Pelvic CT Scan Research Articles

Clinical analysis of robotic-assisted surgery in the treatment of large pheochromocytoma/paraganglioma: a study of 29 cases

This study aimed to compare the safety and clinical efficacy of Da Vinci robotic surgery (control group) versus traditional laparoscopic surgery in the treatment of large (tumor size >6 cm) pheochromocytomas/paragangliomas. The evaluation was based on intraoperative metrics such as operative time, blood loss, conversion to open surgery rates, postoperative drain duration, and length of postoperative hospital stay. A retrospective analysis was conducted on 29 patients (14 males and 15 females) who underwent Da Vinci robotic surgery for large (greater than 6 cm) pheochromocytomas/paragangliomas from October 2019 to September 2023. The average maximum tumor diameter was (7.2±1.6) cm. During the same period, 32 patients underwent laparoscopic resection of challenging pheochromocytomas/paragangliomas.Data showed no significant differences between the two groups, except for the norepinephrine levels. Operative time, blood loss, conversion rate, postoperative drainage duration, and length of hospital stay were recorded and compared between the two groups. The differences between the groups were analyzed using the t-test, and the conversion rates were compared using the chi-square (χ²) test. All surgeries were successfully performed. One patient underwent a one-stage bilateral tumor resection. In the Da Vinci robotic surgery group, the average operative time was (76±32) minutes, compared to (106±45) minutes in the control group (P=0.003). The average intraoperative blood loss was (95±75) ml, compared to (160±90) ml in the control group (P=0.019). The conversion rate to open surgery was 2 cases (6.9%) in the robotic group compared to 5 cases (15.6%) in the control group (P=0.031). The average postoperative drainage duration was (3.0±1.0) days, compared to (3.5±1.5) days in the control group (P=0.128). The average length of hospital stay was (4.5±1.2) days, compared to (4.7±2.2) days in the control group (P=0.657). Postoperative pathological diagnosis confirmed pheochromocytoma or paraganglioma. Blood pressure normalized within 1 to 3 months postoperatively, with an average systolic blood pressure of (116±13) mmHg(1 mmHg=0.133 kPa）and diastolic blood pressure of (73±5) mmHg in the robotic surgery group. Follow-up for 3 to 40 months showed normal levels of blood catecholamines and no recurrence or metastasis on follow-up imaging studies, including chest, abdominal, and pelvic CT scans. The average levels of 3-methoxy-norepinephrine, 3-methoxy-epinephrine, and 3-methoxy-tyramine were (0.42±0.21) nmol/L (normal value≤1.05 nmol/L), (0.11±0.07) nmol/L (normal value≤0.32 nmol/L), and (0.017±0.006) nmol/L (normal value≤0.036 nmol/L), respectively. This study demonstrates that for the treatment of large pheochromocytomas/paragangliomas, the Da Vinci robotic technique offers advantages such as high-definition visualization, precise operation, and flexibility. These advantages enable the safe and efficient completion of surgeries, as evidenced by shorter operative times, less blood loss, and lower conversion rates.

8354 OVARIAN HYPERTHECOSIS: AN UNCOMMON CAUSE OF HYPERANDROGENISM IN A POSTMENOPAUSAL WOMAN

Abstract Disclosure: M.D. Severino: None. F.P. Silva: None. M.V. Lopes: None. C. Nunes: None. M.I. Alexandre: None. M.J. Bugalho: None. Introduction: Severe hirsutism in postmenopausal women demands a careful clinical evaluation to exclude a malignant cause, such as adrenal or ovarian androgen-secreting tumors. Ovarian hyperthecosis is an uncommon and benign cause of hyperandrogenism and, consequently, hirsutism. It is caused by persistent testosterone synthesis due to proliferation of ovarian stromal cells and nests of luteinized theca cells. It occurs more often in postmenopausal women, as aromatization of testosterone to estradiol decreases due to the loss of granulosa cells. It is also frequently associated with obesity and insulin resistance. Clinical case: We present the case of a 61-year-old woman, with a history of hypertension and dyslipidemia, referred to Endocrinology Clinic due to a year long history of hirsutism, most severe on her face, chest, and abdomen. She also mentioned slight clitoromegaly. She had no other virilization symptoms such as acne, male-pattern alopecia, voice deepening or mammary atrophy. Her menarche occurred at the age of 14 and she had regular menses until menopause, at the age of 51. She had a BMI of 32 kg/m2 and an uncharacteristic phenotype. At observation, she had a mild hirsutism (Ferriman-Gallwey score of 9). This contrasted with the biochemical findings of severe androgenism - total testosterone of 366 ng/dL (reference values [RV] for women between 5-48) with free testosterone 7.8 pg/mL and SHBG 74 nmol/L (RV 32-128), resulting in a Free Androgen Index of 17,16 (RV <6.6). DHEAS, androstenedione, 17-hydroxyprogesterone and prolactin were normal, and gonadotropins were in the menopausal range. Blood tests also showed hyperinsulinemia and pre-diabetes with HbA1c 6,2%. She denied exposure to steroids in the form of new medication, supplements, or creams/gels (including second-hand exposure through her partner) and she had no exposure to other drugs with androgenic effect. Abdominal and pelvic CT scan, as well as transvaginal ultrasound, showed no adrenal or ovarian lesions. An ovarian cause was deemed the most likely and laparoscopic diagnostic bilateral salpingo-oophorectomy was performed. Gross pathology revealed ovaries of regular size, while histology showed bilateral ovarian stromal hyperthecosis. Testosterone levels returned to normal one month after surgery (14,2 ng/dL). Conclusion: Benign, ovarian causes of hyperandrogenism are uncommon in postmenopausal women, requiring a high index of suspicion. The diagnosis is difficult, and laparoscopic bilateral salpingo-oophorectomy is essential as both a diagnostic and therapeutic tool. Presentation: 6/2/2024

