Osteoarthritis of the hip: are degenerative tears of the acetabular labrum predictable from features on hip radiographs?

BACKGROUND: A common feature of hip arthritis is the presence of labra tears. Recent literature suggests against the use of magnetic resonance imaging (MRI) in patients aged >45 years for the assessment of hip pain related to arthritis. PURPOSE: To determine if radiographic features of osteoarthritis detectable on routine hip radiographs are accurate and reliable surrogate markers of degenerative acetabular labral tears identified on MR arthrography (MRA) and corroborated during arthroscopy. MATERIAL AND METHODS: A retrospective study involving 86 symptomatic patients (hip pain) with radiologic work-up included MRA and pelvic or hip radiographs that underwent hip arthroscopy within three months. Imaging characteristics assessed on hip radiographs include measurements of superior acetabular, femoral head osteophyte, cortical thickness of the femoral shaft, and minimum joint space as well as presence of subchondral sclerosis of the femoral head and acetabulum, femoral shaft buttressing, and grade of arthritis. Presence of a labral tear was determined by consensus between three readers as well as by surgical correlation. The Pearson's chi-squared and Fisher's exact tests were used to compare presence of labral tears with each radiographic feature. RESULTS: Seventy-one patients (82.6%) had labral tears: 49 (69%) women and 22 (31%) men. Receiver operating characteristic analysis showed statistical significance (P<0.05) between presence of a labral tear and acetabular and femoral head osteophyte sizes but failed to demonstrate any significance regarding acetabular subchondral sclerosis, cortical thickness, buttressing, or minimum joint space. CONCLUSIONS: Radiographic markers such as the acetabular and femoral head osteophyte sizes demonstrated statistical significance with the presence of labral tears.

Reliability of a functional magnetic resonance imaging task of emotional conflict in healthy participants.

Task-based functional neuroimaging methods are increasingly being used to identify biomarkers of treatment response in psychiatric disorders. To facilitate meaningful interpretation of neural correlates of tasks and their potential changes with treatment over time, understanding the reliability of the blood-oxygen-level dependent (BOLD) signal of such tasks is essential. We assessed test-retest reliability of an emotional conflict task in healthy participants collected as part of the Canadian Biomarker Integration Network in Depression. Data for 36 participants, scanned at three time points (weeks 0, 2, and 8) were analyzed, and intra-class correlation coefficients (ICC) were used to quantify reliability. We observed moderate reliability (median ICC values between 0.5 and 0.6), within occipital, parietal, and temporal regions, specifically for conditions of lower cognitive complexity, that is, face, congruent or incongruent trials. For these conditions, activation was also observed within frontal and sub-cortical regions, however, their reliability was poor (median ICC < 0.2). Clinically relevant prognostic markers based on task-based fMRI require high predictive accuracy at an individual level. For this to be achieved, reliability of BOLD responses needs to be high. We have shown that reliability of the BOLD response to an emotional conflict task in healthy individuals is moderate. Implications of these findings to further inform studies of treatment effects and biomarker discovery are discussed.

Performance of a rapid two-sequence screening protocol for osteomyelitis of the foot.

OBJECTIVE: Compare a two sequence protocol to a standard protocol in the detection of pedal osteomyelitis (OM) and abscesses and to identify patients that benefit from a full protocol. MATERIALS AND METHODS: One hundred thirty-two foot MRIs ordered to assess for OM were enrolled, and the following items were extracted from the clinical reports: use of IV contrast, the presence of OM, reactive osteitis, and a soft tissue abscess. Using only one T1 nonfat-suppressed and one fluid sensitive fat-suppressed sequences, two experienced musculoskeletal radiologists reviewed each case for the presence of OM, reactive osteitis, or an abscess. A Kappa test was calculated to assess for interobserver agreement, and diagnostic performance was determined. The McNemar test was used to assess for the effect of contrast. RESULTS: Agreement between both observers and the clinical report on the presence of osteomyelitis was substantial ( k = 0.63 and 0.72, p < 0.001), while the agreement for abscess was fair (k = 0.29 and 0.38, p < 0.001). For osteomyelitis, both observers showed good accuracy (0.85 and 0.86). When screening bone for a normal versus abnormal case, this method was highly sensitive (0.97-0.98), but was less sensitive for abscess (0.63-0.75). Fifty-one percent of exams used contrast, and it did impact the diagnosis of abscess for one observer. CONCLUSION: This rapid protocol is accurate in making the diagnosis of OM, and its high sensitivity makes it useful to screen for patients that would benefit from a full protocol.

