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Background: Patients with chronic obstructive pulmonary disease (COPD) have difficulties inhaling as the diaphragm becomes flattened and weakened due to lung hyperinflation. This weakened respiratory function is compensated for by the increased activity of the accessory respiratory muscles, such as the sternocleidomastoid muscle (SCM). Objectives: This study aimed to evaluate the difference in the SCM thickening fraction (SCM TF) of each respiratory phase (end-expiration, resting inspiration, and end-inspiration), as measured using ultrasonography (US), between patients with COPD and control subjects. We also evaluate the correlation between the SCM TF of each respiratory phase and exercise tolerance in patients with COPD. Methods: Patients with COPD (n = 44) and age-matched controls (n = 20) underwent US for determination of the SCM TF. Ventilation parameters, including the peak oxygen uptake (peak VO2) and the change in the inspiratory capacity, were measured during cardiopulmonary exercise testing. The SCM thickness and TF was measured during end-expiration, resting breathing, and end-inspiration. Results: The SCM was significantly thinner in patients with COPD than in controls at end-expiration. The increase in the SCM TF from end-expiration to end-inspiration in patients with COPD did not differ significantly from that in control subjects. In contrast, the SCM TF from end-expiration to resting inspiration was significantly greater in patients with COPD than in control subjects. The peak VO2 was strongly positively correlated with the SCM TF from end-expiration to end-inspiration in patients with COPD (r = 0.71, p < 0.01). Conclusions: The SCM may be thinner in patients with COPD than in controls. The SCM TF may also be associated with exercise tolerance.

Chronic progressive external ophthalmoplegia (CPEO) is a mitochondrial disease characterized by slowly progressive ptosis and limitations in ocular motility. Although exophthalmos is not considered to be a common feature of CPEO, this study focused on the incidence of exophthalmos in patients with CPEO.Retrospective observational case series METHODS: We reviewed the clinical charts of patients who received a diagnosis of CPEO sometime during the period between January 2010 and December 2018. CPEO was diagnosed on the basis of detection of a deletion of mitochondrial DNA (mtDNA) from saliva, buccal mucosa, or extraocular muscle specimens obtained during strabismus surgery. Horizontal MRI/CT images or Hertel ophthalmometry was used in determining exophthalmos.Seven patients (4 males) were identified. The mean age at diagnosis was 32.6 years (range 13-53 years). mtDNA deletion mutations were detected in the buccal mucous membrane DNA in 5 patients and in the saliva and extraocular muscle DNA in 2 patients. MRI/CT was recorded in 6 patients, four of whom showed exophthalmos (cases 1-4), and case 5 was determined as exophthalmos on the basis of a Hertel ophthalmometer reading. Exophthalmos was bilateral in 4 of the patients (cases 1, 2, 4, and 5) and unilateral in 1 patient (case 3). Exophthalmos was the chief concern of 2 of the patients; however, it was not clinically significant in the other patients.Although exophthalmos may not be recognized by either the patient or the clinician, it may be one of the common features of CPEO. A large multiethnic study should be performed.

Although cancer precision medicine has improved diagnosis and therapy, refractory cancers such as pancreatic cancer remain to be challenging targets. Clinical sequencing has identified the significant alterations in driver genes and traced their clonal evolutions. Recent studies indicated that the tumor microenvironment elicits alterations in cancer metabolism, although its involvement in the cause and development of genomic alterations has not been established. Genomic abnormalities can contribute to the survival of selected subpopulations, recently recognized as clonal evolution, and dysfunction can lead to DNA mutations. Here, we present the most recent studies on the mechanisms of cancer metabolism involved in the maintenance of genomic stability to update current understanding of such processes. Sirtuins, which are NAD+-dependent protein deacetylases, appear to be involved in the control of genomic stability. Alterations of deleterious subpopulations would be exposed to selective pressure for cell survival. Recent studies indicated that a new type of cell death, ferroptosis, determines the survival of clones and exert cancer-restricting or -promoting effects to surrounding cells in the tumor microenvironment. Suppressing genomic instability and eliminating deleterious clones by cell death will contribute to the improvement of cancer medicine. Furthermore, the elucidation of the mechanisms involved is seen as a bridgehead to the pharmacologic suppression of such refractory cancers as pancreatic cancer.

