In-situ assessment of collateral ligaments strain could be key to improving total knee arthroplasty outcomes by improving the ability of surgeons to properly balance the knee intraoperatively. Ultrasound (US) speckle tracking methods have shown promise in their capability to measure in-situ soft tissue strain in large tendons but prior work has also highlighted the challenges that arise when attempting to translate these approaches to the in-situ assessment of collateral ligaments strain. Therefore, the aim of this project was to develop and validate an US speckle tracking method to specifically assess in-situ strains of both the MCL and LCL. We hypothesize that coefficients of determination (R. 2. ) would be above 0.90 with absolute differences below 0.50% strain for the comparison between US-based and the reference strain, with better results expected for the LCL compared with the MCL. Five cadaveric legs with total knee implants (NH019 2017-02-03) were submitted to a varus (LCL) and valgus (MCL) ramped loading (0 – 40N). Ultrasound radiofrequency (rf) data and reference surface strains data, obtained with 3D digital image correlation (DIC), were collected synchronously. Prior to processing, US data were qualitatively assessed and specimens displaying substantial imaging artefacts were discarded, leaving five LCL and three MCL specimens in the analysis. Ultrasound rf data were processed in Matlab (The MathWorks, Inc., Natick, MA) with a custom-built speckle tracking approach adapted from a method validated on larger tendons and based on normalized cross-correlation. Digital image correlation data were processed with commercial software VIC3D (Correlated Solutions, Inc., Columbia, SC). To optimize speckle tracking, several tracking parameters were tested: kernel and search window size, minimal correlation coefficient and simulated frame rate. Parameters were ranked according to three comparative measures between US- and DIC-based strains: R. 2. , mean absolute error and strains differences at 40N. Parameters with best average rank were considered as optimal. To quantify the agreement between US- and DIC-based strain of each specimen, the considered metrics were: R. 2. , mean absolute error and strain differences at 40N. The LCL showed a good agreement with a high average R. 2. (0.97), small average mean absolute difference (0.37%) and similar strains at 40N (DIC = 2.92 ± 0.10%; US = 2.99 ± 1.16%). The US-based speckle tracking method showed worse performance for the MCL with a lower average correlation (0.55). Such an effect has been observed previously and may relate to the difficulty in acquiring sufficient image quality for tracking the MCL compared to the LCL, which likely arises due to structural or mechanical differences; notably MCL is larger, thinner, more wrapped around the bone and stretches less. However, despite these challenges, the MCL tracking still showed small average mean absolute differences (0.44%) and similar strains at 40N (DIC = 1.48 ± 0.06%; US = 1.44 ± 1.89%). We conclude that the ultrasound speckle tracking method developed is ready to be used as a tool to assess in-situ strains of LCL. Concerning the MCL strain assessment, despite some promising results in terms of strain differences, further work on acquisition could be beneficial to reach similar performance

Background. Although there are predictive equations that estimate the total fat mass obtained from multiple-site ultrasound (US) measurements, the predictive equation of total fat mass has not been investigated solely from abdominal subcutaneous fat thickness. Therefore, the aims of this study were; (1) to develop regression-based prediction equations based on abdominal subcutaneous fat thickness for predicting fat mass in young- and middle-aged adults, and (2) to investigate the validity of these equations to be developed. Methods. The study was approved by the Local Research Ethics Committee (Decision number: GO 19/788). Twenty-seven males (30.3 ± 8.7 years) and eighteen females (32.4 ± 9.5 years) were randomly divided into two groups as the model prediction group (19 males and 12 females) and the validation group (8 males and 6 females). Total body fat mass was determined by dual-energy X-ray absorptiometry (DXA). Abdominal subcutaneous fat thickness was measured by US. The predictive equations for total fat mass from US were determined as fat thickness (in mm) × standing height (in m). Statistical analyses were performed using R version 4.0.0. The association between the total fat mass and the abdominal subcutaneous fat thickness was interpreted using the Pearson test. The linear regression analysis was used to predict equations for total body fat mass from the abdominal subcutaneous fat thickness acquired by US. Then these predictive equations were applied to the validation group. The paired t-test was used to examine the difference between the measured and the predicted fat masses, and Lin's concordance correlation coefficient (CCC) was used as a further measure of agreement. Results. There was a significant positive moderate correlation between the total fat mass and the abdominal subcutaneous fat thickness × height in the model prediction group of males (r = 0.588, p = 0.008), whereas significant positive very strong correlation was observed in the model prediction group of females (r = 0.896, p < 0.001). Predictive equations for DXA-measured total body fat mass from abdominal subcutaneous fat thickness using US were as follows: for males “Fat mass-DXA = 0.276 × (Fat thickness-US × Height) + 17.221” (R. 2. = 0.35, SEE = 3.6, p = 0.008); for females “Fat mass-DXA = 0.694 x (Fat thickness-US × Height) + 7.085” (R. 2. = 0.80, SEE = 2.8, p < 0.001). When fat mass prediction equations were applied to the validation groups, measured- and estimated-total fat masses in males and females were found similar (p = 0.9, p = 0.5, respectively). A good level of agreement between measurements in males and females was attained (CCC = 0.84, CCC = 0.76, respectively). Conclusion. We developed and validated prediction equations that are convenient for determining total fat masses in young- and middle-aged adults using abdominal subcutaneous fat thickness obtained from the US. The abdominal subcutaneous fat thickness obtained from a single region by US might provide a noninvasive quick and easy evaluation not only in clinical settings but also on the field

