Intraoperative pelvic neuromonitoring based on bioimpedance signals: a new method analyzed on 30 patients.

PURPOSE: Increasing importance has been attributed in recent years to the preservation of the pelvic autonomic nerves during rectal resection to achieve better functional results. In addition to improved surgical techniques, intraoperative neuromonitoring may be useful. METHODS: This single-arm prospective study included 30 patients who underwent rectal resection performed with intraoperative neuromonitoring by recording the change in the tissue impedance of the urinary bladder and rectum after stimulation of the pelvic autonomic nerves. The International Prostate Symptom Score, the post-void residual urine volume and the Low Anterior Resection Syndrome Score (LARS score) were assessed during the 12-month follow-up period. RESULTS: A stimulation-induced change in tissue impedance was observed in 28/30 patients (93.3%). In the presence of risk factors such as low anastomosis, neoadjuvant radiotherapy and a deviation stoma, an average increase of the LARS score by 9 points was observed 12 months after surgery (p = 0,04). The function of the urinary bladder remained unaffected in the first week (p = 0,7) as well as 12 months after the procedure (p = 0,93). CONCLUSION: The clinical feasibility of the new method for pelvic intraoperative neuromonitoring could be verified. The benefits of intraoperative pelvic neuromonitoring were particularly evident in difficult intraoperative situations with challenging visualization of the pelvic nerves.

Biparametric MRI of the prostate radiomics model for prediction of pelvic lymph node metastasis in prostate cancers : a two-centre study.

OBJECTIVES: Exploring the value of adding correlation analysis (radiomic features (RFs) of pelvic metastatic lymph nodes and primary lesions) to screen RFs of primary lesions in the feature selection process of establishing prediction model. METHODS: A total of 394 prostate cancer (PCa) patients (263 in the training group, 74 in the internal validation group and 57 in the external validation group) from two tertiary hospitals were included in the study. The cases with pelvic lymph node metastasis (PLNM) positive in the training group were diagnosed by biopsy or MRI with a short-axis diameter ≥ 1.5 cm, PLNM-negative cases in the training group and all cases in validation group were underwent both radical prostatectomy (RP) and extended pelvic lymph node dissection (ePLND). The RFs of PLNM-negative lesion and PLNM-positive tissues including primary lesions and their metastatic lymph nodes (MLNs) in the training group were extracted from T2WI and apparent diffusion coefficient (ADC) map to build the following two models by fivefold cross-validation: the lesion model, established according to the primary lesion RFs selected by t tests and absolute shrinkage and selection operator (LASSO); the lesion-correlation model, established according to the primary lesion RFs selected by Pearson correlation analysis (RFs of primary lesions and their MLNs, correlation coefficient > 0.9), t test and LASSO. Finally, we compared the performance of these two models in predicting PLNM. RESULTS: The AUC and the DeLong test of AUC in the lesion model and lesion-correlation model were as follows: training groups (0.8053, 0.8466, p = 0.0002), internal validation group (0.7321, 0.8268, p = 0.0429), and external validation group (0.6445, 0.7874, p = 0.0431), respectively. CONCLUSION: The lesion-correlation model established by features of primary tumors correlated with MLNs has more advantages than the lesion model in predicting PLNM.

Evaluation of the performance of digital x-ray systems in pelvis radiography.

The aim of this study was to investigate the performance of eight digital radiography systems and to optimise the dose-image quality relationship for digital pelvis radiography. The study involved eight digital radiography systems used for general examinations at Vilnius University Hospital Santaros Klinikos. An anthropomorphic pelvic phantom (CIRS, US) was used to simulate a patient undergoing clinical pelvis radiography. Dose quantities entrance surface dose, dose area product (DAP) and exposure parameters (kVp, mA, mAs) were measured and the effects on the images were evaluated, considering physical contrast to noise ratio (CNR) and observer-based evaluations as image quality metrics. Increasing the tube voltage by 5 kVp from standard protocol led to a reduction in radiation dose (DAP) by 12%-20% with a slight impact on image quality (CNR decreases by 2%-10%). There was an inter-observer variability in image rating across different equipment (kappa value between 0 and 0.3); however, both observers agreed that increasing kVp up to 85-90 kV had no effect on perceived image quality. The results indicate that optimisation strategies should be tailored specifically for each x-ray system since significant performance differences and wide variations in radiation dose exist across various digital radiography systems used in clinical settings. The use of high kVp can be used for dose optimisation in digital pelvis radiography without compromising image diagnostic accuracy.