8354 Ovarian Hyperthecosis: an Uncommon Cause of Hyperandrogenism in a Postmenopausal Woman

Abstract Disclosure: M.D. Severino: None. F.P. Silva: None. M.V. Lopes: None. C. Nunes: None. M.I. Alexandre: None. M.J. Bugalho: None. Introduction: Severe hirsutism in postmenopausal women demands a careful clinical evaluation to exclude a malignant cause, such as adrenal or ovarian androgen-secreting tumors. Ovarian hyperthecosis is an uncommon and benign cause of hyperandrogenism and, consequently, hirsutism. It is caused by persistent testosterone synthesis due to proliferation of ovarian stromal cells and nests of luteinized theca cells. It occurs more often in postmenopausal women, as aromatization of testosterone to estradiol decreases due to the loss of granulosa cells. It is also frequently associated with obesity and insulin resistance. Clinical case: We present the case of a 61-year-old woman, with a history of hypertension and dyslipidemia, referred to Endocrinology Clinic due to a year long history of hirsutism, most severe on her face, chest, and abdomen. She also mentioned slight clitoromegaly. She had no other virilization symptoms such as acne, male-pattern alopecia, voice deepening or mammary atrophy. Her menarche occurred at the age of 14 and she had regular menses until menopause, at the age of 51. She had a BMI of 32 kg/m2 and an uncharacteristic phenotype. At observation, she had a mild hirsutism (Ferriman-Gallwey score of 9). This contrasted with the biochemical findings of severe androgenism - total testosterone of 366 ng/dL (reference values [RV] for women between 5-48) with free testosterone 7.8 pg/mL and SHBG 74 nmol/L (RV 32-128), resulting in a Free Androgen Index of 17,16 (RV <6.6). DHEAS, androstenedione, 17-hydroxyprogesterone and prolactin were normal, and gonadotropins were in the menopausal range. Blood tests also showed hyperinsulinemia and pre-diabetes with HbA1c 6,2%. She denied exposure to steroids in the form of new medication, supplements, or creams/gels (including second-hand exposure through her partner) and she had no exposure to other drugs with androgenic effect. Abdominal and pelvic CT scan, as well as transvaginal ultrasound, showed no adrenal or ovarian lesions. An ovarian cause was deemed the most likely and laparoscopic diagnostic bilateral salpingo-oophorectomy was performed. Gross pathology revealed ovaries of regular size, while histology showed bilateral ovarian stromal hyperthecosis. Testosterone levels returned to normal one month after surgery (14,2 ng/dL). Conclusion: Benign, ovarian causes of hyperandrogenism are uncommon in postmenopausal women, requiring a high index of suspicion. The diagnosis is difficult, and laparoscopic bilateral salpingo-oophorectomy is essential as both a diagnostic and therapeutic tool. Presentation: 6/2/2024

Impacts of participation in surgical clinical trial on safety and survival outcomes in patients with right-sided colon cancer

Objective: To explore the impact on safety and prognosis in patients with right-sided colon cancer participating in surgical clinical research. Methods: This retrospective cohort study utilized data from a randomized controlled trial (RELARC study) conducted by the colorectal surgery group at Peking Union Medical College Hospital in which laparoscopic complete mesocolic excision (CME) was compared with D2 radical resection for the management of right-sided colon cancer. The eligibility criteria were age 18-75 years, biopsy-proven colon adenocarcinoma, tumor located between the cecum and right 1/3 of the transverse colon, enhanced chest, abdomen, and pelvic CT scans suggesting tumor stage T2-T4N0M0 or TanyN+ M0, and having undergone radical surgical treatment from January 2016 to December 2019. Exclusion factors included multiple primary colorectal cancers, preoperative stage T1N0 or enlarged central lymph nodes, tumor involving surrounding organs requiring their resection, definite distant metastasis or otherwise unable to undergo R0 resection, history of any other malignant tumors within previous 5 years, intestinal obstruction, perforation, or gastrointestinal bleeding requiring emergency surgery, and assessed as unsuitable for laparoscopic surgery. Patients who had participated in the RELARC study were included in the RELARC group, whereas those who met the inclusion criteria but refused to participate in the RELAEC study were included in the control group. The main indicators studied were the patient's baseline data, surgery and perioperative conditions, pathological characteristics, adjuvant treatment, and postoperative follow-up (including average frequency of follow-up within the first 3 years) and survival (including 3-year disease-free survival rate (DFS) and 3-year overall survival rate (OS). Differences in these indicators between the RELARC and control groups were compared. Results: The study cohort comprised 290 patients, 173 in the RELARC group (RELARC-CME group, 82; RELARC-D2 group, 91) and 117 in the control group (CME control group, 72; D2 control group, 45). There was a significantly higher proportion of overweight patients (BMI ≥24 kg/m2) in the RELARC-CME than in the CME control group (67.1% [55/82] vs. 33.3% [24/72], χ2=17.469, P<0.001). There were no other statistically significant differences in baseline characteristics (all P>0.05). No significant disparities were found between the CME and D2 groups in terms of operation duration, intraoperative blood loss, rate of conversion to open surgery, combined organ resection, intraoperative blood transfusion, or intraoperative complications (all P>0.05). There was a trend toward Clavien-Dindo grade II or higher postoperative complications in the RELARC-CME group (24.4% [20/82]) than in the CME control group (18.1% [13/72]); however, this difference was not statistically significant (χ2=0.914, P=0.339). Similarly, the difference in this rate did not differ significantly between the RELARC-D2 group (25.3% [23/91]) and D2 control group (24.4% [11/45], χ2=0.011, P=0.916). The median duration of postoperative follow-up was significantly shorter in the RELARC groups than in the corresponding control groups. Specifically, the median duration of follow-up was 4.5 (4.5, 4.5) months in the RELARC-CME and 7.2 (6.0, 9.0) months in the CME control group (Z=-10.608, P<0.001). Similarly, the median duration of follow-up was 4.5 (4.5, 4.5) months in the RELARC-D2 group as opposed to 8.3 (6.6, 9.0) months in the D2 control group (Z=-10.595, P<0.001). The 3-year DFS rate (91.5%) and OS rate (96.3%) tended to be higher in the RELARC-CME group than in the CME control group (84.7% and 90.3%, respectively). The 3-year DFS rate (87.9%) and OS rate (96.7%) tended to be higher in the RELARC-D2 group than in the D2 control group (81.8% and 88.6%, respectively); however, these differences were not statistically significant (all P>0.05). Subgroup analysis according to pathological stage revealed that patients in the RELARC-D2 group with pN0 stage achieved a significantly superior 3-year OS rate than did those in the D2 control group (100% vs. 88.9%, P=0.008). We identified no statistically significant differences in survival rates between the remaining subgroups (all P>0.05). Conclusions: A high-quality surgical clinical trial with close follow-up can achieve perioperative safety and a trend toward improved survival outcomes.

