Ultrasonographic measurement of the symphysis pubis: a potential method of studying symphyseolysis in pregnancy

Predicting the shape, size, and placement of adult human pubic symphyses

OBJECTIVES

When reconstructing fossil pelves, the articulation of the pelvic bones largely relies on subjective decisions by researchers. Different positionings at the pubic symphysis can affect the overall morphology of the pelvis and the subsequent biological interpretation associated with that individual or species. This study aims to reduce this subjectivity using quantitative models to predict pubic symphysis morphology.

METHODS

We collected 3D landmarks and semilandmarks on the pubic symphysis and adjacent aspects on the CT scans of 103 adults. Using geometric morphometrics we, (1) quantified pubic symphysis morphology, (2) trained simple and two-stage least-squares linear regression models to predict pubic symphysis shape, and (3) assessed the shape variation in the sample. The model with the lowest prediction error was identified as the best model. Principal components analysis was used to explore the effects of each variable on shape and hypothetical shapes were generated from the model to illustrate these effects.

RESULTS

The best model is a two-stage least-squares model that predicts pubic symphysis size at the first stage using additive effects of sex and age, then subsequently interacts pubic symphysis size with sex and age at the second stage to predict pubic symphysis shape. Other models with low prediction errors included variables reflecting pelvic size and breadth.

CONCLUSION

Linear regression modeling can be used to systematically predict pubic symphysis morphology. This method can be used in addition to other techniques to improve fossil reconstructions by more accurately estimating the morphology of this region of the pelvis.

Association Among Pelvic Girdle Pain, Diastasis Recti Abdominis, Pubic Symphysis Width, and Pain Catastrophizing: A Matched Case-Control Study

OBJECTIVE

Pregnancy-related pelvic girdle pain (PGP) may persist or occur postpartum and negatively affects women's lives. There is uncertainty regarding the association between the structures of the bony pelvis, diastasis recti abdominis (DRA), pain processing, and PGP and to what extent these factors should be considered during physical therapy. This study aimed to evaluate the differences between women with and without PGP shortly after delivery regarding the separation of a pubic symphysis, DRA, and pain catastrophizing.

METHODS

Women diagnosed with PGP 24 to 72 hours after vaginal delivery were matched to pain-free controls according to age and parity. Ultrasound evaluations of diastasis recti (interrecti distance [IRD]) during rest and curl-up task and pubic symphysis (interpubic width) were performed. The Pain Catastrophizing Scale was used to assess the level of catastrophizing. A special Cox regression model was used to fit a conditional logistic regression for a 1:2 matched case-control study.

RESULTS

Thirty-five women with clinically diagnosed PGP and 70 matched controls were included in the study. The PGP group had a significantly higher pre-pregnancy body mass index than the control group. After adjusting for body mass index in multiple conditional logistic regression, the interpubic distance (odds ratio = 1.64; 95% CI = 1.22 to 2.20) and IRD during curl-up (odds ratio = 2.01; 95% CI = 1.08 to 3.74) were significantly associated with PGP. Pain catastrophizing and IRD at rest were not associated with PGP in univariable or multivariable analysis.

CONCLUSIONS

Pain catastrophizing is similar for women with and without PGP early postpartum. However, the degree of the pubic symphysis and rectus abdominis separation during the curl-up task are positively associated with PGP shortly after delivery.

IMPACT

This study indicates that a reconsideration of the way we look at DRA is warranted. The development of a more comprehensive assessment including objective measurements and a biopsychosocial understanding is needed to inform directions for further postpartum physical therapy.

Assessment of postpartum symphysis pubis distention with 3D ultrasonography: a novel method

OBJECTIVES

Determining the accuracy of three-dimensional (3D) sonographic measurement of symphysis pubis (SP) distension in comparison to plain X-ray pelvic radiographs and assessing the interperformer reliability of this method.

METHODS

Pelvic X-ray was performed on 86 women who delivered singleton babies within 36 h of delivery then each woman was examined by 3D transperineal ultrasound imaging by two sonogrographers.

RESULTS

Measurements of SP with 3D transperineal ultrasonography in comparison to pelvic X-ray showed 95% limits of agreement. Interperformer reproducibility was substantial (interclass correlation coefficient 0.66-0.70) for measures of SP.

CONCLUSIONS

Pubic symphysis width, superior pubic ligament length, and SP height can be reliably measured with 3D ultrasonography.