An 84-year-old woman who underwent bilateral cementless total hip arthroplasty (THA) for dysplastic osteoarthritis 22 years ago was subjected to analysis. A huge soft-tissue mass was revealed in her left medial thigh. Plain radiographs of the left hip joint revealed severe osteolysis around the stem, cup, and ischium. Magnetic resonance imaging showed a 25 × 14-cm multilobulated mass with a thick-walled pseudocapsule. Two-stage surgery was performed with resection of the mass followed by a subsequent revision THA. The mass was diagnosed as a chronic expanding hematoma through gross and histologic findings. Two years after the revision THA, there was no recurrence of a hematoma. Two-stage revision THA was useful for definitive diagnosis, and good functional recovery was obtained after surgery.

Minimally invasive surgery (MIS) offers many advantages to patients but it also imposes limitations on surgeons ability, as no tactile or haptic feedback is available. From medical robotics perspective, visualizations issues specific to MIS such as limited field of view and the lack of automatic exposure control of the surgical area make it challenging when it comes to tracking tissue, tools and camera pose as well as in perceiving depth. Lighting plays an important role in 3D reconstruction and variations due to internal illumination conditions are known to degrade vital visual information. In this work, we describe a supervised adaptive light control system to solve some of the image visualization problems of MIS. Our proposed method is able to classify underexposed and over-exposed frames and adjust lighting condition automatically to enrich image quality. Our method uses support vector machines to classify different illumination conditions. Visual feedback is provided by gradient information to assess image quality and justify classifier decision. The output of this system has been tested against two cadaver knee experiment data with an overall accuracy of 97.75% for under-exposed and 89.11% for over-exposed classes. Hardware implementation of this classifier is expected to result in adaptive lighting for robot assisted surgery as well as in providing support to surgeons by freeing them from manual adjustments to lighting controls.

This study aimed to assess the relationship between pancreatic fibrosis measured by the extracellular volume fraction (ECV) using contrast-enhanced computed tomography (CT) and the histologic pancreatic fibrosis fraction and investigate the relationship between pancreatic fibrosis and pancreatic cancer.The study included 88 consecutive patients (48 males, 40 females; median age, 69 years; range, 17-89 years); 47 had pancreatic cancer, and 41 had other diseases. Fifty-two cases were evaluated pathologically for pancreatic fibrosis. The histologic pancreatic fibrosis fraction was quantified using image analysis software in nontumorous pancreatic tissue at the resection stump using 2-µm-thick Azan-stained slides. Two board-certified radiologists measured ECV in the pancreatic parenchyma at an estimated transection line. The correlation between histologic pancreatic fibrosis fraction and ECV was investigated, and whether the ECV value could be used as a biomarker for pancreatic cancer was investigated.The histologic pancreatic fibrosis fraction was significantly correlated with the ECV (r = 0.64, P 0.01). Pancreatic fibrosis evaluated by ECV was higher in pancreatic cancer patients than in other patients (P 0.01). On receiver-operating characteristic curve analysis, the ECV had good diagnostic accuracy for the development of pancreatic cancer (cut-off value 32.8%; sensitivity 61.0%, specificity 85.1%). ECV was identified on multivariate analysis as an independent risk factor for pancreatic cancer (odds ratio 1.16; P 0.01).Extracellular volume fraction was strongly related to the histologic pancreatic fibrosis fraction, which was independently associated with pancreatic cancer. Thus, extracellular volume fraction is an imaging biomarker that reflects the progression of pancreatic fibrosis and may potentially help predict the development of pancreatic cancer, although further investigation will be needed.

