Current trend in elective surgery

While reverse shoulder arthroplasty (RSA) is not generally accepted as a successful procedure until recent years, the concept of RSA has long been proposed. Several RSA designs were originally developed for treatment of cuff tear arthropathy (CTA) in the 1970’s, which all underwent in failure. From 1987 to 1995, Paul Grammont and his team proposed successful modern reverse designs of total shoulder arthroplasty for CTA. Medializing and distalizing the center of rotation are the most distinguished principles of Grammont’s RSA. The use of RSA has been increased dramatically over the past decades. The indications for RSA have expanded to massive irrepairable rotator cuff tears, proximal humerus fractures, fracture sequelae, inflammatory arthropathy, osteoarthritis with abnormal glenoid morphology, revision cases following failed shoulder arthroplasty, and tumor reconstruction, in addition to CTA. Contraindications to RSA includes infection, complete axillary nerve palsy, neuroarthropathy, and substantial glenoid bone erosion or defects. The number of complications and reoperations of RSA has been increased significantly with the wide application of RSA. RSA complications can be classified into non-specific complications, specific complications associated with RSA and brand-related specific problems. Glenoid bone loss is not uncommon in patients undergoing RSA, which is a challenging problem. Current methods for addressing glenoid bone loss during RSA include asymmetric reaming, use of a lateralized implant, bone grafting, and use of an augmented baseplate. Three-dimensional imaging preoperative planning software and patient-specific instruments have become commercially available for guidance in the insertion of the glenoid component in RSA in recent years. Surgeons performing RSA should select proper patients, be familiar with new surgical techniques and pay attention to technical details, so that the currently high complication rate of RSA can be reduced.

Short-term radiographic results of a cemented polyethylene keeled glenoid component with varying backside radiuses of curvature

This study analyzed the radiographic results of a cemented all-polyethylene keeled glenoid component available in different sizes and multiple backside radiuses of curvature. The study group consisted of 118 cases (114 patients). There were 63 women and 51 men. Mean age at the time of arthroplasty was 68 years (range, 51-85 years). True anterior-posterior radiographs obtained postoperatively and at the final follow-up were analyzed for implant seating and the occurrence of radiolucent lines. Glenoid morphology and fatty infiltration of the rotator cuff muscles were examined using computed tomography scans. Mean follow-up was 38 months (range, 24-70 months). The mean radiolucent line score after surgery was 0.54 points (range, 0-3 points), and 90% had no or only 1 radiolucent line. At the final follow-up, the mean score was 1.06 points (range, 0-3 points), and 74% had no or only 1 radiolucent line. The score increased significantly over time (P < .001). No component was at risk for loosening. No correlation was found between patient age, sex, hand dominance, glenoid morphology, or fatty infiltration of the rotator cuff muscles and the occurrence of radiolucent lines. In the short-term, the glenoid component analyzed in this study showed promising radiographic results, with a low number of radiolucent lines without failure. However, the mean radiolucent line score increased significantly over time, and long-term observations are necessary to confirm a possible advantage compared with older component designs.

Technical Developments: Zero Echo Time Imaging of the Shoulder: Enhanced Osseous Detail by Using MR Imaging.

