Redescription of Conniella apterygia Allen and its reassignment in the genus Cirrhilabrus Temminck and Schlegel (Teleostei: Labridae), with comments on cirrhilabrin pelvic morphology

Conniella apterygia is redescribed from re-examination of the holotype, two paratypes, and six additional specimens. The genus is closely allied to Cirrhilabrus, sharing similarities in general morphological and meristic details, but is separated from Cirrhilabrus and most other labrid fishes in lacking pelvic fins and a pelvic girdle. Recent molecular phylogenetic studies have provided strong evidence for the deep nesting of Conniella within Cirrhilabrus, contradicting its generic validity and suggesting that the loss of pelvic elements is autapomorphic. Consequently, the species is redescribed and assigned to the genus Cirrhilabrus, as Cirrhilabrus apterygia new combination. The pelvic morphologies of related cirrhilabrin labrids are discussed, and a new synapomorphy is identified for Paracheilinus.

The role of sagittal pelvic morphology in the development of adult degenerative scoliosis

Purpose Pelvic morphology dictates the alignment and biomechanics of the spine. Recent observations in different types of adolescent idiopathic scoliosis indicate that individual pelvic morphology is related to the spinal levels in which scoliosis develops: primary lumbar adolescent scoliosis is associated with a higher pelvic incidence (PI) than thoracic scoliosis and non-scoliotic controls. We hypothesize that adult degenerative scoliosis (ADS) of the lumbar spine follows the same mechanical principles and is associated with a high PI. Methods This study used an existing CT-scan database, 101 ADS patients were sex and age matched to 101 controls. The PI was measured by two observers with multi-planar reconstruction, perpendicular to the hip-axis according to a previously validated technique. Results The PI was 54.1° ± 10.8° in ADS patients and 47.7° ± 10.8° in non-scoliotic controls (p < 0.001). The median ADS curve apex was the disc L2-3 and median curve length was 4 vertebral levels. The mean supine Cobb angle was 21° ± 8° (ranged 10°–47°). There was no significant correlation between PI and the apex level (p = 0.883), the curve length (p = 0.418) or the Cobb angle (p = 0.518). Conclusions ADS normally develops de novo in the lumbar spine of patients with a higher PI than controls, similar to primary lumbar adolescent idiopathic scoliosis. This suggests a shared mechanical basis of both deformities. Pelvic morphology dictates spinal sagittal alignment, which determines the segments of the spine that are prone to develop scoliosis.

Current Evidence about Developmental Dysplasia of the Hip in Pregnancy

In adults, developmental dysplasia of the hip (DDH) represents a spectrum of disorders. It is commonly found in women in routine orthopedic practice. Hip dysplasia is a leading precursor of joint laxity; when untreated, it can contribute to chronic modifications, such as thickening of the pulvinar and ligamentum teres (which can also elongate), hypertrophy of the transverse acetabular ligament, and osteoarthritis. DDH is presumed to be associated with alterations in pelvic morphology that may affect vaginal birth by the reduction in the transverse diameter of the pelvic inlet or outlet. Here, we provide an overview of the current knowledge of pregnancy-associated DDH. We primarily focused on how a surgical DDH treatment might influence the pelvic shape and size and the effects on the mechanism of birth. We presented the female pelvis from the standpoint of bone and ligament morphology relative to a pelvic osteotomy. Then, we described whether the pregnancy was impacted by previous surgical DDH treatments, performed from infancy to adulthood. In conclusion, hip dysplasia is not associated with high-risk complications during pregnancy or with increased difficulty in vaginal delivery.

