Pelvic Model Research Articles

Development and Validation of a Laparoscopic Sacrocolpopexy Training Model.

Proper training is necessary to develop the highly specialized skills required to safely perform laparoscopic sacrocolpopexy. Currently, there is no validated training model for laparoscopic sacrocolpopexy that includes dissection of the presacral space, both vaginal and presacral mesh attachments, and peritoneal closure. This study aimed to create a procedure specific hierarchical task analysis for laparoscopic sacrocolpopexy and then develop and validate a corresponding laparoscopic sacrocolpopexy pelvic training model for the simulation environment. This was an observational simulation study that was divided into 5 phases: (1) development of hierarchical task analysis, (2) model construction, (3) participant recruitment and simulation testing, (4) reliability and validity testing, and (5) creation of a standard passing performance measure. Construct, face, and content validity were established for this model. According to the participating experts, the model was able to replicate the steps of presacral dissection, anterior vaginal and sacral mesh attachment, and peritoneal closure. Thirteen trainees and 5 experts completed the simulation, and all "agreed" or "strongly agreed" that the model seemed useful for improving suturing technique and learning the procedure. Additionally, a passing performance measure was determined through contrasting groups methodology. We developed a novel, reusable, and validated training model that can be utilized as a training resource for the many critical skills necessary to safely and efficiently perform laparoscopic sacrocolpopexy.

Building a pelvic organ prolapse diagnostic model using vision transformer on multi-sequence MRI.

Although the uterus, bladder, and rectum are distinct organs, their muscular fasciae are often interconnected. Clinical experience suggests that they may share common risk factors and associations. When one organ experiences prolapse, it can potentially affect the neighboring organs. However, the current assessment of disease severity still relies on manual measurements, which can yield varying results depending on the physician, thereby leading to diagnostic inaccuracies. This study aims to develop a multilabel grading model based on deep learning to classify the degree of prolapse of three organs in the female pelvis using stress magnetic resonance imaging (MRI) and provide interpretable result analysis. We utilized sagittal MRI sequences taken at rest and during maximum Valsalva maneuver from 662 subjects. The training set included 464 subjects, the validation set included 98 subjects, and the test set included 100 subjects (training set n=464, validation set n=98, test set n=100). We designed a feature extraction module specifically for pelvic floor MRI using the vision transformer architecture and employed label masking training strategy and pre-training methods to enhance model convergence. The grading results were evaluated using Precision, Kappa, Recall, and Area Under the Curve (AUC). To validate the effectiveness of the model, the designed model was compared with classic grading methods. Finally, we provided interpretability charts illustrating the model's operational principles on the grading task. In terms of POP grading detection, the model achieved an average Precision, Kappa coefficient, Recall, and AUC of 0.86, 0.77, 0.76, and 0.86, respectively. Compared to existing studies, our model achieved the highest performance metrics. The average time taken to diagnose a patient was 0.38s. The proposed model achieved detection accuracy that is comparable to or even exceeds that of physicians, demonstrating the effectiveness of the vision transformer architecture and label masking training strategy for assisting in the grading of POP under static and maximum Valsalva conditions. This offers a promising option for computer-aided diagnosis and treatment planning of POP.

Modification of transvaginal polypropylene mesh with co-axis electrospun nanofibrous membrane to alleviate complications following surgical implantation