Prospective cardiovascular adjustment occurs before starting voluntary exercise, increasing heart rate and arterial pressure followed by muscle vasodilation; however, the precise mechanisms and significance for this vasodilation remain unknown. We found that during the countdown before starting exercise cerebral blood flow velocity increased, followed by increases in heart rate and arterial pressure, which suppressed MSNA through baroreflex, resulting in thigh muscle vasodilation to increase oxygen consumption rate, which might make it easier to start exercise.

Minimally invasive surgery (MIS) is among the preferred procedures for treating a number of ailments as patients benefit from fast recovery and reduced blood loss. The trade-off is that surgeons lose direct visual contact with the surgical site and have limited intra-operative imaging techniques for real-time feedback. Computer vision methods as well as segmentation and tracking of the tissues and tools in the video frames, are increasingly being adopted to MIS to alleviate such limitations. So far, most of the advances in MIS have been focused on laparoscopic applications, with scarce literature on knee arthroscopy. Here for the first time, we propose a new method for the automatic segmentation of multiple tissue structures for knee arthroscopy. The training data of 3868 images were collected from 4 cadaver experiments, 5 knees, and manually contoured by two clinicians into four classes: Femur, Anterior Cruciate Ligament (ACL), Tibia, and Meniscus. Our approach adapts the U-net and the U-net++ architectures for this segmentation task. Using the cross-validation experiment, the mean Dice similarity coefficients for Femur, Tibia, ACL, and Meniscus are 0.78, 0.50, 0.41, 0.43 using the U-net and 0.79, 0.50, 0.51, 0.48 using the U-net++. While the reported segmentation method is of great applicability in terms of contextual awareness for the surgical team, it can also be used for medical robotic applications such as SLAM and depth mapping.

In this work, we proved for the first time the feasibility of using high-refresh-rate 3D ultrasound (US) also known as 4D US imaging to create a volumetric atlas of the knee anterior compartment for an autonomous robotic platform for knee arthroscopy. A dataset of 42 4D US sequences (including 94 US volumes) and 25 MRI volumes was collected from seven volunteers, in several leg positions simulating the surgical scenario of knee arthroscopy. MRI-US volume pairs were manually registered, and the knee structures of interest identified on the US volumes. The resulting atlas comprised the femur, tibia and patella surfaces, patellar tendon, femoral cartilage, the anterior parts of the menisci and the ACL, for knee angles between 0 and 90 degrees flexion. The inter-operator reproducibility of the registrations was calculated as the norm of the difference in the translation and the rotation values selected by two experienced orthopaedic surgeons and resulted to be on average of 4.42 mm ± 1.89 mm SD and 7.77 degrees ± 2.80 degrees SD, respectively. A new metric was introduced to measure the overlap of the US volume located at the position selected from the first and the second experts and the agreement resulted to be on average of 87% ± 3 SD. The US scanning protocol adopted could be considered compatible with the arthroscopy procedure, as proved through six cadaver studies. These preliminary results show that 4D US is an excellent candidate for automatic image-based guidance in knee arthroscopy.

Ultrasound (US) imaging is a complex imaging modality, where the tissues are typically characterised by an inhomogeneous image intensity and by a variable image definition at the boundaries that depends on the direction of the incident sound wave. For this reason, conventional image segmentation approaches where the regions of interest are represented by exact masks are inherently inefficient for US images. To solve this issue, we present the first application of a Bayesian convolutional neural network (CNN) based on Monte Carlo dropout on US imaging. This approach is particularly relevant for quantitative applications since differently from traditional CNNs, it enables to infer for each image pixel not only the probability of being part of the target but also the algorithm confidence (i.e. uncertainty) in assigning that probability. In this work, this technique has been applied on US images of the femoral cartilage in the framework of a new application, where high-refresh-rate volumetric US is used for guidance in minimally invasive robotic surgery for the knee. Two options were explored, where the Bayesian CNN was trained with the femoral cartilage contoured either on US, or on magnetic resonance imaging (MRI) and then projected onto the corresponding US volume. To evaluate the segmentation performance, we propose a novel approach where a probabilistic ground-truth annotation was generated combining the femoral cartilage contours from registered US and MRI volumes. Both cases produced a significantly better segmentation performance when compared against traditional CNNs, achieving a dice score coefficient increase of about 6% and 8%, respectively.

