Rotation Of Complex Research Articles

A laboratory captured “giving way” episode in an individual with chronic ankle instability

This brief report details the first ever instrument-based motion description of an accidental “giving way” episode of the ankle joint incurred by a recreational male athlete (age = 22 years; height = 1.78 m; body mass = 97 kg) with chronic ankle instability whilst he was performing a change of direction task. Five inertial measurement units, as well as a high-speed video camera captured his lower limb kinematics during the performance of a maximum effort Agility T-Test, including his accidental “giving way” episode. This episode was analysed and compared to a previous trial during which no incident occurred. Analysis of the inertial measurement unit data revealed that the “giving way” episode was characterised by plantar flexion of the ankle joint, as well as internal rotation and adduction of the ankle-foot complex, with peak rotational velocities reaching 797°/s, 1088°/s and 1734°/s, respectively. This instrument-based motion description provides a unique insight into the characteristic features of a “giving way” episode experienced by a recreational athlete with chronic ankle instability. These findings could inform the development of rehabilitation programmes and the design of protective equipment for individuals with chronic ankle instability.

Inducing the controlled rotation of single o-MeO-DMBI molecules anchored on Au(111)

A key step towards building single molecule machines is to control the rotation of molecules and nanostructures step by step on a surface. Here, we used the tunneling electrons coming from the tip of a scanning tunneling microscope to achieve the controlled directed rotation of complex o-MeO-DMBI molecules. We studied the adsorption of single o-MeO-DMBI molecules on Au(111) by scanning tunneling microscopy at low temperature. The enantiomeric form of the molecule on the surface can be determined by imaging the molecule by STM at high bias voltage. We observed by lateral manipulation experiments that the molecules chemisorb on the surface and are anchored on Au(111) with an oxygen-gold bond via their methoxy‑group. Driven by inelastic tunneling electrons, o-MeO-DMBI molecules can controllably rotate, stepwise and unidirectional, either clockwise or counterclockwise depending on their enantiomeric form.

A single point mutation on the cucumber mosaic virus surface induces an unexpected and strong interaction with the F1 complex of the ATP synthase in Nicotiana clevelandii plants

A previous study showed that a single amino acid difference in the cucumber mosaic virus (CMV) capsid protein (CP) elicits unusual symptoms. The wild-type strain (CMV-R) induces green mosaic symptoms and malformation while the mutant strain (CMV-R3E79R) causes chlorotic lesions on inoculated leaves and strong stunting with necrosis on systemic leaves. Virion preparations of CMV-R and CMV-R3E79R were partially purified from Nicotiana clevelandii A. Gray and analysed by two-dimensional gel electrophoresis. Their separated protein patterns showed remarkable differences at the 50–75 kDa range, both in numbers and intensity of spots, with more protein spots for the mutant CMV. Mass spectrometry analysis demonstrated that the virion preparations contained host proteins identified as ATP synthase alpha and beta subunits as well as small and large Rubisco subunits, respectively. Virus overlay protein binding assay (VOPBA), immunogold electron microscopy and modified ELISA experiments were used to prove the direct interaction between the virus particle and the N. clevelandii ATP synthase F1 motor complex. Protein-protein docking study revealed that the electrostatic change in the mutant CMV can introduce stronger interactions with ATP synthase F1 complex. Based on our findings we suggest that the mutation present in the CP can have a direct effect on the long–distance movement and systemic symptoms. In molecular view the mutant CMV virion can lethally block the rotation of the ATP synthase F1 motor complex which may lead to cell apoptosis, and finally to plant death.

Decannulation and Airway Outcomes With Maxillomandibular Distraction in Treacher Collins and Nager Syndrome.

Treacher Collins syndrome is a rare disorder (1/50,000 live births) with features that include hypoplastic orbitozygomatic complex with downward slanting eyes, and maxillary/mandibular retrusion. Obstructive sleep apnea and tracheostomy-dependence are common. This study presents the outcomes of skeletal distraction on avoidance of tracheostomy and decannulation in this patient population. The authors reviewed charts of all patients with Treacher Collins syndrome who underwent craniofacial reconstruction from 2003 to 2016. Primary outcome measures included decannulation of tracheostomy dependent patients and avoidance of tracheostomy. Secondary outcome measures included cephalometric parameters, polysomnography scores, and airway exposure scores on direct laryngoscopy. Twenty-five patients underwent mandibular and maxillary advancement to resolve upper airway obstruction. Mandibular distraction was performed in 24 of 25 patients, and maxillary distraction in 14 of 25 patients. Maxillary distraction was combined with mandibular distraction in 13 of 17 to accomplish greater advancement and counter-clockwise rotation of the entire maxillary-mandibular complex. Six of 7 patients, 85.7%, avoided a tracheostomy and 39% (7 of 18) were decannulated. Cephalometric changes in sella-nasion-A point, sella-nasion-B , occlusal plane angle, and posterior airway space were equivalent between the groups who were able to clear their obstruction and those who were not. Treacher Collins is a very challenging disease in which to resolve airway obstruction. Thus, thorough evaluation of the entire airway for all levels of obstruction is critical to successful outcomes. Future collaborative efforts between multiple institutions can help to increase our understanding and effective management of this rare disease.

