Is There a Learning Curve for the 5-Year Implant Survival Rate of Total Hip Arthroplasty Using the Direct Anterior Approach with a Traction Table? - A Prospective Cohort Study.

BACKGROUND: The direct anterior approach (DAA) for total hip arthroplasty (THA) is attracting attention as a minimally invasive surgery, but the learning curve to master this approach is a concern, and its effect on long-term results is unknown. The purpose of this prospective cohort study was to clarify how the learning curve affects the five-year results of DAA THA with a traction table. METHODS: Of 402 THA cases using DAA with a mobile traction table and fluoroscopy, 249 cases composed of the first 50 cases for each surgeon were assessed during a learning curve, and 153 cases were evaluated after more than 50 cases of experience. RESULTS: The five-year-implant survival rate was 99.2% both during and after the learning curve. The two-year complication rate in the learning curve group was 8.9 versus 5.9%, which was not statistically significant. The two-to-five-year complication rates also did not differ between cohorts (0 versus 0.7%). Both groups demonstrated decreased complication rates when comparing two-year complications to the two-to-five-year complications. Clinical scores significantly improved by two years and were maintained at five years in both groups. The cup-safe zone success rates were 96.4% during the learning curve and 98.7% after the learning curve. The stem-safe zone success rates were 97.2% during the learning curve and 96.1% after the learning curve. Surgical time was approximately 20 minutes shorter after the first 50 cases than during the learning curve (70.8 versus 90.6 minutes, P = 0.001). Intraoperative blood loss was significantly less after the learning curve than during the learning curve. CONCLUSION: This study implicates that the learning curve affects perioperative results such as surgical time and intraoperative blood loss, but has little effect on short-term results up to two years after surgery and no effect on mid-term results from two to five years after surgery.

Prophylactic Anticoagulation and Thrombosis in Hospitalized Patients with Clinically Stable COVID-19 at Admission: From the Practice-Based Observational Study.

Objectives: The potential benefit of routine prophylactic anticoagulation for all hospitalized patients with clinically stable coronavirus disease 2019 (COVID-19) is still controversial. Method: The CLOT-COVID Study was a multicenter observational study enrolling 2894 consecutive hospitalized patients with COVID-19. The current study population consisted of 1738 hospitalized patients with mild COVID-19 at admission not requiring oxygen administration, who were divided into 2 groups: patients with prophylactic anticoagulation (n = 326) and those without (n = 1412). Results: Patients with prophylactic anticoagulation had more severe status of the worst severity of COVID-19 during hospitalization compared with those without (mild: 38% versus 82%, moderate: 55% versus 17%, and severe or death at discharge: 6.4% versus 0.7%, P <0.001). During hospitalization, 8 patients (0.5%) developed thrombosis, and the incidences of thrombosis were numerically higher in patients with more severe status of worst severity of COVID-19 during hospitalization (mild: 0.2%, moderate: 1.2%, and severe or death at discharge: 3.2%). Conclusions: Among hospitalized patients with clinically stable COVID-19 at admission, patients who did not worsen in COVID-19 severity after admission rarely developed thrombosis, although patients with worsening of COVID-19 severity after admission more often received prophylactic anticoagulation and might have a higher risk of thrombosis.

Deep learning to assess right ventricular ejection fraction from two-dimensional echocardiograms in precapillary pulmonary hypertension.

