-
American Journal of Biological... Aug 2023Compared to other primates, modern humans face high rates of maternal and neonatal morbidity and mortality during childbirth. Since the early 20th century, this... (Review)
Review
Compared to other primates, modern humans face high rates of maternal and neonatal morbidity and mortality during childbirth. Since the early 20th century, this "difficulty" of human parturition has prompted numerous evolutionary explanations, typically assuming antagonistic selective forces acting on maternal and fetal traits, which has been termed the "obstetrical dilemma." Recently, there has been a growing tendency among some anthropologists to question the difficulty of human childbirth and its evolutionary origin in an antagonistic selective regime. Partly, this stems from the motivation to combat increasing pathologization and overmedicalization of childbirth in industrialized countries. Some authors have argued that there is no obstetrical dilemma at all, and that the difficulty of childbirth mainly results from modern lifestyles and inappropriate and patriarchal obstetric practices. The failure of some studies to identify biomechanical and metabolic constraints on pelvic dimensions is sometimes interpreted as empirical support for discarding an obstetrical dilemma. Here we explain why these points are important but do not invalidate evolutionary explanations of human childbirth. We present robust empirical evidence and solid evolutionary theory supporting an obstetrical dilemma, yet one that is much more complex than originally conceived in the 20th century. We argue that evolutionary research does not hinder appropriate midwifery and obstetric care, nor does it promote negative views of female bodies. Understanding the evolutionary entanglement of biological and sociocultural factors underlying human childbirth can help us to understand individual variation in the risk factors of obstructed labor, and thus can contribute to more individualized maternal care.
Topics: Pregnancy; Animals; Infant, Newborn; Humans; Female; Parturition; Pelvis; Hominidae; Primates; Delivery, Obstetric
PubMed: 37353889
DOI: 10.1002/ajpa.24802 -
Journal of Biomechanics Dec 2023Estimation of the hip joint center in ovine biomechanical analysis is often overlooked or estimated using a marker on the greater trochanter which can result in large...
Estimation of the hip joint center in ovine biomechanical analysis is often overlooked or estimated using a marker on the greater trochanter which can result in large errors that propagate through subsequent analyses. The purpose of this study was to develop a novel method of estimating the hip joint centers in sheep to facilitate more accurate analysis of ovine biomechanics. CT scans from 16 sheep of varying ages, weight, sex, and phenotypes were acquired and the data was used to calculate the known hip joint center by sphere fitting the femoral head. Anatomical measurements and additional subject information were used to create a variety of regression models to estimate the hip joint centers in absence of CT data. The best regression equation created utilized markers placed on the tuber coxae and tuber ischii of the pelvis and resulted in a mean 3D Euclidean distance error of 6.43 ± 2.22 mm (mean ± standard deviation) between the known and estimated hip joint center. The regression models produced allow for more detailed, accurate and robust analysis of sheep biomechanics.
Topics: Animals; Sheep; Hip Joint; Femur Head; Femur; Pelvis; Ilium; Biomechanical Phenomena
PubMed: 37952489
DOI: 10.1016/j.jbiomech.2023.111861 -
Journal of Surgical Oncology Feb 2024The use of three-dimensional printed implants in the field of orthopedic surgery has become increasingly popular and has potentiated hip reconstruction in the setting of... (Review)
Review
The use of three-dimensional printed implants in the field of orthopedic surgery has become increasingly popular and has potentiated hip reconstruction in the setting of oncologic resections of the pelvis and acetabulum. In this review, we examine and discuss the indications and technical considerations for custom implant reconstruction of pelvic defects.
Topics: Humans; Prostheses and Implants; Pelvis; Acetabulum; Orthopedic Procedures; Printing, Three-Dimensional
PubMed: 37754672
DOI: 10.1002/jso.27465 -
Journal of Neurosurgery. Spine Aug 2023The objective was to describe an intraoperative method that accurately predicts postoperative coronal alignment for up to 2 years of follow-up. The authors hypothesized...