[A case in which endoscopic ultrasound-guided transrectal drainage was effective for pelvic abscess].

The patient, a 33-year-old female, presented to her local doctor with lower abdominal pain. She was referred to our hospital for a plain CT scan, which revealed signs of ileitis. Because acute appendicitis could not be ruled out, the patient was hospitalized. On the third day of hospitalization, she underwent laparoscopic appendicectomy for perforated appendicitis. However, the inflammatory response persisted despite continued antibacterial treatment; we diagnosed this to be due to the formation of a postoperative residual abscess. Since drainage of the abscess was deemed necessary, the patient underwent EUS-guided transrectal drainage on the 26th day of hospitalization. The patient had a favorable postoperative course and was discharged on the 31st day of hospitalization. Along with some literature review, this report details a case in which transrectal drainage under ultrasound endoscopy was effective in treating a pelvic abscess. We report a case of a pelvic abscess that was drained through the rectum under EUS guidance and an internal and external fistula tube was placed. The abscess resolved without complications.

Shape variations of pelvis in different classes of dogs using geometric morphometry.

The ossa coxae are the bones that connect the hindlimbs to the axial skeleton. The right and left os coxae join at the median plane to form the pelvis. In this study, variations in pelvis shape and the asymmetric structure of the pelvis were investigated across different classes of dogs. To achieve this, computed tomography images of the pelvis were obtained from 35 dogs, and 3D modelling of the pelvis was created. Subsequently, 45 landmarks were identified on these models. As a result of the Principal Component Analysis, the shape variation was observed in the pelvic canal and crista iliaca. Directional asymmetry between Principal Component 1 and Principal Component 2 accounted for 33.84% of the total variation, while fluctuating asymmetry contributed 23.66%. Canonical variate analysis revealed that canonical variate (CV) 1 explained 56.56% of the total variation between groups, with CV 2 explained 28.98%. Male dogs exhibited greater pelvic variation than females. Procrustes ANOVA indicated that the greatest proportion of shape variation corresponds to the effect of differences among individuals. While directional asymmetry was statistically significant, fluctuating asymmetry was not. Male dogs displayed more pronounced pelvic shape asymmetry, typically towards the right. Gundogs had a narrower pelvic canal and a wide crista iliaca, whereas terriers had a wider pelvic canal and smaller crista iliaca in shape. Geometric morphometry enables statistical analysis and the derivation of average shapes from samples, making it a vital tool in veterinary anatomy. This study provides insights into pelvic geometric morphometry across different classes of dogs.

Synthetic CT generation for pelvic cases based on deep learning in multi-center datasets.

BACKGROUND AND PURPOSE: To investigate the feasibility of synthesizing computed tomography (CT) images from magnetic resonance (MR) images in multi-center datasets using generative adversarial networks (GANs) for rectal cancer MR-only radiotherapy. MATERIALS AND METHODS: Conventional T2-weighted MR and CT images were acquired from 90 rectal cancer patients at Peking University People's Hospital and 19 patients in public datasets. This study proposed a new model combining contrastive learning loss and consistency regularization loss to enhance the generalization of model for multi-center pelvic MRI-to-CT synthesis. The CT-to-sCT image similarity was evaluated by computing the mean absolute error (MAE), peak signal-to-noise ratio (SNRpeak), structural similarity index (SSIM) and Generalization Performance (GP). The dosimetric accuracy of synthetic CT was verified against CT-based dose distributions for the photon plan. Relative dose differences in the planning target volume and organs at risk were computed. RESULTS: Our model presented excellent generalization with a GP of 0.911 on unseen datasets and outperformed the plain CycleGAN, where MAE decreased from 47.129 to 42.344, SNRpeak improved from 25.167 to 26.979, SSIM increased from 0.978 to 0.992. The dosimetric analysis demonstrated that most of the relative differences in dose and volume histogram (DVH) indicators between synthetic CT and real CT were less than 1%. CONCLUSION: The proposed model can generate accurate synthetic CT in multi-center datasets from T2w-MR images. Most dosimetric differences were within clinically acceptable criteria for photon radiotherapy, demonstrating the feasibility of an MRI-only workflow for patients with rectal cancer.

