Deep learning enables the differentiation between early and late stages of hip avascular necrosis.

OBJECTIVES: To develop a deep learning methodology that distinguishes early from late stages of avascular necrosis of the hip (AVN) to determine treatment decisions. METHODS: Three convolutional neural networks (CNNs) VGG-16, Inception ResnetV2, InceptionV3 were trained with transfer learning (ImageNet) and finetuned with a retrospectively collected cohort of (n = 104) MRI examinations of AVN patients, to differentiate between early (ARCO 1-2) and late (ARCO 3-4) stages. A consensus CNN ensemble decision was recorded as the agreement of at least two CNNs. CNN and ensemble performance was benchmarked on an independent cohort of 49 patients from another country and was compared to the performance of two MSK radiologists. CNN performance was expressed with areas under the curve (AUC), the respective 95% confidence intervals (CIs) and precision, and recall and f1-scores. AUCs were compared with DeLong's test. RESULTS: On internal testing, Inception-ResnetV2 achieved the highest individual performance with an AUC of 99.7% (95%CI 99-100%), followed by InceptionV3 and VGG-16 with AUCs of 99.3% (95%CI 98.4-100%) and 97.3% (95%CI 95.5-99.2%) respectively. The CNN ensemble the same AUCs Inception ResnetV2. On external validation, model performance dropped with VGG-16 achieving the highest individual AUC of 78.9% (95%CI 51.6-79.6%) The best external performance was achieved by the model ensemble with an AUC of 85.5% (95%CI 72.2-93.9%). No significant difference was found between the CNN ensemble and expert MSK radiologists (p = 0.22 and 0.092 respectively). CONCLUSION: An externally validated CNN ensemble accurately distinguishes between the early and late stages of AVN and has comparable performance to expert MSK radiologists. CLINICAL RELEVANCE STATEMENT: This paper introduces the use of deep learning for the differentiation between early and late avascular necrosis of the hip, assisting in a complex clinical decision that can determine the choice between conservative and surgical treatment. KEY POINTS: • A convolutional neural network ensemble achieved excellent performance in distinguishing between early and late avascular necrosis. • The performance of the deep learning method was similar to the performance of expert readers.

Imaging of Anatomical Variants Around the Hip.

Considering the current widespread use of imaging as an integral part of managing hip pain, variable hip geometries and anatomical variants are increasingly being detected. These variants are commonly found in the acetabulum and proximal femur, as well as the surrounding capsule-labral tissues. The morphology of specific anatomical spaces confined by the proximal femur and the bony pelvis may also vary significantly among individuals. Familiarity with the spectrum of imaging appearances of the hip is necessary to identify variant hip morphologies with or without potential clinical relevance and reduce an unnecessary work-up and overdiagnosis. We describe anatomical variations and variable morphologies of the bony structures comprising the hip joint and the soft tissues, around the hip. The potential clinical significance of these findings is further analyzed in conjunction with the patient's profile.

The O-Linked N-Acetylglucosamine Containing Epitope H (O-GlcNAcH) is Upregulated in the Trophoblastic and Downregulated in the Fibroblastic Cells in Missed Miscarriage Human Chorionic Villi With Simple Hydropic Degeneration.

Epitope H contains an O-linked N-acetylglucosamine (O-GlcNAcH) residue in a specific conformation and/or environment recognized by the mouse monoclonal antibody H. O-GlcNAcH is present in several types of cells and in several polypeptides, including cytokeratin 8 and vimentin, on the latter in cells under stress. In the present work, we examined the expression of the O-GlcNAcH in 60 cases of endometrial curettings from missed miscarriage cases containing normal and simple hydropic degenerated chorionic villi in each case, using monoclonal antibody H and indirect immunoperoxidase and Western blot immunoblot. In all cases examined the expression of the O-GlcNAcH was cytoplasmic as follows: (1) syncytiotrophoblastic cells showed very low expression in chorionic villi (CV) with nonhydropic degeneration (NHD) and high expression in hydropic degenerated (HD) CV; (2) cytotrophoblastic cells showed low expression in CV with NHD and high expression in HD CV; (3) fibroblastic cells showed high expression in CV with NHD and very low expression in HD CV; (4) histiocytes showed very low expression in both types of CV; (5) endothelial cells showed high expression in both types of CV. An immunoblot of CV from one case of a legal abortion from a normal first-trimester pregnancy showed 5 polypeptides with 118.5, 106.3, 85, 53, and 36.7 kD bearing the epitope H and the 53 kD corresponded to cytokeratin 8. The expression of the O-GlcNAcH is upregulated in the trophoblastic cells and downregulated in the fibroblastic cells in the HD CV in comparison to the NHD CV.