OBJECTIVE
The objective was to describe an intraoperative method that accurately predicts postoperative coronal alignment for up to 2 years of follow-up. The authors hypothesized that the intraoperative coronal target for adult spinal deformity (ASD) surgery should account for lower-extremity parameters, including pelvic obliquity (PO), leg length discrepancy (LLD), lower-extremity mechanical axis difference (MAD), and asymmetrical knee bending.
METHODS
Two lines were drawn on intraoperative prone radiographs: the central sacral pelvic line (CSPL) (the line bisecting the sacrum and perpendicular to the line touching the acetabular sourcil of both hips) and the intraoperative central sacral vertical line (iCSVL) (which is drawn relative to CSPL based on the preoperative erect PO). The distance from the C7 spinous process to CSPL (C7-CSPL) and the distance from the C7 spinous process to iCSVL (iCVA) were compared with immediate and 2-year postoperative CVA. To account for LLD and preoperative lower-extremity compensation, patients were categorized into four preoperative groups: type 1, no LLD (< 1 cm) and no lower-extremity compensation; type 2, no LLD with lower-extremity compensation (PO > 1°, asymmetrical knee bending, and MAD > 2°); type 3, LLD and no lower-extremity compensation; and type 4, LLD with lower-extremity compensation (asymmetrical knee bending and MAD > 4°). A retrospective review of a consecutively collected cohort with ASD who underwent minimum 6-level fusion with pelvic fixation was performed for validation.
RESULTS
In total, 108 patients (mean ± SD age 57.7 ± 13.7 years, 14.0 ± 3.9 levels fused) were reviewed. Mean preoperative/2-year postoperative CVA was 5.0 ± 2.0/2.2 ± 1.8 cm. For patients with type 1, both C7-CSPL and iCVA had similar error margins for immediate postoperative CVA (0.5 ± 0.6 vs 0.5 ± 0.6 cm, p = 0.900) and 2-year postoperative CVA (0.3 ± 0.4 vs 0.4 ± 0.5 cm, p = 0.185). For patients with type 2, C7-CSPL was more accurate for immediate postoperative CVA (0.8 ± 1.2 vs 1.7 ± 1.8 cm, p = 0.006) and 2-year postoperative CVA (0.7 ± 1.1 vs 2.1 ± 2.2 cm, p < 0.001). For patients with type 3, iCVA was more accurate for immediate postoperative CVA (0.3 ± 0.4 vs 1.7 ± 0.8 cm, p < 0.001) and 2-year postoperative CVA (0.3 ± 0.2 vs 1.9 ± 0.8 cm, p < 0.001). For patients with type 4, iCVA was more accurate for immediate postoperative CVA (0.6 ± 0.7 vs 3.0 ± 1.3 cm, p < 0.001) and 2-year postoperative CVA (0.5 ± 0.6 vs 3.0 ± 1.6 cm, p < 0.001).
CONCLUSIONS
This system, which accounted for lower-extremity factors, provided an intraoperative guide to determine both immediate and 2-year postoperative CVA with high accuracy. For patients with type 1 and 2 (no LLD, with or without lower-extremity compensation), C7-intraoperative CSPL accurately predicted postoperative CVA up to 2-year follow-up (mean error 0.5 cm). For patients with type 3 and 4 (LLD, with or without lower-extremity compensation), iCVA accurately predicted postoperative CVA up to 2-year follow-up (mean error 0.4 cm).
Topics: Humans; Adult; Middle Aged; Aged; Sacrum; Retrospective Studies; Radiography; Lower Extremity; Pelvis; Spinal Fusion
PubMed: 37148236
DOI: 10.3171/2023.3.SPINE221364 -
Radiography (London, England : 1995) Jul 20243D positioning cameras that automate the positioning of patients with respect to the CT isocentre have been developed and are in common use in CT departments. This study...