Abstract. Objectives. Ultrasound speckle tracking is a safe and non-invasive diagnostic tool to measure soft tissue deformation and strain. In orthopaedics, it could have broad application to measure how injury or surgery affects muscle, tendon or ligament biomechanics. However, its application requires custom tuning of the speckle-tracking algorithm then validation against gold-standard reference data. Implementing an experiment to acquire these data takes months and is expensive, and therefore prohibits use for new applications. Here, we present an alternative optimisation approach that automatically finds suitable machine and algorithmic settings without requiring gold-standard reference data. Methods. The optimisation routine consisted of two steps. First, convergence of the displacement field was tested to exclude the settings that would not track the underlying tissue motion (e.g. frame rates that were too low). Second, repeatability was maximised through a surrogate optimisation scheme. All settings that could influence the strain calculation were included, ranging from acquisition settings to post-processing smoothing and filtering settings, totalling >1,000,000 combinations of settings. The optimisation criterion minimised the normalised standard deviation between strain maps of repeat measures. The optimisation approach was validated for the medial collateral ligament (MCL) with quasi-static testing on porcine joints (n=3), and dynamic testing on a cadaveric human knee (n=1, female, aged 49). Porcine joints were fully dissected except for the MCL and loaded in a material-testing machine (0 to 3% strain at 0.2 Hz), which was captured using both ultrasound (>14 repeats per specimen) and optical digital image correlation (DIC). For the human cadaveric knee (undissected), 3 repeat ultrasound acquisitions were taken at 18 different anterior/posterior positions over the MCL while the knee was extended/flexed between 0° and 90° in a knee extension rig. Simultaneous optical tracking recorded the position of the ultrasound transducer, knee kinematics and the MCL attachments (which were digitised under direct visualisation post testing). Half of the data collected was used for optimisation of the speckle tracking algorithms for the porcine and human MCLs separately, with the remaining unseen data used as a validation test set. Results. For the porcine MCLs, ultrasound strains closely matched DIC strains (R. 2. > 0.98, RMSE < 0.59%) (Figure 1A). For the human MCL (Figure 1B), ultrasound strains matched the strains estimated from the optically tracked displacements of the MCL attachments. Furthermore, strains developed during flexion were highly correlated with AP position (R = 0.94) with strains decreasing the further posterior the transducer was on the ligament. This is in line with previously reported length change values for the posterior, intermediate and anterior bundles of the MCL. Conclusions. Ultrasound speckle tracking algorithms can be adapted for new applications without ground-truth data by using an optimisation approach that verifies displacement field convergence then minimises variance between repeat measurements. This optimisation routine was insensitive to anatomical variation and loading conditions, working for both porcine and human MCLs, and for quasi-static and dynamic loading. This will facilitate research into changes in musculoskeletal tissue motion due to abnormalities or pathologies. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