Assessment of Cup Placement Impact on Functional Outcomes in Total Hip Replacement: A Retrospective Analysis of 20 Patients

Introduction:Total hip replacement surgery is gaining popularity as a treatment for hip disorders, replacing alternative treatments like excisional arthroplasty, osteotomy, arthrodesis, and hemiarthroplasty. This research aims to evaluate the effect of the acetabular cup on functional outcomes, particularly in younger patients with hip arthritis and femur neck fractures.Materials And Methods:This study aimed to evaluate the placement of the acetabular cup and its association with functional outcomes in total hip replacement (THR). 20 patients were randomly selected from the MRD department and underwent pelvic CT scans postoperatively. Functional results have been analyzed using the Harris Hip Score. The acceptable cup version range was 15 ± 10 degrees, and patients outside this range were closely examined for rotational movements. Results: A study of 20 patients with a neck or femur fracture found that 11 patients had a right knee injury, while 9 had a left knee injury. After a year postoperatively, 18 patients reported no pain, while 2 had mild pain. Functional assessment depicted better outcomes in 17 patients, good outcomes in 2 patients, and fair outcomes in 1 patient. Radiological analysis revealed a mean cup version of 17.77 degrees, with complications including one dislocation and three limb length discrepancies. None of the patients developed an infection.Conclusion:The study found that 90% of patients had excellent functional outcomes, with only 10% exhibiting excessive anteversion. CT scan-based measurements of cup placement provided reliable predictions, consistent with intraoperative assessment of cup positioning.

Synthetic CT generation from CBCT based on structural constraint cycle-EEM-GAN

Objective. Cone beam CT (CBCT) typically has severe image artifacts and inaccurate HU values, which limits its application in radiation medicines. Scholars have proposed the use of cycle consistent generative adversarial network (Cycle-GAN) to address these issues. However, the generation quality of Cycle-GAN needs to be improved. This issue is exacerbated by the inherent size discrepancies between pelvic CT scans from different patients, as well as varying slice positions within the same patient, which introduce a scaling problem during training. Approach. We introduced the Enhanced Edge and Mask (EEM) approach in our structural constraint Cycle-EEM-GAN. This approach is designed to not only solve the scaling problem but also significantly improve the generation quality of the synthetic CT images. Then data from sixty pelvic patients were used to investigate the generation of synthetic CT (sCT) from CBCT. Main results. The mean absolute error (MAE), the root mean square error (RMSE), the peak signal to noise ratio (PSNR), the structural similarity index (SSIM), and spatial nonuniformity (SNU) are used to assess the quality of the sCT generated from CBCT. Compared with CBCT images, the MAE improved from 53.09 to 37.74, RMSE from 185.22 to 146.63, SNU from 0.38 to 0.35, PSNR from 24.68 to 32.33, SSIM from 0.624 to 0.981. Also, the Cycle-EEM-GAN outperformed Cycle-GAN in terms of visual evaluation and loss. Significance. Cycle-EEM-GAN has improved the quality of CBCT images, making the structural details clear while prevents image scaling during the generation process, so that further promotes the application of CBCT in radiotherapy.

