[Verification of Response Uncertainty in Electrometers through Cross-Comparison with a Novel Current Source: A Comparative Study with Guidelines for Electrometers Used in Radiation Therapy Dosimeters].

BACKGROUND: A new quality assurance and control method for electrometers using a new current source, different from the method published in the guidelines for electrometers, has been reported. This current source uses dry batteries and exhibits excellent performance in terms of voltage, temperature, and time characteristics. The electrometer sensitivity coefficient can be calculated by comparing the sensitivity of one electrometer with that of another on the electrometer calibration coefficient that has been calibrated by a calibration laboratory in advance in both methods. The guideline method requires two or more sets of ionization chambers and electrometers in the facility. In contrast, our method does not use ionization chambers; therefore, the sensitivity ratio of the electrometer can be measured in any facility. This study compared the uncertainty of the electrometer sensitivity factor calculated using the new current source method (current method) with that calculated using a linear accelerator (LINAC) and ionization chambers (LINAC method) described in the electrometer guidelines. METHOD: In this study, we used a current source that we invented previously by Kawaguchi Electric Works in Japan. The sensitivity ratios of the electrometers were measured with three manufacture's electrometers. The electrometer sensitivity factor was calculated by multiplying the electrometer calibration coefficient. The ionization chamber was 30013 (PTW), and the current source was the current obtained from 10 MV TrueBeam X-rays under calibration conditions. The mean value, standard deviation, and coefficient of variation were calculated. The time required to set up the ionization chamber for calculating the sensitivity ratio of the electrometer was also measured. The accuracy was confirmed by calculating the expanded uncertainty of the electrometer sensitivity coefficients. RESULTS: The LINAC method had a maximum coefficient of variation of 0.072%. The gross time of the LINAC method was approximately 110 min. The current method had a maximum coefficient of variation of 0.0055% and took less than half the time taken by the LINAC method (35 min) because there was no waiting time for the ionization chamber to be set up and the applied voltage to stabilize under calibration conditions. The expanded uncertainties of the electrometer calibration coefficients were 0.36% and 0.36%, respectively. CONCLUSION: The new cross-comparison method for electrometer sensitivity factors using a current source is more efficient and useful than the linear accelerator method described in the guidelines; furthermore, this method ensured accuracy for quality assurance and control of electrometers.

Xanthogranulomatous appendicitis presenting asymptomatically 3 years after surgery for hilar cholangiocarcinoma: A case report.

INTRODUCTION: Xanthogranulomatous appendicitis (XGA) is a rare condition involving chronic inflammation of the appendix that is often difficult to distinguish from malignancy using imaging because of the formation of a heterogeneous mass with indistinct borders. Herein, we present a case of XGA with unusual clinical manifestations. PRESENTATION OF CASE: A 78-year-old female patient underwent radical resection of hilar cholangiocarcinoma with extended right hepatic lobectomy and biliary reconstruction. Three years postoperatively, she presented with an irregular mass in the right lateral pelvis, which was observed on computed tomography. The patient had not experienced recent clinical symptoms and did not present with abdominal tenderness. Routine blood tests did not indicate an increased inflammatory response; however, carcinoembryonic antigen levels continued to increase. Although disseminated recurrence of hilar cholangiocarcinoma and appendiceal carcinoma were suspected, XGA was diagnosed via laparoscopic appendectomy. DISCUSSION: XGA generally presents with symptoms of acute or chronic appendicitis, and is diagnosed incidentally during surgery. Hilar cholangiocarcinoma has a high recurrence rate, even after radical resection, and disseminated recurrence usually requires chemotherapy. In the present case, XGA was not suspected preoperatively because of the lack of physical symptoms and increased levels of tumor markers during follow-up for hilar cholangiocarcinoma. There have been no reports of XGA with such a confusing clinical course, thus confirming the difficulty in preoperatively diagnosing XGA. CONCLUSION: The preoperative diagnosis of XGA is difficult to differentiate from malignancy because of its clinical and imaging findings. We diagnosed the patient with XGA using laparoscopic surgery.

Assessing the utility of osteoporosis self-assessment tool for Asians in patients undergoing hip surgery.

