Leg Elongation Research Articles

Leg Length Change After Curved Periacetabular Osteotomy and Its Impact on the Clinical Outcomes

BackgroundCurved periacetabular osteotomy (CPO) is one of the periacetabular osteotomies for the treatment of acetabular dysplasia. Several complications have been described after CPO, however, there have been no reports on the leg length change (LLC). This study aimed to investigate the LLC after CPO and its impact on the clinical outcomes. MethodsThis study was a retrospective review of 70 consecutive hips in 67 patients with symptomatic acetabular dysplasia who underwent CPO between March 2016 and April 2019. Preoperative and postoperative leg lengths were measured using anteroposterior radiographs, and the clinical outcomes were evaluated based on the Harris hip score (HHS) and Medical Outcomes Survey 36-item Short Form Health Survey (SF-36). ResultsThe mean LLC (and standard deviation) after CPO was −0.08 ± 3.10 mm. The mean HHS significantly improved from 73.5 points to 91.9 points (P < .001). The physical component and role component scores of SF-36 significantly improved from 35.1 to 46.1 (P < .001) and from 39.5 to 47.0 (P < .001), respectively. No significant differences were found between the preoperative and postoperative mental component scores of SF-36. In addition, among 70 hips, 35 hips exhibited leg length elongation (0 to plus 6.82 mm) after CPO, whereas 35 hips exhibited leg length shortening (0 to minus 6.23 mm). No significant differences were found in HHS and SF-36 between the leg elongation group and leg shortening group. ConclusionThe mean LLC after CPO was −0.08 ± 3.10 mm, and this change does not affect the postoperative clinical outcomes.

The Broad Transcription Factor Links Hormonal Signaling, Gene Expression, and Cellular Morphogenesis Events During Drosophila Imaginal Disc Development.

Imaginal disc morphogenesis during metamorphosis in Drosophila melanogaster provides an excellent model to uncover molecular mechanisms by which hormonal signals effect physical changes during development. The broad (br) Z2 isoform encodes a transcription factor required for disc morphogenesis in response to 20-hydroxyecdysone, yet how it accomplishes this remains largely unknown. Here, we use functional studies of amorphic br5 mutants and a transcriptional target approach to identify processes driven by br and its regulatory targets in leg imaginal discs. br5 mutants fail to properly remodel their basal extracellular matrix (ECM) between 4 and 7 hr after puparium formation. Additionally, br5 mutant discs do not undergo the cell shape changes necessary for leg elongation and fail to elongate normally when exposed to the protease trypsin. RNA-sequencing of wild-type and br5 mutant leg discs identified 717 genes differentially regulated by br, including a large number of genes involved in glycolysis, and genes that encode proteins that interact with the ECM. RNA interference-based functional studies reveal that several of these genes are required for adult leg formation, particularly those involved in remodeling the ECM. Additionally, brZ2 expression is abruptly shut down at the onset of metamorphosis, and expressing it beyond this time results in failure of leg development during the late prepupal and pupal stages. Taken together, our results suggest that brZ2 is required to drive ECM remodeling, change cell shape, and maintain metabolic activity through the midprepupal stage, but must be switched off to allow expression of pupation genes.

Surgical treatment outcomes of the Ilizarov and internal osteosynthesis methods in posttraumatic pseudarthrosis of the tibia\u2014a retrospective comparative analysis

IntroductionThis study compared surgical treatment outcomes of the Ilizarov and internal osteosynthesis methods in posttraumatic pseudarthrosis of the tibia.Material and methodsIn a retrospective comparative study, 75 patients were treated with the Ilizarov technique for aseptic posttraumatic pseudarthrosis of the tibia in the period 2000–2016. We compared them with the 51 patients from the control group, treated for tibial bone union disturbances using internal osteosynthesis methods, i.e., internal-fixation plates and intramedullary nails. The study groups were compared in terms of the rates of union, time to union, and the baseline-to-postoperative difference in lower leg deformity.ResultsUnion rate in the Ilizarov group was 100% and the control group was 51.92% (p < 0.001). The median time to union suggests that patients from the Ilizarov group needed a shorter time to achieve bone union (203.00 days vs. 271.00 days) (p = 0.091). The effect size in the Ilizarov group was larger both in terms of reducing both limb deformity and shortening (it is worth noting, however, that the Ilizarov treatment was used in patients with higher baseline values of both these parameters). We observed no significant difference in terms of time to union between the group of patients with at least one risk factor for disturbance in fracture healing and the group with no risk factors. The following risk factors were considered: diabetes mellitus, corticosteroid therapy, smoking, alcohol dependence, and advanced lower-extremity vascular disease (p = 0.827).DiscussionOur study demonstrated a high effectiveness of the Ilizarov method in the treatment of aseptic posttraumatic pseudarthroses of the tibia. The Ilizarov method seems to be worth considering in all cases where either the patient or the nature of injury is associated with additional risk factors and whenever there is a need for leg deformity correction or leg elongation.