A 64-year-old woman with a spontaneous fused hip sustained a left femoral neck fracture. It was revealed that her left hip joint had a long-standing spontaneous hip fusion due to end-stage osteoarthritis. Additionally, she sustained an ipsilateral femoral intertrochanteric fracture and underwent osteosynthesis using a dynamic hip screw 8 years ago. The one-stage THA was successfully treated with no major complications and good functional recovery was obtained. The hip range of motion improved remarkably at one year after surgery. The Modified Harris Hip Score improved from an estimated 70 points before fracture to 95 points at final follow-up.

Background In patients with chronic obstructive pulmonary disease (COPD), the maximum level of diaphragm excursion (DEmax) is correlated with dynamic lung hyperinflation and exercise tolerance. This study aimed to elucidate the utility of DEmax to predict the improvement in exercise tolerance after pulmonary rehabilitation (PR) in patients with COPD. Methods This was a prospective cohort study. Of the 62 patients with stable COPD who participated in the outpatient PR programme from April 2018 to February 2021, 50 completed the programme. Six-minute walk distance (6MWD) was performed to evaluate exercise tolerance, and ultrasonography was performed to measure DEmax. Responders to PR in exercise capacity were defined as patients who demonstrated an increase of > 30 m in 6MWD. The receiver operating characteristic (ROC) curve was used to determine the cut-off point of DEmax to predict responses to PR. Results Baseline levels of forced expiratory volume in 1 s, 6MWD, maximum inspiratory pressure, DEmax and quadriceps muscle strength were significantly higher, and peak dyspnoea of modified Borg (mBorg) scale score was lower in responders (n = 30) than in non-responders (n = 20) to PR (p max was significantly correlated with an increase of > 30 m in 6MWD. The area under the ROC curve of DEmax to predict responders was 0.915, with a sensitivity and specificity of 83% and 95%, respectively, at a cut-off value of 44.9 mm of DEmax. Conclusion DEmax could adequately predict the improvement in exercise tolerance after PR in patients with COPD.

Objective To evaluate the impact of spinopelvic parameters and hip contracture on change in the pelvic tilt (PT) after Total hip arthroplasty (THA). Methods One hundred patients (15 male and 85 female) who underwent THA were included in this prospective study. Radiographic data were obtained preoperatively and 1 year after THA. Radiographic parameters included sagittal anterior pelvic plane (APP), sagittal vertical axis (SVA), sacral slope (SS), pelvic inclination (PI), and lumbar lordosis angle (LL). The APP was defined as the angle between the anterior pelvic plane and the vertical plane. A positive value indicates pelvic retroversion. Postoperative changes in PT were divided into three groups: the PA group (pelvic anteversion, ΔAPP 5°), and the PT group (minimal change, ΔAPP ≤ ± 5°). The Kruskal–Wallis test and the Steel–Dwass test were used to compare the preoperative and postoperative spinopelvic parameters among the three groups. The Spearman's rank correlation coefficient was used to evaluate the correlation between ΔAPP and spinopelvic parameters. Results Minimal change in pelvic tilt was observed in 59% of patients, while pelvic anteversion was observed in 16% of patients and pelvic retroversion was observed in 25% of patients. There were no significant changes in the spinopelvic parameters, including TK, LL, SVA, LL, SS, and APP after THA. The Femoral angle (FA) was significantly decreased after THA (P