BackgroundSurgeries for treating pelvic organ prolapse involving the utilization of synthetic mesh have been associated with complications such as mesh erosion, postoperative pain, and dyspareunia. This work aimed to reduce the surgical implantation-associated complications by nanofibrous membranes on the surface of the polypropylene mesh. The nanofiber of the nanofibrous membrane, which was fabricated by co-axial electrospinning, was composed of polyurethane as fiber core and gelatin as the fiber out layer. The biocompatibility of the modified mesh was evaluated in vitro by cell proliferation assay, immunofluorescence stain, hematoxylin-eosin (HE) staining, and mRNA sequencing. Polypropylene mesh and modified mesh were implanted in a rat pelvic organ prolapse model. Mesh-associated complications were documented. HE and Picro-Sirius red staining, immunohistochemistry, and western blotting were conducted to assess the interactions between the modified mesh and vaginal tissues.ResultsThe modified mesh significantly enhanced the proliferation of fibroblasts and exerted a positive regulatory effect on the extracellular matrix anabolism in vitro. When evaluated in vivo, no instances of mesh exposure were observed in the modified mesh group. The modified mesh maintained a relatively stable histological position without penetrating the muscle layer or breaching the epidermis. The collagen content in the vaginal wall of rats with modified mesh was significantly higher, and the collagen I/III ratio was lower, indicating better tissue elasticity. The expression of metalloproteinase was decreased while the expression levels of tissue inhibitor of metalloproteinase were increased in the modified mesh group, suggesting an inhibition of collagen catabolism. The expression of TGF-β1 and the phosphorylation levels of Smad3, p38 and ERK1/2 were significantly increased in the modified mesh group. NM significantly improved the biocompatibility of PP mesh, as evidenced by a reduction in macrophage count, decreased expression levels of TNF-α, and an increase in microvascular density.ConclusionsThe nanofibrous membrane-coated PP mesh effectively reduced the surgical implantation complications by inhibiting the catabolism of collagen in tissues and improving the biocampibility of PP mesh. The incorporation of co-axial fibers composed of polyurethane and gelatin with polypropylene mesh holds promise for the development of enhanced surgical materials for pelvic organ prolapse in clinical applications.

A Presacral Fixation Simulation Surgical Training Model for Transvaginal Natural Orifice Transluminal Endoscopic Surgery (vNOTES) Sacrocolpopexy

ObjectiveThe number of sacrocolpopexies performed with transvaginal natural orifice transluminal endoscopic surgery (vNOTES) is increasing, and presacral fixation is the most dangerous step. Therefore, the training opportunities for trainees to become competent in performing vNOTES sacrocolpopexy are very important. Simulation-based training is ideal for filling this gap. The objective of this video article is to demonstrate a simulation surgical training model in vNOTES presacral fixation. SettingThe Department of Gynecology at a university hospital. ParticipantsA urogynecological surgeon. Interventions(1) Establish presacral model (Fig. 1) and pelvic model (Fig. 2). (2) Establish vNOTES single-port platform. (3) Steps of vNOTES presacral fixation: (a) Identify the sacral promontory and right hypogastric nerve (rHN), and incise the right pelvic peritoneum. (b) Expose and open the presacral fascia to expose the middle sacral vessels and anterior longitudinal ligament (ALL). (c) Complete mesh fixation. (d) Close the pelvic peritoneum. This study is exempt from IRB approval. Model materials and corresponding costs are given in Table 1. ConclusionWe present a presacral fixation simulation model during vNOTES sacrocolpopexy. A piece of rubber tissue is attached to pelvic model to accurately simulate the vagina, thus achieving the establishment of the vNOTES single-port platform. The presacral model displays the anatomic hierarchy of presacral exposure: pelvic peritoneum, presacral fascia, presacral space, as well as the ALL, rHN, ureter, and presacral vessels, which are embedded in these layers. Presacral slope design enables realistic presacral suture and mesh fixation. In case of nerve, blood vessel, or ureteral injury during dissection, this model simulates the manifestation through the leakage of different colored liquids. This new model allows the next generation of urogynecological surgeons to acquire adequate training to make them more prepared to perform their initial vNOTES sacrocolpopexy on a patient, possibly increasing future safety and effectiveness.

Automatic 3D pelvimetry framework in CT images and its validation

In the field of spinal pathology, sagittal balance of the spine is usually judged by the spatial structure and morphology of pelvis, which can be represented by pelvic parameters. Pelvic parameters, including pelvic incidence, pelvic tilt and sacral slope, are therefore essential for the diagnosis and treatment of spinal disorders, however, it is a time-consuming and laborious procedure to measure these parameters by traditional methods. In this paper, an automatic measurement framework for pelvic CT images was proposed to calculate three-dimensional (3D) pelvic parameters with the support of deep learning technology. Pelvic images were first preprocessed, and 3D reconstruction was then performed to obtain 3D pelvic model by the Visualization Toolkit. DRINet was trained to segment the femoral head region in the pelvic images, and 3D sphere fitting was performed to locate the femoral heads. In addition, VGG16 was adopted to recognize images containing superior sacral endplate, and the plane growth algorithm was used to fit the plane so that the midpoint and normal vector of the superior sacral endplate could be obtained. Finally, 3D pelvic parameters were automatically calculated, and compared with manual measurements for 15 patients. The proposed framework automatically generated 3D pelvic models, and calculated two-dimensional (2D) and 3D pelvic parameters from continuous CT images. Experiments demonstrated that the framework can greatly speed up the calculation of pelvic parameters, and these parameters are accurate when compared with the manual measurements. In conclusion, the proposed framework demonstrates good performance on automatic pelvimetry measurement by incorporating deep learning technology, and can well replace the traditional methods for pelvic parameter measurement.