Objectives: Diagnosis and treatment of osteoporosis are instrumental in obtaining good outcomes of hip surgery. Measuring bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA) is the gold standard for diagnosing osteoporosis. However, due to limited access to DXA, there is a need for a screening tool to identify patients at a higher risk of osteoporosis. We analyzed the potential utility of the Osteoporosis Self-assessment Tool for Asians (OSTA) as a screening tool for osteoporosis. Methods: A total of 1378 female patients who underwent hip surgery at 8 institutions were analyzed. For each patient, the BMD of the proximal femoral region was measured by DXA (DXA-BMD), and the correlation with OSTA score (as a continuous variable) was assessed. Receiver operating characteristic (ROC) curve analysis was performed to assess the ability of OSTA score to predict osteoporosis. Lastly, the OSTA score was truncated to yield an integer (OSTA index) to clarify the percentage of patients with osteoporosis for each index. Results: DXA-BMD showed a strong correlation with OSTA (r = 0.683; P < 0.001). On ROC curve analysis, the optimal OSTA score cut-off value of -5.4 was associated with 73.8% sensitivity and 80.9% specificity for diagnosis of osteoporosis (area under the curve: 0.842). A decrease in the OSTA index by 1 unit was associated with a 7.3% increase in the probability of osteoporosis. Conclusions: OSTA is a potentially useful tool for screening osteoporosis in patients undergoing hip surgery. Our findings may help identify high-risk patients who require further investigation using DXA.

Minimally Invasive Conversion Surgery for Unresectable Gastric Cancer with Splenic Metastasis and Splenic Vein Tumor Thrombus: A Case Report.

While the importance of conversion surgery has increased with the development of systemic chemotherapy for gastric cancer (GC), reports of conversion surgery for patients with GC with distant metastasis and tumor thrombus are extremely scarce, and a definitive surgical strategy has yet to be established. Herein, we report a 67-year-old man with left abdominal pain referred to our hospital following a diagnosis of unresectable GC. Esophagogastroduodenoscopy and contrast-enhanced abdominal computed tomography (CT) revealed advanced GC with splenic metastasis. A splenic vein tumor thrombus (SVTT) and a continuous thrombus to the main trunk of the portal vein were detected. The patient was treated with anticoagulation therapy and systemic chemotherapy comprising S-1 and oxaliplatin. One year following chemotherapy initiation, a CT scan revealed progressive disease (PD); therefore, the chemotherapy regimen was switched to ramucirumab with paclitaxel. After 10 courses of chemotherapy resulting in primary tumor and SVTT shrinkage, the patient underwent laparoscopic total gastrectomy (LTG) and distal pancreaticosplenectomy (DPS). He was discharged without complications and remained alive 6 months postoperatively without recurrence. In summary, the wait-and-see approach was effective in a patient with GC with splenic metastasis and SVTT, ultimately leading to an R0 resection performed via LTG and DPS.

Prognostic Significance of CONUT Score in Elderly NSCLC.

PURPOSE: This study evaluated the Controlling Nutritional Status (CONUT) score as a prognostic predictor in elderly non-small cell lung cancer (NSCLC) patients with surgical resection. METHODS: Overall, 114 patients over 80 years old undergoing curative resection for NSCLC were retrospectively analyzed. Receiver operating characteristic (ROC) analysis was conducted to evaluate the capacity of immune-inflammatory markers to predict overall survival (OS). Cox-proportional hazards regression analysis was implemented to investigate prognostic markers for OS. RESULTS: Based on ROC curves, the CONUT score was found to be the most valuable prognostic marker (area under the curve = 0.716). The high CONUT (≥2) group included 54 patients, and the low CONUT (0 or 1) group included 60 patients. The high CONUT group had poorer prognosis rates compared to the low CONUT group with regard to OS (5-year OS: 46.3% vs. 86.0%, p = 0.0006). In the multivariate data analysis, histology, lymphatic invasion, and CONUT score (hazard ratio: 4.23, p = 0.0003) were found to be exclusive and independent prognostic markers for OS. CONCLUSION: Preoperatively, the CONUT score can be used as a novel prognostic marker in elderly NSCLC patients. CONUT evaluations can also be used to design nutritional interventions to improve patient outcomes.