EP110 - Chyloperitoneum in Follicular lymphoma – presenting as an inguinal hernia

Abstract Introduction Follicular lymphoma is one of the subtypes of slow growing Non-Hodgkin Lymphoma. Rarely, follicular lymphoma can present with chyloperitoneum or chylous ascites which is characterized by a milky-white coloured fluid with raised triglyceride levels. Case Report We present a case of a 60-year-old diabetic male, complaining of a right sided inguinal swelling for 1 year. Examination revealed a reducible right inguinal swelling with a positive cough impulse. The laboratory workup was unremarkable. Ultrasound scan of anterior abdominal wall showed a defect of 2.1 cm in right inguinal region with protrusion of abdominal contents and a positive cough impulse. A diagnosis of right sided reducible direct inguinal hernia was made. Patient was scheduled for Lichtenstein repair. Per-operatively, the hernial sac contained healthy omentum with milky-white ascitic fluid. Omentum was reduced and suture repair was performed. A drain was placed intra-peritoneally. The postoperative course of the patient was uneventful. Ascitic fluid analysis showed high triglyceride levels and no evidence of malignant cells, suggesting chylous ascites. Contrast enhanced CT scan of abdomen and pelvis revealed a large homogenous minimally enhancing soft tissue density retroperitoneal mass in peri aortic and paravertebral location with abdominal lymphadenopathy suggesting retroperitoneal lymphoma. Excisional biopsy of an enlarged inguinal lymph node confirmed follicular lymphoma with positive BCL2 and CD10 markers. Conclusion Follicular lymphoma presents in a variety of ways including chylous ascites in an inguinal hernia and a high index of suspicion is required to diagnose it.

EP553 - Omental Infarction mimicking acute cholecystitis - A Case Report

Abstract Introduction Spontaneous torsion and infarction of the omentum is a rare presentation with a variety of clinical presentations. We report a middle-aged male patient who presented with signs and symptoms mimicking acute cholecystitis. Case Presentation A 47-year-old man presented with an 18-hour history of right upper quadrant (RUQ) pain. Pain was constant, worse on movement and inspiration. On examination, he was exceptionally tender in the RUQ with positive Murphy’s sign. Initial investigations showed a mild inflammatory response, and the working diagnosis was acute cholecystitis. An abdominal ultrasound scan demonstrated a thin-walled gallbladder, free from gallstones and no evidence of acute cholecystitis. Given the patients ongoing severe pain and examination findings, a CT scan of abdomen and pelvis with contrast was performed. This demonstrated an oval shaped area of localized omental fat stranding in the RUQ, suggestive of omental infarction. The patient was managed conservatively with analgesia and discharged once symptoms were adequately controlled. Discussion Torted, infarcted omentum is a rare cause of acute abdominal pain. It is more frequently observed in 40–50-year-olds with male predominance. Most commonly it mimics symptoms and signs of acute appendicitis. However, this is a rare case mimicking acute cholecystitis. In this case, the necrotic segment was adherent with the anterior abdominal wall, causing significant pain and tenderness. When the clinically presentation of acute cholecystitis is not reflected by abdominal ultrasound, cross sectional imaging should be obtained to ensure definitive diagnosis is established in timely manner.

The Measurement of the Lateral Center-Edge Angle Is Underestimated on Radiographs Compared With 3-Dimensional Computed Tomography

PurposeTo determine if there is a significant difference using Femoral Heads (FH) as anatomical horizon when measuring the LCEA compared to Floor (F), Acetabular Teardrops (AT), and Ischial Tuberosities (IT) and to determine their accuracy by comparing to CT scan with commercially available software. MethodsBetween June 2019 and May 2020, patients with preoperative supine anteroposterior (AP) pelvis radiographs and CT scans were included and retrospectively analyzed. The LCEA was measured on all preoperative supine AP pelvis radiographs four times per hip, using the four methods. The four anatomical horizons used to measure LCEA were compared to each other to determine statistically significant difference. The LCEA measured in the CT scan at the 12 o’clock position was used to compare and determine radiographs’ LCEA accuracy. ResultsNinety-six patients (100 hips) met the inclusion criteria. Sixty-two were females (65%), and the mean age was 35.2 ± 15 years. The mean value for LCEA in CT was 32.2 and 31.1 for the four anatomical horizons in X-ray (P < 0.001). The lowest mean difference between CT scan and X-ray was obtained using the FH (2.3 ± 2.4). Less mean difference was obtained between FH and IT (1.0 ± 0.8). ConclusionIn this study, radiographic measurements underestimated LCEA compared with those from CT scans. Using the FH as an anatomic horizon on radiographs was a more accurate method to measure LCEA than using AT, IT, or F. While this difference is statistically significant, it is not likely to be clinically significant.

A comparative study of four combined methods for planning access to the anterior acetabular column for nail placement