Pelvic ultrasound and pubertal attainment in girls with sexual precocity: the pivotal role of uterine volume in predicting the timing of menarche.

Introduction: Among girls assessed for pubertal precocity, pelvic ultrasound (pUS) may represent a pivotal tool to predict the time expected to elapse between sonographic assessment and the onset of menarche (TUS-M). Accordingly, the present analysis is meant to define the statistical relationship between sonographic parameters and TUS-M, in order to identify the most reliable predictor of the timing of menarche. Methods: Retrospective, multicenter analysis. Girls assessed for sexual precocity and showing sonographic and clinical findings consistent with pubertal onset upon referral were considered eligible. Patients treated with GnRH analogues were excluded and only those who had subsequently achieved complete and spontaneous pubertal attainment and for whom the exact date of menarche was available were included. Overall, we enrolled 184 girls from five tertiary care Italian Centers. Results: The time elapsed (months) between baseline endocrine assessment and spontaneous achievement of menarche showed a negative statistically significant correlation (p<0.0001) with LH (r:-0.61), FSH (r:-0.59), estradiol (r:-0.52) and stimulated LH values (r:-0.58). Among pUS parameters, ovarian volume (r:-0.17 left, -0.30 right) and uterine body-to-cervix ratio (r:-0.18) poorly correlated with TUS-M, while uterine diameters (r:-0.61 longitudinal, -0.64 anteroposterior) and volume (r:-0.70) achieved a highly statistical significance (p<0.0001). Uterine volume (UV) showed a negative logarithmic relationship with TUS-M and represented the most reliable predictor of the timing of menarche in uni- and multivariable analyses (p <0.001). ROC analyses identified the UV thresholds that best predict the onset of menarche within 18, 12 and 6 months, respectively: 3.76, 6.02 and 8.80 ml. Conclusion: The logarithm of UV shows the best statistical performance in predicting the timing of menarche in girls assessed for pubertal precocity. Accordingly, we developed a user-friendly online application that provides clinicians with an estimation of the months expected to elapse before menarche, based on the UV recorded upon pUS.

Hip and pelvic geometry as predictors of knee osteoarthritis severity.

Malalignment is one of the most critical risk factors for knee osteoarthritis (KOA). Biomechanical factors such as knee varus or valgus, hip-knee-ankle angle, and femoral anteversion affect KOA severity. In this study, we aimed to investigate KOA severity predictive factors based on hip and pelvic radiographic geometry. In this cross-sectional study, 125 patients with idiopathic KOA were enrolled. Two investigators evaluated the knee and pelvic radiographs of 125 patients, and 16 radiological parameters were measured separately. KOA severity was categorized based on the medial tibiofemoral joint space widths (JSW). Based on JSW measurements, 16% (n = 40), 8.8% (n = 22), 16.4% (n = 41), and 56.8% (n = 147) were defined as grades 0, 1, 2, 3, respectively. There were significant differences between the JSW groups with respect to hip axis length, femoral neck-axis length, acetabular width, neck shaft angle (NSA), outer pelvic diameter, midpelvis-caput distance, acetabular-acetabular distance, and femoral head to femoral head length (P < .05). Two different functions were obtained using machine learning classification and logistic regression, and the accuracy of predicting was 74.4% by using 1 and 89.6% by using both functions. Our findings revealed that some hip and pelvic geometry measurements could affect the severity of KOA. Furthermore, logistic functions using predictive factors of hip and pelvic geometry can predict the severity of KOA with acceptable accuracy, and it could be used in clinical decisions.