The primary aim was to assess the reliability of ultrasound in the assessment of humeral shaft fracture healing. The secondary aim was to estimate the accuracy of ultrasound assessment in predicting humeral shaft nonunion. Twelve patients (mean age 54yrs [20–81], 58% [n=7/12] female) with a non-operatively managed humeral diaphyseal fracture were prospectively recruited and underwent ultrasound scanning at six and 12wks post-injury. Scans were reviewed by seven blinded observers to evaluate the presence of sonographic callus. Intra- and inter-observer reliability were determined using the weighted kappa and intraclass correlation coefficient (ICC). Accuracy of ultrasound assessment in nonunion prediction was estimated by comparing scans for patients that united (n=10/12) with those that developed a nonunion (n=2/12). At both six and 12wks, sonographic callus was present in 11 patients (10 united, one developed a nonunion) and sonographic bridging callus (SBC) was present in seven patients (all united). Ultrasound assessment demonstrated substantial intra- (6wk kappa 0.75, 95% CI 0.47-1.03; 12wk kappa 0.75, 95% CI 0.46-1.04) and inter-observer reliability (6wk ICC 0.60, 95% CI 0.38-0.83; 12wk ICC 0.76, 95% CI 0.58-0.91). Absence of sonographic callus demonstrated a sensitivity of 50%, specificity 100%, positive predictive value (PPV) 100% and negative predictive value (NPV) 91% in nonunion prediction (accuracy 92%). Absence of SBC demonstrated a sensitivity of 100%, specificity 70%, PPV 40% and NPV 100% (accuracy 75%). Of three patients at risk of nonunion based on reduced radiographic callus formation (Radiographic Union Score for HUmeral fractures <8), one had SBC on 6wk ultrasound (and united) and the other two had non-bridging or absent sonographic callus (both developed a nonunion). Ultrasound assessment of humeral shaft fracture healing was reliable and predictive of nonunion, and may be a useful tool in defining the risk of nonunion among patients with reduced radiographic callus formation

In cartilage tissue engineering (TE),new solutions are needed to effectively drive chondrogenic differentiation of mesenchymal stromal cells in both normal and inflammatory milieu. Ultrasound waves represent an interesting tool to facilitate chondrogenesis. In particular, low intensity pulsed ultrasound (LIPUS)has been shown to regulate the differentiation of adipose mesenchymal stromal cells. Hydrogels are promising biomaterials capable of encapsulating MSCs by providing an instructive biomimetic environment, graphene oxide (GO) has emerged as a promising nanomaterial for cartilage TE due to its chondroinductive properties when embedded in polymeric formulations, and piezoelectric nanomaterials, such as barium titanate nanoparticles (BTNPs),can be exploited as nanoscale transducers capable of inducing cell growth/differentiation. The aim of this study was to investigate the effect of dose-controlled LIPUS in counteracting inflammation and positively committing chondrogenesis of ASCs embedded in a 3D piezoelectric hydrogel. ASCs at 2*10. 6. cells/mL were embedded in a 3D VitroGel RGD. ®. hydrogel without nanoparticles (Control) or doped with 25 µg/ml of GO nanoflakes and 50 µg/ml BTNPs.The hydrogels were exposed to basal or inflammatory milieu (+IL1β 10ng/ml)and then to LIPUS stimulation every 2 days for 10 days of culture. Hydrogels were chondrogenic differentiated and analyzed after 2,10 and 28 days. At each time point cell viability, cytotoxicity, gene expression and immunohistochemistry (COL2, aggrecan, SOX9, COL1)and inflammatory cytokines were evaluated. Ultrasound stimulation significantly induced chondrogenic differentiation of ASCs loaded into 3D piezoelectric hydrogels under basal conditions: COL2, aggrecan and SOX9 were significantly overexpressed, while the fibrotic marker COL1 decreased compared to control samples. LIPUS also has potent anti-inflammatory effects by reducing IL6 and IL8 and maintaining its ability to boost chondrogenesis. These results suggest that the combination of LIPUS and piezoelectric hydrogels promotes the differentiation of ASCs encapsulated in a 3D hydrogel by reducing the inflammatory milieu, thus representing a promising tool in the field of cartilage TE. Acknowledgements: This work received funding from the European Union's Horizon 2020 research and innovation program, grant agreement No 814413, project ADMAIORA (AdvanceD nanocomposite MAterIals for in situ treatment and ultRAsound-mediated management of osteoarthritis)