The Canadian Biomarker Integration Network in Depression (CAN-BIND): magnetic resonance imaging protocols

Studies of clinical populations that combine MRI data generated at multiple sites are increasingly common. The Canadian Biomarker Integration Network in Depression (CAN-BIND; www.canbind.ca) is a national depression research program that includes multimodal neuroimaging collected at several sites across Canada. The purpose of the current paper is to provide detailed information on the imaging protocols used in a number of CAN-BIND studies. The CAN-BIND program implemented a series of platform-specific MRI protocols, including a suite of prescribed structural and functional MRI sequences supported by real-time monitoring for adherence and quality control. The imaging data are retained in an established informatics and databasing platform. Approximately 1300 participants are being recruited, including almost 1000 with depression. These include participants treated with antidepressant medications, transcranial magnetic stimulation, cognitive behavioural therapy and cognitive remediation therapy. Our ability to analyze the large number of imaging variables available may be limited by the sample size of the substudies. The CAN-BIND program includes a multimodal imaging database supported by extensive clinical, demographic, neuropsychological and biological data from people with major depression. It is a resource for Canadian investigators who are interested in understanding whether aspects of neuroimaging ­ alone or in combination with other variables ­ can predict the outcomes of various treatment modalities.

CT can stratify patients as low risk for tibial neuropathy following a talus fracture.

OBJECTIVE: Determine the incidence of tibial neuropathy following talus fractures and CT's ability to stratify patients at risk for developing post-traumatic neuropathy. MATERIALS AND METHODS: In this IRB-approved retrospective analysis, 71 talus fractures and 8 contralateral control ankle CTs were reviewed by one observer blinded to clinical information. CT evidence suggestive of tibial neurovascular bundle injury included nerve displacement, perineural fat effacement/edema, and bone touching nerve. The association between these CT findings and clinically evident tibial neuropathy was analyzed. A semi-quantitative likelihood score was assigned based on the degree of the CT findings around the nerve. Interobserver agreement was calculated between 2 other readers. RESULTS: Twenty-five percent of patients in this cohort had clinical evidence of tibial neuropathy. There was a high specificity (0.87-0.93) and negative predictive value (0.83-0.87), a moderate accuracy (0.80-0.82), but a lower sensitivity (0.33-0.56) associated with the CT findings. Among the CT findings, nerve displacement (p < 0.0001) and bone touching nerve (p = 0.01) were associated with tibial neuropathy. A likelihood score of 2-5 was associated (p = 0.007-0.015) with tibial neuropathy. The presence of tibial neuropathy and nerve recovery were not associated with hospital length of stay, while CT findings were. There was substantial agreement between the three readers: likelihood scores 2+ (k = 0.78) and 3+ (k = 0.72). CONCLUSIONS: Tibial neuropathy occurs following talus fractures, and CT findings may help surgeons narrow down the number of patients requiring close neurological follow-up.

Kinematic differences between gender specific and traditional knee implants.

In the ongoing debate about gender-specific (GS) vs. traditional knee implants, there is limited information about patella-specific outcomes. GS femoral component features should provide better patellar tracking, but techniques have not existed previously to test this accurately. Using novel computed tomography and radiography imaging protocols, 15 GS knees were compared to 10 traditional knees, for the 6 degrees of freedom of the patellofemoral and tibiofemoral joints throughout the range of motion, plus other geometric measures and quality of life (QOL). Significant differences were found for patellar medial/lateral shift, where the patella was shifted more laterally for the GS femoral component. Neither group demonstrated patellar maltracking. There were no other significant differences in this well-functioning group.

Glenoid Version Assessment When the CT Field of View Does Not Permit the Friedman Method: The Robertson Method.