Background Postoperative pain is a significant concern of patients before surgery. Multimodal pain management is an effective method of pain control after major orthopedic surgery. Acetaminophen is the most commonly used analgesic for the management of pain. It was hypothesized that 1000 mg of intravenous acetaminophen (IA) dosed every 6 hours would significantly reduce the postoperative pain score at rest and the opioid consumption volume in patients who would undergo total hip arthroplasty (THA) when compared to a control group. Methods A single-center, prospective, open-label randomized control study was conducted. A total of 97 patients undergoing unilateral primary THA were divided into 2 groups: the study group (IA) (n = 45) and the control group (n = 52). The study group received administered IA after surgery, while the control group received only a standard pain control. Both groups received a preoperative femoral nerve block and postoperative intravenous fentanyl citrate. The primary outcome was the evaluation of the pain score at rest 24 hours after surgery. The pain score was measured using the Numerical Rating Scale. The primary outcome of this study was analyzed using generalized estimating equation. Results The IA group had a significant improvement in Numerical Rating Scale score at rest 24 hours after THA compared to the control group (−0.91, 95% confidence interval −1.56 to −0.26, P = .006), suggesting a positive effect of IA usage for pain relief. The total fentanyl citrate consumption after surgery for 24 hours was significantly lower in the IA group than those of the control group (52.07 ± 7.64 vs 57.83 ± 12.44 mg, P Conclusion Postoperative administration of IA significantly reduced the postoperative pain score and opioid consumption volume after primary THA. IA was useful as one role of multimodal pain management after THA. Level of Evidence: Level 2.

Introduction: We have developed and utilized the Gravity-guide (G-guide) as a simple manual instrument for intraoperative assessment and adjustment of stem anteversion (AV). Since 2013, we simultaneously measured stem AV using the G-guide and image-free navigation during THA procedure. The purpose of this study was to compare the measurement accuracy of the G-guide and navigation system using the postoperative CT results as a reference. Methods: In total, 59 hips in 56 patients who underwent primary THA using both the G-guide and image-free navigation system were included in the study. All patients underwent postoperative CT examination, and the femoral stem AV was assessed using a 3D image analysis system (Zed hip, LEXI, Japan). The AV angle derived from the postoperative CT image analysis was used as the reference value to assess the accuracy of the two intraoperative measurement systems. Results: The discrepancy between the G-guide and the postoperative CT-measured values averaged 5.0° ± 3.9°, while the corresponding value for the navigation system was 5.2° ± 4.1°. Acceptable accuracy with a measurement error of less than 10° was achieved in 86% and 90% of the cases for the G-guide and navigation measurements respectively. Conclusion: Consequently, it was shown that both navigation and G-guide measurements can achieve comparative accuracy and are clinically useful.

In the combined anteversion (CA) technique for total hip arthroplasty (THA) with a cementless stem, cup anteversion is strongly influenced by the native femoral anteversion. It is hypothesized that in cases with large native femoral anteversion, cup anteversion can be decreased, and anterior cup protrusion from the anterior edge of the acetabulum could occur due to the achievement of optimal CA. In this study, the accuracy of CA in THA with the CA technique using imageless navigation and the relationship between the protrusion of the anterior edge of cup and optimum CA was retrospectively evaluated. Ninety-seven patients (104 hips) who underwent primary THA by the CA technique using image-free navigation were enrolled in the study. The femoral stem was placed following the individual femoral anteversion so that the target cup anteversion could be determined following a mathematical formula (37 = femoral stem anteversion × 0.7 + cup anteversion). Results The resulting CA values effectively achieved accurate CA with 39.49 ± 5.03° postoperatively. On the other hand, anterior cup protrusion was measured by computed tomography image. A cup protrusion length of more than 3 mm was indicated for 60 cases (57.7%). All included patients were divided into two groups: Group 1 as protrusion positive and Group 2 as protrusion negative. In Group 1, preoperative femoral anteversion and postoperative stem anteversion were significantly higher, while postoperative cup anteversion was significantly lower. However, the postoperative CA value indicated no significant difference between the groups. The CA (stem-first) technique with image-free navigated THA could effectively achieve accurate CA. On the other hand, a large number of cases revealed anterior cup protrusion due to the low cup anteversion.