Proceeding from direct lateral to anterolateral approach in total hip arthroplasty: A closer look on radiological and clinical aspects

IntroductionSince less invasive approaches for total hip arthroplasty (THA) are promoted, our aim was to compare direct lateral (DLA) and anterolateral approach (ALA) under otherwise identical conditions. MethodsPre - and postoperative x-rays from 200 propensity matched patients (DLA vs. ALA) were evaluated for anatomical reconstruction. ResultsOverall, the cup position was within the safe zone in both group while the mean center of rotation (COR) was placed more medial and cranial in both groups compared to preoperative anatomy (p > 0.05). The mean leg elongation was comparable between both approaches (p > 0.05). Postoperatively the WOMAC improved about 90%. ConclusionThis study confirmed that the ALA can be safely used for THA in minimal invasive setting.

Exploring the morphospace in subterranean spiders

In light of the reduced diversity and abundance of species, subterranean habitats represent ideal models systems in which to investigate characters displacement in species sharing the same habitat. In order to minimize direct competition, it is expected that sibling species occupying the same subterranean habitat should differentiate their morphological niche. Conversely, geographically vicariant species occupying similar microhabitats should display a convergent morphology. We tested these hypotheses by studying character displacement in different species of Troglohyphantes Joseph, 1881 spiders (Araneae: Linyphiidae) in the Western Italian Alps. These spiders underwent a remarkable radiations in subterranean habitats, with numerous stenoendemic elements showing different degrees of subterranean adaptation. For each considered species, we examined 10 to 15 females specimens for a number of morphological characters related to body size, degree of subterranean adaptation (eyes development, flattening of the cephalotorax and leg elongation) and trophic specialization (chelicera and fang length). These traits were combined in a multidimensional space in order to describe the geometry of the n-dimensional Hutchinsonian hypervolume representing the morphological niche of each species. Once the hypervolumes were constructed, pairwise similarity among each species niche was calculated using different overlap indexes. We found that the niche hypervolume of all Troglohyphantes species had a comparable size. However, the distance among niche centroids was lower for species with similar subterranean adaptation and significantly higher in coexisting species. Furthermore, when found in the same cave, species with similar degree of adaptation showed a limited niche overlap. Overall, our results highlight the key role of competition in shaping morphology when competing species are present.

Apical and Basal Matrix Remodeling Control Epithelial Morphogenesis

SummaryEpithelial tissues can elongate in two dimensions by polarized cell intercalation, oriented cell division, or cell shape change, owing to local or global actomyosin contractile forces acting in the plane of the tissue. In addition, epithelia can undergo morphogenetic change in three dimensions. We show that elongation of the wings and legs of Drosophila involves a columnar-to-cuboidal cell shape change that reduces cell height and expands cell width. Remodeling of the apical extracellular matrix by the Stubble protease and basal matrix by MMP1/2 proteases induces wing and leg elongation. Matrix remodeling does not occur in the haltere, a limb that fails to elongate. Limb elongation is made anisotropic by planar polarized Myosin-II, which drives convergent extension along the proximal-distal axis. Subsequently, Myosin-II relocalizes to lateral membranes to accelerate columnar-to-cuboidal transition and isotropic tissue expansion. Thus, matrix remodeling induces dynamic changes in actomyosin contractility to drive epithelial morphogenesis in three dimensions.

Effects of Base Fabric Parameters on the Electro-Mechanical Behavior of Piezoresistive Knitted Sensors

Strain sensors embedded into fabric structure are one of the most interesting research areas for health and engineering monitoring. In this paper, a textile-based strain sensor has been developed using an intrinsically conductive stainless steel-polyester plain knitted fabric. The influence of fabric structural parameters, such as loop length on electro-mechanical properties of sensors was studied under a tensile fatigue set. Knitted fabric structure deformation during tensile fatigue was monitored and image processed. Peak fitting of electric resistant waveforms (ERWs) and tensile fatigue versus time were performed to analyze the ERWs behavior in detail wherein the entire elongation of knit strain sensor partitioned into two distinct phases, such as loop head and loop leg sections. The results evidenced a discrepancy between loop head and loop leg elongation rate at the stretching onset and end of relaxing phase. The ERW with the higher resolution was obtained using the longest loop length along with the higher extension.