Background: To improve spatial resolution, current clinical shoulder cross-sectional imaging studies reduce the field of view of the shoulder, excluding the medial scapula border and preventing glenoid version measurement according to the Friedman method. Purpose: To evaluate a method to accurately and reliably measure glenoid version on cross-sectional shoulder images when the medial scapula border is not included in the field of view, and to establish measurements equivalent to the Friedman method. Study Design: Controlled laboratory study. Methods: Sixty-five scapulae underwent computed tomography (CT) scanning with an optimal shoulder CT-positioning protocol. Glenoid version was measured on CT images of the full scapula using the Friedman method. We developed a measurement method (named the Robertson method) based on the glenoid vault version from partial scapula images, with a correction angle subtracted from the articular-surface-glenoid vault measurement. Comparison with the Friedman method defined the accuracy of the Robertson method. Three observers tested inter- and intraobserver reliability of the Robertson method. Accuracy was statistically evaluated with t tests and reliability with the intraclass correlation coefficient (ICC). Results: The statistical distribution of glenoid version was similar to published data,-0.5° ± 3° [mean ± SD]. The initial measurement using the Robertson method resulted in a more retroverted angle compared with the Friedman method, and a correction angle of 7° was then applied. After this adjustment, the difference between the 2 methods was nonsignificant (0.1° ± 4°; P > .65). Reliability of the Robertson method was excellent, as the interrater ICC was 0.77, the standard error of measurement (SEM) was 1.1° with P < .001. The intrarater ICC ranged between 0.84 and 0.92, the SEM ranged between 0.9° and 1.2° with P < .01. Conclusion: A validated glenoid version measurement method is now available for current clinical shoulder CT protocols that reliably create Friedman-equivalent values. Clinical Relevance: Friedman-equivalent values may be made from common clinical CTs of the shoulder and compared with prior and future Friedman measurements of the scapula.

Escitalopram ameliorates differences in neural activity between healthy comparison and major depressive disorder groups on an fMRI Emotional conflict task: A CAN-BIND-1 study.

BACKGROUND: Identifying objective biomarkers can assist in predicting remission/non-remission to treatment, improving remission rates, and reducing illness burden in major depressive disorder (MDD). METHODS: Sixteen MDD 8-week remitters (MDD-8), twelve 16-week remitters (MDD-16), 14 non-remitters (MDD-NR) and 30 healthy comparison participants (HC) completed a functional magnetic resonance imaging emotional conflict task at baseline, prior to treatment with escitalopram, and 8 weeks after treatment initiation. Patients were followed 16 weeks to assess remitter status. RESULTS: All groups demonstrated emotional Stroop in reaction time (RT) at baseline and Week 8. There were no baseline differences between HC and MDD-8, MDD-16, or MDD-NR in RT or accuracy. By Week 8, MDD-8 demonstrated poorer accuracy compared to HC. Compared to HC, the baseline blood-oxygen level dependent (BOLD) signal was decreased in MDD-8 in brain-stem and thalamus; in MDD-16 in lateral occipital cortex, middle temporal gyrus, and cuneal cortex; in MDD-NR in lingual and occipital fusiform gyri, thalamus, putamen, caudate, cingulate gyrus, insula, cuneal cortex, and middle temporal gyrus. By Week 8, there were no BOLD activity differences between MDD groups and HC. LIMITATIONS: The Emotional Conflict Task lacks a neutral (non-emotional) condition, restricting interpretation of how mood may influence perception of non-emotionally valenced stimuli. CONCLUSIONS: The Emotional Conflict Task is not an objective biomarker for remission trajectory in patients with MDD receiving escitalopram treatment. Escitalopram may have influenced emotion recognition in MDD groups in terms of augmented accuracy and BOLD signal in response to an Emotional Conflict Task, following 8 weeks of escitalopram treatment.

Correlation between subcutaneous fat measurements in knee MRI and BMI: relationship to obesity and related co-morbidities.

BACKGROUND: Obesity is a major public health disorder associated with multiple co-morbidities. Knee magnetic resonance imaging (MRI) permits visualization of the subcutaneous fat anatomy, which can be correlated to body mass index (BMI) and obesity-related co-morbidities. PURPOSE: This study intends to validate a method of correlating measurements of subcutaneous fat around the distal femur on axial MR images to BMI and obesity-related co-morbidities. MATERIAL AND METHODS: The most proximal axial slice of each knee MRI was divided into four quadrants. Measurements of the thickest portion of the subcutaneous fat in each quadrant were independently obtained, yielding a value which was assigned the name of the SubCut fat index. The relationship between the SubCut fat index of each quadrant and the patient's BMI was then evaluated. Receiver operating characteristic curves utilizing both the subcutaneous fat in the medial and lateral quadrants as well as BMI were performed with respect to obesity-related co-morbidities. RESULTS: SubCut fat index measurements in all four quadrants and BMI show the strongest correlation (all four, ANOVA P < 0.0001, r = 0.6), with subcutaneous fat measurements of the anterior medial (p < 0.0001) and posterior medial quadrants (P = 0.01). Additionally, BMI and medial quadrants SubCut indices showed strong association with obesity-related co-morbidities including sleep apnea, asthma, diabetes, hypertension, gastroesophageal reflux disease, and osteoporosis. CONCLUSION: The SubCut fat index, a marker of distal femur subcutaneous fat on axial MRI, correlates with severity of obesity (BI) and associated obesity-related co-morbidities.