Mitochondrial inhibitory factor protein 1 attenuates coupling factor 6-induced aging signal.

Coupling factor 6 (CF6) forces a counter-clockwise rotation of plasma membrane F1 Fo complex, resulting in proton import and accelerated aging. Inhibitory factor peptide 1 (IF1) suppresses a unidirectional counter-clockwise rotation of F1 Fo complex without affecting ATP synthesis. We tested the hypothesis that IF1 may attenuate CF6-induced aging signaling in CF6-overexpressing transgenic (TG) cells. In IF1-GFP overexpressing wild type (WT) cells, the diffuse peripheral staining of tubular mitochondria was observed with a dense widely distributed network around the nucleus. In TG cells, however, the only peri-nuclear network of fragmented mitochondria was observed at 24 h, but it was developed to a widely distributed mitochondrial network of tubular mitochondria at 72 h. TG cells displayed aging hallmarks of telomere attrition, epigenetic alterations, defective proteostasis, and genomic instability with a decrease in emerin and lamin and loss of heterochromatin. IF1 induction rescued TG cells from telomere attrition, expression of genomic instability with the increase in emerin and lamin, and that of epigenetic alterations with recovery of heterochromatin. In defective proteostasis, IF1 induction restored a potent peri-nuclear staining of autolysosomes compared with the baseline weak staining. The decrease in Atg7 was restored, whereas the increase in P62 was abolished. We conclude that genetic disruption of proton signals by IF1 induction suppressed CF6-induced expression of aging hallmarks such as telomere attrition, epigenetic alterations, defective proteostasis, and genomic instability. Given the widespread biological actions of CF6, the physiological and pathological actions of IF1 may be complex.

Is Counterclockwise Rotation With Double Jaw Orthognathic Surgery Stable in the Long-Term in Hyperdivergent Class III Patients?

To evaluate the long-term postsurgical stability of counterclockwise rotation of the occlusal plane (OP) in double-jaw orthognathic surgery in patients with hyperdivergent Class III malocclusion. This retrospective cohort study evaluated the postsurgical stability of orthognathic surgery in patients with skeletal Class III malocclusion and counterclockwise rotation of the maxillomandibular complex with an OP change of at least -2°. Patients were evaluated with lateral cephalometric analysis before surgery, immediately after surgery, and at longest follow-up. The primary predictor variable was the change in angle of the OP and the Frankfort horizontal (FH) after surgery. The primary outcome variable was stability of the OP at longest follow-up. Other study variables were age, gender, and the following cephalometric measurements: mandibular plane angle; gonial angle; angle formed by the sella, nasion, and B point; maxillary height; angle of the palatal plane to the line connecting the sella and nasion; and distances of the posterior nasal spine and A point to the FH and of the A point to the vertical line passing from the nasion. The Mann-Whitney U test was used to compare stability between groups because the variables were not normally distributed. Bonferroni correction was used to evaluate Pvalues. The χ2 test and Fisher exact test, where appropriate, were used to compare the proportions of groups. A P value less than .05 was accepted as statistically significant. The sample was composed of 15 adult patients (mean age at surgery, 23.5yr; 40% men). The median duration of follow-up was 48months (interquartile range, 36 to 60months). The groups had similar demographic properties and similar surgical changes. Ten patients showed very stable results with an OP-FH change no greater than 1°. Four patients showed unstable results with an OP-FH change of 2.25±0.5° during the follow-up period. The change in the mandibular plane angle was notable between patients with stability and those with instability, which was the variable most affected by relapse of the OP. This study found long-term postsurgical skeletal stability of counterclockwise rotation of the OP during double-jaw orthognathic surgery in patients with high angle Class III malocclusion after a median follow-up of 48months.