Simultaneous bilateral posteromedial tibial epiphysis stress fractures in a healthy young man: A case report.

We present a compelling case of simultaneous, bilateral tibial stress fractures occurring in a unique epiphyseal and posterior location, with unclear aetiology. An overweight, Caucasian male in his late 20s developed synchronous bilateral medial knee pain following an intense 10-day training regimen. His radiographies were normal, but MRI revealed almost identical bilateral stress fracture lines in the posteromedial tibial epiphyses. Bone mineral densitometry and a full metabolic and hormonal panel were performed to further investigate potential underlying metabolic bone disease. He was found to have normal bone mineral densitometry and low Vitamin D serum values. Symptomatology greatly improved with activity modification. There were no further complaints and complications at 12 months' follow-up. Diagnosis can be challenging and the treating physician should be acquainted with the basic science of stress fractures and main discriminating clinical, biochemical and radiological characteristics from insufficiency fractures, to avoid pitfalls in treatment decision.

An observational study of complications in patients with established multiple compartments syndrome of the leg.

INTRODUCTION: Established multiple compartments syndrome of the leg (EMCSL) is defined as permanent ischemic lesions of muscles and nerves of the compartment, leading to multiple muscle contractions, muscle weakness and wasting and reduced limb sensation. The leg is seriously affected and the patient is unable to return to prior activities. The objective of this research is to quantify long-term consequences, morbidity and socioeconomic impact of established multiple compartments syndrome of the leg MATERIALS AND METHODS: 28 patients suffering from complications from EMCSL were referred to our clinic for secondary management between January 2012 and April 2016 and were followed for mean 41.4 months. Reconstructive procedures to address multiple conditions following established tibia compartment syndrome were performed. The number of reconstructive procedures, days of hospitalization, relationship, educational and employment status per patient were recorded. Preop and postop SF-12 score at final follow-up was documented for the 21 patients who were operated on. RESULTS: A median of three reconstructive procedures was performed per patient for 21 patients. The hospitalization period ranged from 6 to 365 days, with a mean period of 47.5 days (SD 71.4). At the final follow-up, 19 patients had lost their occupation, 3 patients had returned to lighter manual labor, 5 patients had lost two school years, and 1 patient had abandoned school. At the time of injury, 24 patients were single. At final follow-up, 19 of these patients, with a mean age of 38.5 years, were still single. Preoperative and postoperative (at final follow-up) physical and mental components of the SF-12 score had a statistically significant difference (p < 0.001), but final values were not normal. CONCLUSIONS: Despite advancements in surgical reconstructive intervention, patients with established compartment tibia syndrome experience permanent grave residual disability with personal and social implications.

Morel-Lavallée Lesions of the Knee: MRI Findings Compared With Cadaveric Study Findings.

OBJECTIVE: The purpose of this study is to describe the MRI findings and treatment decisions and outcome for Morel-Lavallée lesions (MLLs) of the knee and to investigate whether evidence exists to support an increased frequency of such lesions on the medial or lateral side by performing a cadaveric experiment. MATERIALS AND METHODS: In a 4-year period, 24 MRI studies of 24 consecutive patients (16 male patients and eight female patients) with knee MLLs were retrospectively reviewed. Patient demographic characteristics, treatment decisions and outcome, and associated injuries were recorded. The location of the MLL was categorized as medial, lateral, or global. Lesions were categorized according to an established MRI classification. During the cadaveric experiment, the compartmental pressures of the medial or lateral aspect of the knee were monitored in 20 cadaveric knees. The chi-square test, t test, and Pearson correlation were used for statistical analysis. RESULTS: MLLs were located medially in 16 patients, laterally in two patients, and globally in six patients. The medial location was significantly more common than a lateral or global location (p < 0.05). MLLs were classified as type I in 14 patients, type II in eight patients, and type III in two patients. MRI type was correlated with the chronicity of injury (r2 = 0.614; p = 0.0014). Fractures were the most common associated injuries, occurring in seven of 24 patients. In 17 patients, all of whom had conservatively treated type I or type II lesions, complete resolution of the MLL occurred. The maximum compartmental pressures were significantly higher on the lateral side than on the medial side (p < 0.0001). CONCLUSION: Knee MLLs have a predilection for the medial side, which may be attributed to the lower resistance in this location, and they have variable patterns on MRI, which correlate with chronicity. Conservative treatment of type I and II lesions seems effective.