Abstract. Objectives. To compare the effectiveness of phonophoresis (PH) and conventional therapeutic ultrasound (US) on the functional and pain outcomes of patients with knee osteoarthritis. Methods. We conducted an electronic search through PubMed, Cochrane Central Register of Clinical Trials (CENTRAL), Web of Science (WOS), and Scopus databases. We screened the retrieved articles to include only English full-text randomized controlled trials that examined the effect of phonophoresis versus conventional therapeutic ultrasound on patients with knee osteoarthritis. Two reviewers screened, extracted the data, and independently assessed the quality of the included articles. Results. A total of five randomized controlled trials met our inclusion criteria out of 267 studies screened. Our results showed no statistically significant differences between the PH and US groups (1), (2), (3),(4), and (5). The PH group demonstrated more significant effects than the UT group in reducing VAS pain scores (P=0.009) and improving WOMAC scores, although this did not reach the level of significance (P=0.143) (5). In the long term, PH therapy was found to be superior to US in improving painless walking duration and distance VAS scores (p=0.034, 0.017) respectively, as well as walking and resting walking VAS scores (p=0.03, 0.007) respectively, which were found to be permanent (3). Conclusions. Both therapies improve pain and function. However, we suggest conducting more high-quality trials with larger sample sizes and do not recommend the use of these therapies in clinical practice due to limitations in gender selection and high risk of bias. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction. Articular cartilage injuries have a limited potential to heal and, over time, may lead to osteoarthritis, an inflammatory and degenerative joint disease associated with activity-related pain, swelling, and impaired mobility. Regeneration and restoration of the joint tissue functionality remain unmet challenges. Stem cell-based tissue engineering is a promising paradigm to treat cartilage degeneration. In this context, hydrogels have emerged as promising biomaterials, due to their biocompatibility, ability to mimic the tissue extracellular matrix and excellent permeability. Different stimulation strategies have been investigated to guarantee proper conditions for mesenchymal stem cell differentiation into chondrocytes, including growth factors, cell-cell interactions, and biomaterials. An interesting tool to facilitate chondrogenesis is external ultrasound stimulation. In particular, low-intensity pulsed ultrasound (LIPUS) has been demonstrated to have a role in regulating the differentiation of adipose mesenchymal stromal cells (ASCs). However, chondrogenic differentiation of ASCs has been never associated to a precisely measured ultrasound dose. In this study, we aimed to investigate whether dose-controlled LIPUS is able to influence chondrogenic differentiation of ASCs embedded in a 3D hydrogel. Materials and Methods. Human adipose mesenchymal stromal cells at 2∗10. 6. cells/mL were embedded in a hydrogel ratio 1:2 (VitroGel RGD®) and exposed to LIPUS stimulation (frequency: 1 MHz, intensity: 250 mW/cm. 2. , duty cycle: 20%, pulse repetition frequency: 1 kHz, stimulation time: 5 min) in order to assess its influence on cell differentiation. Hydrogel-loaded ASCs were cultured and differentiated for 2, 7, 10 and 28 days. At each time point cell viability (Live&Dead), metabolic activity (Alamar Blue), cytotoxicity (LDH), gene expression (COL2, aggrecan, SOX9, and COL1), histology and immunohistochemistry (COL2, aggrecan, SOX9, and COL1) were evaluated respect to a non-stimulated control. Results. Histological analysis evidenced a uniform distribution of ASCs both at the periphery and at the center of the hydrogel. Live & Dead test evidenced that the encapsulated ASCs were viable, with no signs of cytotoxicity. We found that LIPUS induced chondrogenesis of ASCs embedded in the hydrogel, as demonstrated by increased expression of COL2, aggrecan and SOX9 genes and proteins, and decreased expression of COL1 respect to the non-stimulated control. Conclusions. These results suggest that the LIPUS treatment could be a valuable tool in cartilage tissue engineering, to push the differentiation of ASCs encapsulated in a 3D hydrogel

In the native articular cartilage microenvironment, chondrocytes are constantly subjected to dynamic physical stimuli that maintains tissue homeostasis. They produce extra cellular matrix (ECM) components such as collagens (type II mainly, 50-75%), proteoglycans (10-30%) and other type of proteins. 1. . While collagen offers a large resistance in tension, proteoglycans are the responsible of the viscoelastic response under compression due to the negative charge they confer to the ECM allowing it to entrap a large amount of interstitial fluid. In pathologic states (e.g. osteoarthritis), this ECM is degenerated and the negative charge becomes unbalanced, losing the chondroprotective properties and resulting on an overloaded chondrocytes that further degenerate the matrix. Low-Intensity Pulsed Ultrasound Stimulation (LIPUS) has been used to generate acoustic (pressure) waves that create bubbles that collapse with cells, inducing a stimulus that can modulate cell response. 2. This mechanical stimulation promotes the expression of type II collagen, type X collagen, aggrecan and TGF-β, appearing as a great strategy to regenerate cartilage. However, current strategies make use of extrinsic forces to stimulate cartilage formation overlooking the physico-chemical properties of the degenerated cartilage, resulting in an excessive load-transfer to chondrocytes and the consequent hypertrophy and degeneration. Here, interpenetrated networks (IPNs) with different compositions were created using methacrylated gelatin (GelMA), to mimic the collagen, and alginate functionalized with tyramine (Alg-tyr) to mimic glycosaminoglycans and to introduce a negative charge in the model. Within the matrix chondrocytes where encapsulated and stimulated under different conditions to identify the ultrasound parameters that enhance tissue formation. Samples with and without stimulation were compared analysing the expression and deposition of collagen II, aggrecan, collagen X and TGF-β. The results suggested that the chondrogenic marker expression of the samples stimulated for 10 minutes per day for 28 days, was two times higher overall in all of the cases, which was correlated to the tissue formation detected. Acknowledgments: The authors would like to thank the Basque Government for the “Predoctoral Training Program for Non-Doctoral Research Staff 2021-2022” (Grant ref.: PRE_2021_1_0403). This work was supported by the RETOS grant PID2020-114901RA-I00 of the Ministry of Science and Innovation (MICINN)