BACKGROUND: Precapillary pulmonary hypertension (PH) is characterized by a sustained increase in right ventricular (RV) afterload, impairing systolic function. Two-dimensional (2D) echocardiography is the most performed cardiac imaging tool to assess RV systolic function; however, an accurate evaluation requires expertise. We aimed to develop a fully automated deep learning (DL)-based tool to estimate the RV ejection fraction (RVEF) from 2D echocardiographic videos of apical four-chamber views in patients with precapillary PH. METHODS: We identified 85 patients with suspected precapillary PH who underwent cardiac magnetic resonance imaging (MRI) and echocardiography. The data was divided into training (80%) and testing (20%) datasets, and a regression model was constructed using 3D-ResNet50. Accuracy was assessed using five-fold cross validation. RESULTS: The DL model predicted the cardiac MRI-derived RVEF with a mean absolute error of 7.67%. The DL model identified severe RV systolic dysfunction (defined as cardiac MRI-derived RVEF < 37%) with an area under the curve (AUC) of .84, which was comparable to the AUC of RV fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE) measured by experienced sonographers (.87 and .72, respectively). To detect mild RV systolic dysfunction (defined as RVEF ≤ 45%), the AUC from the DL-predicted RVEF also demonstrated a high discriminatory power of .87, comparable to that of FAC (.90), and significantly higher than that of TAPSE (.67). CONCLUSION: The fully automated DL-based tool using 2D echocardiography could accurately estimate RVEF and exhibited a diagnostic performance for RV systolic dysfunction comparable to that of human readers.

Bone union-promoting effect of romosozumab in an ovariectomized rat posterolateral lumbar fusion model.

Spinal fixation surgery has been increasingly performed in patients with osteoporosis. Romosozumab, a drug that was introduced in Japan recently, is known to possibly promote bone healing. However, few studies have reported the therapeutic effects of romosozumab in clinical practice in Japan. Therefore, here, we investigated the effects of romosozumab dosage on bone fusion promotion using an ovariectomized rat spinal fusion model. Eight-week-old female Sprague-Dawley rats were matched by body weight and divided into three groups: 1.0 romosozumab (R) group (Evenity®, 25 mg/kg), 1/10R group (Evenity®, 2.5 mg/kg), and control (C) group (saline). Subcutaneous injections were administered twice a week for 8 weeks postoperatively. Computed tomography scans were performed every 2 weeks from the time of surgery till 8 weeks postoperatively. The mean fusion rates in terms of volume were significantly higher in the R groups [1/10R, 1.0R] than in the C group from 4 weeks postoperatively. The rate of increase was significantly higher in the 1.0R group from 4 weeks postoperatively and in the 1/10R group from 6 weeks postoperatively, than in the C group. The proportion of trabecular bone area was approximately 1.5 times higher in the R groups than in the C group. No significant differences were observed between the R groups. Our results suggest that romosozumab stimulates bone growth at the graft site, and similar effects were achieved at 1/10 of the standard dosage.

Time elapsed from definitive diagnosis to surgery for osteonecrosis of the femoral head: a nationwide observational study in Japan.

OBJECTIVES: This study documents the time elapsed from the diagnosis of osteonecrosis of the femoral head (ONFH) to surgery, exploring the factors that influence ONFH severity. DESIGN: Retrospective observational study of a nationwide database. SETTING: The Kaplan-Meier method with log-rank tests was applied to examine the period from definitive diagnosis of ONFH to surgery using any surgery as the end point. For bilateral cases, the date of the first surgery was the endpoint. PARTICIPANTS: This study included 2074 ONFH cases registered in 34 university hospitals and highly specialised hospitals of the multicentre sentinel monitoring system of the Japanese Investigation Committee between 1997 and 2018. MAIN OUTCOME MEASURE: The primary outcome was the time from diagnosis to surgery. The secondary outcome was the proportion of subjects remaining without surgery at 3, 6 and 9 months, and at 1, 2 and 5 years after diagnosis. RESULTS: The median time to surgery was 9 months (IQR 4-22 months) after diagnosis of ONFH. The time to surgery was significantly shorter in the alcohol alone group and the combined corticosteroid and alcohol group than in the corticosteroid alone group (p=0.018 and p<0.001, respectively), in early stage ONFH with no or mild joint destruction (stages II and III, p<0.001), and with joint preserving surgery (p<0.001). The proportion without surgery was 75.8% at 3 months, 59.6% at 6 months, 48.2% at 9 months, 40.5% at 1 year, 22.2% at 2 years and 8.3% at 5 years. CONCLUSION: ONFH has been considered to be an intractable disease that often requires surgical treatment, but the fact that surgery was performed in more than half of the patients within 9 months from diagnosis suggests severe disease with a significant clinical impact. TRIAL REGISTRATION NUMBER: Chiba University ID1049.