Sonographic anatomy of the pubic symphysis in healthy nulliparous women

Pregnancy-related symphyseal pain is a condition commonly encountered by clinicians but its pathogenesis is poorly understood. The pubic symphysis is readily visualized with ultrasound, yet the normal sonographic anatomy of the joint has not been accurately documented. This study aimed to describe the anatomy of the pubic symphysis in healthy, nulliparous women using ultrasound. An experienced and inexperienced sonographer scanned the joint in 30 female volunteers (mean age 26 years). Interobserver and intraobserver reliability of ultrasound measurements were examined and the accuracy of these measurements was validated by ultrasound and dissection of six female cadaver pelves (mean age 75 years). In healthy young women, pubic symphysis morphology varied, and six categories of anterosuperior joint shape were defined. Mean values of several anatomic parameters were obtained in supine and standing positions: joint width (widest 10.1 mm, narrowest 2.6 mm); superior pubic ligament (SPL) length and depth (41.4 and 3.4 mm, respectively); and pubic crest length (left 24.4 mm, right 24.4 mm). Statistically significant relationships between SPL width and depth and anthropometric variables (body mass index, pelvic width, and body fat percentage) were established. Larger ultrasonographic measurements, such as wide joint width and SPL length, could be measured more reliably than smaller measurements, such as narrow joint width and SPL depth, in both healthy volunteers and cadavers. Findings from this study provide normative reference data for examination of the pubic symphysis in pregnant women and may therefore be relevant to understand pregnancy-related symphyseal pain.

Is pregnancy related pelvic girdle pain associated with altered kinematic, kinetic and motor control of the pelvis? A systematic review

PURPOSE

To determine the level of evidence for altered mechanical and motor control of the pelvis being associated with pregnancy-related pelvic girdle pain (PPGP).

METHODS

This systematic review was undertaken by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six different databases were used for the electronic search. Observational cohorts, cross sectional or case-control studies focused on the association between altered kinematic/kinetic and motor control of the pelvis and PPGP during pregnancy were included. Study selection was conducted by two reviewers who firstly screened for titles, then for abstracts and finally for full articles. The Newcastle-Ottawa scale and the guidelines proposed by the Cochrane back review group were used to assess risk of bias and quality of evidence, respectively.

RESULTS

354 references were identified, and after excluding unwanted articles, 10 studies met the final inclusion criteria. Studies not related to motor control or pelvic mobility were the main reason for exclusion. Seven studies were case-control and three were prospective cohort studies. Seven studies were ranked as high while three were ranked as low quality. Among the high quality studies, six found association between PPGP and altered motor control and mobility of the pelvis.

CONCLUSIONS

The level of evidence for an association between PPGP and altered motor control and kinematic or kinetic parameters of the pelvis was found to be moderate.

Peripartum pubic symphysis separation: a case report and review of the literature

Although peripartum pubic symphysis diastasis is an uncommon complication of delivery, it can lead to considerable and sometimes long-term disability. Although the initial clinical examination and diagnostic workup for this complication are relatively straightforward, the best treatment for a peripartum pubic symphysis diastasis is less clear. Historically, nearly all women were treated conservatively with bed rest and pelvic binders. However, more recent case reports have described more invasive orthopedic procedures being used to help speedy recovery. In this study, we present a case of a 22-year-old primigravida who had a severe pubic symphysis separation after a vaginal delivery complicated by a shoulder dystocia. We also reviewed the literature on this topic over the past 20 years to gain a better understanding of the clinical factors surrounding peripartum pubic symphysis separation and the treatment option available to women with this complication.

TARGET AUDIENCE

Obstetricians & Gynecologists.

LEARNING OBJECTIVES

After completing this CME activity, physicians should be better able to identify the clinical factors that associated with peripartum pubic symphysis separation; perform a diagnostic workup when a peripartum pubic symphysis separation is suspected; distinguish the conservative and invasive orthopedic interventions available for the treatment of peripartum pubic symphysis separation; and show that the degree of patient disability after peripartum pubic symphysis separation varies greatly and no clinical factors or diagnostic studies effectively predict the course of patient recovery.

Pregnancy-related pelvic girdle pain: an update

A large number of scientists from a wide range of medical and surgical disciplines have reported on the existence and characteristics of the clinical syndrome of pelvic girdle pain during or after pregnancy. This syndrome refers to a musculoskeletal type of persistent pain localised at the anterior and/or posterior aspect of the pelvic ring. The pain may radiate across the hip joint and the thigh bones. The symptoms may begin either during the first trimester of pregnancy, at labour or even during the postpartum period. The physiological processes characterising this clinical entity remain obscure. In this review, the definition and epidemiology, as well as a proposed diagnostic algorithm and treatment options, are presented. Ongoing research is desirable to establish clear management strategies that are based on the pathophysiologic mechanisms responsible for the escalation of the syndrome's symptoms to a fraction of the population of pregnant women.