Abstract. Objectives. Three-dimensional visualisation of sonographic callus has the potential to improve the accuracy and accessibility of ultrasound evaluation of fracture healing. The aim of this study was to establish a reliable method for producing three-dimensional reconstruction of sonographic callus. Methods. A prospective cohort of ten patients with a closed tibial shaft fracture managed with intramedullary nailing were recruited and underwent ultrasound scanning at 2-, 6- and 12-weeks post-surgery. Ultrasound B-mode capture was performed using infrared tracking technology to map each image to a three-dimensional lattice. Using echo intensity, semi-automated mapping was performed by two independent reviewers to produce an anatomic three-dimensional representation of the fracture. Agreement on the presence of sonographic bridging callus on three-dimensional reconstructions was assessed using the kappa coefficient. Results. Nine of the ten patients achieved union at six months. At six weeks, seven patients had bridging callus at ≥1 cortex on the three-dimensional reconstruction; when present all united. Compared to radiographs, no bridging callus was present in any patient. Of the three patients lacking sonographic bridging callus, one went onto a nonunion (77.8%-sensitive and 100%-specific to predict union). At twelve weeks, nine patients had bridging callus at ≥1 cortex on three-dimensional reconstruction and all united (100%-sensitive and 100%-specific to predict union). Compared to radiographs, seven of the nine patients that united had bridging callus. Three-dimensional reconstruction of the anteromedial and anterolateral tibial surface was achieved in all patients, and detection of sonographic bridging callus on the three-dimensional reconstruction demonstrated substantial inter-observer agreement (kappa=0.78, 95% confidence interval 0.29–1.0, p=0.011). Conclusions. Three-dimensional fracture reconstruction can be created using multiple ultrasound images in order to evaluate the presence of bridging callus. This imaging modality has the potential to identify impaired healing at an early stage in fracture management. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction and Objective. Nonunion is incomplete healing of fracture and fracture that lacks potential to heal without further intervention. Nonunion commonly presents with persistent pain, swelling, or instability. Those symptoms affect patient quality of life. It is known that using low intensity pulsed ultrasound (LIPUS) for fresh fractures promotes healing. However, effectiveness of LIPUS for nonunion is still controversial. If LIPUS is prove to be effective for healing nonunion, it can potentially provide an alternative to surgery. In addition, we can reduce costs by treating nonunion with LIPUS than performing revision surgery. Materials and Methods. The two authors carried out a systematic search of PubMed, Ovid MEDLINE, and the Cochrane Library. Meta-analysis of healing rate in nonunion and delayed union patients who underwent LIPUS was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) instruction method using a random effects model. Results. The initial search identified 652 articles. Of these, 541 were excluded on the basis of the title because they were either a review paper or covered an unrelated topic. The abstracts of the remaining 111 articles were examined further. That review resulted in a sample of 12 articles. We performed a meta-analysis with a random effects model using Open Meta Analyst software. The result of pooled effect size of healing rate was 73.4% (95%CI: 65.3–81.6%). Due to the fact that nonunion lacks potential to heal without further intervention, we suggest that the therapeutic effect of 73.4% from LIPUS is sufficiently effective. As far as we know, there are no trials comparing the therapeutic effectiveness of surgery and LIPUS, so it cannot be said which is more advantageous. However, the healing rate of revision surgery was reported between 68–96%; therefore, our result is within that range. Thus, if surgery is difficult due to complications, we can recommend LIPUS. Conclusions. Meta-analysis of healing rate of nonunion treated by low-intensity pulsed ultrasound is 73.4%, which suggests sufficient therapeutic effectiveness. Furthermore, we can say that LIPUS may provide an alternative treatment for nonunion patients who cannot tolerate revision surgery due to complications