Functional outcome of the anterior vaginal wall in a pelvic surgery injury rat model after treatment with stem cell-derived progenitors of smooth muscle cells

BackgroundStem-cell-derived therapy is a promising option for tissue regeneration. Human iPSC-derived progenitors of smooth muscle cells (pSMCs) exhibit limited proliferation and differentiation, which minimizes the risk of tumor formation while restoring smooth muscle cells (SMCs). Up to 29% of women suffer from recurrence of vaginal prolapse after prolapse surgery. Therefore, there is a need for therapies that can restore vaginal function. SMCs contribute to vaginal tone and contractility. We sought to examine whether human pSMCs can restore vaginal function in a rat model.MethodsFemale immunocompromised RNU rats were divided into 5 groups: intact controls (n = 12), VSHAM (surgery + saline injection, n = 35), and three cell-injection groups (surgery + cell injection using pSMCs from three patients, n = 14/cell line). The surgery to induce vaginal injury was analogous to prolapse surgery. Menopause was induced by surgical ovariectomy. The vagina, urethra, bladder were harvested 10 weeks after surgery (5 weeks after cell injection). Organ bath myography was performed to evaluate the contractile function of the vagina, and smooth muscle thickness was examined by tissue immunohistochemistry. Collagen I, collagen III, and elastin mRNA and protein expressions in tissues were assessed.ResultsVaginal smooth muscle contractions induced by carbachol and KCl in the cell-injection groups were significantly greater than those in the VSHAM group. Collagen I protein expression in the vagina of the cell-injections groups was significantly higher than in the VSHAM group. Vaginal elastin protein expression was similar between the cell-injection and VSHAM groups. In the urethra, gene expression levels of collagen I, III, and elastin were all significantly greater in the cell-injection groups than in the VSHAM group. Collagen I, III, and elastin protein expression of the urethra did not show a consistent trend between cell-injection groups and the VSHAM group.ConclusionsHuman iPSC-derived pSMCs transplantation appears to be associated with improved contractile function of the surgically injured vagina in a rat model. This is accompanied by changes in extracellular protein expression the vagina and urethra. These observations support further efforts in the translation of pSMCs into a treatment for regenerating the surgically injured vagina in women who suffer recurrent prolapse after surgery.

Fetus descent simulation with the active uterine contraction during the vaginal delivery: MRI-based evaluation and uncertainty quantification

Finite element models ranging from single to multiscale models have been widely used to gain valuable insights into the physiological delivery process and associated complication scenarios. However, the fetus descent simulation with the active uterine contraction is still challenging for validation and uncertainty quantification issues. The present study performed a fetus descent simulation using the active uterine contraction. Then, simulation outcomes were evaluated using theoretical and in vivo MRI childbirth data. Moreover, parameter uncertainty and propagation were also performed. A maternal pelvis model was developed. The active uterine contraction was modeled using a transversely isotropic Mooney–Rivlin material. Displacement trajectories were compared between simulation, theoretical and in vivo MRI childbirth data. Monte Carlo (M.C) and Polynomial Chaos Expansion (PCE) methods were applied to quantify uncertain parameters and their propagations. Obtained results showed that fetal descent behavior is consistent with the MRI-based observation as well as the theoretical trajectory (curve of Carus). The head downward vertical displacement ranges from 0 to approximately 47 mm. A reduction of 50% in uterine size was observed during the simulation. Three high-sensitive parameters ( C 1 , C 2 , Ca 0 ) were also identified. Our study suggested that the use of the active uterine contraction is essential for simulating vaginal delivery but the global parameter sensitivity, parameter uncertainty, and outcome evaluation should be carefully performed. As a perspective, the developed approach could be extrapolated for patient-specific modeling and associated delivery complication simulations to identify risks and potential therapeutic solutions.