Variations of transverse foramina in cervical vertebrae: what happens to the vertebral artery?

PURPOSE: The purpose of this study is to examine variations of the foramen transversarium and the vertebral artery in computed tomography angiographies (CTa) of the cervical spine, investigate their coexistence, and present possible considerations regarding such variations in spine surgical procedures. METHODS: Fifty CTa of the neck were retrospectively reviewed. Transverse and anteroposterior diameter of the foramen and diameter of the vertebral artery were measured. Variations of the foramen and the vertebral artery were detected. RESULTS: Cervical CTa of 32 males and 18 females (mean age 66.4 ± 10.78 years), all belonging to the Indo-European race, were reviewed. Variations of the foramen transversarium were found in 17 vertebrae (4.85%) of 15 patients (30%). Duplication of the foramen was the most frequent variation, followed by the open foramen, the absence of the foramen, the triple foramen, and the hypoplastic foramen. Variations of the vertebral artery were found in 7 patients (14%) and asymmetry was found in 12 (24%) patients. Moreover, six patients presented with hypoplastic vertebral arteries (12%). When examining coexistence, 60% of patients exhibiting variations in the transverse foramen were also exhibiting variations or asymmetry in the vertebral artery, compared to 25.7% of patients with no foramen variations (p = 0.02). CONCLUSIONS: Vertebral artery injury is not common but may be a disastrous complication during cervical spine surgery. Proper preoperative planning is essential for any surgeon and exact knowledge of the anatomy in each patient is essential. This study strongly recommends the preoperative use of a CTa when suspicion of a variation is present and implied by a foramen variation. These slides can be retrieved under Electronic Supplementary Material.

Great trochanter bursitis vs sciatica, a diagnostic-anatomic trap: differential diagnosis and brief review of the literature.

PURPOSE: The purpose of this study is to point out the difficulty of differentiating great trochanter bursitis (GTB) from sciatica and estimating the prevalence of GTΒ, in patients poorly diagnosed with sciatica in their first visit to the general practitioner and referred to a spine infirmary. METHODS: The diagnosis of GTΒ was made based on history and physical examination, and was confirmed by ultrasonography and/or response to an anesthetic plus corticosteroid injection to the trochanteric bursa. Demographic and clinical characteristics of the study group were evaluated. The statistical analysis was held with the SPSS pc package (version 24.0). RESULTS: In a total of 657 referrals for sciatica, 72 patients (10.95%) were incorrectly diagnosed as suffering from sciatica, whereas, in fact, they were suffering from GTΒ. In addition, 18 patients (2.74%) were diagnosed as suffering from persistent sciatica with coexisting GTΒ. More women than men had GTΒ (79-11). Mean age for patients with sciatica diagnosis but suffering from GTΒ was 60 years. Mean age for patients with both sciatica and GTΒ was 61 years. CONCLUSIONS: The GTB is a common clinical entity in middle-aged women, which can escape from the physician in cases of incomplete medical history and clinical examination, leading to unnecessary imaging tests and treatment approaches, burdening both the patient and the health system. Early diagnosis of GTB may dramatically reduce cost, prevent unwanted and inappropriate imaging exams and treatment, and make the patient free of symptoms immediately. These slides can be retrieved under Electronic Supplementary Material.

Magnetic resonance morphometry of the adult normal lumbar intervertebral space.