Purpose. Ultrasound of the neonatal and infantile hip is a useful tool in diagnosis and treatment of the developmental dysplasia of the hip (DDH), especially given the fact that numerous cases of DDH do not present any findings in the clinical examination. Methods. Between January 2014 and May 2020, 10536 (5273 neonates and infants, 53% girls, 47% boys) consecutive neonatal and infantile hip joints were studied using the Graf Hip Ultrasound method. Results. 607 hips were diagnosed as abnormal. 523 (5%) hip joints were type IIA, 18 (0.17%) were type ΙΙΒ, 19 (0.18%) were type ΙΙC, 33 (0.31%) were type ΙΙΙ and 14 (0.13%) were type IV. 72% of patients were girls, 55% of patients were firstborns, 35,7% presented breech, 8,2% had a positive family history of DDH, 6% were part of a multiple pregnancy, while 27,2% had no predisposing factor for the disease. Type ΙΙΑ hips were treated with follow- up only and had all matured (turned to normal- type I hips) within a trimester. Type ΙΙΒ και ΙΙC hips were treated using an abductor harness and were normal (type I) within three months. 35.7% of type ΙΙΙ were treated with an abductor harness and 64.3% with hip spica. All type IV hips were treated with hip spica. The duration of therapy for type III and type IV hips was 3 months. Conclusion. The early use of a hip ultrasound provides us with the ability to diagnose and treat DDH efficiently, resulting in a normal hip joint within the first months of life

Quantitative ultrasound (QUS) is a promising tool to estimate bone structure characteristics and predict fragile fracture. The aim of this pilot cross-sectional study was to evaluate the performance of a multi-channel residual network (MResNet) based on ultrasonic radiofrequency (RF) signal to discriminate fragile fractures retrospectively in postmenopausal women. Methods. RF signal and speed of sound (SOS) were obtained using an axial transmission QUS at one‐third distal radius for 246 postmenopausal women. Based on the involved RF signal, we conducted a MResNet, which combines multi-channel training with original ResNet, to classify the high risk of fragility fractures patients from all subjects. The bone mineral density (BMD) at lumber, hip and femoral neck acquired with DXA was recorded on the same day. The fracture history of all subjects in adulthood were collected. To assess the ability of the different methods in the discrimination of fragile fracture, the odds ratios (OR) calculated using binomial logistic regression analysis and the area under the receiver operator characteristic curves (AUC) were analyzed. Results. Among the 246 postmenopausal women, 170 belonged to the non-fracture group, 50 to the vertebral group, and 26 to the non-vertebral fracture group. MResNet was discriminant for all fragile fractures (OR = 2.64; AUC = 0.74), for Vertebral fracture (OR = 3.02; AUC = 0.77), for non-vertebral fracture (OR = 2.01; AUC = 0.69). MResNet showed comparable performance to that of BMD of hip and lumbar with all types of fractures, and significantly better performance than SOS all types of fractures. Conclusions. the MResNet model based on the ultrasonic RF signal can significantly improve the ability of QUS device to recognize previous fragile fractures. Moreover, the performance of the proposed model modified by age, weight, and height is further optimized. These results open perspectives to evaluate the risk of fragile fracture applying a deep learning model to analyze ultrasonic RF signal

The treatment of extremity ballistic injury is challenging in that the zone of injury can be extensive and determining the surgical exposure can be difficult. We describe a method of pre-operative evaluation of the zone of injury in conjunction with the regional anesthesiologist utilizing ultrasound to determine the presence of nerve disruption. This non-invasive method of examination may elucidate whether significant nerve exists and may also serve to pinpoint the location of injury. Such information allows the surgeon to more effectively and efficiently surgically expose the zone of injury and understand the boundaries of the nerve outside the zone of injury. Moreover, such preoperative evaluation may at times obviate the need for exploratory surgery at all. It is important for the anesthesiologist and surgeon to work together with respect to the ability to both interpret the ultrasound images and to clinically correlate the findings. The zone of tissue disruption in ballistic injuries is extremely variable. It is beneficial to both the surgeon and patient to engage in a collaborative effort with an experienced regional anesthesiologist who is well-versed in interpretation of ultrasound images and tissue plane disruption in an effort to minimize surgical time and the potential unintended consequences of unnecessary exploration. We present a series of cases representing instances wherein the zone of injury was small, extensive, and a unique situation in which there was in fact no injury present despite clinical symptoms and MRI consistent with radial nerve disruption

This study was designed to test the hypothesis that the sensory innervation of bone might play an important role in sensing and responding to low-intensity pulsed ultrasound and explain its effect in promoting fracture healing. In 112 rats a standardised mid-shaft tibial fracture was created, supported with an intramedullary needle and divided into four groups of 28. These either had a sciatic neurectomy or a patellar tendon resection as control, and received the ultrasound or not as a sham treatment. Fracture union, callus mineralisation and remodelling were assessed using plain radiography, peripheral quantitative computed tomography and histomorphology. Daily ultrasound treatment significantly increased the rate of union and the volumetric bone mineral density in the fracture callus in the neurally intact rats (p = 0.025), but this stimulating effect was absent in the rats with sciatic neurectomy. Histomorphology demonstrated faster maturation of the callus in the group treated with ultrasound when compared with the control group. The results supported the hypothesis that intact innervation plays an important role in allowing low-intensity pulsed ultrasound to promote fracture healing