Associativity of selected traits in Aginskaya semicoarse wool sheep

Research findings in the phenotypic correlations of the live weight to the body measurements and the body conformation indices in the replacement young stock of the semicoarse wool sheep of the Aginskaya breed have been reported. It is ascertained that males surpass the females in the live weight and the body measurements. The calculation of the conformation indices has shown that the rams compared to the ewes are more massive, more compact, and wider, while the ewes differ in leg length and elongation. A high positive correlation between the live weight and the chest girth is established both in males and females (r = 0.751; r = 0.688, respectively). In ram lambs, a high positive correlation between the live weight and the measurements characterizing the meat quality of sheep (the depth, width, and girth of the chest; the width between hip bones) has been revealed.

Key patterning genes contribute to leg elongation in water striders.

BackgroundHow adaptive phenotypes are shaped by the action of key developmental genes during ontogeny remains poorly understood. Water striders, a group of hemipteran insects, present a unique example of adaptation to life on the fluid water surface substrate. The group has undergone a set of leg modifications allowing them to efficiently move on the water surface and hence invade a variety of niches from ponds to open oceans. The elongated legs of water striders play a key role in generating efficient movement on the fluid by acting as propelling oars.ResultsTo determine the developmental mechanisms underlying leg elongation, we examined the function of the key developmental genes decapentaplegic (dpp), wingless (wg), epidermal growth factor receptor (egfr), and hedgehog (hh) during embryonic development in the water strider Limnoporus dissortis. By analyzing expression patterns and RNAi knockdown phenotypes, we uncover the role of these genes in leg growth and patterning during embryogenesis. Our results indicate that wg and egfr contribute to the elongation of all the three segments of all thoracic legs, whereas hh specifies distal leg segments.ConclusionsTogether, our results suggest that key patterning genes contribute to the dramatic elongation of thoracic appendages in water striders.

Scaling of the appendicular skeleton of the giraffe (Giraffa camelopardalis).

Giraffes have remarkably long and slender limb bones, but it is unknown how they grow with regard to body mass, sex, and neck length. In this study, we measured the length, mediolateral (ML) diameter, craniocaudal (CC) diameter and circumference of the humerus, radius, metacarpus, femur, tibia, and metatarsus in 10 fetuses, 21 females, and 23 males of known body masses. Allometric exponents were determined and compared. We found the average bone length increased from 340 ± 50 mm at birth to 700 ± 120 mm at maturity, while average diameters increased from 30 ± 3 to 70 ± 11 mm. Fetal bones increased with positive allometry in length (relative to body mass) and in diameter (relative to body mass and length). In postnatal giraffes bone lengths and diameters increased iso- or negatively allometric relative to increases in body mass, except for the humerus CC diameter which increased with positive allometry. Humerus circumference also increased with positive allometry, that of the radius and tibia isometrically and the femur and metapodials with negative allometry. Relative to increases in bone length, both the humerus and femur widened with positive allometry. In the distal limb bones, ML diameters increased isometrically (radius, metacarpus) or positively allometric (tibia, metatarsus) while the corresponding CC widths increased with negative allometry and isometrically, respectively. Except for the humerus and femur, exponents were not significantly different between corresponding front and hind limb segments. We concluded that the patterns of bone growth in males and females are identical. In fetuses, the growth of the appendicular skeleton is faster than it is after birth which is a pattern opposite to that reported for the neck. Allometric exponents seemed unremarkable compared to the few species described previously, and pointed to the importance of neck elongation rather than leg elongation during evolution. Nevertheless, the front limb bones and especially the humerus may show adaptation to behaviors such as drinking posture.

基于机构条件数的30 m望远镜三镜Stewart平台

The rotation accuracy of large Stewart platform of a three mirror system in a 30 m telescopy was explored based on the error transfer. Firstly, the singular value method was used to analyze the Stewart platform velocity Jacob matrix, and to obtain the relationship between mechanism condition number and leg elongation. Then, using condition number and system error transfer function , the relationship between the leg elongation error and the platform attitude error was discussed in TMT special kinematical forms, and a group of optimal solution was given out by the MATLAB optimization. After using the ADAMS to validate the theoretical derivation, the known error transfer model combined with precision experiment was used to identify the leg elongation error for evenly distribution and the mobile platform rotation error for bimodal distribution . The MATLAB simulation indicates when the leg elongation error is distributed from 0 to 1 evenly, the expectation of mobile platform rotation error vector norm has reduced from 5.345 410-4to 4.272 110-4 with optimizing quantity by 20%. It concludes that the error distributions of the two shoulder peaks are close to each other and move to 0 point integratively.

