Establishing reference values for the pubofemoral distance in normal infant medial hips by ultrasound

BACKGROUND

Measuring the pubofemoral distance (PFD) is important for evaluating the effectiveness of hip reduction in the treatment of developmental dysplasia of the hip (DDH). However, reference PFD values have not been established in normal infants.

PURPOSE

To investigate variations in PFD values measured in normal infant medial hips stratified by age, laterality, and gender.

MATERIAL AND METHODS

A total of 240 infants diagnosed with Graf type Ia and/or Graf type Ib hips by ultrasonography were stratified into eight age groups: 0-1 month; 1-2 months; 2-3 months; 3-4 months; 4-5 months; 5-6 months; 6-7 months; and 7-12 months. The bilateral medial hips were scanned with transinguinal ultrasound. The PFD was defined as the distance between the lateral edge of the superior ramus of pubic bone and the medial edge of the femoral head. Inter-observer reproducibility was assessed.

RESULTS

Among the 240 infants, there were 371 Graf type Ia hips and 109 Graf type Ib hips. Mean ± SD bilateral PFD values of eight groups were measured separately. There were no significant differences in mean PFD values for left or right hips (t = 0.946, P = 0.345) or mean bilateral PFD values in male and female infants (t = 1.445, P = 0.149). Mean PFD values increased linearly with age (left: r = 0.680, P < 0.0001; right: r = 0.682, P < 0.0001). Inter-observer reproducibility was excellent.

CONCLUSION

This study established reference PFD values from the medial hip in infants aged 0-12 months. PFD values increased with age, but were not significantly influenced by laterality or gender. These data provide detailed information that can support follow-up of infants treated for DDH.

Morphological variation in the hyperapolytic lecanicephalidean species Anteropora japonica (Yamaguti, 1934) (Eucestoda)

In November of 2013, a specimen of Japanese sleeper ray, Narke japonica (Temminck et Schlegel), caught off Nanfang-ao, Taiwan was found to be parasitised by the cestode Anteropora japonica (Yamaguti, 1934). Specimens comprised whole worms and free proglottids, both of varying degrees of maturity. This material allowed for the opportunity to examine in detail the developmental progression of this hyperapolytic lecanicephalidean species with regard to overall size, scolex dimensions, and microthrix pattern. Complete immature worms ranged in size from 2.4 mm to 14 mm. The smallest scoleces were half as wide as larger scoleces and exhibited a much smaller ratio of apical organ width to bothridial width. Proglottids more than quadrupled in length during maturation from terminal attached immature to detached proglottids. In addition, a change in microthrix pattern was observed on the anterior region of the proglottids from immature to gravid proglottids; the anterior region of attached immature proglottids is covered with gladiate to coniform spinitriches with capilliform filitriches only rarely visible, whereas this region in detached proglottids is covered with gladiate to coniform spinitriches and conspicuous capilliform filitriches. This is the first report of A. japonica from outside Japan expanding its distribution south to Taiwan. In addition, a preliminary phylogenetic analysis of the genus is presented that suggests congeners from the same host species are not each other's closest relatives, nor is there an apparent phylogenetic signal for apical organ type or reproductive strategy (apolysis). However, reproductive strategy does seem to be correlated with host group such that euapolytic species parasitise dasyatid stingrays while hyperapolytic species parasitise either torpediniform rays or orectolobiform sharks.

Partite hallux sesamoid bones: Relationship with sesamoid bones at other metatarsophalangeal joints

Partite hallux sesamoids are clinically meaningful but their association with other sesamoids is not clear. The objective was to relate the prevalence of the partite hallux sesamoid bones to sesamoid bones at other metatarsophalangeal (MTP) joints. We conducted a retrospective review of plain radiographs of 7946 adult feet between November 2005 and September 2012 to identify partite hallux sesamoids and sesamoids at other MTP joints. Coexistence patterns of the partition and extra sesamoids were studied. Presence or absence of sesamoids at other MTP joints as well as sex and laterality were compared between the feet with and without partite hallux sesamoids using Pearson Chi-square test. Association between age and partition was evaluated using Spearman's correlation coefficient. Overall partite prevalence rate is 6.82%, and coexistence with extra MTP sesamoids was 0.42%. One pattern was partition in hallux sesamoid only, and 4 patterns were coexistence with extra sesamoids. The prevalence rates of partite hallux sesamoids were 7.17% (508/7081) and 3.93% (34/865) in feet without and with extra sesamoids, respectively. The relative risk of 1.889 (95% CI, 1.325-2.693) of partite hallux sesamoids was noted in feet without than with extra sesamoids (Χ² = 12.759, P < 0.001). A negative correlation between age and distribution of partition was identified (r = -0.061, P < 0.001). Partition of hallux sesamoid bones is a developmental variation, it can coexist with sesamoids at other MTP joints following a certain pattern; and its prevalence rate is almost twice higher in feet without than with extra MTP sesamoids. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:34-38, 2018. © 2017 Wiley Periodicals, Inc.

A rare presentation of bilateral maxillary dens invaginatus diagnosed using cone beam computed tomography

Dens invaginatus is a developmental variation in the formation of a tooth that causes changes in the internal anatomy of the tooth. The presence of double dens invaginatus is extremely rare. Understanding the type, extension, and complex morphology of dens invaginatus is essential. Diagnosis of this condition using conventional radiographic techniques is not easy. Advanced imaging techniques, such as cone beam computed tomography (CBCT) are very helpful in diagnosis of these complex anatomic variations. In the present case report, we demonstrate the use of CBCT in the evaluation and treatment planning of bilateral maxillary dens invaginatus, of which one presented as a case of double dens.

Variation in rates of early development in Haliotis asinina generate competent larvae of different ages

INTRODUCTION

Inter-specific comparisons of metazoan developmental mechanisms have provided a wealth of data concerning the evolution of body form and the generation of morphological novelty. Conversely, studies of intra-specific variation in developmental programs are far fewer. Variation in the rate of development may be an advantage to the many marine invertebrates that posses a biphasic life cycle, where fitness commonly requires the recruitment of planktonically dispersing larvae to patchily distributed benthic environments.

RESULTS

We have characterised differences in the rate of development between individuals originating from a synchronised fertilisation event in the tropical abalone Haliotis asinina, a broadcast spawning lecithotrophic vetigastropod. We observed significant differences in the time taken to complete early developmental events (time taken to complete third cleavage and to hatch from the vitelline envelope), mid-larval events (variation in larval shell development) and late larval events (the acquisition of competence to respond to a metamorphosis inducing cue). We also provide estimates of the variation in maternally provided energy reserves that suggest maternal provisioning is unlikely to explain the majority of the variation in developmental rate we report here.

CONCLUSIONS

Significant differences in the rates of development exist both within and between cohorts of synchronously fertilised H. asinina gametes. These differences can be detected shortly after fertilisation and generate larvae of increasingly divergent development states. We discuss the significance of our results within an ecological context, the adaptive significance of mechanisms that might maintain this variation, and potential sources of this variation.