We have evaluated in vitro the accuracy of percutaneous and ultrasound registration as measured in terms of errors in rotation and version relative to the bony anterior pelvic plane in computer-assisted total hip replacement, and analysed the intra- and inter-observer reliability of manual or ultrasound registration. Four clinicians were asked to perform registration of the landmarks of the anterior pelvic plane on two cadavers. Registration was performed under four different conditions of acquisition. Errors in rotation were not significant. Version errors were significant with percutaneous methods (16.2°; p < 0.001 and 19.25° with surgical draping; p < 0.001), but not with the ultrasound acquisition (6.2°, p = 0.13). Intra-observer repeatability was achieved for all the methods. Inter-observer analysis showed acceptable agreement in the sagittal but not in the frontal plane. Ultrasound acquisition of the anterior pelvic plane was more reliable in vitro than the cutaneous digitisation currently used

This study of collegiate basketball players evaluated change over time (COT) in ultrasound shear wave (SW) elastography metrics across the basketball season, and correlated to morphologic changes on conventional ultrasound imaging, and VISA-P scores. In eleven male collegiate basketball players (mean age 19, age range 18–21), patella tendon (PT) ultrasound and SW elastography of both knees were performed at pre-season and post-season time points, and players reported their VISA-P scores throughout the season. Patella tendinopathy grade and SW metrics were correlated to VISA-P scores using Spearman correlation coefficients. Paired t-test was used to assess differences in mean SW metrics at pre-and post-season timepoints, accounting for leg dominance. 6 of 11 players (54.5%) had baseline patella tendinopathy on ultrasound progressing in 4 players. The mean change in VISA-P score was 15.18 (+/−8.55). No significant correlation was seen between ultrasound grades of tendinopathy and VISA-P. Pre-season SW velocities did not significantly correlate with baseline VISA-P scores. Post-season SW values and SW COT demonstrated strong correlation with change in VISA-P score in dominant and non-dominant knees. Although not statistically significant, there was a trend towards higher SW velocity for tendinopathy in both dominant and non-dominant knees at both study visits. SW metrics of the PT correlated to change in VISA-P scores in the dominant and non-dominant knees, whereas conventional ultrasound grades of patella tendinopathy did not. There was a trend towards higher SW velocities in patella tendinopathy which may indicate detection of change in intrinsic tissue stiffness

Background. We searched -in transverse ultrasound view- the value of the difference (Delta) between -proximal to the tunnel- CSA (a) and -in the tunnel's inlet- CSA (b) for separating normal from abnormal median nerves. Methods. 51 patients –suspicious for CTS- underwent Phalen and Tinnel tests. After that, we used a high frequency ultrasound to measure CSAa, CSAb and Delta CSA in both hands. 33 of our 51 patients did not experience any clinical symptoms at the contralateral hand, so that we could perform a comparative study of normal and pathological median nerves (on the same patients). Then, all of them completed a Q-DASH questionnaire and a visual analogue scale (VAS 100/100) and they carried through with a nerve conduction study (NCS). Results. We found that a CSAb more than 0,010 and a Delta CSA > 0,003 are both very sensitive findings for CTS, but only DeltaCSA has good specificity. Comparing to NCS the Delta CSA>0,003 had no statistical difference in sensitivity, specificity, true negative and true positive results. Furthermore, patients with Delta CSA>0,009 were suffering from heavy CTS according to NCS, Q-DASH and VAS. On the other way, a Delta CSA between 0,003 and 0,006 suggests a mild or moderate CTS. Conclusion. Delta CSA could be the golden standard for the detection of CTS in patients that feel uncomfortable to undergo NCS. We propose a grading scale that distinguish mild or moderate syndromes (where we could try a conservative treatment) from heavy syndromes and help as on decision-making