Bispherical metal augment improved biomechanical stability in severe acetabular deficiency reconstruction: a comparative finite element analysis

BackgroundThis study used finite element analysis (FEA) to compare the biomechanical stability of bispherical metal augment (BA) and wedge-shaped trabecular-metal augment (TA) in different acetabular defect reconstruction models, thereby explaining the application value of this novel bispherical augment in complex hip revision.MethodsThree different acetabular defect pelvis models originating from three representative patients with different types of severe acetabular defects (Paprosky IIC, IIIA, and IIIB) were constructed and reconstruction with BA and TA technique was simulated. Based on the FEA models, the displacement of reconstruction implants, relative displacement of bone implants, and hemi-pelvic von Mises stress were investigated under static loads.ResultsBA acquired smaller reconstruction system displacement, less relative displacement of bone implants, and lower pelvic von Mises stress than TA in all Paprosky IIC, IIIA, and IIIB defect reconstructions.ConclusionThe FEA results show that BA could acquire favourable biomechanical stability in severe acetabular defect reconstruction. This technique is a reliable method in complex hip revision.

Polycaprolactone-based shape memory foams as self-fitting vaginal stents

There is an urgent critical need for a patient-forward vaginal stent that can prevent debilitating vaginal stenosis that occurs after pelvic radiation treatments and vaginal reconstruction. To this end, we developed a self-fitting vaginal stent based on a shape-memory polymer (SMP) foam that can assume a secondary, compressed shape for ease of deployment. Upon insertion, the change in temperature and hydration initiates foam expansion to shape fit to the individual patient and restore the lumen of the stent to allow egress of vaginal secretions. To achieve rapid actuation at physiological temperature, we investigated the effect of architecture of two photocurable, polycaprolactone (PCL) macromers. Star-PCL-tetraacrylate displayed a reduced melting temperature as compared to a linear-PCL-diacrylate. Upon fabrication into high porosity foams with emulsion-templating, both compositions displayed shape fixity (>90 %) in a crimped, temporary shape. However, only the PCL star-foams displayed shape recovery (∼84 %) at 37 °C with expansion back to its permanent shape. A custom mold and curing system were then used to fabricate the PCL star-foams into hollow, cylindrical stents. The stent was crimped to its temporary insertion shape (50 % reduction in diameter, OD ∼ 11 mm) with a custom radial crimper and displayed excellent shape fixity for deployment (> 95 %) and shape recovery (∼ 100 %). To screen vaginal stents, we developed a custom benchtop pelvic model that simulated vaginal anatomy, temperatures, and pressures with an associated computational model. The crimped SMP vaginal stent was deployed in the model and expanded to walls of the canal (∼70 % increase in cross-sectional area) in less than 5 min after irrigation with warm water. The vaginal stent demonstrated retention of vaginal caliber with less than 10 % decrease in cross-sectional area under physiological pressures. Collectively, this work demonstrates the potential for SMP foams as self-fitting vaginal stents to prevent stenosis and provides new open-source tools for the iterative design of other gynecological devices. Statement of significanceVaginal stenosis, a painful narrowing of the vaginal canal, is a common complication after pelvic radiation therapy or reconstructive surgery. To address this clinical need, we have created a self-fitting vaginal stent from a shape-memory polymer foam. The stent compresses for easy insertion and then expands to adapt to each patient's anatomy to maintain an open vaginal canal and prevent stenosis. This innovative stent provides a patient-friendly solution that could make a significant difference for women undergoing pelvic treatments by reducing pain, aiding recovery, and improving quality of life.

Lumbopelvic Stabilization with Two Methods of Triangular Osteosynthesis: A Biomechanical Study.