Volumetric evaluation of lumbar epidural fat distribution in epidural lipomatosis and back pain in patients who are obese: introducing a novel technique (Fat Finder algorithm).

Objective: Spinal epidural lipomatosis (EL) represents an excessive deposition of unencapsulated adipose tissue in the spinal canal that can result in chronic back pain in patients who are obese with and without diabetes. We aim to calculate the total volumetric epidural fat on lumbar spine MRI in a predominately obese population and correlate total epidural fat to lower back pain (LBP) and body mass index (BMI). Research design and methods: We developed a program (Fat Finder) to quantify volumetric distribution of epidural fat throughout the lumbar spine. Eleven patients with LBP were imaged using two MRI protocols: parallel axial slices and conventional clinical protocol. The distribution of epidural fat per level was analyzed and normalized to the spinal canal size. Results: Our sample had an average age of 59.9 years and BMI of 31.57 kg/m2. EL subgroup consisted of seven patients. The L2-L5 total fat volume was 3477.6 mm3 (1431.1-5595.9) in the EL group versus 1783.8 mm3 (815.0-2717.5) in the age-similar non-EL group. A higher percentage of fat volume in the canal was associated with higher LBP scores. The fat percentage was 32.2% among patients with EL versus 15.4% for age-similar non-EL with LBP score of 6.1 and 4.0, respectively. Conclusions: The Fat Finder is a novel volumetric method to quantify epidural lumbar spinal fat. The epidural fat favors the lower spinal segment with direct proportionality between the fat volume and LBP score, independent of BMI.

Reduced accuracy accompanied by reduced neural activity during the performance of an emotional conflict task by unmedicated patients with major depression: A CAN-BIND fMRI study.

METHODS: We studied 48 MDD and 30 HC who performed an emotional conflict task in a functional magnetic resonance imaging (fMRI) scanner. RESULTS: On the emotional conflict task, MDD and HC demonstrated a robust emotional Stroop effect in reaction time and accuracy. Overall, accuracy was lower in MDD compared to HC with no significant reaction time differences. The fMRI data indicated lower BOLD activation in MDD compared to HC on comparisons of all trials, congruent, incongruent, and incongruent > congruent trials in regions including right inferior temporal gyrus, lateral occipital cortex, and occipital fusiform gyrus. Behavioural and neuroimaging data indicated no group differences in fearful versus happy face processing. LIMITATIONS: Inclusion of a neutral condition may have provided a valuable contrast to how MDD and HC process stimuli without emotional valence compared to stimuli with a strong emotional valence. CONCLUSIONS: MDD and HC demonstrated a robust emotional Stroop effect. Compared to HC, MDD demonstrated an overall reduced accuracy on the emotional conflict task and reduced BOLD activity in regions important for face perception and emotion information processing, with no differences in responding to fearful versus happy faces. These findings provide support for the theory of emotion context insensitivity in individuals with depression.

Torsional strength estimates of femoral diaphyses with endosteal lytic lesions: dual-energy X-ray absorptiometry study.

Pathologic fracture is a significant problem for individuals with metastatic bone disease. Current guidelines for prophylactic internal fixation are neither reliable nor easily applied. The purpose of this study was to validate dual-energy X-ray absorptiometry (DXA) as an accurate method for estimating torsional bone strength of diaphyseal bone with endosteal lytic lesions. Endosteal lesions of varying sizes were simulated in the diaphyses of 12 adult cadaveric femurs. Unaltered contralateral femurs served as matched controls. Machined lesions ranged from 3 to 6.5 cm in length, 1 to 3 cm in width, 15 to 48 cm(2) in elliptical area, with 10% to 100% removal of the cortical thickness. Morphology and density data obtained from DXA images were used to estimate torsional strength. All femora were mechanically tested to failure in torsion. Physically measured torsional strength was not significantly correlated to lesion elliptical area (r = 0.542, p > 0.05) or percentage cortical thickness removed (r = 0.257, p > 0.05). Measured torsional strength was significantly correlated to DXA-based torsional strength estimates (r = 0.855, p < 0.01). Lesion size alone did not correlate with the strength of bones with simulated endosteal lytic lesions. In contrast, calculations based on DXA (morphology, density) did correlate with torsional strength. This is the first step in the development of a DXA-based tool for objectively estimating bone strength in the presence of endosteal lytic lesions.