Purpose To determine the intermodality agreement of morphologic grading and clinically relevant quantitative measurements between computed tomography (CT) and zero echo time (ZTE) magnetic resonance (MR) imaging of the shoulder. The primary objective was to demonstrate the clinical applicability of ZTE in osseous shoulder imaging. Materials and Methods Thirty-four patients undergoing standard-of-care (SOC) MR imaging with concomitant CT were enrolled in this institutional review board-approved study. ZTE images were acquired after SOC MR imaging. Glenoid morphology (version, vault depth, erosion), injury or disease (osteoarthritis, Bankart and Hill-Sachs lesions, subchondral cysts), and evidence of prior surgery were graded or measured. κ Values, intraclass correlation coefficients (ICCs), and Bland-Altman limits of agreement were used to establish agreement. Qualitative comparison of osseous findings was performed between ZTE and SOC MR imaging. Results Binary classification and nominal/ordinal grades showed substantial or better agreement between raters and modalities (κ or ICC > 0.6). Continuous measurements exhibited strong correlation between raters and modalities, although not universally. Bankart ICCs were not significant, owing to low prevalence. ZTE exhibited greater conspicuity of enthesopathic cysts and marrow edema. In 21 of 34 cases, ZTE imaging of osseous features exceeded SOC MR imaging. Conclusion ZTE MR imaging provides "CT-like" contrast for bone. The results of this study demonstrate strong intermodality agreement between measurements and grades from CT and ZTE images in a cohort of patients undergoing imaging with both modalities. A majority of ZTE image sets provided superior visualization of osseous features when compared with SOC MR image sets. This superiority coupled with strong quantitative agreement with CT suggests that ZTE may be used clinically in lieu of CT in some cases. © RSNA, 2017 Online supplemental material is available for this article.

"Shaped" humeral head autograft reverse shoulder arthroplasty : Treatment for primary glenohumeral osteoarthritis with significant posterior glenoid bone loss (B2, B3, and Ctype).

Posterior glenoid bone loss in primary glenohumeral osteoarthritis (GHOA) presents achallenge when considering replacement surgery. Results with anatomic shoulder arthroplasty are unpredictable due to posterior humeral instability and limited bone stock for glenoid component fixation. To describe and evaluate the results of a"shaped" humeral head autograft with reverse shoulder arthroplasty (RSA) for the treatment of primary GHOA with significant posterior glenoid bone loss and an intact, functional rotator cuff. We retrospectively reviewed 29 "shaped" humeral head autografts with RSA for the treatment of GHOA with B2 (n= 16), B3 (n= 10), or C (n= 3) glenoid morphology based on the Walch classification system. Average glenoid retroversion was 32.3°. Humeral head autografts were "shaped" to match each patient's individual glenoid morphology. Functional outcome scores, range of motion, strength, and radiographic outcomes were evaluated. At average follow-up of 34.6months (range 23.7-88.9months), significant improvements were seen in all functional outcome scores, ranges of motion, and strength (p<0.01). No recurrent instability or glenoid fixation failure occurred. Two complications (1superficial and 1deep infection) in 2patients were identified. All autografts incorporated without radiographic evidence of loosening. Scapular notching was observed in 8shoulders. No negative correlations were identified with glenoid morphology. "Shaped" humeral head autograft with RSA for the treatment of primary GHOA with significant posterior glenoid bone loss is associated with excellent clinical and radiographic outcomes and alow complication profile at short- to mid-term follow-up.

Individual Shoulder Anatomy and Degenerative Rotator Cuff Tear (Rct): Comparison of Radiographic Parameters of 800 Patients with Rct and 800 Non-Affected

