Quantitative anatomy of the primary ossification center in the fetal pubis bone.

PURPOSES: Skeletodysplasiae and hereditary dysostoses constitute a group of over 350 disorders of the skeletal system. Knowledge about development of the pubic primary ossification center may be useful in both determining the fetal stage and maturity, and for detecting congenital disorders. The present study was performed to quantitatively examine the pubic primary ossification center with respect to its linear, planar, and volumetric parameters. MATERIALS AND METHODS: Using methods of computed tomography (CT), digital-image analysis and statistics, the size of the pubic primary ossification center in 33 spontaneously aborted human fetuses (18 males and 15 females) aged 22-30 weeks was studied. RESULTS: With no sex and laterality differences, the best-fit growth dynamics for the pubic primary ossification center was modeled by the following functions: y = - 13.694 + 0.728 × age ± 0.356 for its sagittal diameter, y = - 3.350 + 0.218 × age ± 0.159 for its vertical diameter, y = - 61.415 + 2.828 × age ± 1.519 for its projection surface area, and y = - 65.801 + 3.173 × age ± 2.149 for its volume. CONCLUSIONS: The size of the pubic primary ossification center shows neither sex nor laterality differences. The growth dynamics of the vertical and sagittal diameters, projection surface area, and volume of the pubic ossification centers follow proportionately to fetal age. The obtained numerical findings of the pubic ossification center are considered age-specific reference data with clinical implications in the diagnostics of congenital defects.

Morphological convergence in the pubis of slow-moving primates and xenarthrans.

OBJECTIVES: Determining the functional significance of pubic rami is important for reconstructing locomotor behavior of fossil species. The slow loris pelvis, characterized by long pubic rami, is unusual among primates. Long pubic rami may be related to increasing the moment arm of the abdominal musculature during ventroflexion after the termination of hindlimb suspension, which is a common component of slow arboreal quadrupedalism (AQ). Some extant xenarthran species are also slow AQ taxa, and provide an ideal group to test hypotheses of morphologically convergent adaptations to slow AQ. MATERIALS AND METHODS: A model relating abdominal moment arms to pubic morphology is tested in three genera of slow-moving xenarthrans (Bradypus, Choloepus, and Cyclopes) and two species of slow loris (Nycticebus coucang and Perodicticus potto), using a comparative sample of 37 species of primates and xenarthrans. Phylogenetic analyses of variance and regression were performed on pubic dimensions (superior and inferior pubic ramus length, pubic symphysis length). RESULTS: As a locomotor group, slow-moving xenarthrans and lorises share superior pubic rami that are longer than all other locomotor groups; at the species level, there is some overlap among slow AQ and non-slow-AQ taxa. Inferior pubic ramus and pubic symphysis lengths also differ according to locomotor category, but multiple comparisons among locomotor groups are non-significant. DISCUSSION: These results support the hypothesis that superior pubic ramus length is functionally related to slow, suspensory locomotion by increasing the leverage of the ventral abdominal musculature, and demonstrates morphological convergence among two phylogenetically distant groups of mammals that have evolved adaptations for slow, suspensory locomotion.

The functional role of the ischiopubic membrane for the mechanical loading of the pubis in the domestic fowl (Gallus gallus).

Soft tissues other than muscles are supposed to be of mechanical importance, yet they are rarely integrated into finite element models. Here, we investigate the functional role of the ischiopubic membrane for the loading of the pubis of the domestic fowl using 2D finite element analysis. For this purpose, a specimen of the domestic fowl was dissected and soft tissues attaching to the pubis were studied in great detail. Muscles were removed and measurements taken. For the 2D finite element model, the outline was taken from the dissected specimen. Two 2D finite element models were generated: one without and one with ischiopubic membrane. The same muscular loading based on own measurements and electromyographic data was applied to both models. The model without ischiopubic membrane shows anteroventral bending deformation of the scapus pubis, resulting in high compressive and tensile principal stresses at the level of ultimate bone stress values. The model with ischiopubic membrane shows low compressive principal stresses in the pubis consistent with the levels of steady state remodelling of bone. Based on these results, the ischiopubic membrane of the domestic fowl potentially establishes a physiological loading of the pubis and therefore might be of great mechanical significance for the loading of the bone.

A Review of the ischium-pubis index: accuracy,reliability, and common errors.

