Deep learning approach to femoral AVN detection in digital radiography: differentiating patients and pre-collapse stages.

OBJECTIVE: This study aimed to evaluate a new deep-learning model for diagnosing avascular necrosis of the femoral head (AVNFH) by analyzing pelvic anteroposterior digital radiography. METHODS: The study sample included 1167 hips. The radiographs were independently classified into 6 stages by a radiologist using their simultaneous MRIs. After that, the radiographs were given to train and test the deep learning models of the project including SVM and ANFIS layer using the Python programming language and TensorFlow library. In the last step, the test set of hip radiographs was provided to two independent radiologists with different work experiences to compare their diagnosis performance to the deep learning models' performance using the F1 score and Mcnemar test analysis. RESULTS: The performance of SVM for AVNFH detection (AUC = 82.88%) was slightly higher than less experienced radiologists (79.68%) and slightly lower than experienced radiologists (88.4%) without reaching significance (p-value > 0.05). Evaluation of the performance of SVM for pre-collapse AVNFH detection with an AUC of 73.58% showed significantly higher performance than less experienced radiologists (AUC = 60.70%, p-value < 0.001). On the other hand, no significant difference is noted between experienced radiologists and SVM for pre-collapse detection. ANFIS algorithm for AVNFH detection with an AUC of 86.60% showed significantly higher performance than less experienced radiologists (AUC = 79.68%, p-value = 0.04). Although reaching less performance compared to experienced radiologists statistically not significant (AUC = 88.40%, p-value = 0.20). CONCLUSIONS: Our study has shed light on the remarkable capabilities of SVM and ANFIS as diagnostic tools for AVNFH detection in radiography. Their ability to achieve high accuracy with remarkable efficiency makes them promising candidates for early detection and intervention, ultimately contributing to improved patient outcomes.

Total hip replacement among sickle cell patients in a low-income country-Yemen.

PURPOSE: Sickle cell patients presented with progressive hip pain and limitation of daily activities, as evidenced by low preoperative hip scores and failed conservative therapy. Management of femoral head avascular necrosis (AVN) using total hip replacement (THR) in sickle cell disease (SCD) is widespread in developed countries, but it is still in its initiation stage in developing countries. The outcome of using cementless THR among SCD patients is still unknown with lack of published studies from regional countries. This study aimed to evaluate the outcome of using cementless primary THR among patients with sickle cell disease with end-stage hip avascular necrosis in Yemen. METHODS: Thirty cementless primary total hip arthroplasty (THA) were performed for AVN of the femoral head in 27 sickle cell patients, at Al.-Thawra Modern General Hospital-Sana'a, Yemen, from January 2018 to December 2022. RESULTS: The mean age of the patients was 27 ± five years (ranged 18-37 years) with a male to female ratio was 3:1. Steinberg staging for hip AVN was stage IV, one patient (3%); stage VI, thirteen patients (45%); and stage V, sixteen patients (51%). THR was on right side 14 (52%), left side 10 (37%), and bilateral 3 (11%). The implant used was ceramic on polyethylene acetabular liner. All patients showed improvement in Harris hip score from preoperative mean hip score was 25 ± 8 points to postoperative mean hip score was 88 ± 6 points at the last follow-up. Mean of the length of stay in hospital was 12.7 ± eight days (ranged from 4 to 32 days); the mean operating time was 107 ± 23 min. Three cases had superficial wound infection; four patients had five intraoperative fractures; two cases had pulmonary complications; one case had abdominal crisis. All patients had postoperative leg length discrepancy less than 2 cm. None had deep infection, nerve injury, wound hematoma, aseptic loosing, dislocation, DVT, heterotopic ossification, or death. CONCLUSION: THR in SCD has a good outcome using cementless THA with a low rate of complication in Yemen, a developing country.

Hyperbaric oxygen therapy for avascular necrosis of the femoral head: A case report.

The hip is the most common location for avascular necrosis of the femoral head (AVN), with an estimated incidence in the United States of 10,000 to 20,000 new cases per year. The current standard of care for early disease is core decompression, with bone marrow injections becoming more commonplace. Hyperbaric oxygen enhances oxygen delivery to tissue, promotes an anti-inflammatory and pro-healing environment, and helps initiate angiogenesis. We believe that these properties of HBO2 make it a unique tool for AVN and applied it in conjunction with the standard of care for our patient.