Current Concepts of Cervical Spine Alignment, Sagittal Deformity, and Cervical Spine Surgery.

There are not many reports on cervical spine alignment, and only a few analyze ideal surgical approaches and optimal amounts of correction needed for the various types of deformity. We comprehensively reviewed the present literature on cervical spinal deformities (with or without myelopathy) and their surgical management to provide a framework for surgical planning. A general assessment of the parameters actually in use and correlations between cervical and thoracolumbar spine alignment are provided. We also analyzed posterior, anterior, and combined cervical surgical approaches and indications for the associated techniques of laminoplasty, laminectomy and fusion, and anterior cervical discectomy and fusion. Finally, on the basis of the NDI, SF-36, VAS, and mJOA questionnaires, we fully evaluated the outcomes and measures of postoperative health-related quality of life. We found the need for additional prospective studies to further enhance our understanding of the importance of cervical alignment when assessing and treating cervical deformities with or without myelopathy. Future studies need to focus on correlations between cervical alignment parameters, disability scores, and myelopathy outcomes. Through this comprehensive literature review, we offer guidance on practical and important points of surgical technique, cervical alignment, and goals surgeons can meet to improve symptoms in all patients.

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.

Fracture risk assessment of vascularized medial femoral condylar bone graft: A finite element analysis.

BACKGROUND: Vascularized medial femoral condyle (MFC) bone graft is useful for pseudarthrosis and osteonecrosis, but has the risk of fracture as a complication. This study aimed to create multiple three-dimensional (3D) finite element (FE) femur models to biomechanically evaluate the fracture risk in the donor site of a vascularized MFC bone graft. METHODS: Computer tomography scans of the femurs of nine patients (four males and five females) with no left femur disease were enrolled in the study. A 3D FE model of the left femur was generated based on the CT images taken from the patients. The descending genicular artery (DGA), the main nutrient vessel in vascularized MFC bone grafts, divides into the proximal transversal branch (TB) and the distal longitudinal branch (LB) before entering the periosteum. Thirty-six different bone defect models with different sizes and locations of the harvested bone were created. RESULTS: The highest stress was observed in the proximal medial and metaphyseal portions under axial and external rotation, respectively. In the bone defect model, the stress was most elevated in the extracted region's anterior or posterior superior part. Stress increased depending on proximal location and harvested bone size. CONCLUSION: Increasing the size of the bone graft proximally raises the stress at the site of bone extraction. For bone grafting to non-load-bearing areas, bone grafting distally using LB can reduce fracture risk. If TB necessitates a larger proximal bone extraction, it is advisable to avoid postoperative rotational loads.

Novel subtype of coxitis knee associated with acetabular dysplasia of the hip: a case series.

BACKGROUND: Multiple joint arthritis patterns require a comprehensive understanding to optimize patient management. This study aimed to present a patient cohort that deviated from known definitions of coxitis knee (CK), identifying and characterizing this atypical group. METHODS: Patients undergoing both total hip arthroplasty and total knee arthroplasty between January 2008 and December 2018 were retrospectively reviewed. The patients were classified into a typical coxitis knee group (classic, long leg arthropathy, and windswept deformity) and an atypical coxitis knee group. Leg-length discrepancy, body mass index (BMI), and radiographic parameters of the groups were compared and analyzed. RESULTS: A total of 31 patients were allocated to the typical coxitis knee group (n = 10), and atypical coxitis knee group (n = 21). In the atypical group, 27 hips were involved, of which 21 had acetabular dysplasia, 5 exhibited subchondral insufficiency fracture-like changes, and only 1 had classic osteoarthritis. Among the 27 knees undergoing total knee arthroplasty, 26 showed varus alignment, 1 was within the normal range, and none was valgus. Acetabular dysplasia involved ipsilateral (n = 1), contralateral (n = 14), and bilateral (n = 6) hips, showing atypical coxitis knee. Patients with acetabular dysplasia were more likely to exhibit atypical CK. CONCLUSION: Most patients in the cohort displayed acetabular dysplasia and contralateral varus knees, constituting a pattern referred to as acetabular dysplasia-associated gonarthritis. Identifying this novel subtype may have important clinical implications for regions with high risk factors, where acetabular dysplasia and constitutional genu varum are prevalent.