This article examines the utility of the ischium-pubic index (IPI), a sexing technique that compares the lengths of pubis and ischium. The ratio was adapted by Washburn from a primate index devised by Schultz and was tested by Washburn on documented remains from the Hamann-Todd Human Osteological Collection. The IPI is used by forensic investigators, and indeed, the method is found in standard forensic textbooks and thus appears to be valid to early-stage researchers. However, its reliability has been questioned by physical anthropologists almost from its inception due to the intrinsic subjectivity of locating the base point from which both lengths are taken. In addition, at least one variation of the original technique is found in the literature, which alters the base point profoundly. To explore both the original method and the ramifications of altering the base point, in this article the IPI is calculated from os coxae recovered from the Mary Rose, a 16th-century English warship lost in a documented disaster; the sample is assumed to be from males. Using the original index, 20.4% of individuals (11 of 54) or, viewing the remains as commingled, 15.5% of individual pelves (15 of 97) were misclassified. Results with the base point shifted were disastrous: 95.5% (21 of 22) individuals and 91.4% (32 of 35) pelves were misclassified. Accuracy may be influenced by the technician's expertise; however, when the original methodology is altered, the results become meaningless. This article aims to promote more careful reading of our sources and to suggest that the IPI is not appropriate as a tool for sexing forensic remains.

Attachment of the levator ani muscle extends to the superior ramus of the pubic bone through electrophysiological and anatomical examinations.

Myofascial pelvic pain (MFPP) of pelvic floor muscles is a common cause of chronic pelvic pain (CPP). The pathological mechanisms and treatments of MFPP are complex and still unclear until now. The levator ani muscle (LAM) is the major pelvic floor muscle. The purpose of this study was to examine the fascia and attachment of LAM through the electromyogram (EMG) and cadaver dissection. Electrophysiological stimulation of the obturator fascia above the arcus tendinous levator ani (ATLA) could trigger contraction and electrophysiological changes in LAM insertion. The LAM of embalmed adult cadavers was examined especially in the area above the ATLA. Some skeletal muscle fibers were found above the ATLA within the obturator fascia and were confirmed by Masson's trichrome section staining. Our electromyography (EMG) and anatomical data implied that the attachment of LAM aponeurosis extended beyond ATLA to the inferior border of the superior ramus of the pubic bone. The new discovered attachment of LAM could provide a reference position for clinical diagnosis and treatment of MFPP or CPP.

Anthropometric characteristics of the pubic arch and proper function of the defense mechanisms against hernia formation.

In 33 inguinal regions, we determined the anthropometric characteristics of the pubic arch and the anatomic structures of the suprainguinal space and assessed whether there is a relationship between anatomic features and function of the defense mechanisms. There was a low position of the pubic arch (pubic tubercle and interspinal line distance >75 mm) in 23 cases. The low-pubic-arch group showed a significantly longer inguinal ligament and a greater angle made by the superior border of the suprainguinal space and the inguinal ligament at its medial insertion. The position of the pubic arch correlated significantly with the diameter of the internal ring, the length of the inguinal ligament, and the angle made by the superior border of the suprainguinal space and the medial insertion of the inguinal ligament. A low pubic arch would represent an unfavorable condition for an adequate function of the anatomic defense mechanism against hernia.

Titanium-bone-anchored penile epithesis: preoperative planning and immediate postoperative results.

The principle of osseointegration is accepted and used in reconstructive surgery. This study presents the first series of five patients where titanium implants have been implanted into the pubic bones of female-to-male (FTM) transsexual patients, in order to attach a "bone-anchored" penile epithesis. Following patient selection based on patients' wishes, pubic bones of 10 FTM transsexuals were analysed by CT-scan and a virtual planning was made. A surgical plan was also developed. To date, five FTM transsexuals have undergone the two-stage surgery. During stage-1, two titanium implants ("fixtures") are implanted onto the pubic bone. Four weeks postop, a new CT scan is performed to analyze osseointegration and the final implant position. During stage-2, the soft tissue of the pubic area is reduced; abutments are inserted and passed through the skin. A few weeks after stage 2 surgery, a penile epithesis is connected to the skin-penetrating titanium implants. Two out of 10 patients who received preoperative CT scan presented with smaller pubic bones, not able to accommodate the fixtures as chosen originally. Preoperative virtual planning is crucial for the selection of the appropriate implants size. The stage-1 and stage-2 surgery occurred uneventfully in all five patients. One patient presented with a wound infection 1 week after stage-2 surgery. Postoperative CT scan demonstrates implant osseointegration in all cases. This experimental clinical study demonstrates that titanium osseointegration is feasible onto the pubic bone. This new approach for penile reconstruction constitutes another alternative for both transsexual patients and cases following genital development disorders, post-trauma and surgery.