The Impact of Leg Length Discrepancy on Clinical Outcome of Total Hip Arthroplasty: Comparison of Four Measurement Methods

In a single-surgeon series of 119 patients with unilateral primary uncemented total hip arthroplasty, four leg-length discrepancy measurement methods (absolute, relative, trochanteric, standardized-trochanteric) were analyzed for their impact on WOMAC score, Oxford Hip Score and self-perceived leg-length discrepancy. After adjustment for age, gender and BMI, postoperative WOMAC scores correlated only with clinical absolute measurements of leg elongation (P=0.05). Self-perceived leg-length discrepancy corresponded best to the clinically measured relative leg-length discrepancy (11 mm perceived vs. 7 mm unperceived; P=0.04) while there was no significant correspondence with radiographic measurements or leg elongation magnitudes. Within the <10 mm range of mean postoperative leg length discrepancy in the studied series, its impact on the overall clinical satisfaction was detectable but not considerable.

The green leafhopper,Cicadella viridis(Hemiptera, Auchenorrhyncha, Cicadellidae), jumps with near-constant acceleration

Jumping insects develop accelerations that can greatly exceed gravitational acceleration. Although several species have been analysed using different tools, ranging from a purely physical to a morpho-physiological approach, instantaneous dynamic and kinematic data concerning the jumping motion are lacking. This is mainly due to the difficulty in observing in detail events that occur in a few milliseconds. In this study, the behaviour of the green leafhopper, Cicadella viridis, was investigated during the take-off phase of the jump, through high-speed video recordings (8000 frames s(-1)). We demonstrate that C. viridis is able to maintain fairly constant acceleration during overall leg elongation. The force exerted at the foot-ground interface is nearly constant and differs from the force expected from other typical motion models. A biomechanical model was used to highlight that this ability relies on the morphology of C. viridis hind legs, which act as a motion converter with a variable transmission ratio and use the time-dependent musculo-elastic force to generate a nearly constant thrust at the body-ground interface. This modulation mechanism minimizes the risk of breaking the substrate thanks to the absence of force peaks. The results of this study are of broad relevance in different research fields ranging from biomechanics to robotics.

Highlights in DD

Highlights in <i>DD</i>

A Case of 2-stage Total Hip Arthroplasty with Leg Elongation for High-riding Developmental Dysplastic Hip Using 3D Preoperative Planning

A Case of 2-stage Total Hip Arthroplasty with Leg Elongation for High-riding Developmental Dysplastic Hip Using 3D Preoperative Planning

Cyclin Y Is a Novel Conserved Cyclin Essential for Development in Drosophila

The Drosophila gene CG14939 encodes a member of a highly conserved family of cyclins, the Y-type cyclins, which have not been functionally characterized in any organism. Here we report the generation and phenotypic characterization of a null mutant of CG14939, which we rename Cyclin Y (CycY). We show that the null mutant, CycY(E8), is homozygous lethal with most mutant animals arresting during pupal development. The mutant exhibits delayed larval growth and major developmental defects during metamorphosis, including impaired gas bubble translocation, head eversion, leg elongation, and adult tissue growth. Heat-shock-induced expression of CycY at different times during development resulted in variable levels of rescue, the timing of which suggests a key function for zygotic CycY during the transition from third instar larvae to prepupae. CycY also plays an essential role during embryogenesis since zygotic null embryos from null mothers fail to hatch into first instar larvae. We provide evidence that the CycY protein (CycY) interacts with Eip63E, a cyclin-dependent kinase (Cdk) for which no cyclin partner had previously been identified. Like CycY, the Eip63E gene has essential functions during embryogenesis, larval development, and metamorphosis. Our data suggest that CycY/Eip63E form a cyclin/Cdk complex that is essential for several developmental processes.

Two new species of the enigmatic genus Stenophareus (Opiliones: Laniatores: Stygnidae) from the Venezuelan Guiana Shield

Two new species of Stenophareus are described from the Guiana Shield region of Venezuela. S. aonda sp. n. (type-locality: Auyán-tepui, Bolívar) is characterized by ocular and tegumentary depigmentation and by extreme pedipalp and leg elongation, representing the first troglomorph stygnid. S. guerreroi sp. n. (type-locality: Chimantá-tepui, Bolívar) is distinguished by a swollen proximal-most tarsomere of leg I and by the presence of an anterior tubercle on the anal opercle. Putative phylogenetic affinities of the genus Stenophareus within the Stygninae are discussed.Se describen dos especies nuevas del género Stenophareus provenientes de la región del escudo guayanés de Venezuela. S. aonda sp. n. (localidad tipo: Auyán-tepui, Bolívar) es caracterizado por depigmentación ocular y del tegumento y pedipalpo y patas extremadamente largos, representando el primer estígnido troglomorfo. S. guerreroi sp. n. (localidad tipo: Chimantá-tepui, Bolívar) es diagnosticado por el engrosamiento del tarsómero más proximal de la pata I y presencia de un tubérculo anterior en el opérculo anal. Las afinidades filogenéticas putativas del género Stenophareus dentro de la subfamilia Stygninae son discutidas.