To investigate global optimisation of anterior acetabular column pinning channels can be achieved based on large density point cloud data. Data were collected on the CT scans of the normal pelvis in 40 adults from January 2022 to January 2023, including 22 males and 18 females, aged 20 to 54 years old. Medical imaging data from three of the samples were selected for experimental study. In planning access for anterior acetabular column pinning, to address the issue of whether the current CAD planning methods were advanced or not, four combinations of the same point cloud acquisition channels, different directional line creation software, and the same 3D design and virtual experiment software were proposed: Mimics+Imageware+UG, Mimics+3DReshaper+UG, Mimics+ZEISS Quality Suite+UG and Mimics+Design X+UG, and directional lines created based on the centroid point set and solid point cloud of the secondary pruning model, respectively, and it applied to the planning of the left anterior column pinning channel of the three acetabular samples. The maximum internally connected cylinder without acetabular socket and pubic bone penetration was used as a safe passage for nailing of the anterior acetabular column to evaluate the advancement of each method. The fitting effect of the directional line was better than that of the unnoised solid point cloud when the central point set with obvious relevant features was selected as the sample points;and the combination of Mimics+Imageware+UG and Mimics+3DReshaper+UG could efficiently and stably obtain the desirable planning results when planning with the central point set, respectively, in the three acetabular samples 1, 2, 3. The maximum internal joint circle diameters obtained in samples 1, 2, and 3 were 10.35 mm, 9.62 mm, and 9.24 mm;and when the directional lines were based on the solid point cloud the combined methods of Mimics+ZEISS Quality Suite+UG and Mimics+Design X+UG were not applicable;whereas the Mimics+3DReshaper+UG the solid point cloud denoising planning method could stably obtain the maximum value of the safe channel for nail placement, and the maximum internal joint circle diameters obtained in acetabular samples 1, 2, and 3 are 10.66 mm, 10.96 mm, and 9.48 mm, respectively. It is recommended that the nail placement channel planners use robust Mimics+Imageware+UG or Mimics+3DReshaper+UG centre point set planning method, and if there is enough time, it is recommended to use the solid point cloud denoising planning method of Mimics+3DReshaper+UG in order to obtain the maximum value of safe channels for nail placement.

One Haemolytic Anaemia May Hide Another: Paroxysmal Nocturnal Haemoglobinuria Masquerading As Plasmodium Falciparum Infection.

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare, genetic and acquired haematologic disease that causes complement-mediated intravascular haemolytic anaemia, thrombosis and bone marrow failure. A 27-year-old migrant patient attended the emergency department in a context of fever and chills over the previous few days as well as chronic fatigue, dyspnoea and chest pain. His medical history included chronic anaemia and erectile dysfunction. Initial biology showed a haemoglobin of 6.3 g/dl, platelets of 25,000/μl, total leucocytes of 3,500/μl with 1,500 neutrophils. B12 vitamin, folic acid, ferritin and thyroid stimulating hormone were normal. Lactate dehydrogenase levels were high and haptoglobin was non-measurable. C-reactive protein was 46.1 mg/l. A thick blood smear revealed Plasmodium falciparum infection with 0.1% parasitaemia. The patient was treated with an oral combination of artemether and lumefantrine. Three weeks later, the patient consulted the infectious disease department given the lack of clinical improvement. The cytopenias worsened, and lactate dehydrogenase (LDH) and reticulocytes increased. Tests for schistocytes, a thick blood smear for malaria and a direct Coombs test were negative; a myelogram was reassuring. An abdominal, pelvic and thoracic CT scan showed a mild hepatomegaly with no focal lesion and no splenomegaly or adenomegaly. A 12-colour flow cytometry unveiled a PNH clone on 90.9545% of neutrophils and 80.7371% of monocytes. PNH patients can be vulnerable to parasites infection (such as P. falciparum) as it may trigger breakthrough haemolysis through uncontrolled resurgence of activity of the complement system. In our patient, P. falciparum infection was a confounding factor, as it commonly causes haemolytic anaemia and thrombocytopenia, and patients living in malaria-endemic regions can carry low parasitaemia while being slightly symptomatic or asymptomatic. Plasmodium falciparum infection can cause breakthrough haemolysis in patients with paroxysmal nocturnal haemoglobinuria.Low P. falciparum parasitemia in patients living in malaria-endemic regions is not always significant as these patients often carry acquired immunity.Patients from malaria-endemic regions presenting with severe sickness and low P. falciparum parasitemia must be assessed for other diseases, as it cannot explain heavy illness.Patients presenting with haemolytic anaemia, no schistocytes, a negative direct Coombs test and other unexplained cytopenia such as thrombocytopenia/neutropenia and other unexplained clinical manifestations such as dyspnoea, chest pain or erectile dysfunction should be assessed for paroxysmal nocturnal haemoglobinuria.

How Strong Is the Ligamentum Teres of the Hip? A Biomechanical Analysis.