INTRODUCTION
3D positioning cameras that automate the positioning of patients with respect to the CT isocentre have been developed and are in common use in CT departments. This study aimed to compare the performance of radiographers and a 3D camera system with respect to positioning accuracy and the effect on patient radiation dose for chest-abdomen-pelvis scans.
METHODS
Patient positioning and dose data obtained from a dose management system was evaluated over a two-month period for patients positioned with (CAM) and without (CAM) the positioning camera. Median vertical and lateral offset values were compared between the groups whilst doses were evaluated as a function of patient water equivalent diameter (WED) for the thorax and abdomen-pelvis acquisitions for both cohorts.
RESULTS
Radiographers demonstrated high levels of positioning accuracy, however significant improvements in median vertical offset were identified for the CAM cohort for both thorax (8 mm vs. 17 mm (p = 0.001)) and abdomen-pelvis (7 mm vs. 16 mm (p = 0.003)) scans. The percentage of patients positioned within 5 mm of the isocentre was 39.0% and 16.1% for the CAM and CAM cohorts. For CAM scans, 77.4% of patients were positioned below the isocentre, but this was reduced to 45.8% for CAM scans. No significant changes in dose as a function of WED were identified related to the camera use (thorax: p = 0.569, abdomen-pelvis: p = 0.760).
CONCLUSION
Use of a 3D camera delivered significant improvements in the accuracy and reproducibility of patient positioning when compared with radiographers.
IMPLICATIONS FOR PRACTICE
Improvements in positioning accuracy were observed at the research site and hence positioning camera use has the potential to become standard practice in CT to help ensure appropriate doses are delivered to patients according to their size.
Topics: Humans; Patient Positioning; Radiation Dosage; Tomography, X-Ray Computed; Imaging, Three-Dimensional; Radiography, Thoracic; Radiography, Abdominal; Male; Female; Pelvis; Middle Aged; Aged; Adult; Reproducibility of Results
PubMed: 38733956
DOI: 10.1016/j.radi.2024.04.016 -
Current Problems in Diagnostic Radiology 2024CT is often the first imaging test in female patients with lower abdominal and pelvic pain because of the wide availability of CT and differential diagnoses that span... (Review)
Review
CT is often the first imaging test in female patients with lower abdominal and pelvic pain because of the wide availability of CT and differential diagnoses that span both gynecologic and gastrointestinal disease. Pathology within the female pelvis may be difficult to diagnose on CT owing to suboptimal delineation of anatomy in comparison to MRI and ultrasound. These challenges are confounded by overlapping imaging features of a wide range of gynecologic entities and can lead to diagnostic dilemmas. High value CT interpretation will direct the clinician to the best next diagnostic step as ultrasound and MRI provide superior soft tissue delineation. Other imaging modalities, laboratory investigations, or tissue sampling may be necessary to definitively characterize indeterminate lesions. In this review, we illustrate various cases of mistaken identity on CT of the female pelvis involving the ovaries, uterus, and peritoneal cavity while highlighting clinical pearls that may aid the radiologist in arriving at the correct diagnosis and avoiding potential pitfalls.
Topics: Humans; Female; Ovary; Tomography, X-Ray Computed; Pelvis; Pelvic Pain; Abdomen; Magnetic Resonance Imaging
PubMed: 38365459
DOI: 10.1067/j.cpradiol.2024.01.021 -
Neurosurgery Clinics of North America Oct 2023There are a range of anterior-based approaches to address flexible adult spinal deformity from the thoracic spine to the sacrum, with each approach offering access to a... (Review)
Review
There are a range of anterior-based approaches to address flexible adult spinal deformity from the thoracic spine to the sacrum, with each approach offering access to a range of vertebral levels. It includes the transperitoneal (L5-S1), paramedian anterior retroperitoneal (L3-S1), oblique retroperitoneal (L1-2 to L5-S1), the thoracolumbar transdiaphragmatic approach (T9-10 to L4-5), and thoracotomy approach (T4-T12). The lumbar and lumbosacral spine is especially favorable for anterior-based approaches given the relative mobility of the peritoneal organs and position of the vasculature.