Internodal conduction pathways: revisiting a century-long debate on their existence, morphology, and location in the context of 2023 best science.

Internodal conduction pathways are the communication apparatus of the cardiac conduction system conveying sinus node action potentials (APs) to the atrioventricular node and atrial working myocytes. In 1910, at the Deutschen Pathologischen Gesellschaft held in Erlangen, Charles Thörel related his discovery of an internodal bundle structured with Purkinje-like cells, which was rejected by the participants, who endorsed the then-leading doctrine that atrial contractile cardiomyocytes operate as internodal routes. Starting in 1963 and for five subsequent decades, two groups have revisited this issue. The first group, led by Thomas James, defended the histological existence of uninsulated, high-speed cordlike internodal conduction tracts. Although not supported by robust experimental data, this hypothesis achieved the status of a physiological creed in the scientific community. The second group, led by Robert Anderson, systematically refuted this stance and adopted anisotropy as an innovative internodal conduction mechanism operating via spindle-shaped atrial contractile myocytes structured in anisotropic muscular bundles relaying sinoatrial node (SAN) APs to their atrial destinations at physiologically required (fit for purpose) velocities to enable electromechanical synchrony of atrial systoles. Modern imaging and electrophysiological techniques can now clearly visualize muscular internodal and interatrial tracts and SAN depolarization electrical waves, confirming the existence of atrial conduction paths consisting of anisotropically arranged contractile cardiomyocytes. Mastery of the current best-science anatomy and physiology of the human atria is required for electrophysiologists to safely perform atrial radiofrequency ablation interventions to restore sinus rhythm in patients distressed by supraventricular arrhythmias.NEW & NOTEWORTHY This report reexamines disparate historical views on internodal pathway existence and nature. The conflicting research, ongoing since 1963, regarding these issues, is appraised. The discovery of myocytes anisotropically structured in atrial bundles relaying sinoatrial node (SAN) action potentials (APs) to atrioventricular node (AVN) and atrial wall destinations is emphasized, since it is still a relatively unfamiliar subject in physiology teaching. Modern imaging technologies can now visualize internodal pathways as muscular bundles displaying SAN electrical waves traversing the atrial walls.

Impact of sickle cell disease in shoulder arthroplasty: a matched cohort analysis.

BACKGROUND: Sickle cell disease (SCD) is a genetic disorder of abnormal hemoglobin synthesis that is known to cause glenohumeral avascular necrosis (AVN). Little has been published on the use of shoulder arthroplasty (SA) for the treatment of glenohumeral AVN in SCD. We report on the clinical and radiographic results and postoperative complications following SA in the patient cohort. METHODS: A retrospective review was performed identifying 17 primary SAs (9 hemiarthroplasties, 7 anatomic total SAs, and 1 reverse total SA) in patients with a confirmed diagnosis of SCD and a minimum of 2-year follow-up. This cohort was matched (1:2) according to age, sex, body mass index, type of prosthesis, and year of surgery with patients who had undergone hemiarthroplasty or total SA for osteoarthritis (OA) or reverse total SA for cuff tear arthropathy. Outcomes included the visual analog scale (VAS) for pain, American Shoulder and Elbow Surgeons score, range of motion, and strength measurements in forward elevation (FE), external rotation (ER), and internal rotation (IR). RESULTS: Our cohort included 9 (52.9%) men with a mean age of 43 yr. The average follow-up time was 5.9 yr. In patients with SCD, SA provided significant improvements in VAS pain (9.1-3.8; P < .001), FE (95°-128°; P < .001), ER (24°-38°; P < .001), IR score (3.2-5.2; P < .001), FE strength (4.2-4.8; P < .001), ER strength (4.1-4.7; P < .001), IR strength (4.1-4.7; P < .001), and American Shoulder and Elbow Surgeons scores (48.6-73.5; P < .001). When compared to the matched cohort, the SCD group demonstrated higher preoperative (9.1 vs. 3.8; P < .001) and postoperative VAS scores (3.8 vs. 1.3; P < .001). Other clinical outcomes demonstrated no significant differences. There were 5 (29%) complications, 2 (11.8%) episodes of sickle cell crisis, and 3 (18%) reoperations in the SCD cohort. When compared to the matched cohort, there were no statistical differences with respect to complications (29% vs. 12%; P = .140) or reoperations (18% vs. 12%; P = .387). CONCLUSIONS: SA is an effective treatment modality for glenohumeral AVN in patients with SCD. Patients may expect improvements in pain, function, motion, and strength. However, final postoperative pain relief may be less than those treated with SA without SCD. Unique perioperative management is necessary to mitigate the risk of postoperative sickle cell crises.