Gender differences in unintended anterior pelvic roll during primary THA in the lateral position.

BACKGROUND: Fundamental morphologic differences between male and female pelvises are historically recognised. Despite this, little consideration has been given as to whether or not conventional positioning supports used for primary total hip arthroplasties (THAs) performed in the lateral position do an equally effective job of maintaining the intended set up position when comparing genders. Given that recent research has highlighted that unintended pelvic roll occurs commonly during hip surgery, and that such movement may have a mechanically-deleterious consequence upon final construct performance and complication rates, this study was undertaken to explore the differences in pelvic roll between genders. METHODS: The output of a high-precision, commercially-available, imageless intra-operative navigation system was prospectively-collected for 85 consecutive patients undergoing unilateral, primary THAs. These data were separated by gender and were utilised to determine differences in pelvic movement around a central sagittal axis. RESULTS: Demographic data were similar between genders, with no between-group differences in mean BMI (p = 0.09) or indication for surgery (p = 0.66), however participating males (mean 68.04) were slightly younger than females (mean 73.31). The mean anterior pelvic roll for females was 9.50°, and for males 8.68°. There were no statistically significant independent correlations observed between gender (p = 0.21) and pelvic roll. CONCLUSION: The findings of this novel study do not suggest gender differences in the magnitude of unintended, intra-operative, anterior roll, even when corrected for BMI and surgical indication. Average roll of ~ 9° was demonstrated across both groups. An awareness of such positional change during THA surgery may reduce potentially-avoidable post-operative complications.

The Incidence and Characteristics of Pelvic-Origin Varicosities in Patients with Complex Varices Evaluated by Ultrasonography.

OBJECTIVE: The purpose of this study was to evaluate the incidence of gonadal vein refluxes associated with lower-extremity varicose veins with Doppler ultrasonography (DUS). METHOD: A total of 6279 patients with venous disease-related symptoms of the lower extremity were evaluated with DUS in the vascular lab. Gonadal vein reflux using abdominal ultrasound was further evaluated in patients with unusual varices, defined as varices in the inguinal, inner or upper thigh and the vulvar area without refluxes in the saphenofemoral junction (SPJ). Those patients who showed gonadal vein reflux were diagnosed as having pelvic-origin varicosity. RESULTS: Unusual varices were found in a total of 237 patients (3.8%), and of these patients, pelvic-origin varicosity was discovered with transabdominal ultrasound in 156 (65.8%). A total of 66.7% (n = 38/57) of unusual varix patients with pelvic pain had gonadal vein reflux. The measurement of gonadal vein diameter was larger in ultrasonography than CT scans (8.835 vs. 8.81, p < 0.001). Two patients with severe symptoms but no obstructive venous diseases were treated with gonadal vein embolization. CONCLUSION: The incidence of pelvic-origin varicosities was 2.5% (n = 156/6279). However, more than half of the patients with unusual varices had gonadal vein reflux and 24.4% of these patients also presented with pelvic pain. The evaluation of pelvic-origin varicosities should be performed in patients who present with unusual forms of varices of the lower extremity.

Spinal loads during dynamic full flexion and return to standing posture in different age and sex groups: A musculoskeletal model study.