Topics: Adult; Humans; Lumbosacral Region; Pelvis; Sacrococcygeal Region; Sacrum
PubMed: 37718101
DOI: 10.1016/j.nec.2023.06.005 -
International Journal of Radiation... Mar 2024
Topics: Female; Humans; Uterine Cervical Neoplasms; Vagina; Pelvis; Neoplasm Recurrence, Local; Retrospective Studies
PubMed: 38401972
DOI: 10.1016/j.ijrobp.2023.11.018 -
Journal of Biomechanics Mar 2024Full-length radiographs contain information from which many anatomical parameters of the pelvis, femur, and tibia may be derived, but only a few anatomical parameters...
Full-length radiographs contain information from which many anatomical parameters of the pelvis, femur, and tibia may be derived, but only a few anatomical parameters are used for musculoskeletal modeling. This study aimed to develop a fully automatic algorithm to extract anatomical parameters from full-length radiograph to generate a musculoskeletal model that is more accurate than linear scaled one. A U-Net convolutional neural network was trained to segment the pelvis, femur, and tibia from the full-length radiograph. Eight anatomic parameters (six for length and width, two for angles) were automatically extracted from the bone segmentation masks and used to generate the musculoskeletal model. Sørensen-Dice coefficient was used to quantify the consistency of automatic bone segmentation masks with manually segmented labels. Maximum distance error, root mean square (RMS) distance error and Jaccard index (JI) were used to evaluate the geometric accuracy of the automatically generated pelvis, femur and tibia models versus CT bone models. Mean Sørensen-Dice coefficients for the pelvis, femur and tibia 2D segmentation masks were 0.9898, 0.9822 and 0.9786, respectively. The algorithm-driven bone models were closer to the 3D CT bone models than the scaled generic models in geometry, with significantly lower maximum distance error (28.3 % average decrease from 24.35 mm) and RMS distance error (28.9 % average decrease from 9.55 mm) and higher JI (17.2 % average increase from 0.46) (P < 0.001). The algorithm-driven musculoskeletal modeling (107.15 ± 10.24 s) was faster than the manual process (870.07 ± 44.79 s) for the same full-length radiograph. This algorithm provides a fully automatic way to generate a musculoskeletal model from full-length radiograph that achieves an approximately 30 % reduction in distance errors, which could enable personalized musculoskeletal simulation based on full-length radiograph for large scale OA populations.
Topics: Neural Networks, Computer; Radiography; Tibia; Femur; Pelvis; Image Processing, Computer-Assisted
PubMed: 38467079
DOI: 10.1016/j.jbiomech.2024.112046 -
Scientific Reports Dec 2023Seoi-nage performance requires a high level of skill and proficiency. The aim of this study was to compare the motor planning, regulation, and control skills of elite...
Seoi-nage performance requires a high level of skill and proficiency. The aim of this study was to compare the motor planning, regulation, and control skills of elite versus non-elite seoi-nage judo athletes. Twenty subjects (10 elites and 10 non-elite) performed the three-phase seoi-nage skills of unbalancing, positioning, and throwing while an optical motion capture 3D camera monitored their shoulder, pelvis, hip, and knee joint movements to calculate their force magnitude and direction. Elite athletes performed better than non-elite athletes in terms of the shoulder (247.4° vs. 208.3° in Event 4) and pelvic (235.4° vs. 194.4° in Event 4) rotation, tilt angle (15.13° vs. - 0.74° in Event 4) characteristics, as well as hip (136.1° vs. 125.0° in Event 4) and knee joint (124.0° vs. 120.8° in Event 3) flexion-extension angle. Compared to non-elite athletes, elite athletes also showed more controlled force and movement in all bodily areas. These results can help to guide the development of seoi-nage skills as judo athletes advance from the non-elite to the elite level.
Topics: Humans; Martial Arts; Shoulder; Athletes; Movement; Pelvis
PubMed: 38066092
DOI: 10.1038/s41598-023-49188-w