PURPOSE: This study aims to: (a) quantify and evaluate normal relationships between neighboring spinal units using MR imaging indices, (b) propose an easy-to-apply-and-reproduce method of estimating the correct amount of distraction when surgically restoring a collapsed intervertebral disc, based on individualized measurements. METHODS: This is a retrospective cross-sectional MR imaging study of 119 adult subjects, aged 18-54, asymptomatic for low back pain. Each of the examinees should demonstrate two or more consecutive intervertebral discs classified as Pfirrmann grade I or II to be included. We measured and studied the relationships of disc height index, Dabbs index, Farfan index, disc convexity index and mean and posterior disc height per spinal level using multiple regression analysis. All measurements were tested for intra- and interobserver agreement by two raters. RESULTS: DHI, Dabbs, Farfan, and mean disc height had a statistically significant correlation with the spinal level and age. Our results were highly reproducible, with excellent inter- and intraobserver agreement and reliability between two raters (ICC = 0.992 and 0.994, respectively). Furthermore, we expressed each intervertebral space as a percentage of its adjacent space, introducing the coefficient α factor for every intervertebral space. CONCLUSIONS: Our results suggest that a normal values' database to refer during preoperative planning of correction of a degenerated intervertebral disc is feasible. Our study offers new anatomical and radiological insight in terms of spinal measurements and their potential correlation with current surgical techniques. A new approach for calculating disc space as an expression of its adjacent disc has been introduced with various potential applications.

Anatomical variations of the foramen transversarium in cervical vertebrae: findings, review of the literature, and clinical significance during cervical spine surgery.

PURPOSE: To describe certain anatomical variations of the foramen transversarium, in spine cervical vertebrae in a contemporary specimen of an Indo-European population and approach their clinical importance during cervical spine surgery. METHODS: 102 cervical vertebrae (C2-C7) from 17 different skeletons, intact without any degenerative or traumatic disorders, which belonged to the collection of the Department of Anatomy, were examined. The age of specimens at the time of their death was between 25 and 65 years. All foramina were measured with a digital caliper. RESULTS: The average size of the normal foramina was: 6.49 mm × 5.74 mm on the right side and 6.65 mm × 5.76 mm on the left side. Regarding the variations, we found two cervical vertebrae (1.96 %), one C3 and one C6, in which the right foramen transversarium is clearly smaller than the left. The exact dimensions of these foramina are: 2.3 mm × 2.5 mm on the right side and 6.54 mm × 8 mm on the left side in the first vertebra and 2.8 mm × 3.74 mm on the right side and 6 mm × 7.5 mm on the left side, in the second one. We also observed double foramina in 14 vertebrae (13.72 %). In seven vertebrae, the duplication was bilateral (6.86 %). We finally found one vertebra (0.98 %) with triplication of the foramen transversarium on the left side. CONCLUSIONS: Summarizing, 10 out of our 17 skeletons were presented with variations (extremely narrow or multiple foramina). This finding of hypoplastic, duplicated and triplicated foramina transversaria in unexpectedly high rates raises questions about the integrity of the contained structures, the possibility of a different path for them. These variations may induce an extra-osseous position of the vertebra artery, and the ignorance of such an event may have catastrophic consequences during a surgery in the cervical spine.

Normal Magnetic Resonance Imaging Anatomy of the Anterolateral Knee Ligament With a T2/T1-Weighted 3-Dimensional Sequence: A Feasibility Study.

PURPOSE: The anatomy of the lateral knee compartment has been recently further explored with description of the anterolateral knee ligament (ALL). The purpose of this study was to confirm the presence of ALL on cadaveric knees and to describe its normal anatomy in young healthy volunteers, utilizing a high-resolution 3-dimensional (3D) pulse sequence. METHODS: Dissection was performed on 9 cadaveric knees in order to confirm the presence of ALL. Conventional 2-dimensional sequences of 10 knees at 1.5 T and 10 knees at 3 T, with a slice thickness of 2-4 mm, were reviewed for the presence of ALL. A 3D T2/T1-weighted gradient echo sequence (constructive interference in steady state [CISS]), yielding in-plane resolution of 0.4 mm × 0.4 mm × 0.4 mm, was applied in 14 healthy volunteers (26 knees). All 3D images were manipulated using multiplanar reconstruction (MPR) and the presence and width of ALL were recorded. RESULTS: Cadaveric dissection disclosed the presence of ALL in 8 of 9 knees. Conventional knee MR imaging depicted ALL only on coronal images (18 of 20) whereas the CISS revealed ALL on 24 of 26 studied knees (92.3%). ALL has a mean thickness of 1.1 ± 0.27 mm measured on coronal MR images. CONCLUSIONS: ALL can be thoroughly assessed in young healthy individuals with the use of high-resolution 3D MR imaging with MPR at 1.5 T.