Echocardiographic estimation of right ventricular diastolic stiffness based on pulmonary regurgitant velocity waveform analysis in precapillary pulmonary hypertension.

Right ventricular (RV) diastolic stiffness is an independent predictor of survival and is strongly associated with disease severity in patients with precapillary pulmonary hypertension (PH). Therefore, a fully validated echocardiographic method for assessing RV diastolic stiffness needs to be established. This study aimed to compare echocardiography-derived RV diastolic stiffness and invasively measured pressure-volume loop-derived RV diastolic stiffness in patients with precapillary PH. We studied 50 consecutive patients with suspected or confirmed precapillary PH who underwent cardiac catheterization, magnetic resonance imaging, and echocardiography within a 1-week interval. Single-beat RV pressure-volume analysis was performed to determine the gold standard for RV diastolic stiffness. Elevated RV end-diastolic pressure (RVEDP) was defined as RVEDP ≥ 8 mmHg. Using continuous-wave Doppler and M-mode echocardiography, an echocardiographic index of RV diastolic stiffness was calculated as the ratio of the atrial-systolic descent of the pulmonary artery-RV pressure gradient derived from pulmonary regurgitant velocity (PRPGDAC) to the tricuspid annular plane movement during atrial contraction (TAPMAC). PRPGDAC/TAPMAC showed significant correlation with ß (r = 0.54, p < 0.001) and RVEDP (r = 0.61, p < 0.001). A cut-off value of 0.74 mmHg/mm for PRPGDAC/TAPMAC showed 83% sensitivity and 93% specificity for identifying elevated RVEDP. Multivariate analyses indicated that PRPGDAC/TAPMAC was independently associated with disease severity in patients with precapillary PH, including substantial PH symptoms, stroke volume index, right atrial size, and pressure. PRPGDAC/TAPMAC, based on pulmonary regurgitation velocity waveform analysis, is useful for the noninvasive assessment of RV diastolic stiffness and is associated with prognostic risk factors in precapillary PH.

Short-Term Clinical and Radiographic Evaluation of Patients Treated With Expandable and Static Interbody Spacers Following Lumbar Lateral Interbody Fusion.

OBJECTIVE: The goal of this study was to evaluate, using computed tomography (CT) and magnetic resonance imaging (MRI), patients who underwent oblique lateral interbody fusion (OLIF) using either expandable or static interbody spacers. METHODS: Thirty-five patients with degenerative disc disease were surgically treated with one-level OLIF and were followed up for more than 6 months. The Static group consisted of 22 patients, and 13 patients were in the Expandable group. Intraoperative findings included operative time (min), blood loss (ml), and cage size. Low back pain, leg pain, and leg numbness were measured using the Japanese Orthopedic Association score, visual analogue score, and the Roland-Morris Disability Questionnaire. Radiologic evaluation using computed tomography (CT) and magnetic resonance imaging (MRI) allowed measurement of cage subsidence, cross-sectional area (CSA) of the dural sac, disc height, segmental lordosis, foraminal height, and foraminal CSA preoperatively and 6 months postoperatively. RESULTS: The Expandable group had significantly larger cage height and lordosis than the Static group (P < 0.05). The Expandable group also had greater dural sac area expansion and enlargement of the intervertebral foramen, as well as better correction of vertebral body slip (P < 0.05). Cage subsidence was significantly lower in the Expandable group (P < 0.05). JOA and VAS scores for leg numbness were significantly better in the Expandable group (P < 0.05). CONCLUSIONS: Compared with static spacers, expandable spacers significantly enlarged the dural sac area, corrected vertebral body slippage, expanded the intervertebral foramen, and achieved good indirect decompression while reducing cage subsidence, resulting in improvement in clinical symptoms.

Evaluation of exclusive internal endoscopic drainage for complex biloma with transluminal and transpapillary stenting.