Prevalence of avascular necrosis in idiopathic inflammatory myopathies: a single-centre experience.

OBJECTIVES: To assess the prevalence of avascular necrosis (AVN) in a large cohort of patients with idiopathic inflammatory myopathies (IIM) and define the major associated risk factors. METHODS: We retrospectively reviewed the electronic medical records of all patients with a definitive diagnosis of IIM enrolled in our registry between 2003 and 2017, and followed until 2020. Pertinent demographic, clinical, serologic and imaging data were collected. A matched group of patients without AVN was then selected for comparison. RESULTS: A total of 1680 patients were diagnosed with IIM. Fifty-one patients developed AVN, with an overall prevalence of 3%. Musculoskeletal MRI was available for 1085 patients and AVN was present in 46 patients (43 lower extremities and 3 upper extremities MRI studies), with a relative prevalence of 4.2%. Most patients with AVN were Caucasian females (57%) with a mean (s.d.) age at diagnosis of 44.5 (12.4) years. Sixty-one percent had DM and 29% had PM. The median time from onset of IIM to diagnosis of AVN was 46 months. The hip joint was most commonly involved in 76% of cases, followed by the knee joint in 15% and shoulder joint in 9%. Some 81% of patients were asymptomatic. Established risk factors for AVN were not found to be associated with the development of AVN in IIM patients. CONCLUSION: Although mostly asymptomatic and incidental, the overall prevalence of AVN in IIM was 3% and the prevalence by MRI was 4.2%. None of the established risk factors was found to be associated with AVN development.

Fracture dislocations of the proximal humerus treated with open reduction and internal fixation: a systematic review.

BACKGROUND: The treatment of proximal humerus fracture dislocations can be challenging given the extensive injury to the proximal humeral anatomy and increased risk of devascularization of the humeral head often seen in these injuries. The purpose of this study is to undertake a systematic review of the literature on the functional outcomes, rate of revision, and short- and long-term complications for proximal humerus fracture dislocations treated with open reduction and internal fixation (ORIF). METHODS: The PubMed and OVID Embase databases were queried for literature reporting on proximal humerus fracture dislocations treated with ORIF. Data including study design, patient demographics, functional outcomes, and complications were recorded. RESULTS: Twelve studies including 294 patients with Neer type 2-, 3-, or 4-part proximal humerus fracture dislocations met the criteria for inclusion. The mean patient age was 53.4 years (19-89 years) with an average follow-up of 2.9 years (1.15-4.9 years). At the final follow-up, the mean Constant score was 73.2 (52-87.3) and the mean Disabilities of the Arm Shoulder and Hand score was 26.6 (17.5-32). Avascular necrosis was observed in 20.0% (0%-82.3%) and nonunion was observed in 3.0% (0%-7.7%) of patients. Conversion to arthroplasty was observed in 10.7% (5%-20%) and a total reoperation was observed in 35.6% (11.8%-89.1%) of patients in studies explicitly reporting these outcomes. In addition to conversion to arthroplasty, common causes of reoperation were revision ORIF (5.2%) and hardware removal (22.2%). CONCLUSION: Patients undergoing ORIF for proximal humerus fracture dislocations have reasonable functional outcomes but relatively high avascular necrosis and reoperation rates. This information can be used to counsel patients and set expectations about the potential for further surgeries.

Reverse shoulder arthroplasty yields similar results to anatomic total shoulder arthroplasty for the treatment of humeral head avascular necrosis.