Osteoid Osteoma of the Femoral Neck: Use of the Half-Moon Sign in MRI Diagnosis.

OBJECTIVE: Osteoid osteoma is a benign bone tumor that is commonly located in the proximal femur. Although CT is helpful in the diagnosis of osteoid osteoma, patients in whom the clinical presentation of the tumor is atypical are first referred to undergo MRI, which yields a high percentage of false-negative or inconclusive results. We sought to explore the association between a half-moon sign of bone marrow edema and the presence of osteoid osteoma of the femoral neck. SUBJECTS AND METHODS: The MRI examinations of 11 consecutive patients with osteoid osteoma (group 1) were prospectively included in the study. In addition, 950 consecutive hip MRI examinations of 485 patients were retrospectively analyzed for the presence of bone marrow edema of the femoral neck, with 19 patients identified as having bone marrow edema resulting from causes other than osteoid osteoma (group 2). Patients in both study groups were evaluated for the presence of the half-moon sign. RESULTS: The half-moon sign of bone marrow edema was significantly associated with the presence of osteoid osteoma (p < 0.0001), having been seen on the MR images of all 11 patients in group 1 and only one of 19 patients in group 2. MRI examination was therefore 94.7% specific and 100% sensitive for the detection of osteoid osteoma, with positive and negative predictive values of 91.7% and 100%, respectively. CONCLUSION: The half-moon sign is an MRI finding that is highly specific and sensitive for an accurate diagnosis of osteoid osteoma of the femoral neck.

Expression of the O-Linked N-Acetylglucosamine-containing Epitope H (O-GlcNAcH) in Human Uterine Cervical Mucosa.

BACKGROUND/AIM: Epitope H contains an O-linked N-acetylglucosamine (O-GlcNAcH) residue in a specific conformation or environment, recognized by a site-specific monoclonal mouse IgM antibody H. O-GlcNAcH occurs in several normal and pathological cells and in several polypeptides, including keratin-8 and vimentin, on the latter in cells under stress. MATERIALS AND METHODS: In this work, we studied the distribution of O-GlcNAcH on cells of endocervical mucosa in 60 specimens of endocervical curettings, 10 of which contained 15 inflamed polyps. RESULTS: In our results, expression of O-GlcNAcH was weak in the mucosa with <5% mucin-secreting cells and up to 30% of the polyps staining positively. All non-ciliated, non-mucin-secreting cells, normal and hyperplastic 'reserve' cells, as well as the cells of immature squamous metaplasia, showed strong diffuse cytoplasmic staining for O-GlcNAcH. In mature squamous epithelium, fewer than 5% of basal cells and all the intermediate and superficial cells showed cytoplasmic staining for O-GlcNAcH, whereas parabasal cells were negative. All ciliated cells showed patchy or diffuse cytoplasmic staining. Nuclear staining for O-GlcNAcH was weak with fewer than 5% of hyperplastic 'reserve' and ciliated cells staining positively. Moreover, mucosal fibroblasts were negative, whereas all stromal cells of the polyps showed strong cytoplasmic staining for O-GlcNAcH. CONCLUSION: O-GlcNAcH is: a) differentially expressed among the cellular elements of mucosa and polyps, b) upregulated in mucin-secreting cells of polyps, c) induced in stromal cells of inflamed polyps, and d) can be used as a marker to differentiate between 'reserve' (positive) and parabasal (negative) cells, which have similar morphology using conventional cytological stains.

Generative adversarial networks for spine imaging: A critical review of current applications.

