The relation between head circumference and mid pelvic circumference: A simple index for cephalo-pelvic disproportion evaluation

Introduction: Cephalo-pelvic-disproportion (CPD) is one of the most common obstetric complications. Since CPD is the disproportion between the fetal head and maternal bony pelvis, evaluation of the head-circumference (HC) relative to maternal bony pelvis may be a useful adjunct to pre-labor CPD evaluation. The aim of the present study was a proof-of-concept evaluation of the ratio between HC to pelvic circumference (PC) as a predictor of CPD. Methods: Of 11,822 deliveries, 104 cases that underwent an abdomino-pelvic CT for any medical indication and who underwent normal vaginal deliveries (NVD) (n=84) or cesarean deliveries (CD) due to CPD (n=20) were included retrospectively. Maternal pelvis dimensions were reconstructed and neonatal HC, as a proxy for fetal HC, were measured. The correlation between cases of CPD and Cephalo-Pelvic Circumference Index (CPCI), which represents the ratio between the HC and PC in percent (HC/PC *100) was evaluated. Results: The mid-pelvis cephalo-pelvic circumference index (MP-CPCI) was larger in CD groups as compared to the NVD group: 103±11 vs. 97±8% respectively (p=0.0003). In logistic regression analysis, the MP-CPCI was found to be independently associated with CD due to CPD: each 1% increase in MP-CPCI increased the likelihood of CD for CPD by 11% (aOR 1.11, CI 95% 1.03-1.19, p=0.004). The adjusted odds ratio for CD due to CPD increased incrementally as the MP-CPCI increased, from 3.56 (95%CI, 1.01-12.6) at MP-CPCI of 100, to 5.6 (95%CI, 1.63-19.45) at 105, 21.44 (95%CI, 3.05-150.84) at 110, and 28.88 (95%CI, 2.3-362.27) at MP-CPCI of 115 Conclusions: The MP-CPCI, representing the relative dimensions of the fetal HC and maternal PC, is a simple tool that can potentially distinguish between parturients at lower and higher risk of CPD. Prospective randomized studies are required to evaluate the feasibility of prenatal pelvimetry and MP-CPCI to predict the risk of CPD during labor.

Dynamic finite-element simulations reveal early origin of complex human birth pattern

Human infants are born neurologically immature, but whether this originates from conflicting selection pressures between bipedal locomotion and encephalization as suggested by the obstetrical dilemma remains controversial. Australopithecines are ideal for investigating this trade-off as they have a bipedally adapted pelvis, yet relatively small brains. Our finite-element birth simulations based on different pelvic reconstructions and a range of fetal head sizes indicate that australopithecines already possessed a human-like rotational birth pattern. Since only newborn head sizes smaller than those predicted for non-human primates leave adequate space for soft tissue between the bony pelvis and fetal skull, our data imply that australopithecines had secondarily altricial newborns and likely evolved cooperative breeding to care for their helpless infants. These prerequisites for advanced cognitive development therefore seem to have been corollary to skeletal adaptations to bipedal locomotion that preceded the appearance of the genus Homo and the increase in encephalization.

Computer-Assisted Surgical Navigation for Primary and Metastatic Bone Malignancy of the Pelvis: Current Evidence and Future Directions

Computer-assisted navigation and robotic surgery have gained popularity in the treatment of pelvic bone malignancies, given the complexity of the bony pelvis, the proximity of numerous vital structures, and the historical challenges of pelvic bone tumor surgery. Initial interest was on enhancing the accuracy in sarcoma resection by improving the quality of surgical margins and decreasing the incidence of local recurrences. Several studies have shown an association between intraoperative navigation and increased incidence of negative margin bone resection, but long-term outcomes of navigation in pelvic bone tumor resection have yet to be established. Historically, mechanical stabilization of pelvic bone metastases has been limited to Harrington-type total hip arthroplasty for disabling periacetabular disease, but more recently, computer-assisted surgery has been employed for minimally invasive percutaneous fixation and stabilization; although still in its incipient stages, this procedure is potentially appealing for treating patients with bone metastases to the pelvis. The authors review the literature on navigation for the treatment of primary and metastatic tumors of the pelvic bone and discuss the best practices and limitations of these techniques.

A wretched condition

Although rare, cleft bladder was known to the ancients: the infants did not die after birth, but grew up incontinent. Combined with abnormal genitalia, the malformation was confused with hermaphroditism, the most loathed congenital anomaly. Three grades were discerned in the 17th century: epispadias, where the urethra opens at the anterior side of the penis; bladder exstrophy with open anterior bladder wall; and cloacal exstrophy with common outlet for stool and urine. Explanations of its origin included obstructed urethra, short umbilical cord, and bursting allantois, bladder, abdominal wall, or cloacal membrane. As the incontinent children suffered from painful inguinal eczema, urine collecting devices were constructed from copper and tin, and from rubber once vulcanization was invented. Correcting operations were attempted from 1852 with limited success. Today, stepwise corrective surgery begins by closing the bony pelvis, bladder, and the abdominal wall, followed by epispadias repair and penis remodelling. No controlled trials or international protocols have come forth, and the long-term prognosis is all but satisfying.

Human Birth Imaging Using MRI: Prospective cohort study (Preprint)

UNSTRUCTURED Childbirth is a physiologic process with significant medical risk, as neurological impairment due to the birthing process can occur at any time. Improvements in risk assessment and anticipatory interventions are constantly needed; however, the birthing process is difficult to assess using simple imaging technology since the maternal bony pelvis and fetal skeleton interfere with visualizing the soft tissues. Magnetic resonance imaging (MRI) is a non-invasive technique with no ionizing radiation that can monitor the biomechanics of the birthing process. Effective utilization of this modality, however, requires teamwork and implementation of the appropriate safeguards to achieve appropriate safety levels. This article describes a clinically effective and safe method to perform real-time MRI during the birthing process. We report the experience of our team as part of the IMAGINAITRE research protocol (France), which aimed better understand of the biomechanics of childbirth.

Bilateral Sacroiliac Joint Fusion: A Case Report

Sacroiliac (SI) joint is the articulation which forms the part of the bony pelvis. It plays an important role in locomotor activity, and childbirth during labour. It helps in the transmission and distribution of axial body weight from the spine to the pelvis. This synovial joint exhibit limited gliding movements within the joint cavity. About 15-30% of low backache aetiologies are attributed to SI joint dysfunction. People who are overweight, have co-morbid conditions, and pregnant women are at higher risk of developing vertebral joint deformities called spondylarthropathies. They are group of inflammatory disorders which are involving the vertebral spines and peripheral joints, where the symptom of stiffness is prominently seen. The anatomical variations in the SI joint morphology like accessory SI joint, iliosacral complex and sacral defect, dismorphic joint, are of compelling interest concerning SI joint pathologies from the orthopaedic viewpoint. This case report presents a bilateral fusion of SI joint, found in a skeleton in the museum of medical college.