Autologous Chondrocyte Implantation With Collagen Membrane Using a Knotless Suture Bridge Technique.

Autologous chondrocyte implantation (ACI) has been covered by insurance in Japan since April 2013, expanding the range of treatments for extensive knee cartilage damage. Initially, the periosteum was used for the fixation of cultured cartilage, but since February 2019, the introduction of collagen membranes has shortened surgery time and simplified the procedure. We report a case where we used the knotless suture bridge technique for a more straightforward and secure fixation with a collagen membrane. The patient was a 61-year-old male who experienced right knee pain a year earlier when stepping downstairs. Conservative treatment at a local hospital was ineffective, and he was referred to our department. At the initial examination, the right knee had an extension of -5° and a flexion of 130°. A simple X-ray of the right knee showed osteosclerosis with a translucent bone image at the medial femoral condyle. Weight-bearing full-length X-ray of the lower limb showed a femorotibial angle (FTA) of 186°, a hip-knee-ankle (HKA) angle of 12.5° varus, a percentage of mechanical axis (%MA) of 15%, and a medial proximal tibial angle (MPTA) of 78°, indicating a significant varus deformity. CT and MRI revealed a cartilage defect of 36 mm in length and 16 mm in width and a bone defect with a maximum depth of 15 mm at the medial femoral condyle. The patient underwent surgery for a traumatic cartilage defect of the medial femoral condyle. For the bone defect, autologous bone grafting was performed, and for the cartilage defect, ACI was done. The ACI involved fixation with a collagen membrane using 1.3 mm suture tape and BC PushLock anchor (Arthrex, Naples, Florida, United States) in a knotless suture bridge technique. Additionally, hybrid closed-wedge high tibial osteotomy (HCWHTO) was performed for alignment correction. At eight months post surgery, MRI proton density sagittal images confirmed the joint surface by the cartilage layer, and the Modified Outerbridge Cartilage Repair Assessment (MOCART) score was 80. At 12 months post surgery, the Japanese version of the Knee Injury and Osteoarthritis Outcome Score (J-KOOS) improved from 46.43 to 82.14 for symptoms, 58.33 to 83.33 for pain, 95.59 to 100 for activities of daily living (ADL), 45 to 75 for sports, and 68.75 to 87.50 for quality of life (QOL). X-rays showed an FTA of 173°, an HKA of 0°, and a %MA of 58%, indicating a favorable course. The knotless suture bridge technique for collagen membrane fixation during ACI is considered a convenient and time-saving method.

Impact of partial pressure of arterial oxygen and radiologic findings on postoperative acute exacerbation of idiopathic interstitial pneumonia in patients with lung cancer.

PURPOSE: To establish accurate diagnostic criteria and predictors of treatment response for postoperative acute exacerbation (AE) in patients with lung cancer and idiopathic interstitial pneumonia (IIP). METHODS: Among 93 patients with IIP who underwent surgery for lung cancer, suspected postoperative AE developed in 20 (21.5%). Patients were divided into a progressive AE group, comprising patients with bilateral alveolar opacities and decreasing PaO2 ≥ 10 mmHg (n = 5); an incipient AE group, comprising patients with unilateral alveolar opacities and decreasing PaO2 ≥ 10 mmHg (n = 10); and an indeterminate AE group, comprising patients with alveolar opacities but decreasing PaO2 < 10 mmHg (n = 5). RESULTS: The progressive AE group had significantly higher 90-day mortality (80%) than the incipient AE group (10%, P = 0.017) or the indeterminate AE group (0%, P = 0.048). Bilateral opacities may indicate advanced AE and poor prognosis, whereas unilateral opacities may indicate an early stage of AE and a good prognosis. PaO2 < 10 mmHg may indicate conditions other than AE. CONCLUSIONS: In patients with lung cancer and IIP, decreasing PaO2 and HRCT findings may allow for the initiation of rapid and accurate treatment strategies for postoperative AE.

The significance of regular chest computed tomography in postoperative surveillance for surgically resected non-small cell lung cancer based on TNM 8th staging system.