Statistically significant higher Acromion Index and higher Critical Shoulder Angle were found in patients affected by degenerative rotator cuff tears undergoing arthroscopic repair, compared to controls. Other parameters were not strongly related to rotator cuff disease, with no statistically significant difference between mean values measured in affected patients and healthy subjects. Specific anatomic variants of the glenoid were associated with degenerative rotator cuff tears (RCTs). In particular, an increased rate of RCTs was found in relation to a decreased lateral acromion angle and a flatter acromial slope. The aim of the present study was to evaluate the predictive power of commonly used radiologic parameters of glenoid morphology to discriminate between patients with intact rotator cuff tendons and those with torn rotator cuff tendons. One thousand six hundred patients extrapolated from a single surgeon’s database were included in the study: 800 consecutive patients undergoing arthroscopic rotator cuff repair for degenerative RCT were compared with 800 non-affected subjects with healthy rotator cuff undergoing shoulder arthroscopy for other pathologies. Acromion Index (AI = glenoid–acromion distance/gleno–humeral distance, GA/GH), Lateral Acromion Angle (LAA), Critical Shoulder Angle (CSA), Humeral-Acromion Index (HAI), Acromial slope (AS) and Cervico-Diaphyseal angle (CDA) were assessed on standard antero-posterior radiographs of all patients. Moreover, the acromial type, based on Bigliani classification, was determined on true outlet views. Three independent examiners performed all measurements and intra-observer and inter-observer reliability was calculated with intraclass correlation coefficients. Student’s t-test was used to compare all these parameters and mean age of both groups. Intra-observer and inter-observer intraclass correlation coefficients (ICCs) ranged between 0.74 and 0.87 for all assessed parameters. Patients affected by RCTs were statistically significant older than patients without tears (65 versus 59, p = 0.009). There was a statistically significant difference between the two groups in mean value of Acromion Index 0.83±0.15 vs. 0.76±0.10 (p < 0.001) and Critical Shoulder Angle 39.64°±7.41° vs. 36.34°±9.27° (p = 0.002). No significant difference were found as regards Lateral Acromion Angle 72.03°±9.80° vs. 72.58°±9.86° (p = 0.379), Humeral-Acromion Interval 10.61mm±2.68mm vs. 10.52mm±2.14mm (p = 0.421) and Cervico-Diaphyseal angle 91.35°±6.21° vs. 90.83°±7.64° (p = 0.214). Statistically significant higher Acromion Index and higher Critical Shoulder Angle were found in patients affected by degenerative rotator cuff tears undergoing arthroscopic repair, compared to controls. Other parameters were not strongly related to rotator cuff disease, with no statistically significant difference between mean values measured in affected patients and healthy subject. All parameters measured obtained an excellent reliability.

Glenoid morphology and the safe zone for protecting the suprascapular nerve during baseplate fixation in reverse shoulder arthroplasty.

The purpose of this study was to investigate glenoid morphology and define the safe zone for protecting the suprascapular nerve baseplate screw during baseplate fixation in reverse shoulder arthroplasty (RSA) in a Chinese population. Shoulder computed tomography (CT) scans from 56 subjects were retrospectively reviewed. Three-dimensional (3D) reconstruction was performed using Mimics software, and corresponding bony references were used to evaluate glenoid morphology. To standardize evaluation, the coronal scapular plane was defined. Safe fixation distances and screw placements were investigated by constructing a simulated cutting plane of the baseplate during RSA. Mean glenoid height was 35.83±2.95mm, and width was 27.32±2.78mm, with significant sexual dimorphism (p<0.01). According to the cutting plane morphology, the average baseplate radius was 13.84±1.34mm. The distances from the suprascapular notch and from two bony reference points at the base of the scapular spine to the cutting plane were 30.27±2.77mm, 18.39±1.67mm and 16.52±1.52mm, respectively, with a gender-related difference. Based on the clock face indication system, the danger zone caused by the suprascapular nerve projection was oriented between the two o'clock and eight o'clock positions in reference to the right shoulder. Glenoid size and the safe zone for screw fixation during RSA were characterized in a Chinese population. Careful consideration of baseplate fixation and avoidance of suprascapular nerve injury are important for improved clinical outcome.

Reverse Total Shoulder Arthroplasty With Humeral Head Autograft Fixed Onto Glenoid for Treatment of Severe Glenoid Retroversion

Advanced glenohumeral osteoarthritis can transform glenoid morphology and, in some cases, is found in association with severe glenoid retroversion. The associated glenoid retroversion leads to difficulty in fixation of the glenoid component in reverse total shoulder arthroplasty. In the context of extreme glenoid wear, structural grafts can be used to restore glenoid volume and version in order for the glenoid component of the reverse total shoulder arthroplasty to be more easily implanted. Nevertheless, literature regarding structural grafts remains limited, with optimal graft choice and technique still controversial at best. This article details our technique for humeral head autograft transplantation before reverse total shoulder arthroplasty in the context of extreme glenoid retroversion with advanced osteoarthritis.