Orthodontic Clockwise Rotation of Maxillomandibular Complex for Improving Facial Profile in Late Teenagers with Class III Malocclusion: A Preliminary Report

Objective Orthodontic camouflage treatments improve occlusion but might worsen facial profile in patients with Class III malocclusion. It has been reported that surgical clockwise rotation of maxillomandibular complex (MMc) improves facial profile by reducing chin prominence and chin throat length in patients with Class III malocclusion. The purpose of this report was to illustrate two orthodontic techniques for clockwise rotation of the MMc in late teenagers with Class III malocclusion and preliminarily evaluate their clinical effects. Patients and Methods Six patients in late teenage with Class III malocclusion were included in this preliminary report. Bite raisers were first placed on the upper molars to open the bite and clockwise rotate the mandible. Intermaxillary elastics were then applied vertically between the upper and lower dentitions in 3 patients for bimaxillary extrusion (Technique-1) or between the upper dentition and the lower temporary anchorage devices (TADs) in another 3 patients (Technique-2) for upper dentition extrusion and closure of the anterior open bite. The three-dimensional cone-beam computed tomography images taken before and after orthodontic treatment were superimposed to evaluate the treatment effects of MMc clockwise rotation for both techniques. Results The Technique-1 extruded the upper and lower dentitions, rotated the mandible clockwise 2.01°, moved chin down 2.98 mm, and back −1.64 mm, although the mandible grew 2.47 mm during the treatment period. The Technique-2 extruded the upper dentition, rotated the mandible clockwise 0.90°, moved chin down 1.78 mm, but slightly forward 0.47 mm due to the mandible grew 2.50 mm and lower dentition was not extruded. Conclusions The orthodontic clockwise rotation of MMc is an effective technique for orthognathic camouflage. The applications of bite raisers and bimaxillary dentition extrusion could be more effective than single dentition extrusion with TADs in the mandible for clockwise rotation of MMc and improvement of occlusion and facial profile in late teenagers with Class III malocclusion. However, the comprehensive clinical effects and long-term stability need further clinical studies.

Cryo EM structure of intact rotary H+-ATPase/synthase from Thermus thermophilus

Proton translocating rotary ATPases couple ATP hydrolysis/synthesis, which occurs in the soluble domain, with proton flow through the membrane domain via a rotation of the common central rotor complex against the surrounding peripheral stator apparatus. Here, we present a large data set of single particle cryo-electron micrograph images of the V/A type H+-rotary ATPase from the bacterium Thermus thermophilus, enabling the identification of three rotational states based on the orientation of the rotor subunit. Using masked refinement and classification with signal subtractions, we obtain homogeneous reconstructions for the whole complexes and soluble V1 domains. These reconstructions are of higher resolution than any EM map of intact rotary ATPase reported previously, providing a detailed molecular basis for how the rotary ATPase maintains structural integrity of the peripheral stator apparatus, and confirming the existence of a clear proton translocation path from both sides of the membrane.

Quantification of land cover and land use within the rural complex of the Democratic Republic of Congo

The rural complex is the inhabited agricultural land cover mosaic found along the network of rivers and roads in the forest of the Democratic Republic of Congo. It is a product of traditional small-holder shifting cultivation. To date, thanks to its distinction from primary forest, this area has been mapped as relatively homogenous, leaving the proportions of land cover heterogeneity within it unknown. However, the success of strategies for sustainable development, including land use planning and payment for ecosystem services, such as Reduced Emissions from Deforestation and Degradation, depends on the accurate characterization of the impacts of land use on natural resources, including within the rural complex. We photo-interpreted a simple random sample of 1000 points in the established rural complex, using 3106 high resolution satellite images obtained from the National Geospatial-Intelligence Agency, together with 406 images from Google Earth, spanning the period 2008–2016. Results indicate that nationally the established rural complex includes 5% clearings, 10% active fields, 26% fallows, 34% secondary forest, 2% wetland forest, 11% primary forest, 6% grasslands, 3% roads and settlements and 2% commercial plantations. Only a small proportion of sample points were plantations, while other commercial dynamics, such as logging and mining, were not detected in the sample. The area of current shifting cultivation accounts for 76% of the established rural complex. Added to primary forest (11%), this means that 87% of the rural complex is available for shifting cultivation. At the current clearing rate, it would take ~18 years for a complete rotation of the rural complex to occur. Additional pressure on land results in either the cultivation of non-preferred land types within the rural complex (such as wetland forest), or expansion of agriculture into nearby primary forests, with attendant impacts on emissions, habitat loss and other ecosystems services.