OBJECTIVES: Although several societies recommend regular chest computed tomography (CT) scans for the surveillance of surgically resected non-small cell lung cancer (NSCLC), there is paucity of evidence to support these statements. This study aimed to clarify whether regular CT scans improved the prognosis of patients with surgically resected NSCLC based on TNM 8th classification. METHODS: Patients with pathologic Stage 0-III NSCLC who underwent complete surgical resection other than sublobar resection procedures were enrolled in the study. For these patients, clinicopathological data and postoperative surveillance data were collected by the retrospective review of medical records. Patients were categorized into the chest X-ray (CXR) group or the CT group according to whether they were followed-up with basic examinations including CXR or basic examinations plus regular chest CT. Postoperative overall survival was compared between the two groups. RESULTS: Six hundred sixty five patients were categorized into the CXR (n = 245) and CT (n = 420) groups. The clinicopathological backgrounds did not differ to a statistically significant extent. Recurrence was seen in 68 (27.3%) patients in the CXR group and 117 (27.8%) patients in the CT group. The 5-year overall survival rates of the two groups did not differ to a statistically significant extent (CXR, 76.5%; CT, 78.3%, P = 0.22). CONCLUSION: Regular chest CT scans may not improve the prognosis of surgically resected NSCLC. Further study is warranted to precisely evaluate the benefit of CT-based postoperative surveillance of NSCLC.

Acute exacerbation of immunoglobulin A nephropathy complicated by alveolar hemorrhage after coronavirus disease 2019 vaccination: A case report.

RATIONALE: Reports have suggested a relationship between coronavirus disease 2019 (COVID-19) vaccination and new-onset or recurring renal diseases, of which immunoglobulin A (IgA) nephropathy is a representative disease. Alveolar hemorrhage in patients with IgA nephropathy is rare but reportedly has a high mortality and morbidity. To our knowledge, there have been no reports regarding the development of IgA nephropathy with alveolar hemorrhage following COVID-19 vaccination. PATIENTS CONCERN: A 23-year-old Japanese man presented with hemoptysis and peripheral edema a few days after receiving a second dose of a COVID-19 mRNA vaccine. Severe renal failure and alveolar hemorrhage were noted thereafter, and renal biopsy showed crescentic glomerulonephritis with mesangial proliferation accompanied by mesangial electron-dense deposits containing IgA. Renal biopsy tissue also showed chronic histological changes suggestive of acute exacerbation of preexisting IgA nephropathy. DIAGNOSIS: The diagnosis of IgA nephropathy complicated by alveolar hemorrhage was made. INTERVENTIONS AND OUTCOMES: Renal function did not recover despite treatment with high-dose steroids; the patient was maintained on hemodialysis and eventually underwent successful renal transplantation. LESSONS: The present case suggested that although extremely rare, severe renal failure requiring renal replacement therapy could occur in patients with IgA nephropathy after COVID-19 vaccination. Future accumulation of similar cases is needed to predict the risk of renal injury following vaccination.

Negative correlation between central sensitization and forgotten joint score-12 after total hip arthroplasty.

BACKGROUND: Central sensitization is a condition in which even mild stimuli cause pain due to increased neuronal reactivity in the dorsal horn of the spinal cord. It is one of factors of chronic pain in patients with osteoarthritis. However, it is unknown whether central sensitization relates to clinical outcomes after total hip arthroplasty (THA). This study aimed to clarify whether preoperative central sensitization relates to the forgotten joint score-12 (FJS) after THA. Moreover, the secondary outcome was to identify which items in the FJS were most related by central sensitization. METHODS: This retrospective analysis included 263 hips (263 patients; 51 males and 212 females) that underwent primary THA in our institute and were available for evaluation one year postoperatively. The average patient age was 64.8 ± 11.9 years. The Central Sensitization Inventory (CSI) part A, which is a patient-reported outcome, was used to measure preoperative central sensitization. The correlation between preoperative CSI and postoperative FJS and the association between postoperative FJS and preoperative CSI severity were determined. Moreover, difference in each FJS item was evaluated by CSI severity. RESULTS: Twenty-six patients (9.9%) had central sensitization preoperatively. Preoperative CSI scores and postoperative FJS were negatively correlated (r = - 0.331, p < 0.0001). The postoperative FJS was significantly lower in patients with moderate or higher preoperative CSI severity than that in patients with subclinical or mild preoperative CSI severity (p < 0.05). FJS items with movement of daily life were significantly worse in the moderate or higher CSI severity compared with subclinical group (p < 0.05 or p < 0.01). CONCLUSION: Central sensitization prior to THA negatively related to postoperative FJS. In particular, the relationship of central sensitization was found to be significant in FJS items with movement, which would lead to lower patient satisfaction after THA. To get better postoperative outcomes in patients with preoperative central sensitization, improving central sensitization would be important.