During forward flexion, spine motion varies due to age and sex differences. Previous studies showed that lumbar/pelvis range of flexion (RoF) and lumbo-pelvic ratio (L/P) are age/sex dependent. How variation of these parameters affects lumbar loading in a normal population requires further assessment. We aimed to estimate lumbar loads during dynamic flexion-return cycle and the differences in peak loads (compression) and corresponding trunk inclinations due to variation in lumbar/pelvis RoF and L/P. Based on in vivo L/P (0.11-3.44), temporal phases of flexion (early, middle, and later), the lumbar (45-55°) and hip (60-79°) RoF; full flexion-return cycles of six seconds were reconstructed for three age groups (20-35, 36-50 and 50+ yrs.) in both sexes. Six inverse dynamic analyses were performed with a 50th percentile model, and differences in peak loads and corresponding trunk inclinations were calculated. Peak loads at L4-L5 were 179 N higher in younger males versus females, but 228 N and 210 N lower in middle-aged and older males, respectively, compared to females. Females exhibited higher trunk inclinations (6°-20°) than males across all age groups. Age related differences in L4-L5 peak loads and corresponding trunk inclinations were found up to 415 N and 19° in males and 152 N and 13° in females. With aging, peak loads were reduced in males but were found non-monotonic in females, whereas trunk inclinations at peak loads were reduced in both sexes from young to middle/old age groups. In conclusion, lumbar loading and corresponding trunk inclinations varied notably due to age/sex differences. Such data may help distinguishing normal or pathological condition of the lumbar spine.

Finite element analysis of hip fracture risk in elderly female: The effects of soft tissue shape, fall direction, and interventions.

This study investigates the effects of fall configurations on hip fracture risk with a focus on pelvic soft tissue shape. This was done by employing a whole-body finite element (FE) model. Soft tissue thickness around the pelvis was measured using a standing CT system, revealing a trend of increased trochanteric soft tissue thickness with higher BMI and younger age. In the lateroposterior region from the greater trochanter, the soft tissues of elderly females were thin with a concave shape. Based on the THUMS 5F model, an elderly female FE model with a low BMI was developed by morphing the soft tissue shape around the pelvis based on the CT data. FE simulation results indicated that the lateroposterior fall led to a higher femoral neck force for the elderly female model compared to the lateral fall. One reason may be related to the thin soft tissue of the pelvis in the lateroposterior region. Additionally, the effectiveness of interventions that can help mitigating hip fractures in lateroposterior falls on the thigh-hip and hip region was assessed using the elderly female model. The attenuation rate of the femoral neck force by the hip protector was close to zero in the thigh-hip fall and high in the hip fall, whereas the attenuation rate of the compliant floor was high in both falls. This study highlights age-related changes in the soft tissue shape of the pelvis in females, particularly in the lateroposterior regions, which may influence force mitigation for the hip joint during lateroposterior falls.

Pelvic lymph node mapping in prostate cancer: examining the impact of PSMA PET/CT on radiotherapy decision-making in patients with node-positive disease.

INTRODUCTION: Prostate Specific Membrane Antigen (PSMA) imaging with Positron Emission Tomography (PET) plays a crucial role in prostate cancer management. However, there is a lack of comprehensive data on how PSMA PET/CT (Computed Tomography) influences radiotherapeutic decisions, particularly in node-positive prostate cancer cases. This study aims to address this gap by evaluating two primary objectives: (1) Mapping the regional and non-regional lymph nodes (LNs) up to the aortic bifurcation and their distribution using conventional methods with CT compared to PSMA PET/CT, and (2) assessing the impact of PSMA PET/CT findings on radiotherapeutic decisions. METHODS: A retrospective analysis of 95 node-positive prostate cancer patients who underwent both CT and PSMA PET/CT imaging prior to primary radiotherapy and androgen deprivation therapy (ADT) was conducted. The analysis focused on identifying LNs in various regions including the common iliac, external iliac, internal iliac, obturator, presacral, mesorectal, inguinal, and other stations. Treatment plans were reviewed for modifications based on PSMA PET/CT findings, and statistical analysis was performed to identify predictors for exclusive nodal positivity on PSMA PET/CT scans. RESULTS: PSMA PET/CT identified additional positive nodes in 48% of cases, resulting in a staging shift from N0 to N1 in 29% of patients. The most frequent metastatic LNs were located in the external iliac (76 LNs; 34%), internal iliac (43 LNs; 19%), and common iliac (35 LNs; 15%) stations. In patients with nodes only detected on PSMA PET the most common nodes were in the external iliac (27, 40%), internal iliac (13, 19%), obturator (11, 15%) stations. Within the subgroup of 28 patients exclusively demonstrating PSMA PET-detected nodes, changes in radiotherapy treatment fields were implemented in 5 cases (18%), and a dose boost was applied for 23 patients (83%). However, no discernible predictors for exclusive nodal positivity on PSMA PET/CT scans emerged from the analysis. DISCUSSION: The study underscores the pivotal role of PSMA PET/CT compared to CT alone in accurately staging node-positive prostate cancer and guiding personalized radiotherapy strategies. The routine integration of PSMA PET/CT into diagnostic protocols is advocated to optimize treatment precision and improve patient outcomes.