BACKGROUND: Avascular necrosis (AVN) of the humeral head frequently results in humeral head collapse and end-stage arthritic changes of the glenohumeral joint. Despite the recent proliferation of reverse total shoulder arthroplasty (RTSA), reports on the use of RTSA for AVN remain limited. The purpose of this study was to document the outcomes of shoulders indicated for RTSA in the setting of humeral head AVN and compare these with AVN shoulders indicated for the gold standard, anatomic total shoulder arthroplasty (aTSA). METHODS: A retrospective review of a multinational shoulder arthroplasty database was performed between August 2005 and August 2017. All shoulders with a preoperative diagnosis of AVN (aTSA in 52 and RTSA in 67) were reviewed. The shoulders in the RTSA cohort were matched (1:1) to shoulders with cuff tear arthropathy, whereas the shoulders in the aTSA cohort were matched (1:1) to shoulders with primary osteoarthritis. The mean follow-up period was 47 months (range, 24-130 months) for RTSA and 54 months (range, 24-124 months) for aTSA. Shoulders were evaluated for active range of motion (ROM) and patient-reported outcome measures (PROMs) prior to surgery and at latest follow-up. Patients treated with RTSA were compared with both the aTSA study cohort and the control group using the Student t test or χ2 test as indicated. RESULTS: RTSAs performed for AVN demonstrated significant improvements in all ROMs and PROMs. Patients undergoing aTSA for AVN were significantly younger than those undergoing RTSA (59 years vs. 73 years, P < .001). At similar follow-up points, the RTSA cohort demonstrated significantly greater improvement in abduction (+51° vs. +32°, P = .03) whereas the aTSA cohort demonstrated significantly greater improvement in internal rotation. Postoperative University of California, Los Angeles scores (30 vs. 27, P = .014) and visual analog scale scores (1.4 vs. 2.4, P = .025) were better after RTSA; however, these differences between prosthesis types did not exceed the minimal clinically important difference. When compared with the control patients, the patients undergoing RTSA for AVN showed similar improvements in all ROMs and PROMs. Similarly, aTSA performed for AVN resulted in comparable improvements in pain, ROMs, and PROMs compared with aTSA performed for primary osteoarthritis. CONCLUSION: RTSA results in similar PROMs to aTSA in the treatment of AVN. Therefore, surgeons should continue to consider other patient factors such as glenoid bone loss and rotator cuff status when selecting implant polarity in patients with AVN.

Moderate-severe grade of chronic graft versus host disease and younger age (less than 45 years old) are risk factors for avascular necrosis in adult patients undergoing allogeneic hematopoietic cell transplantation.

Avascular necrosis (AVN) is a debilitating complication of allogeneic hematopoietic cell transplantation (HCT). A retrospective review of 845 patients who underwent HCT was conducted. Cumulative incidence of AVN was 6.3% at 4 years. The following risk factors were significantly associated with AVN risk on univariate analysis: age < 45 (p=0.004), moderate to severe chronic GvHD (p<0.001), reduced intensity conditioning (p=0.02), and a diagnosis of acute leukemia (p=0.045). Multivariate analysis confirmed two risk factors: younger age (<45 years), 9.0% vs 4.4% (p=0.011, hazard ratio (HR) 2.134), and moderate-severe chronic GvHD, 15.4% vs 2.1% (p<0.001, HR 4.950). A risk score model was generated assigning a score to each risk factor. A score of 1 was assigned to moderate-severe GvHD or those with age <45. Total score was calculated, thus dividing patient into three groups: low (score 0, n=349, 41.3%), intermediate (score 1, n=379, 44.9%), and high risk (score 2; n=116, 13.7%). This risk score could stratify the patients according to AVN risk (p<0.001). The risk of AVN was 1.5% in the low risk, 6.2% in the intermediate risk, and 20.8% in the high risk groups. Moderate-severe chronic GvHD and younger age (<45 years) are key risk factors for AVN following allogeneic HCT.

Developmental dysplasia of the hip: can contrast-enhanced MRI predict the development of avascular necrosis following surgery?

OBJECTIVE: To investigate the performance of contrast-enhanced MRI for predicting avascular necrosis (AVN) of the treated femoral head after surgical reduction for developmental dysplasia of the hip (DDH) using qualitative and quantitative methods. METHODS AND MATERIALS: This IRB-approved, HIPAA compliant retrospective study included 47 children who underwent same-day contrast-enhanced MRI following unilateral surgical hip reduction between April 2009 and June 2018. Blinded to the clinical outcome, 3 reviewers (2 pediatric radiologists and 1 pediatric orthopedist) independently categorized the enhancement pattern of the treated femoral head. Signal intensities, measured using regions of interest (ROI), were compared between treated and untreated hips and percent enhancements were compared between hips that developed and did not develop AVN. Post-reduction radiographs were evaluated using Salter's criteria for AVN and Kalmachi and MacEwen's classification for growth disturbance. Non-parametric tests and Fisher exact test were used to compare enhancement values between AVN and non-AVN hips. Bonferroni correction was used for multiple comparisons. RESULTS: Ten (21%) out of the 47 children (7 boys and 40 girls; mean age 9.0 ± 4.7 months) developed AVN. Age at surgical reduction was significantly higher (p = 0.03) for hips that developed AVN. No significant differences were found in gender (p = 0.61), laterality (p = 0.46), surgical approach (p = 0.08), history of pre-operative bracing (p = 0.72), abduction angle (p = 0.18-0.44), enhancement pattern (p = 0.66-0.76), or percent enhancement (p = 0.41-0.88) between AVN and non-AVN groups. CONCLUSION: Neither enhancement pattern nor percent enhancement predicted AVN, suggesting that post-reduction conventional MRI does not accurately distinguish between reversible and permanent vascular injury.