Development and validation of an open-source tool for opportunistic screening of osteoporosis from hip CT images.

Aims: This study aimed to develop and validate a fully automated system that quantifies proximal femoral bone mineral density (BMD) from CT images. Methods: The study analyzed 978 pairs of hip CT and dual-energy X-ray absorptiometry (DXA) measurements of the proximal femur (DXA-BMD) collected from three institutions. From the CT images, the femur and a calibration phantom were automatically segmented using previously trained deep-learning models. The Hounsfield units of each voxel were converted into density (mg/cm3). Then, a deep-learning model trained by manual landmark selection of 315 cases was developed to select the landmarks at the proximal femur to rotate the CT volume to the neutral position. Finally, the CT volume of the femur was projected onto the coronal plane, and the areal BMD of the proximal femur (CT-aBMD) was quantified. CT-aBMD correlated to DXA-BMD, and a receiver operating characteristic (ROC) analysis quantified the accuracy in diagnosing osteoporosis. Results: CT-aBMD was successfully measured in 976/978 hips (99.8%). A significant correlation was found between CT-aBMD and DXA-BMD (r = 0.941; p < 0.001). In the ROC analysis, the area under the curve to diagnose osteoporosis was 0.976. The diagnostic sensitivity and specificity were 88.9% and 96%, respectively, with the cutoff set at 0.625 g/cm2. Conclusion: Accurate DXA-BMD measurements and diagnosis of osteoporosis were performed from CT images using the system developed herein. As the models are open-source, clinicians can use the proposed system to screen osteoporosis and determine the surgical strategy for hip surgery.

Pediatric Spinal Giant Cell-rich Osteosarcoma: Case Report and Brief Literature Review.

BACKGROUND: Osteosarcoma, the most common primary malignant bone tumor in childhood, very rarely occurs in the spine. Criteria of complete tumor resection/stable reconstruction of osteosarcoma and the latest protocol of neoadjuvant chemotherapy of the spine have not been reported because of its rarity, technical difficulties, and its continued severe surgical risk. CASE REPORT: A 11-year-old female complained of back pain for several months and walking disability. The workup discovered a large destructive bone lesion in the thoracic 12th (Th12) with vertebral body collapse and subluxation, large amount of associated anteroposterior soft tissue components, and narrowing of the spinal canal. Histology at the 1st decompression and emergent instrumentation surgery revealed giant cell-rich osteosarcoma. Following the 1st surgery, we performed three cycles of neoadjuvant chemotherapy based on the osteosarcoma 95J (NECO95J) protocol and evaluated efficacy of chemotherapy on the Th12 tumor. The tumor was isolated only to Th12 spine following chemotherapy. Therefore, following vascular embolization of the Th12 tumor, we performed surgical resection by single posterior approach that included total en bloc spondylectomy (TES). She recovered well postoperatively, without motor or sensory deficit and no back pain. Six cycles of postoperative neoadjuvant chemotherapy were administered after the 2nd surgery and TES. The patient was disease-free at the 8-months clinical and radiological follow-up and showed no neurological involvement at 8-months. CONCLUSION: We reported a case of pediatric spinal osteosarcoma, the surgical technique of complete tumor resection, and stable reconstruction of spinal osteosarcoma. We also discussed the recent neoadjuvant chemotherapy protocol for osteosarcoma.

[Validity of Video-assisted Thoracic Surgery for Thymoma].