Background and study aims Biloma is treated endoscopically with endoscopic retrograde cholangiography (ERCP) or endoscopi ultrasound-guided transluminal biloma drainage (EUS-TBD). However, almost all previous studies have used both internal and external drainage. External drainage has the disadvantages of poor cosmetic appearance and self-tube removal. The aim of the present study was to evaluate the internal endoscopic drainage for complex biloma after hepatobiliary surgery with an ERCP- or EUS-guided approach, without external drainage. Patients and methods This retrospective study included consecutive patients who had bilomas. A 7F plastic stent was deployed from the biloma to the duodenum in the ERCP group and the metal stent was deployed from the biloma to the stomach in the EUS-TBD group. Results Forty-seven patients were enrolled. The technical success rate was similar between the groups (ERCP 94% vs EUS-TBD 100%, P =0.371); however, mean procedure time was significantly shorter in the EUS-TBD group (16.9 minutes) than in the ERCP group (26.6 minutes) ( P =0.009). The clinical success rate was 87% (25 of 32 patients) in the ERCP group and 84% (11 of 13 patients) in the EUS-TBD group ( P =0.482). The duration of median hospital stay was significantly shorter in the EUS-TBD group (22 days) than in the ERCP group (46 days) ( P =0.038). There was no significant difference in procedure-associated adverse events between the groups. Conclusions In conclusion, ERCP and EUS-TBD are complementary techniques, each with its own merits in specific clinical scenarios. If both techniques can be performed, EUS-TBD should be considered because of the short times for the procedure, hospital stay. and biloma resolution.

Transluminal antegrade drill dilation technique for hepaticojejunostomy stricture with cholangioscopic evaluation (with video).

Background and study aims Balloon dilation and plastic stent deployment have been performed as hepaticojejunostomy stricture (HJS) treatment techniques under endoscopic ultrasound guidance (EUS). Although these techniques have shown favorable clinical results, the treatment period can be long because stent deployment is required. In addition, HJS may recur even after treatment because the scar tissue itself remains. To overcome these challenges, we developed an EUS-guided antegrade drill dilation technique for treating HJS. The aim of this study was to evaluate the technical feasibility and safety of this technique in terms of the pre- and post-cholangioscopic findings. Patients and methods This retrospective study included consecutive patients whose conditions were complicated with symptomatic HJS between November 2022 and February 2023. Transluminal antegrade drill dilation (TAD) using a novel drill dilator was attempted within 14 days after EUS-guided hepaticogastrostomy (HGS). HJS was diagnosed with cholangioscopy before TAD, and resolution was evaluated after TAD using cholangioscopy. Results TAD was attempted at approximately 11 days after EUS-HGS. The cholangioscope was inserted successfully in all patients after this procedure. Cholangioscopy revealed stricture without evidence of malignancy in 19 patients. In the remaining three patients, stricture was not observed and these patients underwent stent exchange rather than TAD. Among the 19 patients, passage of the guidewire across the HJS into the intestine was unsuccessful in four patients, and the technical success rate for this procedure was 78.9%. TAD was successful in all 15 patients in whom passage of the guidewire was achieved. Conclusions In conclusion, TAD appears to be technically feasible and safe.

Association between Osteoporosis and Skeletal Muscle Mass in Men.