Objectives. The aim of the current study was to assess whether calcaneal broadband ultrasound attenuation (BUA) can predict whole body and regional dual-energy x-ray absorptiometry (DXA)-derived bone mass in healthy, Australian children and adolescents at different stages of maturity. Methods. A total of 389 boys and girls across a wide age range (four to 18 years) volunteered to participate. The estimated age of peak height velocity (APHV) was used to classify children into pre-, peri-, and post-APHV groups. BUA was measured at the non-dominant heel with quantitative ultrasonometry (QUS) (Lunar Achilles Insight, GE), while bone mineral density (BMD) and bone mineral content (BMC) were examined at the femoral neck, lumbar spine and whole body (DXA, XR-800, Norland). Associations between BUA and DXA-derived measures were examined with Pearson correlations and linear regression. Participants were additionally ranked in quartiles for QUS and DXA measures in order to determine agreement in rankings. Results. For the whole sample, BUA predicted 29% of the study population variance in whole body BMC and BMD, 23% to 24% of the study population variance in lumbar spine BMC and BMD, and 21% to 24% of the variance in femoral neck BMC and BMD (p < 0.001). BUA predictions were strongest for the most mature participants (pre-APHV R. 2. = 0.03 to 0.19; peri-APHV R. 2. = 0.05 to 0.17; post-APHV R. 2. = 0.18 to 0.28) and marginally stronger for girls (R. 2. = 0.25-0.32, p < 0.001) than for boys (R. 2. = 0.21-0.27, p < 0.001). Agreement in quartile rankings between QUS and DXA measures of bone mass was generally poor (27.3% to 38.2%). Conclusion. Calcaneal BUA has a weak to moderate relationship with DXA measurements of bone mass in children, and has a tendency to misclassify children on the basis of quartile rankings. Cite this article: B. K. Weeks, R. Hirsch, R. C. Nogueira, B. R. Beck. Is calcaneal broadband ultrasound attenuation a valid index of dual-energy x-ray absorptiometry-derived bone mass in children? Bone Joint Res 2016;5:538–543. DOI: 10.1302/2046-3758.511.BJR-2016-0116.R1

We investigated the effects of low-intensity pulsed ultrasound on distraction osteogenesis in a rabbit model. Callotasis of the right tibia was performed in 70 male Japanese white rabbits using mini-external fixators. In the first part of the study in 64 animals using normal distraction (waiting period seven days; distraction rate 0.5 mm/12 hours; distraction period ten days), we evaluated the distraction site by radiography, measurement of the bone mineral density (BMD), mechanical testing, and histology. In the second part in six rabbits using fast distraction (waiting period 0 days; distraction rate 1.5 mm/12 hours; distraction period seven days) the site was evaluated radiologically. Half of the animals (35) had received ultrasound to their right leg (30mW/cm. 2. ) for 20 minutes daily after ceasing distraction (ultrasound group), while rigid fixation only was maintained in the other half (control group). With normal distraction, the hard callus area, as shown by radiography, the BMD, and the findings on mechanical testing, were significantly greater in those receiving ultrasound than in the control group. Histological analysis showed no tissue damage attributable to exposure to ultrasound. With fast distraction, immature bone regeneration was observed radiologically in the control group, while bone maturation was achieved in the ultrasound group. We conclude that ultrasound can accelerate bone maturation in distraction osteogenesis in rabbits, even in states of poor callotasis

Objectives. The objective of this study was to determine if combining variations in mixing technique of antibiotic-impregnated polymethylmethacrylate (PMMA) cement with low frequency ultrasound (LFUS) improves antibiotic elution during the initial high phase (Phase I) and subsequent low phase (Phase II) while not diminishing mechanical strength. Methods. Three batches of vancomycin-loaded PMMA were prepared with different mixing techniques: a standard technique; a delayed technique; and a control without antibiotic. Daily elution samples were analysed using flow injection analysis (FIA). Beginning in Phase II, samples from each mix group were selected randomly to undergo either five, 15, 45, or 0 minutes of LFUS treatment. Elution amounts between LFUS treatments were analysed. Following Phase II, compression testing was done to quantify strength. A-priorit-tests and univariate ANOVAs were used to compare elution and mechanical test results between the two mix groups and the control group. Results. The delayed technique showed a significant increase in elution on day one compared with the standard mix technique (p < 0.001). The transition point from Phase I to Phase II occurred on day ten. LFUS treatments significantly increased elution amounts for all groups above control. Delayed technique resulted in significantly higher elution amounts for the five-minute- (p = 0.004) and 45-minute- (p < 0.001) duration groups compared with standard technique. Additionally, the correlations between LFUS duration and total elution amount for both mix techniques were significant (p = 0.03). Both antibiotic-impregnated groups exhibited a significant decrease in offset yield stress compared with the control group (p < 0.001), however, their lower 95% confidence intervals were all above the 70 MPa limit defined by International Standards Organization (ISO) 5833-2 reference standard for acrylic bone cement. Conclusion. The combination of a delayed mix technique with LFUS treatments provides a reasonable means for increasing both short- and long-term antibiotic elution without affecting mechanical strength. Cite this article: Dr. T. McIff. Combination of modified mixing technique and low frequency ultrasound to control the elution profile of vancomycin-loaded acrylic bone cement. Bone Joint Res 2016;5:26–32. doi: 10.1302/2046-3758.52.2000412