Pelvic rotation correction combined with Schroth exercises for pelvic and spinal deformities in mild adolescent idiopathic scoliosis: A randomized controlled trial.

INTRODUCTION: Individualized treatment of spinal deformity is needed for adolescent idiopathic scoliosis (AIS), and the integration of pelvic rotation correction based on proprioceptive neuromuscular facilitation (PNF) into regular physiotherapy may be a promising approach. However, few high-quality studies have investigated its effects. This study aimed to evaluate the efficacy of pelvic rotation correction combined with Schroth exercises in the treatment of mild AIS. METHODS: This was a randomized controlled trial. Forty-two AIS patients were randomly divided into experimental and control groups. Both groups underwent 20 therapeutic sessions over 24 weeks. All patients (n = 42) performed Schroth exercises at each session. In addition, the experimental group (n = 21) also participated in a pelvic rotation correction program based on PNF at each session. The primary outcome was the concave/convex ratio of hipbone widths, and the secondary outcomes included the Cobb angle, trunk rotation angle, self-perception, apical vertebral translation, and apical vertebral rotation. Patients were evaluated before and after 24 weeks of intervention. RESULTS: There was a significant between-group difference in the change from baseline between the experimental and control groups for the following parameters: concave/convex ratio 2.89% (95% confidence interval [CI], 1.58 to 4.20, P<0.001), trunk rotation angle -1.26° (95% CI, -2.20 to -0.32; P = 0.01), and apical vertebral rotation improved by at least one class from baseline in 3 patients (14.3%) in the control group and 9 patients (42.9%) in the experimental group (P = 0.04). While Cobb angle -1.60° (95% CI, -7.75 to 0.54; P = 0.14), self-image 0.149 (95% CI, 0.001 to 0.297; P = 0.049), apical vertebral translation -0.58 mm (95% CI, -3.83 to 2.67; P = 0.72), and pelvic obliquity 0.10° (95% CI, -0.21 to 0.41; P = 0.52) did not differ significantly. CONCLUSIONS: Pelvic rotation correction combined with Schroth exercises more effectively improved pelvic axial rotation and other spinal deformities, including trunk rotation and apical vertebral rotation, than Schroth exercises alone in the treatment of mild AIS.

Pediatric Pelvis.

The development of the pelvis follows a predictable pattern of ossification that involves the maturation of bone, synchondroses, and apophyses. These growth centers appear and close at distinct times during skeletal maturity and give rise to structural changes in the pelvis that can be distinctively appreciated on various imaging modalities. Accurate interpretation of radiologic images requires knowledge of skeletal development because the varying appearance of the maturing pediatric pelvis may be mistaken for pathology. In addition, many normal features within the pelvis can be erroneously perceived as injury. This article incorporates a multimodality review of normal pelvic maturation, a discussion of developmental variants, and a description of common injuries unique to the pediatric pelvis.

A propensity-score-matched comparison of standard and extended pelvic lymph node dissection in robot-assisted laparoscopic radical cystectomy.