STUDY DESIGN: Cross-sectional study. PURPOSE: This cross-sectional study aimed to investigate the risk factors for osteoporosis in men by assessing bone mineral density (BMD), skeletal muscle mass, body fat mass, grip strength, and advanced glycation end products (AGEs). OVERVIEW OF LITERATURE: Fewer studies have reported the correlation between BMD and skeletal muscle mass in women. Moreover, a few studies have examined the relationship between osteoporosis and skeletal muscle mass. METHODS: This study included 99 men (mean age, 74.9 years; range, 28-93 years) who visited Qiball Clinic for BMD and body composition examinations. The osteoporosis group consisted of 24 patients (mean age, 72.5 years; range, 44-92 years), and the control group consisted of 75 individuals (mean age, 74.9 years; range, 28-93 years). Whole-body skeletal muscle mass was measured using a bioelectrical impedance analyzer. BMD was measured by dual X-ray absorptiometry. Skin autofluorescence (SAF), a marker of dermal AGE accumulation, was measured using a spectroscope. Osteoporosis was defined as a bone density T score of -2.5 or less. Physical findings, skeletal muscle mass, BMD, grip strength, and SAF were compared between the osteoporosis and control groups. RESULTS: The osteoporosis group had significantly lower trunk muscle mass (23.1 kg vs. 24.9 kg), lower leg muscle mass (14.4 kg vs. 13.0 kg), and skeletal mass index (7.1 kg/m2 vs. 6.7 kg/m2) than the control group (all p<0.05). Lower limb muscle mass was identified as a risk factor for osteoporosis in men (odds ratio, 0.64; p=0.03). CONCLUSIONS: Conservative treatment of osteoporosis in men will require an effective approach that facilitates the maintenance or strengthening of skeletal muscle mass, including exercise therapy with a focus on lower extremities and nutritional supplementation.

Quantitative evaluation of the lumbar ligamentum flavum using MRI T2-mapping: Efficacy of its clinical application in patients with lumbar spinal stenosis.

OBEJECTIVE: To perform a magnetic resonance imaging T2-mapping of the ligamentum flavum in healthy individuals and patients with lumbar spinal stenosis scheduled for surgery and compare the T2 relaxation times. SUBJECTS AND METHODS: The T2 relaxation time of the ligamentum flavum was compared among 3 groups, healthy young individuals (H group (age< 50)), healthy middle-aged and older individuals (H group (age≥50)), and patients with lumbar spinal stenosis (L group). Additionally, the thickness of the ligament was measured in the axial image plane, and the occupied area ratio of each fiber was measured by staining the surgically obtained ligament, and each was correlated with the T2 relaxation time. We also evaluated the adhesion of the ligamentum flavum with the dura mater during the surgery. RESULTS: The T2 relaxation times were significantly prolonged in H group (age ≥50) and L group (P < 0.001) compared to H group (age<50). The relationship between collagen fiber and T2 relaxation times was significantly positive (r = 0.720, P < 0.001). Moreover, the relaxation times were significantly prolonged in those with adhesion of the ligamentum flavum with the dura mater (P < 0.05). The cut-off for the relaxation time was 50 ms (sensitivity: 62.50%, false positive rate: 10.8%). CONCLUSION: Healthy middle-aged and older individuals and patients with lumbar spinal stenosis and adhesion of the ligamentum flavum with the dura mater have prolonged T2 relaxation times. Hence, the adhesion between the ligamentum flavum and dura mater should be considered in cases with a relaxation time ≥50 ms.

Analysis of Light Intensity and Charge Holding Time Dependence of Pinned Photodiode Full Well Capacity.

In this paper, the light intensity and charge holding time dependence of pinned photodiode (PD) full well capacity (FWC) are studied for our pixel structure with a buried overflow path under the transfer gate. The formulae for PDFWC derived from a simple analytical model show that the relation between light intensity and PDFWC is logarithmic because PDFWC is determined by the balance between the photo-generated current and overflow current under the bright condition. Furthermore, with using pulsed light before a charge holding operation in PD, the accumulated charges in PD decrease with the holding time due to the overflow current, and finally, it reaches equilibrium PDFWC. The analytical model has been successfully validated by the technology computer-aided design (TCAD) device simulation and actual device measurement.

Leg position effects on the femoral neurovascular bundle location during a direct anterior approach total hip arthroplasty: a radiographic study.