Load transfer across the pelvic bone.

Earlier experimental and finite element studies notwithstanding, the load transfer and stress distribution in the pelvic bone and the acetabulum in normal conditions are not well understood. This hampers the development of orthopaedic reconstruction methods. The present study deals with more precise finite element analyses of the pelvic bone, which are used to investigate its basic load transfer and stress distributions under physiological loading conditions. The analyses show that the major part of the load is transferred through the cortical shell. Although the magnitude of the hip joint force varies considerably, its direction during normal walking remains pointed into the anterior/superior quadrant of the acetabulum. Combined with the fact that the principal areas of support for the pelvic bone are the sacro-iliac joint and the pubic symphysis, this caused the primary areas of load transfer to be found in the superior acetabular rim, the incisura ischiadaca region and, to a lesser extent, the pubic bone. Due to the 'sandwich' behavior of the pelvic bone, stresses in the cortical shell are about 50 times higher than in the underlying trabecular bone (15 to 20 MPa vs 0.3-0.4 MPa at one-legged stance). Highest intraarticular pressures are found to occur during one-legged stance and measured about 9 MPa. During the swing phase, these pressures decrease less than linearly with the magnitude of the hip joint force. Muscle forces have a stabilizing effect on the pelvic load transfer. Analysis without muscle forces show that at some locations stresses are actually higher than when muscle forces are included.

What is the normal pattern of uterine involution? An investigation of postpartum uterine involution measured by the distance between the symphysis pubis and the uterine fundus using a paper tape measure.

OBJECTIVE: To describe normal postnatal uterine involution in a small sample of healthy primiparous women, and estimate the proportion who have a decline in the distance between the symphysis pubis and the uterine fundus (S-FD) slow enough to have the potentiality to trigger further clinical action, using currently accepted criteria for intervention. SETTING: A maternity unit in the south of England that has approximately 6000 deliveries per annum and the related community areas. METHODS: Daily measurement of the S-FD was carried out in 28 healthy women from within 18 hours of delivery until the uterine fundus was no longer palpable abdominally. Graphs showing the daily measurements and correlation coefficients were used to describe involution. The proportion of healthy women who would have been identified as healthy by the screening method was estimated (its specificity). FINDINGS: Considerable variability was found in the pattern of uterine involution that was experienced by the women who had a normal puerperium. The measurement of the S-FD has a low specificity with only 6 of the 28 women (21.4%; 95% CI 8.3% to 40.9% having had no episodes of the S-FD declining slowly (less than 1 cm over three days). There was a weak, positive correlation between the S-FD measurement on day one and the day on which the uterus ceased to be palpable (r = 0.426, P = 0.03). No relationship was found between method of baby feeding and the day on which the uterus ceased to be palpable. IMPLICATIONS FOR PRACTICE: The measurement of S-FD using a paper tape measure should not form part of routine postpartum assessment.

Evaluation of seven methods of estimating age at death from mature human skeletal remains.

Different approaches to the estimation of age at death in mature human skeletal remains were evaluated utilizing samples from 19 recent French autopsy individuals of known age at death. Methods of estimating age at death from single-rooted teeth, the sternal ends of the fourth ribs, the symphyseal face of the pubis and femoral cortical remodeling were evaluated by two independent observers (three observers for the teeth). Comparison included ages estimated from three more comprehensive approaches utilizing data from the application of two or more of the individual methods. The results indicate that the comprehensive approaches are superior to the individual ones and the success of the latter reflects not only the morphological expression of the aging process, but also the technique complexity and the experience of the investigator. Of the individual techniques, the "Lamendin" dental technique was most effective for individuals of ages greater than 25 years.

Concentric and eccentric strength of trunk muscles in osteitis pubis soccer players.