PURPOSE: In recent years, the field of medical imaging has witnessed remarkable advancements, with innovative technologies which revolutionized the visualization and analysis of the human spine. Among the groundbreaking developments in medical imaging, Generative Adversarial Networks (GANs) have emerged as a transformative tool, offering unprecedented possibilities in enhancing spinal imaging techniques and diagnostic outcomes. This review paper aims to provide a comprehensive overview of the use of GANs in spinal imaging, and to emphasize their potential to improve the diagnosis and treatment of spine-related disorders. A specific review focusing on Generative Adversarial Networks (GANs) in the context of medical spine imaging is needed to provide a comprehensive and specialized analysis of the unique challenges, applications, and advancements within this specific domain, which might not be fully addressed in broader reviews covering GANs in general medical imaging. Such a review can offer insights into the tailored solutions and innovations that GANs bring to the field of spinal medical imaging. METHODS: An extensive literature search from 2017 until July 2023, was conducted using the most important search engines and identified studies that used GANs in spinal imaging. RESULTS: The implementations include generating fat suppressed T2-weighted (fsT2W) images from T1 and T2-weighted sequences, to reduce scan time. The generated images had a significantly better image quality than true fsT2W images and could improve diagnostic accuracy for certain pathologies. GANs were also utilized in generating virtual thin-slice images of intervertebral spaces, creating digital twins of human vertebrae, and predicting fracture response. Lastly, they could be applied to convert CT to MRI images, with the potential to generate near-MR images from CT without MRI. CONCLUSIONS: GANs have promising applications in personalized medicine, image augmentation, and improved diagnostic accuracy. However, limitations such as small databases and misalignment in CT-MRI pairs, must be considered.

Anatomy and terminology of groin pain: Current concepts.

Groin pain is a common symptom in athletes. The complex anatomy of the area and the various terms used to describe the etiology behind groin pain have led to a confusing nomenclature. To solve this problem, three consensus statements have been already published in the literature: the Manchester Position Statement in 2014, the Doha agreement in 2015, and the Italian Consensus in 2016. However, when revisiting recent literature, it is evident that the use of non-anatomic terms remains common, and the diagnoses sports hernia, sportsman's hernia, sportsman's groin, Gilmore's groin, athletic pubalgia, and core muscle injury are still used by many authors. Why are they still in use although rejected? Are they considered synonyms, or they are used to describe different pathology? This current concepts review article aims to clarify the confusing terminology by examining to which anatomical structures authors refer when using each term, revisit the complex anatomy of the area, including the adductors, the flat and vertical abdominal muscles, the inguinal canal, and the adjacent nerve branches, and propose an anatomical approach, which will provide the basis for improved communication between healthcare professionals and evidence-based treatment decisions.

The Impact of Distance Learning and COVID-19 Lockdown on Students' Physical Activity and Musculoskeletal Health.

PURPOSE: During the past two years, in most institutions worldwide, educational activities were remodeled for remote delivery, due to the COVID-19 pandemic. The purpose of this study is to assess the effects of two-year distance learning on the physical activity and musculoskeletal health of university students. METHODS: This was a national, cross-sectional study using data collected via an online questionnaire distributed through university communication platforms, which included questions on online education routines, musculoskeletal health, and physical activity of university students. RESULTS: In total, 1,366 students (65% female, 35% male) from 11 universities took part in the survey. The most common sites of reported pain were the neck (59.5%), shoulders (22.8%), back (29%), and low back (66.7%). Musculoskeletal pain significantly increased during the lockdown, according to the visual analog scale (VAS) for pain (before: 2.7 ± 1.6; during: 5.5 ± 2.2, p<0.001). Everyday pain was referred by significantly more students during the lockdown (4.5% vs 36.1 %, p<0.001), while the percentage of asymptomatic students was significantly decreased (40.5% vs 6.1%, p<0.001). Concerning physical activity, the percentage of students who did not exercise significantly increased during the lockdown (15.1% vs 23.2%, p<0.001). Distance learning and total screen time were positively correlated with VAS for pain scores. On the contrary, an increased frequency of ergonomic position, walking intervals, and physical activity was associated with significantly decreased VAS for pain scores. CONCLUSIONS: Distance learning and limited physical activity led to a significant increase in musculoskeletal pain in university students, while exercise and ergonomic body position were considered protective factors. Interventions to encourage physical activity and healthy studying habits should be developed by universities, since distance learning may be again necessary for the future.