Edema-like marrow signal intensity: a narrative review with a pictorial essay.

The term edema-like marrow signal intensity (ELMSI) represents a general term describing an area of abnormal signal intensity at MRI. Its appearance includes absence of clear margins and the possibility of exceeding well-defined anatomical borders (for example, physeal scars). We can define "ELMSI with unknown cause" an entity where the characteristic MR appearance is associated with the absence of specific signs of an underlying condition. However, it is more often an important finding indicating the presence of an underlying disease, and we describe this case as "ELMSI with known cause." It presents a dynamic behavior and its evolution can largely vary. It initially corresponds to an acute inflammatory response with edema, before being variably replaced by more permanent marrow remodeling changes such as fibrosis or myxomatous connective tissue that can occur over time. It is important to study ELMSI variations over time in order to evaluate the activity state and therapeutic response of an inflammatory chronic joint disease, the resolution of a trauma, and the severity of an osteoarthritis. We propose a narrative review of the literature dealing with various subjects about this challenging topic that is imaging, temporal evolution, etiology, differential diagnoses, and possible organization, together with a pictorial essay.

What are the outcomes of core decompression without augmentation in patients with nontraumatic osteonecrosis of the femoral head?

PURPOSE: Core decompression (CD) of the femoral head is performed to preserve the hip in avascular necrosis (AVN). The outcome following this procedure differs based on the medical centre and the technique. Also, the time to total hip replacement (THR) and the percentage of patients subsequently undergoing a THR are controversial. METHODS: A systematic review was performed following PRISMA guidelines. The search included CENTRAL, MEDLINE, EMBASE, Scopus, AMED and Web of Science Core Collection databases. Studies reporting the outcome of CD for AVN were assessed. Studies using additional implants, vascularized grafts or any type of augmentation were excluded. Quality assessment was performed using the Joanna Briggs Institute Critical Appraisal Checklist (JBI CAC) tool. TRIAL REGISTRATION: International prospective register of systematic reviews (PROSPERO) - CRD42018100596 . RESULTS: A total of 49 studies describing 2540 hips were included. The mean weighted follow-up time was 75.1 months and the mean age at surgery was 39 years. Twenty-four of 37 studies reported improvement in all outcome scores, whilst 9/37 studies report only partial improvement post-operatively. Four studies (4/37) described poor clinical outcomes following intervention. Data was pooled from 20 studies, including 1134 hips with a weighted mean follow-up of 56 months. The percentage of hips undergoing THR averaged 38%. The time to THR had a weighted mean of 26 months after CD. CONCLUSION: Pooled results from 1134 hips and of these nearly 80% with early stage of osteonecrosis, showed that approximately 38% of patients underwent a total hip replacement at an average of 26 months following core decompression without augmentation.

Inhibitory Effect of Avenanthramides (Avn) on Tyrosinase Activity and Melanogenesis in α-MSH-Activated SK-MEL-2 Cells: In Vitro and In Silico Analysis.

Melanin causes melasma, freckles, age spots, and chloasma. Anti-melanogenic agents can prevent disease-related hyperpigmentation. In the present study, the dose-dependent tyrosinase inhibitory activity of Avenanthramide (Avn)-A-B-C was demonstrated, and 100 µM Avn-A-B-C produced the strongest competitive inhibition against inter-cellular tyrosinase and melanin synthesis. Avn-A-B-C inhibits the expression of melanogenesis-related proteins, such as TRP1 and 2. Molecular docking simulation revealed that AvnC (-7.6 kcal/mol) had a higher binding affinity for tyrosinase than AvnA (-7.3 kcal/mol) and AvnB (-6.8 kcal/mol). AvnC was predicted to interact with tyrosinase through two hydrogen bonds at Ser360 (distance: 2.7 Å) and Asn364 (distance: 2.6 Å). In addition, AvnB and AvnC were predicted to be skin non-sensitizers in mammals by the Derek Nexus Quantitative Structure-Activity Relationship system.