(1) Background: Pelvic fractures, and particularly instabilities of the dorsal pelvic ring, are becoming increasingly prevalent, particularly in orthogeriatric patients. Spino-pelvic triangular osteosynthesis is an effective approach to achieve sufficient stabilization in vertically unstable fractures. This study compares two types of osteosynthesis: the conventional one and a novel instrumentation where the iliosacral screw is placed through a fenestrated iliac screw. (2) Methods: Sixteen artificial osteoporotic L5+pelvis models with an unstable sacral fracture have been instrumented with either an iliac screw connected with a rod to a L5 pedicle screw and an iliosacral screw (TF) or a fenestrated ilium screw connected with a rod to a L5 pedicle screw and an iliosacral screw passing through the fenestra of the iliac screw (TFS). Biomechanical testing was performed using cyclic loading until failure. (3) Results: Both configurations yielded comparable results with regard to initial stiffness, implant loosening, and cycles to failure. The TFS exhibited markedly higher values for cycles to failure and markedly lower values for loosening. However, due to the characteristics of the artificial bone model, these findings were not significant. (4) Conclusions: The novel triangular fixation systems demonstrated comparable results to the standard triangular osteosynthesis configuration.

Biomechanical assessment and comparison of fixation methods for bilateral sacroiliac joint luxation in 3D-printed feline pelvic bone models.

Bilateral sacroiliac joint luxation, a condition primarily observed in cats, can significantly impact their quality of life. This study aimed to compare a control with three distinct fixation methods to identify the most robust fixation method capable of withstanding significant tensile stress. Twenty pelvic bone models of cats were made using a 3D printer with polylactic acid plastic. Each model was assembled by cutting the sacroiliac joints and pelvic girdle symphysis with a handsaw, then bonded with cyanoacrylate glue. 3D feline pelvic bone models were categorized into four significant groups, each consisting of five models. The study discovered that the three groups used distinct fixation methods: Two lag screws (DS), K-wires at the ilium wing and sacroiliac joints (TK), and K-wires at the sacroiliac joints (DK). The final group, not fixed, was the control. The results were characterized further through a mechanical compression force test using a universal testing machine. The most robust method at the sacroiliac joints, the DK technique, sustained a maximum force of up to 183.86 N while maintaining the correct bone alignment. The fixation method is more accessible and faster to implement in comparison to the DS method. The DK group exhibited the greatest maximum load capacity among all groups. Sacroiliac joint luxation treatment can effectively be addressed using the K-wires fixation method. However, the DK need space of sacral body same as DS for fixation. Further clinical study should be performed.

Implantation of S1AIS has priority as a sacroiliac joint fixation technique.

The sacral alar-iliac screw (SAIS) fixation technique has evolved from spinopelvic fixation which originated from S2AIS to sacroiliac joint fixation, with more reports regarding its application of S2AIS than S1AIS. However, there is a lack of comparative evidence to determine which technique is superior for sacroiliac joint fixation. This study aimed to determine which of the screws was superior in terms of implantation safety and biomechanical stability for sacroiliac joint fixation. CT data of 80 normal pelvises were analyzed to measure the insertable range, trajectory lengths and widths of both S1AIS and S2AIS on 3D reconstruction models. Φ 6.5mm and 8.0mm screws were implanted on the left and right sides of fifty 3D printed pelvic models respectively to observe for breach of screw implantation. Ten synthetic pelvis models were used to simulate type C Tile injuries, and divided into 2 groups with an anterior plate and posterior fixation using one S1AIS or S2AIS on each side. The stiffness and maximum load of the plated and fixated models were measured under vertical loading. The trajectory lengths and widths of the S1AIS and S2AIS were similar (p > 0.05) and there was no breach for Φ 6.5mm SAIS. However, both the insertable range and trajectory length on the sacral side of S2AIS (234.56 ± 10.06mm2, 40.97 ± 2.81mm) were significantly less, and the breach rate of the posterior lateral cortex of the Φ 8.0mm S2AIS (46%) was significantly higher than the S1AIS (307.55 ± 10.42 mm2, 42.16 ± 3.06mm, and 2%, p < 0.05). The stiffness and maximum load of S2AIS were less than S1AIS but the difference was not statistically significant (p > 0.05). S1AIS and S2AIS have similar screw trajectories and stability. However, S1AIS has a larger insertable range, less breach of the posterior lateral sacral cortex and longer trajectory length on the sacral side than S2AIS, which indicates S1AIS has higher implantation safety and a trend of better mechanical performance over S2AIS for sacroiliac joint fixation. Furthermore, S2AIS with an excessively large diameter should be used with caution for sacroiliac joint fixation.