BACKGROUND AND OBJECTIVES: Osteitis pubis refers to a painful, inflammatory condition involving the pubic bones, pubic symphysis, and adjacent structures. So, the aims of the study were to evaluate the strength of trunk muscles of soccer players suffering from osteitis pubis, and to compare the agonist/antagonist ratio of trunk muscles in osteitis pubis athletes with that of healthy athletes. MATERIALS AND METHODS: Twenty-five soccer male athletes with osteitis pubis, and 25 healthy soccer athletes. Peak torque/body weight (PT/BW) was recorded from trunk muscles during isokinetic concentric and eccentric contraction modes at a speed of 120°/s for healthy and osteitis pubis soccer players. RESULTS: There was a significant decrease in concentric contraction of back muscles in osteitis pubis group (p=0.01). A significant decrease in eccentric contraction of abdominal muscles was also recorded in osteitis pubis group (p=0.008). Concentric abdominal/back muscles ratio was significantly higher in osteitis pubis group (p=0.016), with no significant difference in eccentric abdominal/back muscles ratio between both groups (p>0.05). CONCLUSION: Osteitis pubis group displayed concentric weakness of back muscle and eccentric weakness of abdominal muscles that lead to disturbance of the normal concentric abdominal/back ratio.

Abdominal muscle and epipubic bone function during locomotion in Australian possums: insights to basal mammalian conditions and Eutherian-like tendencies in Trichosurus.

Mammals have four hypaxial muscle layers that wrap around the abdomen between the pelvis, ribcage, and spine. However, the marsupials have epipubic bones extending anteriorly into the ventral hypaxial layers with two additional muscles extending to the ventral midline and femur. Comparisons of South American marsupials to basal eutherians have shown that all of the abdominal hypaxials are active bilaterally in resting ventilation. However, during locomotion marsupials employ an asymmetrical pattern of activity as the hypaxial muscles form a crosscouplet linkage that uses the epipubic bone as a lever to provide long-axis support of the body between diagonal limb couplets during each step. In basal eutherians, this system shifts off the femur and epipubic bones (which are lost) resulting in a shoulder to pelvis linkage associated with shifts in both the positions and activity patterns of the pectineus and rectus abdominis muscles during locomotion. In this study, we present data on hypaxial function in two species (Pseudocheirus peregrinus and Trichosurus vulpecula) representing the two major radiations of possums in Australia: the Pseudocheiridae (within the Petauroidea) and the Phalangeridae. Patterns of gait, motor activity, and morphology in these two Australian species were compared with previous work to examine the generality of 1) the crosscouplet lever system as the basal condition for the Marsupialia and 2) several traits hypothesized to be common to all mammals (hypaxial tonus during resting ventilation, ventilation to step synchrony during locomotion, and bilateral transversus abdominis activity during locomotor expiration). Our results validate the presence of the crosscouplet pattern and basic epipubic bone lever system in Australian possums and confirm the generality of basal mammalian patterns. However, several novelties discovered in Trichosurus, reveal that it exhibits an evolutionary transition to intermediate eutherian-like morphological and motor patterns paralleling many other unique features of this species.

Sacral orientation revisited.

STUDY DESIGN: A descriptive study of the sacral anatomic orientation (SAO) and its association with pelvic incidence (PI). OBJECTIVE: To introduce the concept of SAO, establish a method for measuring it, and evaluate its association with pelvic orientation. SUMMARY OF BACKGROUND DATA: Pelvic orientation (PO) is considered a key factor in spinal shape and balance. Sacral slope (SS), PI, and pelvic tilt (PT) are the most frequently used parameters for evaluating PO. Nevertheless, the association between the anatomic orientation of the sacrum and these parameters has never been established. The aim of the present study is to define the anatomic orientation of the sacrum, to establish a reliable method for measuring it, and to examine its association with PI. METHODS: SAO was defined as the angle created between the intersection of a line running parallel to the superior endplate surface of the sacrum and a line running between the anterior superior iliac spine (ASIS) and the anterior-superior edge of the symphysis pubis. Methods for measuring SAO and PI on both skeletal populations and living individuals are described. The study was carried out on 424 skeletons (articulated pelves) using a three-dimensional digitizer and on 20 adult individuals using CT three-dimensional images (volume-rendering method). Reliability (intratester and intertester) was assessed using intraclass correlation test. A regression analysis was carried out to evaluate the association between the two measurements. RESULTS: The mean SAO and PI in the human skeletal population were found to be 48.46 degrees +/- 10.17 degrees and 54.08 degrees +/- 12.64 degrees , respectively and of the living individuals (CT) 52.76 degrees +/- 10.31 degrees and 57.14 degrees +/- 13.08 degrees , respectively. SAO and PI measurements were highly correlated (r = -0.824, and r = -0.828, P < 0.001 for skeletal material and living individuals, respectively). PI can be predicted via SAO, i.e., PI = [-0.971 x SAO] + 101.16 degrees . CONCLUSIONS: The newly suggested parameter (SAO) may be an important tool in defining the sagittal shape of the spine and understanding its association with spinal diseases.