The purpose of the present study was to investigate the results of total hip arthroplasty (THA) using the Bicontact D stem with a minimum 10 year follow-up that focused on patients with developmental dysplasia of the hip (DDH). One hundred five patients with osteoarthritis due to DDH who underwent primary THA were included in this study. The mean final follow-up period was 12.7 ± 1.2 years (range 10–15 years). All cases were evaluated both clinically and radiographically, and Kaplan–Meier survivorship was determined as stem revision for any reason as the end point. Modified Harris hip score averaged 89.0 ± 1.1 (range 60–98) at the final follow-up. The survivorship was 99.0% (95% confidence interval 93.4–99.9%) at 15.0 years, and only one hip with a well-fixed stem required stem revision due to recurrent dislocations. Cortical hypertrophy (CH) was observed in 40 of 105 hips (38.1%), and stress shielding (SS) progressed to grade 3 or 4 in six hips (6 of 105 hips: 5.7%) during the study period. Among the six hips with progressed SS, Dorr type C proximal femoral geometry was seen in five hips. This study of 105 THAs using the Bicontact D stem that focused on DDH patients with a minimum 10 year follow-up period achieved satisfactory clinical and radiological outcomes. Dorr type C proximal femoral geometry could be considered a risk factor for progressed SS.

One-carbon (1C) metabolism plays a key role in biological functions linked to the folate cycle. These include nucleotide synthesis; the methylation of DNA, RNA, and proteins in the methionine cycle; and transsulfuration to maintain the redox condition of cancer stem cells in the tumor microenvironment. Recent studies have indicated that small therapeutic compounds affect the mitochondrial folate cycle, epitranscriptome (RNA methylation), and reactive oxygen species reactions in cancer cells. The epitranscriptome controls cellular biochemical reactions, but is also a platform for cell-to-cell interaction and cell transformation. We present an update of recent advances in the study of 1C metabolism related to cancer and demonstrate the areas where further research is needed. We also discuss approaches to therapeutic drug discovery using animal models and propose further steps toward developing precision cancer medicine.

Background Although the pathophysiological mechanisms involved in the development of dyspnoea and poor exercise tolerance in patients with COPD are complex, dynamic lung hyperinflation (DLH) plays a central role. Diaphragmatic excursions can be measured by ultrasonography (US) with high intra- and interobserver reliability. The objective of this study was to evaluate the effect of diaphragmatic excursions as assessed by US on exercise tolerance and DLH in patients with COPD. Methods Patients with COPD (n=20) and age-matched control subjects (n=20) underwent US, which was used to determine the maximum level of diaphragmatic excursion (DEmax). Ventilation parameters, including the change in inspiratory capacity (ΔIC), were measured in the subjects during cardiopulmonary exercise testing (CPET). We examined the correlations between DEmax and the ventilation parameters. Results The DEmax of patients with COPD was significantly lower than that of the controls (45.0±12.8 mm versus 64.6±6.3 mm, respectively; p, Reduced diaphragmatic excursion, as measured on ultrasound images, might predict decreased exercise capacity and increased dyspnoea due to dynamic lung hyperinflation in COPD patients https://bit.ly/3jkERxZ