Deep learning-based fully automatic Risser stage assessment model using abdominal radiographs.

Artificial intelligence has been increasingly used in medical imaging and has demonstrated expert level performance in image classification tasks. To develop a fully automatic approach for determining the Risser stage using deep learning on abdominal radiographs. In this multicenter study, 1,681 supine abdominal radiographs (age range, 9-18years, 50% female) obtained between January 2019 and April 2022 were collected retrospectively from three medical institutions and graded manually using the United States Risser staging system. A total of 1,577 images from Hospitals 1 and 2 were used for development, and 104 images from Hospital 3 for external validation. From each radiograph, right and left iliac crest patch images were extracted using the pelvic bone segmentation model DeepLabv3 + with the EfficientNet-B0 encoder trained with 90 digitally reconstructed radiographs from pelvic computed tomography scans with a pelvic bone mask. Using these patch images, ConvNeXt-B was trained to grade according to the Risser classification. The model's performance was evaluated using accuracy, area under the receiver operating characteristic curve (AUROC), and mean absolute error. The fully automatic Risser stage assessment model showed an accuracy of 0.87 and 0.75, mean absolute error of 0.13 and 0.26, and AUROC of 0.99 and 0.95 on internal and external test sets, respectively. We developed a deep learning-based, fully automatic segmentation and classification model for Risser stage assessment using abdominal radiographs.

Bone remodeling after revision total hip arthroplasty for large acetabular defects.

Large acetabular bone defects are challenging in hip revision surgery. Clinical assessment is crucial to evaluate modern technologies in surgical reconstruction. We aimed to better understand the bone remodeling that occurs following acetabular reconstruction. Our objectives were: (1) To characterize changes in the shape of the pelvis by studying sequential computed tomography (CT) scans collected immediately and 1-year postoperatively and (2) to identify which part of the pelvis is most susceptible to remodeling. We used the CT scans taken at two timepoints, of 24 patients with acetabular bone defects classified as Paprosky IIIB, treated with three-dimensional (3D)-printed custom-made acetabular implants. Segmented 3D models of the bony pelvis were co-registered using three different techniques. A global co-registration of the full pelvis was conducted, followed by the co-registration of the innominate bone and then ilium only, on the ipsilateral reconstructed side. The relative movements of the ilium, ischium, and pubis were analyzed from visual inspection and using co-registration metrics (root mean square error and intersection over union). No bone remodeling was found in 14/24 patients (58%). The co-registration of the innominate bone indicated bone remodeling in five cases (21%), while the remaining five cases (21%) presented remodeling in the global co-registration but not the innominate bone co-registration, suggestive of changes occurring at the sacroiliac joint. Changes in the pelvic shape were greatest at the pubis and ischium. Bone remodeling may occur in complex cases of Paprosky type IIIB defects, after acetabular reconstruction (occurrence of 21%, 5/24 cases). Surgeons and engineers should consider this when monitoring implant migration.

Effect of different lumbar–iliac fixation and sacral slope for Tile C1.3 pelvic fractures: a biomechanical study

BackgroundLumbar–iliac fixation (LIF) is a common treatment for Tile C1.3 pelvic fractures, but different techniques, including L4–L5/L5 unilateral LIF (L4–L5/L5 ULIF), bilateral LIF (BLIF), and L4–L5/L5 triangular osteosynthesis (L4–L5/L5 TOS), still lack biomechanical evaluation. The sacral slope (SS) is key to the vertical shear of the sacrum but has not been investigated for its biomechanical role in lumbar–iliac fixation. The aim of this study is to evaluate the biomechanical effects of different LIF and SS on Tile C1.3 pelvic fracture under two-legged standing load in human cadavers.MethodsEight male fresh-frozen human lumbar–pelvic specimens were used in this study. Compressive force of 500 N was applied to the L4 vertebrae in the two-legged standing position of the pelvis. The Tile C1.3 pelvic fracture was prepared, and the posterior pelvic ring was fixed with L5 ULIF, L4–L5 ULIF, L5 TOS, L4–L5 TOS, and L4–L5 BLIF, respectively. Displacement and rotation of the anterior S1 foramen at 30° and 40° sacral slope (SS) were analyzed.ResultsThe displacement of L4–L5/L5 TOS in the left–right and vertical direction, total displacement, and rotation in lateral bending decreased significantly, which is more pronounced at 40° SS. The difference in stability between L4–L5 and L5 ULIF was not significant. BLIF significantly limited left–right displacement. The ULIF vertical displacement at 40° SS was significantly higher than that at 30° SS.ConclusionsThis study developed an in vitro two-legged standing pelvic model and demonstrated that TOS enhanced pelvic stability in the coronal plane and cephalad–caudal direction, and BLIF enhanced stability in the left–right direction. L4–L5 ULIF did not further improve the immediate stability, whereas TOS is required to increase the vertical stability at greater SS.