BACKGROUND: Femoral neurovascular injury is a serious complication in a direct anterior approach (DAA) total hip arthroplasty. However, dynamic neurovascular bundle location changes during the approach were not examined. Thus, this study aimed to analyze the effects of leg position on the femoral neurovascular bundle location using magnetic resonance imaging (MRI). METHODS: This study scanned 30 healthy volunteers (15 males and 15 females) with 3.0T MRI in a supine and 30-degree hip extension position with the left leg in a neutral rotation position and the right leg in a 45-degree external extension position. The minimum distance from the edge of the anterior acetabulum to the femoral nerve (dFN), artery, and vein were measured on axial T1-weighted images at the hip center level, as well as the angle to the horizontal line of the femoral nerve (aFN), artery (aFA), and vein from the anterior acetabulum. RESULTS: The dFN in the supine position with external rotation was significantly larger than supine with neutral and extension with external rotation position (20.7, 19.5, and 19.0; p = 0.031 and 0.012, respectively). The aFA in supine with external rotation was significantly larger than in other postures (52.4°, 34.2°, and 36.2°, p < 0.001, respectively). The aFV in supine with external rotation was significantly larger than in supine with a neutral position (52.3° versus 47.7°, p = 0.037). The aFN in supine and external rotation was significantly larger than other postures (54.6, 38.2, and 33.0, p < 0.001, respectively). CONCLUSIONS: This radiographic study revealed that the leg position affected the neurovascular bundle location. These movements can be the risk of direct neurovascular injury or traction.

Moving scope technique improves technical success rate of device insertion during EUS-guided hepaticogastrostomy (with video).

Background: Technical tips for device insertion during endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) have not been reported. To improve the technical success rate of device insertion without unnecessary tract dilation, the pushing force should be transmitted directly from the channel of the echoendoscope to the intrahepatic bile duct. Objectives: We developed a novel technique, termed the 'moving scope technique', the feasibility of which during EUS-HGS is described. Design: Retrospective study. Methods: The primary outcome of this study was the technical success rate of dilation device insertion without electrocautery dilation after the moving scope technique. The initial technical success rate of dilation device insertion was defined as successful insertion into the biliary tract. If dilation device insertion failed, the moving scope technique was attempted. Results: A total of 143 patients were enrolled in this study. The initial technical success rate for device insertion was 80.4% (115/143). The moving scope technique was therefore attempted in 28 patients. The mean angle between the intrahepatic bile duct and the guidewire was improved to 141.0° and resulted in a technical success rate of 100% (28/28). The area under the ROC curve (AUC) was 0.88, and 120° predicted successful dilation device insertion with sensitivity of 88.0% and specificity of 78.8%. Bile peritonitis (n = 8) and cholangitis (n = 2) were observed as adverse events, but were not severe. Conclusion: In conclusion, the moving scope technique may be helpful during EUS-HGS to achieve successful insertion of the dilation device into the biliary tract. These results should be evaluated in a prospective randomized controlled trial.

Liver impaction technique improves technical success rate of guidewire insertion during EUS-guided hepaticogastrostomy (with video).

Background: If the guidewire becomes kinked by the needle, guidewire manipulation may be difficult, and can cause complications such as guidewire shearing or injury during endoscopic ultrasound (EUS)-guided hepaticogastrostomy (HGS). To overcome this matter, we have previously described a technical tip for preventing guidewire injury, termed 'liver impaction technique'. However, its technical feasibility has been not reported in the setting of a large patient cohort. Objectives: The aim of study was to evaluate the clinical usefulness of the liver impaction technique during EUS-HGS. Design: Retrospective, single-center study. Methods: This retrospective study included consecutive patients who underwent EUS-HGS between April 2018 and September 2022. The primary outcome of this study was the technical success rate of guidewire insertion using the liver impaction technique. Results: A total of 166 patients were enrolled in this study. Initial successful guidewire insertion without using liver impaction technique was obtained in 108 patients (65.1%). Among 58 patients in whom guidewire insertion failed initially, guidewire advancement into the periphery of the bile duct was observed in 32 patients (55.2%) and into a non-interest bile duct branch was observed in 26 patients (44.8%). Liver impaction technique contributed to increasing the technical success rate of guidewire insertion from 65.1% to 95.8%. Overall, adverse events were observed in 12 patients (7.2%; bile peritonitis n = 9, cholangitis n = 3), and these adverse events were Grade I. Among patients who underwent liver impaction technique (n = 58), adverse events were observed in two patients (3.4%; bile peritonitis). Also, guidewire sharing was not observed in any patients during liver impaction technique. Conclusions: In conclusion, the liver impaction technique may be helpful during EUS-HGS to obtain successful guidewire insertion into the biliary tract of interest.