Anterior and Posterior Cruciate Ligaments Mechanoreceptors: A Review of Basic Science.

Proprioception is a specialized sensory modality encompassing the movement of the joint and its position in space, and it involves the conversion of mechanical deformation of tissues into neural signals. Mechanoreceptors are specialized nerve structures able to transmit mechanical deformation through electrical signals to dorsal root ganglion sensory neurons and are abundant in the muscles, tendons and ligaments of the knee joint. They are believed to play an important role in knee proprioception and dynamic knee stability. Proprioception should always be taken into consideration for successful reconstruction of the cruciate-deficient knee and for pain and function management in the arthritic knee. Advances in histological methods of detection are numerous and continue to highlight the presence and role of mechanoreceptors after ligament reconstruction, depending on choice of graft. In this review, we present the current knowledge of anterior and posterior cruciate ligaments and grafts mechanoreceptors, and their role in proprioception of knee joint, focusing on each type of mechanoreceptors.

Deep Learning for the Differential Diagnosis between Transient Osteoporosis and Avascular Necrosis of the Hip.

Differential diagnosis between avascular necrosis (AVN) and transient osteoporosis of the hip (TOH) can be complicated even for experienced MSK radiologists. Our study attempted to use MR images in order to develop a deep learning methodology with the use of transfer learning and a convolutional neural network (CNN) ensemble, for the accurate differentiation between the two diseases. An augmented dataset of 210 hips with TOH and 210 hips with AVN was used to finetune three ImageNet-trained CNNs (VGG-16, InceptionResNetV2, and InceptionV3). An ensemble decision was reached in a hard-voting manner by selecting the outcome voted by at least two of the CNNs. Inception-ResNet-V2 achieved the highest AUC (97.62%) similar to the model ensemble, followed by InceptionV3 (AUC of 96.82%) and VGG-16 (AUC 96.03%). Precision for the diagnosis of AVN and recall for the detection of TOH were higher in the model ensemble compared to Inception-ResNet-V2. Ensemble performance was significantly higher than that of an MSK radiologist and a fellow (P < 0.001). Deep learning was highly successful in distinguishing TOH from AVN, with a potential to aid treatment decisions and lead to the avoidance of unnecessary surgery.

Differentiation between subchondral insufficiency fractures and advanced osteoarthritis of the knee using transfer learning and an ensemble of convolutional neural networks.

PURPOSE: Subchondral insufficiency fractures (SIF) and advanced osteoarthritis (OA) of the knee are usually seen in conjunction with bone marrow lesions (BMLs) and their differentiation may pose a significant diagnostic challenge. We aimed to develop a convolutional neural network (CNN) ensemble which could successfully differentiate between these two entities. MATERIALS AND METHODS: A total of 212 knees with SIF and 102 knees with advanced OA with BMLs were retrospectively included. Coronal fat suppressed PD-w images were augmented, resized and normalized, reaching a total of 1174 images. Data was used to fine-tune three ImageNet-pretrained CNNs (VGG-16, InceptionV3 and Inception-ResNet-V2). Agreement of at least two networks was recorded as the decision of the network ensemble. Ensemble performance was compared to that of two MSK radiologists on the validation set. Receiver operating characteristics (ROC) curves and the respective areas under the curve (AUC) were used to evaluate human and machine performance. RESULTS: InceptionV3 achieved the highest AUC (93.68%) and VGG-16 the lowest AUC (82.18%) among individual CNNs. CNN ensemble achieved the highest overall performance with an AUC of 95.97%. The first of the two MSK radiologists achieved a performance similar to the ensemble, reaching an AUC of 91.95%. The second radiologist achieved lower AUC of 82.76% which was lower than both the other specialist and the ensemble (P < 0.001). CONCLUSION: A CNN ensemble was highly accurate in differentiating between SIF and OA, achieving a higher or equal performance to MSK radiologists.