Functional outcome of the anterior vaginal wall in a pelvic surgery injury rat model after treatment with stem cell-derived progenitors of smooth muscle cells.

Background : Stem-cell-derived therapy is a promising option for tissue regeneration. Human iPSC-derived progenitors of smooth muscle cells (pSMCs) have limited proliferation and differentiation, which may minimize the risk of in vivo tumor formation while restoring smooth muscle cell deficiencies. Up to 30 % of women who suffer from recurrence of vaginal prolapse after prolapse surgery are faced with reoperation. Therefore, there is an unmet need for therapies that can restore vaginal tissue function. We hypothesize that human pSMCs can restore vaginal function in a vaginal-injury rat model. Methods : Female immune-compromised RNU rats were divided into 5 groups: intact controls (n=12), VSHAM (surgery + saline injection, n=33), and cell-injection group (surgery + cell injection using three patient pSMCs lines, n=14/cell line). The surgery, similar to what is done in vaginal prolapse surgery, involved ovariectomy, urethrolysis, and vagina injury. The vagina, urethra, bladder dome and trigone were harvested 10 weeks after surgery (5 weeks after injection). Organ bath myography was performed to evaluate the contractile function of vagina, and smooth muscle thickness was examined by tissue immunohistochemistry. Collagen I, collagen III, and elastin mRNA and protein expressions in tissues were assessed. Results : When compared to the VSHAM group, cell-injection groups showed significantly increased vaginal smooth muscle contractions induced by carbachol (groups A and C) and by KCl (group C), and significantly higher collagen I protein expression in the vagina (groups A and B). Elastin mRNA and protein expressions in the vagina did not correlate with injection group. In the urethra, mRNA expressions of collagen I, collagen III, and elastin were all significantly higher in the cell-injection groups compared to the VSHAM group. Collagen I protein expression of the urethra was also higher in the cell-injection group compared to the VSHAM group. Elastin protein expression in the urethra did not correlate with injection group. Conclusions : Human iPSC-derived pSMCs improved contractile function of the post-surgery vagina. Additionally, pSMC injection modulated collagen I, collagen III and elastin mRNA and protein expressions in the vagina and urethra. These findings suggest that pSMCs may be a possible therapy for vaginal prolapse recurrence after surgical intervention.

Specific pelvic shape in patients with developmental dysplasia of the hip on 3D morphometric homologous model analysis.

To clarify the morphological factors of the pelvis in patients with developmental dysplasia of the hip (DDH), three-dimensional (3D) pelvic morphology was analyzed using a template-fitting technique. Three-dimensional pelvic data of 50 patients with DDH (DDH group) and 3D pelvic data of 50 patients without obvious pelvic deformity (Normal group) were used. All patients were female. A template model was created by averaging the normal pelvises into a symmetrical and isotropic mesh. Next, 100 homologous models were generated by fitting the pelvic data of each group of patients to the template model. Principal component analysis was performed on the coordinates of each vertex (15,235 vertices) of the pelvic homologous model. In addition, a receiver-operating characteristic (ROC) curve was calculated from the sensitivity of DDH positivity for each principal component, and principal components for which the area under the curve was significantly large were extracted (p<0.05). Finally, which components of the pelvic morphology frequently seen in DDH patients are related to these extracted principal components was evaluated. The first, third, and sixth principal components showed significantly larger areas under the ROC curves. The morphology indicated by the first principal component was associated with a decrease in coxal inclination in both the coronal and horizontal planes. The third principal component was related to the sacral inclination in the sagittal plane. The sixth principal component was associated with narrowing of the superior part of the pelvis. The most important factor in the difference between normal and DDH pelvises was the change in the coxal angle in both the coronal and horizontal planes. That is, in the anterior and superior views, the normal pelvis is a triangle, whereas in DDH, it was more like a quadrilateral.