A REVIEW OF LEG ORNAMENTATION IN MALE WOLF SPIDERS, WITH THE DESCRIPTION OF A NEW SPECIES FROM AUSTRALIA, ARTORIA SCHIZOCOIDES (ARANEAE, LYCOSIDAE)

Morphological modifications of the first pair of legs in addition to widespread color var- iations of these legs among males of closely related species have been reported in a variety of spiders. Here, the evidence for sexual dimorphism in male foreleg morphology within wolf spiders (family Ly- cosidae) is reviewed and shown to occur in a number of species belonging to at least seven genera in five subfamilies: Alopecosa, Hogna, Schizocosa (all Lycosinae) Pirata (Piratinae), Evippa, (Evippinae), Par- dosa (Pardosinae) and Artoria (Artoriinae). These modifications, often in combination with distinct dark pigmentation, can be divided into three major groups: leg elongation, segment swelling and exaggerated setation (''brushes''). The latter two occur mainly on the tibial segment of the first leg. The function of these foreleg modifications has been studied most extensively in the genus Schizocosa. Since the courtship displays of all male Schizocosa incorporate a seismic component, foreleg ornamentation (namely pigmen- tation and associated ''brushes'') composes only one part of a multimodal courtship display. The function of this foreleg ornamentation appears to vary across closely related Schizocosa species and in some instances involves an interaction with the seismic signaling component. In most instances it appears to play a role in female mate choice and/or mate choice learning. In addition to reviewing lycosid foreleg modifications, we describe a new species of wolf spider, Artoria schizocoides from southwestern Western Australia that possesses sexually dimorphic modifications of the tibia of the first leg. Unique within the Artoriinae, males of this species carry spatulate setae on the ventral side of the tibia of the first leg that differ morphologically from other leg modifications in wolf spiders.

GENDER SPECIFIC DIFFERENCES IN ACTIVITY AND HOME RANGE REFLECT MORPHOLOGICAL DIMORPHISM IN WOLF SPIDERS (ARANEAE, LYCOSIDAE)

Abstract Sexual dimorphism of locomotory organs appears to be common in a variety of arthropods, however, the underlying evolutionary mechanisms remain poorly understood and may be the consequence of natural or sexual selection, or a combination of both. I analyzed the activity pattern of seven cohorts of a wolf spider, Venatrix lapidosa, over four consecutive years. Males appear to be the more active sex in search for a mate as they show temporarily higher activity prior to the periods of female brood care. Morphometric data on leg length showed comparatively longer legs for males than females. Allometric leg elongation in all four legs of males arises only after the final molt suggesting its significance in reproductive behavior such as mate search. A comparative analysis of two Australasian wolf spider genera with different activity profile of females, Venatrix (sedentary females) and Artoria (vagrant females) provides further evidence that limb elongation in males mainly arises due to indirect male ma...

Orphan nuclear receptor βFTZ-F1 is required for muscle-driven morphogenetic events at the prepupal–pupal transition in Drosophila melanogaster

In Drosophila melanogaster, fluctuations in 20-hydroxyecdysone (ecdysone) titer coordinate gene expression, cell death, and morphogenesis during metamorphosis. Our previous studies have supported the hypothesis that βFTZ-F1 (an orphan nuclear receptor) provides specific genes with the competence to be induced by ecdysone at the appropriate time, thus directing key developmental events at the prepupal–pupal transition. We are examining the role of βFTZ-F1 in morphogenesis. We have made a detailed study of morphogenetic events during metamorphosis in control and βFTZ-F1 mutant animals. We show that leg development in βFTZ-F1 mutants proceeds normally until the prepupal–pupal transition, when final leg elongation is delayed by several hours and significantly reduced in the mutants. We also show that βFTZ-F1 mutants fail to fully extend their wings and to shorten their bodies at the prepupal–pupal transition. We find that βFTZ-F1 mutants are unable to properly perform the muscle contractions that drive these processes. Several defects can be rescued by subjecting the mutants to a drop in pressure during the normal time of the prepupal–pupal transition. Our findings indicate that βFTZ-F1 directs the muscle contraction events that drive the major morphogenetic processes during the prepupal–pupal transition in Drosophila.