Background Unloading of the proximal medial femoral cortex is usually associated with an increased bone strain at the distal part of the prosthesis, which may cause distal femoral cortical hypertrophy (CH). The objective of this study was to determine the factors that may be considered a predisposition to distal femoral CH and its effect on the stress shielding (SS) or durability of the fixation of the stem. Methods A total of 240 total hip arthroplasties were performed between January 2006 and December 2016, with all hips implanted with a Bicontact stem. The minimum follow-up period was more than 2 years, and the mean follow-up period was 7.2 years. The radiographic outcome was assessed on an anteroposterior hip radiograph. CH and SS were assessed on postoperative radiographs in the Gruen zone. We defined CH that appeared in zone 3 or 5 as ‘the focal type’ and defined CH that appeared in zones 2, 3, 4, 5, and 6 as ‘the diffuse type.’ SS followed the procedures from the Engh classification. Results CH was found in 72 hips (30% of the 240 hips), the focal type was found in 23 hips (9.6% of the 240 hips), and the diffuse type was found in 49 hips (20.4% of the 240 hips). SS was found in 41 hips (17.1% of 240 hips), including 32 hips with SS, which was found after the development of CH. One hip was from the focal-type CH and 31 hips were from the diffuse-type CH. SS, which is typically found in Engh classification types 1 and 2 developed in 13 hips, and SS, which is widely seen in Engh classification types 3 and 4 developed in 19 hips. All 19 hips with progressed SS were found after the diffuse-type CH had developed. In addition, among the 19 hips with progressed SS, Dorr type A was found in 0 hips, Dorr type B in 8 hips, and Dorr type C in 11 hips. Conclusions According to the results of our radiological evaluation, development of the diffuse-type CH after total hip arthroplasty using Bicontact stems is one of the critical causes of the later development of SS and could be predicted to progress to SS. To prevent the development of the diffuse-type CH, the indication to choose a Bicontact stem for a Dorr type C with osteoporotic bone should be considered.

Combined anteversion (CA) technique (stem-first procedure) has become generally accepted as an ideal means to achieve optimal CA value in THA. However, we hypothesized that CA technique for patients with various native femoral anteversions could pose a risk of anterior or posterior cup protrusion. In the present study, we examined whether it is possible to use the taper wedge stem to change the stem version to achieve optimal CA while avoiding cup protrusions with the cup-first procedure through minimally invasive (MIS) antero-lateral approach. Eighty-one patients underwent cup-first THA with a taper wedge stem. The acetabular cup was placed following the preoperative planning of the cup alignment to avoid anterior cup protrusions using CT-based navigation. Following the CA theory, anteversion of the taper wedge stem was changed to the target anteversion from the patient’s native femoral anteversion. The native femoral anteversion, the change in version angle of the stem, postoperative CA and the length of anterior cup protrusions were evaluated in postoperative CT measurements. The native femoral anteversion averaged 25.7° ± 8.9° (range 8°–45°). Cases with increased and decreased stem anteversion were observed in 42 hips (51.8%) and 33 hips (40.7%), respectively. The amount of increased and decreased version angles averaged 7.7° ± 4.8° (range 2°–21°) and 7.8° ± 5.1° (range 2°–20°), respectively. Postoperative CA values averaged 36.7° ± 3.4° (range 29.4°–44.2°) and anterior cup protrusion length averaged 2.0 mm ± 2.6 mm (0 ~ 8.8 mm) in axial view and 0.4 mm ± 1.0 mm (0 ~ 3.6 mm) in sagittal view. Anterior cup protrusion of more than 10 mm was not observed in any hips. This procedure can be considered as an option to achieve optimal CA anteversion while avoiding anterior cup protrusion in THA.

The tracking of the knee femoral condyle cartilage during ultrasound-guided minimally invasive procedures is important to avoid damaging this structure during such interventions. In this study, we propose a new deep learning method to track, accurately and efficiently, the femoral condyle cartilage in ultrasound sequences, which were acquired under several clinical conditions, mimicking realistic surgical setups. Our solution, that we name Siam-U-Net, requires minimal user initialization and combines a deep learning segmentation method with a siamese framework for tracking the cartilage in temporal and spatio-temporal sequences of 2D ultrasound images. Through extensive performance validation given by the Dice Similarity Coefficient, we demonstrate that our algorithm is able to track the femoral condyle cartilage with an accuracy which is comparable to experienced surgeons. It is additionally shown that the proposed method outperforms state-of-the-art segmentation models and trackers in the localization of the cartilage. We claim that the proposed solution has the potential for ultrasound guidance in minimally invasive knee procedures.