The effectiveness of preliminary traction in the treatment of congenital dislocation of the hip.

BACKGROUND: Historical papers on the treatment of congenital dislocation of the hip suggest the use of preliminary traction to facilitate closed reduction or to decrease the risk of avascular necrosis (AVN) of the femoral head. In the 1980s, some authors questioned the role of preliminary traction and suspended its use, yielding satisfactory results. Since then, several studies called into question this method, and some authors have continued to recommend preliminary traction while other authors have discouraged its use. MATERIALS AND METHODS: We reanalysed the full set of radiographs of 71 hips (52 patients) surgically treated by a medial approach after 4 weeks of preoperative longitudinal traction. The mean age at operation was 16 months. Before and after traction, the height of the dislocation was graded according to the Gage and Winter method. The hips were divided into two groups: group 1, in which the traction was effective, and group 2, in which the traction was not effective. These two groups were statistically analysed regarding the severity of the dislocation, the age of the patient at surgery and the incidence of AVN. RESULTS: Preliminary traction was effective in 48 hips (68%, group 1), while it was not effective in the remaining 23 (32%, group 2). The effectiveness of preliminary traction was statistically related to the height of the dislocation and to the age of the patient at surgery, with traction being less effective in more severe dislocations and in older children. The incidence of AVN was statistically lower in group 1 than in group 2. CONCLUSIONS: In our study population, despite not having a control group, preliminary traction-when effective-seemed to reduce the incidence of AVN in patients surgically treated for congenital dislocation of the hip. The effectiveness of the traction was influenced by the severity of the dislocation and the age of the patient; it worked better for less severe dislocations and in younger children. To reduce hospital costs, traction should be applied at home. LEVEL OF EVIDENCE: 3.

Treatment of non-united femoral neck fracture by a novel subtrochanteric angulation lateral translation valgus osteotomy (SALVA osteotomy).

PURPOSE: The ideal treatment of non-united and neglected fracture neck femur in the young adult still remains unclear and is characterized by many biological and biomechanical challenges. METHODS: Twenty-one patients with non-united or neglected fracture neck femur aged between 19 and 50 years were treated by a novel subtrochanteric valgus osteotomy and were followed up for a mean of 26.7 months. Patients were assessed by radiological parameters, the Harris Hip Score, Oxford Knee Score, and Askin Bryan Criteria to categorize the overall outcome of the patients at 24 months. Other outcome measures included the occurrence of AVN, adductor lever arm, leg length discrepancy, and mechanical implant failure. RESULTS: All patients treated with the SALVA osteotomy consolidated and displayed a marked improvement of functional and radiological outcome measures. Nevertheless, there were 2 mechanical failures in patients with marked osteopenia and three developed AVN. CONCLUSIONS: In patients with un-united/neglected fracture neck femur, SALVA osteotomy appears to be reliable and reproducible. It also restores the abductor lever arm and improves the leg length discrepancy. Technically less demanding conversion to arthroplasty remains still possible prospectively.

Bone manifestations in neuronopathic Gaucher disease while receiving high-dose enzyme replacement therapy.

Avascular necrosis (AVN), one type of bone infarction, is a major irreversible complication of Gaucher disease (GD). In this report, two pediatric patients with GD type 3, homozygous for the L483P pathogenic variant (formerly L444P), developed AVN despite treatment on long-term, high-dose enzyme replacement therapy (ERT). ERT was initiated in both patients, who had intact spleens, shortly after diagnosis with an initial dramatic response. However, both patients exhibited AVN after 5.5 and 11 years on high-dose ERT, respectively, despite good compliance and normalized hematological findings and visceral symptoms. This report demonstrates the importance of careful, regular surveillance of the musculoskeletal system in addition to monitoring the neurological symptoms associated with neuronopathic GD. Additionally, it highlights the limitations of ERT in terms of targeting certain sanctuary sites such as bone marrow and suggests the need for new treatment modalities other than ERT monotherapy to address these limitations.