Pelvic ultrasound-based deep learning models for accurate diagnosis of ovarian cancer: Retrospective multicenter study.

Pelvic ultrasound-based deep learning models for accurate diagnosis of ovarian cancer: Retrospective multicenter study.

Evaluating pelvic tilt using the pelvic antero-posterior radiographs: A novel method.

Pelvic tilt (PT) is an important parameter for orthopedic surgeries involving hip and spine, typically determined from sagittal pelvic radiographs. However, various challenges can compromise the feasibility of measurement from sagittal imaging, including obscured landmarks, anatomical variations, hardware interference, and limited medical resources. Addressing these challenges and with the aim of reducing radiation exposure to patients, our study developed a novel method to estimate PT from antero-posterior (AP) radiographs, using vertical distances from the pelvic outlet and obturator foramen. We correlated these measurements with PT, defined both anatomically (anterior pelvic plane, PTa) and mechanically (centers of femoral heads and sacral plate, PTm). The study explored creating linear, exponential, and multivariate regression models based on twelve 3D CT-derived pelvic models (six men, six women), simulating AP radiograph projections with controlled PTs. We then validated these models against 105 pairs of patient stereoradiographs. Statistical analysis revealed that combined exponential-linear models yielded the most accurate results, with Pearson correlation coefficients of 0.75 for PTa and 0.77 for PTm, and mean absolute errors of 3.7° ± 2.6° for PTa and 4.5° ± 3.4° for PTm, showing excellent measurement reliability (all ICCs > 0.9) without significant gender discrepancies. In conclusion, this study presents a validated, simple, and accessible method for estimating PT using AP radiograph parameters, supported by the Supporting Information S1: Excel Tool, showing great potential for clinical application in hip and spine procedures.

Surgical treatment outcomes of acetabular posterior wall and posterior column fractures using 3D printing technology and individualized custom-made metal plates: a retrospective study

BackgroundFractures involving the posterior acetabulum with its rich vascular and neural supply present challenges in trauma orthopedics. This study evaluates the effectiveness of 3D printing technology with the use of custom-made metal plates in the treatment of posterior wall and column acetabular fractures.MethodsA retrospective analysis included 31 patients undergoing surgical fixation for posterior wall and column fractures of the acetabulum (16 in the 3D printing group, utilizing 3D printing for a 1:1 pelvic model and custom-made plates based on preoperative simulation; 15 in the traditional group, using conventional methods). Surgical and instrument operation times, intraoperative fluoroscopy frequency, intraoperative blood loss, fracture reduction quality, fracture healing time, preoperative and 12-month postoperative pain scores (Numeric Rating Scale, NRS), hip joint function at 6 and 12 months (Harris scores), and complications were compared.ResultsThe surgical and instrument operation times were significantly shorter in the 3D printing group (p < 0.001). The 3D printing group exhibited significantly lower intraoperative fluoroscopy frequency and blood loss (p = 0.001 and p < 0.001, respectively). No significant differences were observed between the two groups in terms of fracture reduction quality, fracture healing time, preoperative pain scores (NRS scores), and 6-month hip joint function (Harris scores) (p > 0.05). However, at 12 months, hip joint function and pain scores were significantly better in the 3D printing group (p < 0.05). Although the incidence of complications was lower in the 3D printing group (18.8% vs. 33.3%), the difference did not reach statistical significance (p = 0.433).ConclusionCombining 3D printing with individualized custom-made metal plates for acetabular posterior wall and column fractures reduces surgery and instrument time, minimizes intraoperative procedures and blood loss, enhancing long-term hip joint function recovery.Clinical Trial Registration12/04/2023;Trial Registration No. ChiCTR2300070438; http://www.chictr.org.cn.