Intraarticular hip pain represents a substantial clinical challenge, with recent studies implicating lesions in the ligamentum teres as potential contributors. Even more so, damage to the ligamentum teres is particularly prevalent among young patients undergoing joint-preserving interventions. Although several studies have investigated the biomechanical attributes of the ligamentum teres, inconsistencies in reported findings and reliance on cadaveric or animal models have raised concerns regarding the extrapolation of results to clinical practice. Furthermore, there is a lack of research examining ligamentum teres biomechanics specifically within the relevant patient cohort-individuals who benefit from joint-preserving surgical interventions. We sought (1) to determine the biomechanical properties (ultimate load to failure, tensile strength, stiffness, and elastic modulus) of fresh-frozen ligaments from patients undergoing surgical hip dislocation, and (2) to identify patient-specific factors that are associated with them. This was an institutional review board-approved study on intraoperatively harvested ligamentum teres from 74 consecutive patients undergoing surgical hip dislocation for joint preservation (August 2021 to September 2022). After the exclusion of patients with previous surgery, posttraumatic deformities, avascular necrosis, slipped capital femoral epiphysis, and Perthes disease, 31 ligaments from 31 patients were analyzed. The mean age of the study group was 27 ± 8 years, and 61% (19) of participants were male. The main indication for surgery was femoroacetabular impingement. Standardized AP pelvic and axial radiographs and CT scans were performed in all patients for better radiological description of the population and to identify associated radiological factors. The ligament was thoroughly transected at its origin on the fossa acetabuli and at the insertion area on the fovea capitis and stored at -20°C until utilization. Specimens were mounted to a materials testing machine via custom clamps that minimized slippage and the likelihood of failure at the clamp. Force-displacement and stress-strain curves were generated. Ultimate failure load (N), tensile strength (MPa), stiffness (N/mm), and elastic modulus (MPa) were determined. Using a multivariate regression analysis and a subgroup analysis, we tested demographic, degenerative, and radiographic factors as potential associated factors. The ligamentum teres demonstrated an ultimate load to failure of 126 ± 92 N, and the tensile strength was 1 ± 1 MPa. The ligaments exhibited a stiffness of 24 ± 15 N/mm and an elastic modulus of 7 ± 5 MPa. After controlling for potential confounding variables like age, fossa/fovea degeneration, and acetabular/femoral morphologies, we found that female sex was an independent factor for higher tensile strength, stiffness, and elastic modulus. Excessive femoral version was independently associated with lower load to failure (HR 122 [95% CI 47 to 197]) and stiffness (HR 15 [95% CI 2 to 27]). Damage to the acetabular fossa was associated with reduced load to failure (HR -93 [95% CI -159 to -27]). Overall, the ligamentum teres is a relatively weak ligament. Sex, degeneration, and excessive femoral version are influencing factors on strength of the ligamentum teres. The ligamentum teres exhibits lower strength compared with other joint-stabilizing ligaments, which calls into question its overall contribution to hip stability. Young patients undergoing hip-preserving surgery are the population at risk for ligamentum teres lesions. Baseline values for load to failure, tensile strength, elastic modulus, and stiffness are needed to better understand those lesions in this cohort of interest.

Nonmetric sex estimation in a contemporary Indonesian population: a validation study using clinical pelvic MSCT scans

Klales et al. (2012) is a popular standard for the estimation of skeletal sex. Since its publication, a number of studies have demonstrated that population-specific applications of Klales improve classification accuracy. However, it has also been shown that age appears to affect the expression of dimorphism in the pelvis across the lifespan. As such, the present study examines the accuracy of Klales, and the modified global standard of Kenyhercz et al. (2017), in a contemporary Indonesian population, including quantifying the effect of age. Pelvic multi-slice CT scans of 378 individuals (213 female; 165 male) were analysed in OsiriX®. Both standards were tested and Indonesian-specific models thereafter derived.When applied to the Indonesian sample, both the Klales and Kenyhercz standards resulted in lower classification accuracy relative to the original studies. In considering the Indonesian-specific models, the ventral arc was the most accurate for the classification of sex, at 93.3% with a − 3.0% sex bias. The accuracy of the three-trait model was 94.4%, with a − 5.5% sex bias. Age was shown to significantly affect the distribution of pelvic trait scores. As such, age-dependent models were also derived, with the standard for individuals between 30 and 49 years the most accurate, at 93.1% and a sex bias of − 4.0%. Accuracy was lower in individuals aged ≥ 50 years, at 91.3% and a sex bias of 4.1%. These findings support the importance of establishing population-specific standards and to facilitate improved accuracy and capabilities for forensic practitioners in Indonesia.

Hip joint biomechanical analysis of the acetabular anatomical reconstruction and nonanatomical reconstruction in total hip arthroplasty for Crowe type Ⅲ developmental dysplasia of the hip by finite element method

To analyze the hip joint biomechanics of the acetabular anatomical reconstruction and nonanatomical reconstruction in total hip arthroplasty (THA) for Crowe type Ⅲ developmental dysplasia of the hip (DDH) by finite element method, which provided theoretical foundation and experimental basis for the anatomical acetabular reconstruction during THA in clinical practice. One patient with left end-stage hip arthritis secondary to Crowe type Ⅲ DDH was selected in this study, who underwent total hip arthroplasty in the orthopedic department of the First Affiliated Hospital of Bengbu Medical College in April 2020. This patient was female, 57 years old. The preoperative and postoperative three dimentional CT scan of the patient's pelvis were performed. Fourteen acetabular cup models with different anteversion, inclination and rotation center height were established in Mimics and 3-Matic software. The boundary and load conditions were set in Abaqus software. The Von Mises and stress distribution of the hip joint were calculated and observed. In the Crowe type Ⅲ DDH THA, if the hip rotation center was restored anatomically and the acetabular cup's inclination was set as 40°, the cup's anteversion varied from 5° to 25°, the lowest Von Mises value of acetabular cup and polyethylene liner occured in 20°anteversioin;if the hip rotation center was restored anatomically and the acetabular cup's anteversion was set as 15°, the cup's inclination varied from 35° to 55°, the lowest Von Mises value of acetabular cup and polyethylene liner occured in 35° inclination;if the acetabular cup's anteversion and inclination were set as 15°and 40°respectively, the up migration of hip rotaion center varied from 0 mm to 20 mm, the lowest Von Mises value of acetabular cup and polyethylene liner occured in 10 mm up migration. In all fourteen models, the Von Mises value of the acetabulum, acetabulum cup and polyethylene liner were lowest when the acetabular cup's anteversion and inlcination were 15°, 35° respectively, as well as the rotation center was restored anatomically. In total hip arthroplasty for Crowe type Ⅲ DDH, the anatomical restoration of hip rotation center with 15° anteversion and 35° inclination of the acetabular cup are suggested, bone graft above the acetabular cup and additional screws are recommended simultaneously to further reduce the Von Mises of hip joint.