OBJECTIVES: This study aimed to identify the validity of video-assisted thoracic surgery (VATS) for thymoma, including myasthenia gravis( MG). METHODS: A total of 20 patients who underwent VATS for thymoma at our institution between 2011 and 2019 were included in the study. Preoperative complications and prognosis were analyzed to detect the safety and efficiency of VATS thymectomy. MG improvement after VATS extended thymectomy was evaluated using a quantitative myasthenia gravis score( QMGS) and Myasthenia Gravis Foundation of America post-intervention status( MGFA-PIS). RESULTS: The median tumor size was 2.6 cm (range, 1.0-8.0 cm). All thymomas were classified as TNM stageⅠ. Two patients had type A thymoma, five had type AB, six had type B1, six had type B2, and one had type B3. Postoperative complications were only observed in one patient with pneumonia. The median follow-up period was 5.1 years;no recurrence and disease-related deaths were observed. However, three patients died of other diseases. In patients with MG, postoperative crisis was not observed, and the symptoms improved in all the patients as evaluated by QMGS and MGFA-PIS. CONCLUSIONS: VATS thymectomy and VATS extended thymectomy for patients with thymoma may be effective methods to improve not only prognosis but also MG, provided the range of resections are comparable to that of conventional open surgery.

Medial Soft Tissue-Preserving Technique Impact on Sagittal Stability in Bi-cruciate Stabilized Total Knee Arthroplasty.

Background: Sagittal stability in total knee arthroplasty is achieved through complex processes enabled by prosthetic design and intraoperative soft tissue balancing. This study investigated the effects of preserving medial soft tissue on sagittal stability in bicruciate stabilized total knee arthroplasty (BCS TKA). Method: This retrospective study included 110 patients who underwent primary BCS TKA. The patients were divided into two groups: 44 TKAs were performed releasing medial soft tissue (CON group), and 66 TKAs were performed preserving medial soft tissue (MP group). We assessed joint laxity using tensor device and anteroposterior translation immediately after surgery using the arthrometer at 30° knee flexion. Propensity score matching (PSM) was performed according to preoperative demographic and intraoperative medial joint laxity, and further comparisons between the two groups were performed. Result: After PSM analysis, medial joint laxity in the mid-flexion range tended to be smaller in the MP group than in the CONT group, with a significant difference at 60 degrees (CON group: - 0.2 ± 0.9 mm, MP group: 0.8 ± 1.3 mm, P < 0.05). Anteroposterior translation was significantly different between the two cohorts (CON group: 11.6 ± 2.5 mm, MP group: 8.0 ± 3.1 mm, P < 0.001). Conclusion: This study demonstrated the effects of preserving medial soft tissue on postoperative sagittal stability in BCS TKA. We concluded that this surgical procedure enhances postoperative sagittal stability in the mid-flexion range in BCS TKA.

Fracture risks and their mechanisms in atopic dermatitis, focusing on receptor activator of nuclear factor kappa-B ligand.

Recent multiple studies have shown that the long-term consequences of atopic dermatitis (AD) include an increased risk of osteoporosis and fracture, especially an increase in hip, pelvic, spinal and wrist fractures. AD is very common worldwide, and some kinds of fractures, such as hip fractures, are associated with increased mortality, which has a substantial socioeconomic impact; however, the precise mechanisms for this remain unclear. Receptor activator of nuclear factor kappa-Β (RANK) ligand (RANKL) and osteoprotegerin (OPG) are members of the tumour necrosis factor ligand and receptor family, members of which also are known as bone biomarkers. Alterations in the RANKL/RANK/OPG system and the balance among these factors (represented by the RANKL/OPG ratio) are central to the pathogenesis of bone loss from osteoporosis, and it is postulated that there is a potential association between the serum levels of RANKL and OPG, and bone density or fracture. Recently, our research group demonstrated that the serum RANKL/OPG ratio positively correlated with AD severity and suggests fracture risk in older women with AD. This review summarizes and discusses the risk and mechanisms of osteoporotic fracture in AD. RANKL may be involved in the pathogenesis of AD, regarding not only bone abnormality but also inflammation. Although further investigation will be needed to verify the hypotheses, recent findings may provide new insights into the pathogenesis of AD and therapeutic targets.