To compare the difference in perioperative outcomes between standard pelvic lymph node dissection (sPLND) and extended pelvic lymph node dissection (ePLND) in robot-assisted radical cystectomy (RARC) and evaluate the survival outcomes. The clinical data were retrospectively collected from patients who underwent RARC between January 2016 and December 2020 in Nanjing Drum Hospital. The patients were divided into sPLND and ePLND group according to the extent of pelvic lymph node dissection. Finally, 80 pairs of patients obtained for two groups by propensity score matching (PSM) and their perioperative and survival outcomes were analyzed. The median number of dissected lymph nodes (LN) after PSM was 13 in sPLND group and 16 in ePLND group (P = 0.004). Perioperative complications were similar between 2 groups. After PSM, ePLND improved 5-year RFS and OS in all patients (85.74 vs. 61.94%, P = 0.004; 82.80 vs. 67.50%, P = 0.033), patients with ≥ T3 disease (73.66 vs. 23.86%; P = 0.007; 68.20 vs. 36.20%; P = 0.032) and patients with LN metastasis (67.70 vs. 7.33%; P = 0.004; 60.60 vs. 16.67%; P = 0.045) compared to sPLND. Extended PLND significantly increased lymph node yield without increasing complication and improved RFS and OS compared to sPLND.

Pelvic Necrosis with Formation of a Pelvic "Cloaca" and Necrotizing Soft Tissue Infection After Radiation for Anal Squamous Cell Carcinoma.

BACKGROUND Anal squamous cell carcinoma (SCC) is a rare cancer commonly treated with the Nigro protocol, which combines chemotherapy and radiation. Patients who received radiation therapy prior to modern advances, such as computer-based tumor targeting, volumetric planning, and intensity-modulated radiation therapy, experience more acute and chronic adverse effects. Though exceedingly rare, radiation necrosis is of particular concern, as it can result in significant morbidity and mortality, including complex pelvic fistula formation and predisposition to potentially life-threatening necrotizing soft-tissue infections. CASE REPORT Here, we present a case of a 66-year-old woman with a prior history of anal SCC stage T3N×M0 who was treated with the Nigro protocol. Her treatment course was complicated by radiation proctitis, necessitating fecal diversion and ureteral strictures, requiring frequent stent exchanges. She presented 18 years after her cancer treatment, with widespread necrosis of her pelvic organs and surrounding soft tissue, resulting in formation of a large pelvic "cloaca", with a superimposed necrotizing soft-tissue infection. She was successfully treated by expedited resuscitation, septic source control, using multiple extensive debridements, and complete urinary diversion, utilizing a multidisciplinary team. CONCLUSIONS This case highlights the importance of monitoring patients for signs of radiation toxicity, particularly in patients who received radiation prior to the latest technological advancements, as they are at increased risk of developing severe, late adverse effects decades after treatment. When these complications are recognized, early and aggressive intervention is required to spare the patient significant morbidity and mortality.

Triangular spinopelvic fixation for U-shaped sacral fractures and tile C pelvic disruptions: counter-nutation (anteflexion and rotation) load-bearing instability requires complementary anterior pelvic ring fixation.

Unstable trauma lesion of the spinopelvic junction, including U-shaped sacral fractures and Tile C pelvic ring disruptions, require surgical stabilization in order to realign the bone arches of the pelvis thus reducing the upcoming orthopaedic impairment during sitting, standing, and walking positions, decompress the nerves roots of the cauda equina in a view of reducing neurological impairment, and allow early weight bearing. Even though posterior open modified triangular spinopelvic fixation is particularly efficient for treating unstable trauma lesions of the spinopelvic junction, it may not be sufficient alone in order to prevent long-term counter-nutation, i.e. rotation and anteflexion deformity of the anterior pelvis under load bearing conditions. Such progressive deformation is caused by either the slight rotation of the iliac connectors within the head of iliac screws for spinopelvic constructs, or the slight rotation of sacral cancellous bone around transsacral screws in case of percutaneous procedure. Regardless of the posterior surgical technique that is used, complementary anterior pelvic fixation appears mandatory in order to prevent such deformation over time, which can lead to pelvic asymmetry and then gait imbalance.