The adult human pubic symphysis: a systematic review

The pubic symphysis is a unique joint consisting of a fibrocartilaginous disc sandwiched between the articular surfaces of the pubic bones. It resists tensile, shearing and compressive forces and is capable of a small amount of movement under physiological conditions in most adults (up to 2 mm shift and 1° rotation). During pregnancy, circulating hormones such as relaxin induce resorption of the symphyseal margins and structural changes in the fibrocartilaginous disc, increasing symphyseal width and mobility. This systematic review of the English, German and French literature focuses on the normal anatomy of the adult human pubic symphysis. Although scientific studies of the joint have yielded useful descriptive data, comparison of results is hampered by imprecise methodology and/or poorly controlled studies. Several aspects of the anatomy of the pubic symphysis remain unknown or unclear: the precise attachments of surrounding ligaments and muscles; the arrangement of connective tissue fibres within the interpubic disc and the origin, structure and function of its associated interpubic cleft; the biomechanical consequences of sexual dimorphism; potential ethnic variations in morphology; and its precise innervation and blood supply. These deficiencies hinder our understanding of the normal form and function of the joint, which is particularly relevant when attempting to understand the mechanisms underlying pregnancy-related pubic symphyseal pain, a neglected and relatively common cause of pubic pain. A better understanding of the normal anatomy of the human pubic symphysis should improve our understanding of such problems and contribute to better treatments for patients suffering from symphyseal pain and dysfunction.

Changes in symphysis pubis width during labor

We studied changes in the width of the symphysis pubis in 32 women examined serially by ultrasound during labor. Measurements were made at the superior border of the symphysis and at its narrowest breadth in the latent phase, the active phase, and the second stage of labor. There was a significant increase in the width of the symphysis between the first and second stages of labor at both measured levels. Widening was observed in 94% at the superior symphyseal breadth and in 59% at the narrowest. Of those cases in which the width of the symphysis increased, there was a large spectrum of change, ranging from 9 to 98% of the original width at the narrowest measurement site and from 2 to 139% at the superior breadth. There was a strong inverse correlation between maternal age and the degree of symphyseal widening in nulliparas, but not in multiparas. We conclude that labor is associated with a substantial widening of the symphysis pubis in most, but not all women.

Symphysiotomy in Zimbabwe; postoperative outcome, width of the symphysis joint, and knowledge, attitudes and practice among doctors and midwives

BACKGROUND

Obstructed labour remains one of the leading causes of maternal and foetal death and morbidity in poorly resourced areas of the world, where the 24 hours availability of a caesarean section (CS) cannot be guaranteed, and the CS related mortality rate is still high. In these settings, reinstatement of symphysiotomy has been advocated. The objectives were, in1994; to study perioperative and long-term complications of symphysiotomy and compare them to those related to CS for similar indications, in 1996; to measure the symphyseal width after symphysiotomy and compare it to that after normal vaginal delivery, and, in 1998; to assess knowledge, attitudes and practice related to symphysiotomy among doctors and midwives in Zimbabwe.

METHODS AND FINDINGS

Thirty-four women who had undergone symphysiotomy and 29 women who had undergone a CS for obstructed labour were interviewed. The symphyseal widths of 19 women with a previous symphysiotomy were compared to that of 92 women with previous normal vaginal deliveries, using ultrasound technique. Forty-one doctors and 39 midwives, in three central hospitals and seven district hospitals in Zimbabwe, were interviewed about symphysiotomy. None of the 34 women reported serious soft tissue injuries or infections post symphysiotomy. Long-term complications after symphysiotomy do not differ notably from those after CS for similar indications. The intra-articular width of the symphysis pubis is increased after a symphysiotomy. Seventy-nine of the 80 interviewed health care workers knew about symphysiotomy. One obstetrician had performed symphysiotomies. Two-thirds of the participants considered symphysiotomy an obsolete and second-class operation, but lifesaving and appropriate in remote areas of Zimbabwe. Ten of 13 midwives in remote areas wanted to carry out symphysiotomies themselves.

CONCLUSIONS

No severe complications due to symphysiotomy were revealed in this study. The results suggest that a modest permanent enlargement of the pelvis post symphysiotomy (together with the absence of a scarred uterus) may facilitate subsequent vaginal delivery. Doctors and midwives working in district hospitals have a more positive attitude to symphysiotomies than the colleagues in central hospitals. Obstetricians (who would have to do the teaching), working in the large urban hospitals almost exclude symphysiotomy as an alternative management in Zimbabwe.