Machine learning based analytics of micro-MRI trabecular bone microarchitecture and texture in type 1 Gaucher disease.

Type 1 Gaucher disease (GD) is an autosomal recessive lysosomal storage disease, affecting bone metabolism, structure and strength. Current bone assessment methods are not ideal. Semi-quantitative MRI scoring is unreliable, not standardized, and only evaluates bone marrow. DXA BMD is also used but is a limited predictor of bone fragility/fracture risk. Our purpose was to measure trabecular bone microarchitecture, as a biomarker of bone disease severity, in type 1 GD individuals with different GD genotypes and to apply machine learning based analytics to discriminate between GD patients and healthy individuals. Micro-MR imaging of the distal radius was performed on 20 type 1 GD patients and 10 healthy controls (HC). Fifteen stereological and textural measures (STM) were calculated from the MR images. General linear models demonstrated significant differences between GD and HC, and GD genotypes. Stereological measures, main contributors to the first two principal components (PCs), explained ~50% of data variation and were significantly different between males and females. Subsequent PCs textural measures were significantly different between GD patients and HC individuals. Textural measures also significantly differed between GD genotypes, and distinguished between GD patients with normal and pathologic DXA scores. PCA and SVM predictive analyses discriminated between GD and HC with maximum accuracy of 73% and area under ROC curve of 0.79. Trabecular STM differences can be quantified between GD patients and HC, and GD sub-types using micro-MRI and machine learning based analytics. Work is underway to expand this approach to evaluate GD disease burden and treatment efficacy.

Validating Dual Fluoroscopy System Capabilities for Determining In-Vivo Knee Joint Soft Tissue Deformation: A Strategy for Registration Error Management.

Knee osteoarthritis (OA) causes structural and mechanical changes within tibiofemoral (TF) cartilage affecting tissue load deformation behavior. Quantifying in-vivo TF soft tissue deformations in healthy and early OA may provide a novel biomechanical marker, sensitive to alterations occurring prior to radiographic change. Dual Fluoroscopy (DF) allows accurate in-vivo TF soft tissue deformation assessment but requires validation. In-vivo healthy and early OA TF cartilage deforms 0.3-1.2mm during static standing full body-weight loading. Our aim was to establish minimum detectable displacement (MDD) for femoral translation in a DF system using a marker-based and markerless approach with variable image intensifier magnifications. An instrumented frame allowed controlled femur specimen translations. Bone positions were reconstructed from DF data using centroids of affixed steel beads (marker-based) and 2D-3D bone feature registration (markerless). Statistical analyses included independent samples t-tests and reliability analysis. Markerless measurements by three trained operators had large variations making it prudent to have an appropriate error management strategy when performing 2D-3D registration. Marker-based MDD improved with image resolution and was 0.05 mm at 3.2 LP/mm (LP: line pairs). Markerless MDD at 3.2 LP/mm was 0.08 mm. Average femur and tibia 2D-3D registrations yielded excellent reliability (84.4%). Therefore, DF images acquired at resolution greater than 3.2 LP/mm would be capable for determining accurate and reliable in-vivo healthy and early OA TF soft tissue deformation. This study provides a registration error management strategy for in-vivo TF soft tissue deformation assessment that could be applied for future clinical applications to establish non-invasive biomechanical markers for early OA diagnosis.

Rigorous geometric self-calibrating bundle adjustment for a dual fluoroscopic imaging system.

High-speed dual fluoroscopy is a noninvasive imaging technology for three-dimensional skeletal kinematics analysis that finds numerous biomechanical applications. Accurate reconstruction of bone translations and rotations from dual-fluoroscopic data requires accurate calibration of the imaging geometry and the many imaging distortions that corrupt the data. Direct linear transformation methods are commonly applied for performing calibration using a two-step process that suffers from a number of potential shortcomings including that each X-ray source and corresponding camera must be calibrated separately. Consequently, the true imaging set-up and the constraints it presents are not incorporated during calibration. A method to overcome such drawbacks is the single-step self-calibrating bundle adjustment method. This procedure, based on the collinearity principle augmented with imaging distortion models and geometric constraints, has been developed and is reported herein. Its efficacy is shown with a carefully controlled experiment comprising 300 image pairs with 48 507 image points. Application of all geometric constraints and a 31 parameter distortion model resulted in up to 91% improvement in terms of precision (model fit) and up to 71% improvement in terms of 3-D point reconstruction accuracy (0.3-0.4 mm). The accuracy of distance reconstruction was improved from 0.3±2.0 mm to 0.2 ±1.1 mm and angle reconstruction accuracy was improved from -0.03±0.55(°) to 0.01±0.06(°). Such positioning accuracy will allow for the accurate quantification of in vivo arthrokinematics crucial for skeletal biomechanics investigations.