OP0255 THE ROLE OF PELVIC MORPHOLOGY IN AXIAL SPONDYLOARTHRITIS

Background:Axial Spondyloarthritis (axSpA) is a chronic inflammatory disease affecting the axial skeleton. It includes non-radiographic axSpA and radiographic axSpA [Ankylosing Spondylitis (AS)]. Male axSpA patients often have greater damage, while women report a higher disease burden. The role of pelvic morphology in the axSpA phenotype has not been explored. There is anatomic sexual dimorphism between the male and female pelvis. Given the phenotypic gender differences in axSpA, the role of pelvic morphometry is of interest.Objectives:The purpose of this study is to determine whether an association exists between pelvic dimensions and radiographic damage in patients with axSpA, as well as to compare these measurements in axSpA patients and healthy controls.Methods:This was a cross-sectional analysis comparing axSpA cases from a prospective cohort and non-axSpA controls from the UCSF radiology databank. Informed consent was obtained from axSpA cohort patients and this study was approved by the institutional IRB. To be included in the analysis, we limited inclusion to age ≤ 50 with an Anterior Posterior (AP) pelvis radiograph in the system. We excluded non-nulliparity, pelvic fracture history, BMI ≥ 30kg/m2, any prosthetic history and avascular necrosis. We measured the pelvic inlet, pelvic outlet, and subpubic angle (based on validated scoring methods) (Figure 1) and assessed its relation to sacroiliac joint (SIJ) damage (average SIJ score, New York criteria) and modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) in cases. AxSpA patients were also compared to age/gender matched controls. Pelvic measurements were performed by 2 blinded independent-trained readers in randomized, blinded image order. Inter-rater reliability was assessed. When examining the relationship between pelvic measurements and damage, linear regression was used to stratify by gender and adjust for potential confounders.Results:The axSpA cohort included 481 patients, of which 210 men and 89 women were included in this analysis and gender/age matched controls. Rater inter-class correlation was above 0.70 for pelvic outlet and above 0.80 for other measures. Cases and controls were similar (Table 1). The regression analysis showed a significant relationship between the sub-pubic angle and damage in the spine (coeff=-0.342, p=0.003) in men with axSpA. A sensitivity analysis, excluding mSASSS outliers (mSASSS ≥ 16) upheld the relationship (coeff=-1.40, p=0.002).Conclusion:In men with axSpA, there appears to be a relationship between sub-pubic angle and spinal radiographic damage. This is consistent with our finding that women have larger sub-pubic angles and lower spinal radiographic damage than men. A greater sub-pubic angle may protect against spinal involvement or associate with other protective factors. Further work should be performed to understand the contribution of pelvic anatomy to damage in axSpA.Disclosure of Interests:Ethan Zaccagnino: None declared, Rina Patel: None declared, Lianne S. Gensler Consultant of: AbbVie, Eli Lilly, Gilead, Novartis, Pfizer and UCB., Grant/research support from: Pfizer and UCB.

Shaping birth: variation in the birth canal and the importance of inclusive obstetric care

Regional variation in pelvic morphology and childbirth has long occurred alongside traditional labour support and an understanding of possible normal courses of childbirth for each population. The process of migration and globalization has broken down these links, while a European model of ‘normal’ labour has become widespread. The description of ‘normal’ childbirth provided within obstetrics and midwifery textbooks, in fact, is modelled on a specific pelvic morphology that is common in European women. There is mounting evidence, however, that this model is not representative of women's diversity, especially for women of non-white ethnicities. The human birth canal is very variable in shape, both within and among human populations, and differences in pelvic shapes have been associated with differences in the mechanism of labour. Normalizing a white-centred model of female anatomy and of childbirth can disadvantage women of non-European ancestry. Because they are less likely to fit within this model, pelvic shape and labour pattern in non-white women are more likely to be considered ‘abnormal’, potentially leading to increased rates of labour intervention. To ensure that maternal care is inclusive and as safe as possible for all women, obstetric and midwifery training need to incorporate women's diversity. This article is part of the theme issue ‘Multidisciplinary perspectives on social support and maternal–child health’.

Puberty and fertility in classic galactosemia

Classic galactosemia is a rare inborn error of galactose metabolism with a birth prevalence of about 1/30 000-60 000. Long-term complications occurring despite dietary treatment consist of premature ovarian insufficiency (POI) and neurodevelopmental impairments. We performed with the French Reference Centers for Rare Diseases a multisite collaborative questionnaire survey for classic galactosemic patients. Its primary objective was to assess their puberty, pregnancy, gonadotrop axis, and pelvic morphology by ultrasound The secondary objective was to determine predictive factors for potent pregnancy without oocyte donation. Completed questionnaires from 103 patients, 56 females (median age, 19 years [5-52 years]) and 47 males (median age, 19 years [3-45 years]), were analyzed. Among the 45 females older than 11 years old, mean age for breast development first stage was 12 years; spontaneous menarche occurred in 25 females at a mean age of 14.6 years. After puberty, 60% of females had irregular menstrual cycles and 50% experienced amenorrhea at a median age of 30 years [15;42]. All age-groups confounded, FSH was above normal range for 65% of the patients, anti-Müllerian hormone and inhibin B were below the normal range according to age, and the ovaries were small with few or no follicles detected. Among the 5 females who sought to conceive, 4 had pregnancies. Among the 47 males, 1 had cryptorchidism, all have normal testicular function and none had tried to conceive. Thus, spontaneous puberty and POI are both common in this population. Spontaneous menarche seems to be the best predictive factor for successful spontaneous pregnancy.