Analysis of Eligibility of the S1 Corridor for the Trans-Sacral Screw Placement in Geriatric Patients

Abstract Background Minimal-invasive placement of a trans-sacral screw represents an increasingly popular method of fixation for Fragility Fractures of the Pelvis (FFP), with variable upper sacral anatomy representing the main challenge. Little is known about the variability of sacral anatomy in the geriatric population and the potential effect of osteoporosis on the upper sacral anatomy and thus S1 corridor morphology. Aims To examine the eligibility (&amp;gt;12 mm) of the S1 corridor for the trans-sacral screw placement in a geriatric population and to analyse what pelvic dysmorphism signs might serve as predictors for an ineligible S1 corridor. Methods We analysed S1 corridor in pelvic CT scans of 107 geriatric patients without history of fracture or other pelvic pathology. First, the eligibility for the trans-sacral screw placement was determined by measuring the width and the height of the central portion of the S1 corridor. Then, pelvises were examined for signs of dysmorphism. The correlation of these signs with the ineligible S1 corridor was analysed. Results In our geriatric population with average age of 79,55 ± 8.79 years (male : female 0.88) 44% of S1 corridors were not eligible for a trans-sacral screw. In this ineligible group the height was shown to be a more significant limiting dimension (90,9%), compared to the width in 68,2% (p&amp;lt;0.05). Mamillary processes, not recessed sacrum and dysmorphic sacral foramina were present in 38,3%, 34,6%, and 26,2% respectively, with not recessed sacrum demonstrating a significant correlation with a too narrow S1 corridor (p&amp;lt;0.05). Conclusion The analysed geriatric population demonstrates a high prevalence of a too narrow S1 corridor, which makes a placement of a trans-sacral screw risky or even impossible. The height of the S1 corridor represents the main limiting factor with a dysmorphism sign of a not recessed sacrum being a significant predictor for the ineligible S1 corridor.

Sex Estimation from Computed Tomography of Os Coxae—Validation of the Diagnose Sexuelle Probabiliste (DSP) Software in the Romanian Population

This study aimed to evaluate the DSP method’s applicability to Romania’s contemporary population and to assess the accuracy and reliability of variables derived from CT images. A total of 80 pelvic CT scans were analyzed. Participants ranged from 22 to 93 years, with a mean age of 59.51 ± 22.7 years. All variables measured from the CT scans were analyzed using DSP software. The study found that sex estimation was possible in 71.25% of cases overall, with varying rates between males (57.50%) and females (85%). Despite encountering undetermined specimens comprising 42.5% males and 15% females, only one misclassification occurred. Regarding accuracy, the overall rate remained notably high at 98.24%. All female specimens that could be estimated were correctly classified (100% accuracy), while for males, the accuracy rate was 95.65%. Undetermined cases were noted to potentially impact the accuracy of sex classification, underscoring the critical role of precision in forensic contexts. In conclusion, the study highlights the importance of accuracy in forensic sex estimation. It emphasizes the confidence with which DSP software can be utilized, if not the only method, at least as a preliminary or adjuvantly accurate technique for sex estimation in forensic anthropology.

Spontaneous Bladder Wall Rupture Due to Emphysematous Cystitis in a Diabetic Patient: A Case Report

Spontaneous rupture of the urinary bladder (SRUB) secondary to emphysematous. Cystitis (EC) in diabetic patients is extremely rare. Emphysematous cystitis is a relatively rare disease entity characterized by intramural and/or intraluminal bladder gas best depicted by cross-sectional imaging. Its disease mechanism is not well understood. Case report: A 61-year-old diabetic woman presented to the emergency department with diffuse abdominal pain and hematuria of tree hours duration. Physical examination revealed generalized abdominal tenderness. Multi-slice abdominal and pelvic CT scans showed parietal pneumatosis of bladder and communicating continuity solutions with a pre-vesical collection (extravasation of PDC into the collection). After proper resuscitation, the patient was transferred to the operating room for exploratory laparotomy. A thickness bladder rupture was noted, which was repaired. Conclusions: SRUB in patients with poorly controlled diabetes and EC is highlighted in this case study. Urinary bladder rupture secondary to EC should be considered when a diabetic patient with a history of urinary symptoms presents with an acute onset of abdominal pain. Uneventful recovery from SRUB is dependent on early diagnosis and treatment.

Impact of tumour stroma-immune interactions on survival prognosis and response to neoadjuvant chemotherapy in bladder cancer