Structure modeling of the glenoid: Relevance to shoulder arthroplasty.

We applied shape modeling and principal component analysis (PCA) to discover glenoid bone structural relationships relevant to improving glenoid prosthesis features, fixation, and instrumentation. Knowledge of external bone morphology guides prosthesis shape and positioning, while internal bone morphology and bone density influence fixation. CT-based modeling defined nonarthritic glenoid subchondral bone surface and internal structure. First and second principal shape components were related to size and density. Reproducible structural parameters and glenoid feature relationships were discovered. Subchondral bone surface was approximated by a circle inferiorly and a triangle superiorly with the circle's center at a reproducible point along a superior-inferior line. Glenoid vault's maximum depth was at the circle's center, and the highest bone density was in posterior glenoid. Glenoid subchondral bone surface version varied from superior to inferior, but not by sex or side. Male subchondral bone surfaces were larger and more retroverted. Even if subchondral bone surfaces are deformed by arthritis, glenoid morphology can be identified by extra-articular landmarks, permitting location of the glenoid center and scapular orientation (glenoid version). Knowledge obtained from this study directs design of novel prosthesis features and instrumentation for use without pre-op CT or computer aided surgery.

Effect of glenoid prosthesis design on glenoid bone remodeling: adaptive finite element based simulation.

Glenoid prosthesis loosening is the most common cause for revision total shoulder arthroplasty. Improved glenoid prosthesis design requires looking beyond initial post-implantation static stress analyses. Adaptive bone remodeling simulations based on Wolff's law are needed for predicting long-term glenoid prosthesis results. This study demonstrates the capability of predicting glenoid bone remodeling produced by changing prosthesis design features. Twelve glenoid prostheses were designed to fit each of six donor human glenoids, using combinations of three peg types and four backing-peg material combinations (polyethylene and or metal). The twelve FE prosthesis models were individually combined, simulating surgical implantation, with the glenoid models. Remodeling simulations, using a validated adaptive bone remodeling simulation, commenced with homogeneous glenoid bone density. To produce bone remodeling, center, posterior-offset, and anterior-offset physiologic loads were consecutively applied to the bone-prosthesis FE models for 300 iterations. Upon completion, region-specific mean predicted bone apparent densities were compared between bone-prosthesis and intact glenoid FE models. Metal fixations significantly increased proximal-center bone density. Polyethylene fixations resulted in bone density approximately equal to intact. Two angled polyethylene peg designs with longer-anterior and shorter-posterior pegs, reflecting natural glenoid shape, best maintained mid and distal glenoid bone density. While these initial results were not validated, they demonstrate the capability and potential of adaptive glenoid bone remodeling simulation. We expect FE glenoid bone remodeling simulations to become powerful and robust tools in the design and evaluation of glenoid prostheses.

Adaptive glenoid bone remodeling simulation.

Glenoid prosthesis loosening is the most common cause for revision total shoulder arthroplasty. Stress-induced bone remodeling may compromise long-term prosthesis fixation and significantly contribute to loosening. Realistic, robust analysis of bone-prosthesis constructs need to look beyond initial post-implantation mechanics provided by static finite element (FE) simulation. Adaptive bone remodeling simulations based on Wolff's law are needed for evaluating long-term glenoid prostheses fixation. The purpose of this study was to take a first step towards this goal and create and validate two-dimensional FE simulations, using the intact glenoid, for computing subject-specific adaptive glenoid remodeling. Two-dimensional glenoid FE models were created from scapulae computed tomography images. Two distinct processes, "element" and "node" simulations, used the forward-Euler method to compute bone remodeling. Initial bone density was homogeneous. Center and offset load combinations were iteratively applied. To validate the simulations we performed location-specific statistical comparisons between predicted and actual bone density, load combinations, and "element" and "node" processes. Visually and quantitatively "element" simulations produced better results (p>0.22), and correlation coefficients ranged 0.51-0.69 (p<0.001). Having met this initial work's goals, we expect subject-specific FE glenoid bone remodeling simulations together with static FE stress analyses to be effective tools for designing and evaluating glenoid prostheses.