Multifocal avascular necrosis in a patient with refractory immune thrombocytopenia and antiphospholipid antibodies; case report and review of literature.

Avascular necrosis (AVN) is a devastating condition that is rarely reported in patients with immune thrombocytopenia (ITP). Treatment with steroids remains a major risk factor for developing AVN. However, the incidence of AVN in patients with ITP requiring corticosteroid therapy is much less than that observed with other clinical conditions requiring corticosteroids. ITP is a bleeding disorder but can be also be a pro-thrombotic state via different mechanisms and thus could result in AVN. Among the possible causes of this pro-thrombotic state is the presence of antiphospholipid antibodies (aPLs). In this case, we report a patient with refractory ITP who developed multifocal AVN around the time she acquired new aPLs. We also discuss different mechanisms by which risk of thrombosis is increased in ITP and the relationship between ITP, aPLs and antiphospholipid syndrome.

His-Bundle Pacing for Identifying Optimal Ablation Sites in Patients Undergoing Atrioventricular Junction Ablation: Teaching an Old Dog a New Trick.

BACKGROUND: Atrioventricular (AV) junction (AVJ) ablation is conventionally performed by localizing the His-bundle electrogram (HBE). Identification of HBE in the presence of atrial fibrillation (AF) can be difficult, and can make this simple procedure challenging. In this study, we describe our experience with an alternative approach to localize optimal ablation sites using His-bundle pacing (HBP). METHODS: Between 1/1/2014 and 12/31/2015, we performed 13 AVJ ablations using the standard electrogram-guided approach and 11 ablations using HBP. All cases utilized a long femoral guiding sheath and an 8-mm-tip electrode radiofrequency (RF) energy ablation catheter. Pacing was performed at high output (10 mA at 2 ms) to initially achieve right bundle branch capture. The catheter was withdrawn until a narrow QRS morphology and increased stim-to-QRS time were observed. HBP was confirmed when paced and native QRS were identical in morphology. RF energy was applied at the site of HBP capture until AV block was observed. RESULTS: Baseline characteristics of patients in each arm were not significantly different. Compared with the standard approach, HBP was associated with trends toward lower RF applications (3 vs. 2, P = 0.16) and shorter mean RF time (208 seconds vs. 128 seconds, P = 0.19). CONCLUSION: HBP is an effective technique to identify optimal ablation sites during AVJ ablation and may shorten procedure time. HBP can be used to identify the AV node during AF without recording the His potential. Future studies with larger sample size are needed to better characterize the utility of this technique.

Administrative Algorithms to identify Avascular necrosis of bone among patients undergoing upper or lower extremity magnetic resonance imaging: a validation study.

BACKGROUND: Studies of the epidemiology and outcomes of avascular necrosis (AVN) require accurate case-finding methods. The aim of this study was to evaluate performance characteristics of a claims-based algorithm designed to identify AVN cases in administrative data. METHODS: Using a centralized patient registry from a US academic medical center, we identified all adults aged ≥18 years who underwent magnetic resonance imaging (MRI) of an upper/lower extremity joint during the 1.5 year study period. A radiologist report confirming AVN on MRI served as the gold standard. We examined the sensitivity, specificity, positive predictive value (PPV) and positive likelihood ratio (LR+) of four algorithms (A-D) using International Classification of Diseases, 9th edition (ICD-9) codes for AVN. The algorithms ranged from least stringent (Algorithm A, requiring ≥1 ICD-9 code for AVN [733.4X]) to most stringent (Algorithm D, requiring ≥3 ICD-9 codes, each at least 30 days apart). RESULTS: Among 8200 patients who underwent MRI, 83 (1.0% [95% CI 0.78-1.22]) had AVN by gold standard. Algorithm A yielded the highest sensitivity (81.9%, 95% CI 72.0-89.5), with PPV of 66.0% (95% CI 56.0-75.1). The PPV of algorithm D increased to 82.2% (95% CI 67.9-92.0), although sensitivity decreased to 44.6% (95% CI 33.7-55.9). All four algorithms had specificities >99%. CONCLUSION: An algorithm that uses a single billing code to screen for AVN among those who had MRI has the highest sensitivity and is best suited for studies in which further medical record review confirming AVN is feasible. Algorithms using multiple billing codes are recommended for use in administrative databases when further AVN validation is not feasible.