The tumour stroma is associated with unfavourable prognosis in diverse solid tumours, but its prognostic and predictive value in bladder cancer (BCa) is unclear. In this multicentre, retrospective study, we included 830 patients with BCa from six independent cohorts. Differences in overall survival (OS) and cancer-specific survival (CSS) were investigated between high-tumour stroma ratio (TSR) and low-TSR groups. Multi-omics analyses, including RNA sequencing, immunohistochemistry, and single-cell RNA sequencing, were performed to study stroma-immune interactions. TSR prediction models were developed based on pelvic CT scans, and the best performing model was selected based on receiver operator characteristic analysis. Compared to low-TSR tumours, high-TSR tumours were significantly associated with worse OS (HR=1.193, 95% CI: 1.046-1.361, P=0.008) and CSS (HR=1.337, 95% CI: 1.139-1.569, P<0.001), and lower rate of pathological complete response (pCR) to neoadjuvant chemotherapy (NAC). High-TSR tumours exhibited higher infiltration of immunosuppressive cells, including Tregs and tumour-associated neutrophils, while low-TSR tumours exhibited higher infiltration of immune-activating cells such as CD8+ Teff and XCR1+ dendritic cells. The TSR prediction model was developed by combining the intra-tumour and tumour base radiomics features, and showed good performance to predict high-TSR, as indicted by area under the curve of 0.871 (95% CI: 0.821-0.921), 0.821 (95% CI: 0.731-0.911), and 0.801 (95% CI: 0.737-0.865) in the training, internal validation, and external validation cohorts, respectively. In patients with low predicted TSR, 92.3% (12/13) achieved pCR, while only 35.3% (6/17) of patients with high predicted TSR achieved pCR. The tumour stroma was found to be significantly associated with clinical outcomes in patients with BCa as a result of tumour stroma-immune interactions. The radiomics prediction model provided non-invasive evaluation of TSR and was able to predict pCR in patients receiving NAC for BCa. This work was supported by National Natural Science Foundation of China (Grant No. 82373254 and 81961128027), Guangdong Provincial Natural Science Foundation (Grant No. 2023A1515010258), Science and Technology Planning Project of Guangdong Province (Grant No. 2023B1212060013). Science and Technology Program of Guangzhou (SL2022A04J01754), Sun Yat-Sen Memorial Hospital Clinical Research 5010 Program (Grant No. SYS-5010Z-202401).

AZUR-2, a phase III, open-label, randomized study of perioperative dostarlimab monotherapy vs standard of care in previously untreated patients with T4N0 or stage III dMMR/MSI-H resectable colon cancer.

TPS240 Background: Emerging evidence suggests neoadjuvant therapy may benefit patients (pts) with advanced colon cancer. Neoadjuvant immunotherapy has shown promising efficacy for early-stage mismatch repair deficient (dMMR) colon cancer [1,2]. Evidence from other immunogenic tumors suggests that a perioperative approach with immunotherapy may further improve survival outcomes [3,4]. Dostarlimab (anti-PD-1) has shown a favorable benefit:risk profile in previously untreated dMMR locally advanced rectal cancer [5] and in advanced dMMR/microsatellite instability-high (MSI-H) solid tumors [6]. AZUR-2 (NCT05855200) will evaluate the efficacy and safety of perioperative dostarlimab monotherapy vs standard of care (SOC) in pts with previously untreated T4N0 or Stage III dMMR/MSI-H resectable colon adenocarcinoma. Methods: AZUR-2 is a global, multicenter, randomized, open-label Phase III study. Approximately 711 pts will be enrolled. Key eligibility criteria include age ≥18 years, no prior therapy or surgery for colon cancer, ECOG PS 0–1, and no symptomatic bowel obstruction. Central prescreening is available at sites without local dMMR/MSI-H testing (not required if dMMR/MSI-H already determined). Pts stratified by clinical tumor/node (TN) staging will be randomized 2:1 to receive dostarlimab pre- and post-surgery, or surgery followed by SOC (adjuvant FOLFOX/CAPEOX for 3–6 months or watch and wait approach per physician’s discretion). Primary endpoint is event-free survival (EFS) (events: recurrence based on radiological assessment by blinded independent central review or pathological assessment of new lesions, disease progression precluding surgery, treatment (tx)-related toxicity precluding surgery, or death). Secondary endpoints include pathological response, OS, and safety. Disease assessments will consist of CT scans of chest, abdomen, and pelvis. Pts will undergo safety follow-up at end of tx and at 30 and 90 days after last dose. Efficacy will be assessed in all pts randomized (intent-to-treat) and safety in all pts who receive surgery or ≥1 dose of study tx. A stratified log-rank test will be used for primary analysis. The primary analysis for EFS with &gt;90% power will be conducted after all pts have been followed for ≥3 years. An interim EFS analysis will be conducted ~12 months earlier. Exploratory endpoints include pt-reported outcomes to evaluate health-related quality of life.

Laparoscopic Tumorectomy for an Unusual Pelvic Retroperitoneal Leiomyoma: A Case Report

Leiomyomas are benign tumors, mostly located in the uterus. The pelvic localization is quite rare, and it is associated with unusual growth patterns. It is important to make an adequate differential diagnosis between malignant and benign retroperitoneal neoplasm because treatment is different. When it is not possible to have a precise preoperative diagnosis, a laparoscopic or laparotomy surgical tumorectomy is often required. To obtain a certain diagnosis, the goal of surgery is ensuring the complete excision of neoplasms and preservation of urination, defecation, and sexual function. We report a rare case of a 58-year-old woman who underwent a laparoscopic tumorectomy for a pelvic retroperitoneal leiomyoma. The patient reported occasional episodes of dull pain in the pelvic region. Pelvic contrast CT scan and magnetic resonance imaging (MRI) showed a retroperitoneal solid mass in contiguity with the posterior wall of the uterine body-isthmus, to be referred to as a pedunculated uterine fibroma strictly posteriorly adherent to the sigma. She first underwent to explorative laparoscopy by a gynecologist who did not find any uterine mass. The patient was subsequently admitted to the department of general surgery and has done a second operative laparoscopy which highlighted the presence of an extra-peritoneal para-rectal mass which was completely excised. The histological examination of tumor indicated that it was a leiomyoma. The postoperative course was uneventful, and the patient was discharged in III post-operative day (POD).