Impact of cancer on the prevalence, management, and outcome of patients with chronic thromboembolic pulmonary hypertension.

INTRODUCTION: Chronic thromboembolic pulmonary hypertension (CTEPH) results from unresolved thrombotic obstruction of the pulmonary vasculature. Cancer is a known risk factor for CTEPH. This study aimed to determine the impact of cancer on the prevalence, management, and outcomes of patients with CTEPH. MATERIALS AND METHODS: In this retrospective study involving 99 patients sequentially diagnosed with CTEPH in our hospital, the prevalence of 10 comorbid conditions including a past history of cancer at the time of CTEPH diagnosis were calculated. RESULTS: Among the 99 patients, 17 (17%) had a history of cancer. Breast cancer (n = 6) was the most common cancer type, followed by gastrointestinal cancer (n = 3), uterine cancer (n = 2), and malignant lymphoma (n = 2). Between patients with and without cancer, there were no differences in the demographics, severity of CTEPH, and management; however, the 5-year survival rate was lower for patients with cancer (65%) than for those without (89%). In addition, patients with cancer had significantly worse survival than those without (p = 0.03 by log-rank test). During follow-up, nine patients developed cancer after the diagnosis of CTEPH. Among the 99 patients, 13 died during follow-up, 6 (46%) of whom died of cancer. CONCLUSIONS: 17% of our patients with CETPH were diagnosed with cancer, with breast and gastrointestinal tract cancers being the most common. Cancer comorbidity was associated with a poor prognosis and contributed to death in 46% of deceased patients. The impact of cancer on CTEPH should be further evaluated in the future.

Correlation between Femoral Head Lateralization and Bone Morphology in Primary Hip Osteoarthritis.

Background: Osteoarthritis (OA) is the most common disease of the hip in adults, and its etiology is divided into two groups: primary and secondary. Although acetabular dysplasia is the most frequent reason for total hip arthroplasty (THA) in Japan, primary OA has increased recently. Although there are two types of femoral head migration in primary OA: superior and medial, there are some patients with prominent femoral head lateralization. This study aimed at evaluating the relationship between femoral head lateralization and bone morphology of the acetabulum and proximal femur using radiographic factors in primary OA of the hip. Methods: A retrospective study was conducted between 2008 and 2017 to assess 1308 hips with OA who underwent primary THAs at our institute. The diagnostic criteria for primary OA were Crowe type 1, Sharp's angle <45°, and center-edge (CE) angle >25°. We classified patients with primary OA into two groups based on femoral head lateralization: group L with lateralization or group N without. Radiographic factors included Sharp's angle, CE angle, acetabular inclination, acetabular depth ratio (ADR), acetabular head index (AHI), and femoral neck-shaft angle (FNA), all examined on an anteroposterior pelvic radiograph. Femoral neck anteversion was calculated using computerized axial tomography. Results: Primary OA was diagnosed in 210/1308 hips (16.1%) (group L: 112 hips (8.6%); group N: 98 (7.5%)). Patient demographics were not significantly different. Radiographic factors with observed significant differences between group L and group N were the average CE angle (33.0° vs. 35.1°, respectively, p = 0.009), ADR (251.6 vs. 273.4, p < 0.001), AHI (77.2 vs. 80.4, p < 0.001), and FNA (136.9° vs. 134.8°, p = 0.012). Conclusions: This investigation suggests that primary OA with femoral head lateralization demonstrated specific identifiable radiographic characteristics in the acetabulum and proximal femur that might contribute to hip joint instability such as the dysplastic hip.