Airway Changes after Cleft Orthognathic Surgery Evaluated by Three-Dimensional Computed Tomography and Overnight Polysomnographic Study

Cleft lip and palate is the most common congenital craniofacial anomaly. Up to 60% of these patients will benefit from cleft orthognathic surgery, which consists primarily of maxillary advancement and mandibular setback to address midface retrusion and relative mandibular protrusion, respectively. It is believed that maxillary advancement can enlarge the airway whilst mandibular setback can reduce the airway, but this has not previously been quantified for cleft patients undergoing orthognathic surgery. This unique longitudinal prospective study of 18 patients was conducted between April 2013 and July 2016. No significant changes occurred by six months postoperatively in body mass index, apnoea-hypopnoea index or lowest oxygen saturation (LSAT). There was a mean increase of 0.73 cm3 in velopharyngeal volume, a mean decrease of 0.79 cm3 in oropharyngeal volume, an improvement in snoring index, and no statistically significant change in hypopharyngeal volume. In conclusion, cleft orthognathic surgery that produced anterior advancement of the maxilla, setback of the mandible and clockwise rotation of the maxillo-mandibular complex resulted in increased velopharyngeal, decreased oropharyngeal and unchanged hypopharyngeal airways, and improved snoring, but did not significantly alter objective sleep-related breathing function.

Frontal Changes in the Lower Face After Clockwise Rotation of the Maxillomandibular Complex Without Perisurgical Orthodontic Treatment in Angle Class I and Skeletal Class III Women.

Orthognathic surgery has become more popular to slenderize a wide lower face and to improve facial esthetics in Asian patients with normal occlusion. Clockwise rotation (CR) of the maxillomandibular complex (MMC) steepens the mandibular plane. This study performed a quantitative analysis on the influence of CR on slenderness of the lower face from the frontal view. This retrospective study included 36 female patients with Angle Class I occlusion and skeletal Class III pattern. The subjects underwent CR of the MMC without perioperative orthodontic treatment and change in the occlusion only for the purpose of esthetic improvement. Linear and angular variables were measured on a cephalogram and three-dimensional computed tomography (3D CT) obtained before and at least 6months after surgery. Data were analyzed using paired t tests and Spearman correlations. Univariate regression analysis was used to predict the postoperative change according to the amount of posterior impaction. The mean posterior impaction was 3.81mm. All mandibular plane angle (MPA) measurements were increased (ranged from 5.69° to 13.12°, p<0.001), exhibiting a significant correlation with the amount of posterior impaction. Bigonial width measurements were decreased after surgery (ranged from 4.97 to 5.51mm, p<0.001). Among the MPAs derived from the 3D CT, the coronal projection from the frontal view exhibited a discrepancy between right and left side. The changes in linear and angular measurements in this study indicate that the lower face becomes narrower and more slender as the MMC rotates in a clockwise direction. Orthognathic surgery with CR has the advantage of increasing the MPAs and obtaining natural soft tissue contouring while minimizing the amount of bone resection. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266c .

Cytoplasmic flows as signatures for the mechanics of mitotic positioning.

The proper positioning of mitotic spindle in the single-cell Caenorhabditis elegans embryo is achieved initially by the migration and rotation of the pronuclear complex (PNC) and its two associated astral microtubules (MTs). Pronuclear migration produces global cytoplasmic flows that couple the mechanics of all MTs, the PNC, and the cell periphery with each other through their hydrodynamic interactions (HIs). We present the first computational study that explicitly accounts for detailed HIs between the cytoskeletal components and demonstrate the key consequences of HIs for the mechanics of pronuclear migration. First, we show that, because of HIs between the MTs, the cytoplasm-filled astral MTs behave like a porous medium, with its permeability decreasing with increasing the number of MTs. We then directly study the dynamics of PNC migration under various force-transduction models, including the pushing or pulling of MTs at the cortex and the pulling of MTs by cytoplasmically bound force generators. Although achieving proper position and orientation on reasonable time scales does not uniquely choose a model, we find that each model produces a different signature in its induced cytoplasmic flow. We suggest that cytoplasmic flows can be used to differentiate between mechanisms.

Counterclockwise maxillomandibular advancement: a choice for Chinese patients with severe obstructive sleep apnea

Maxillomandibular advancement (MMA) is an effective alternative for treating severe obstructive sleep apnea (OSA). However, the promotion of MMA in China is limited by many Chinese patients having a convex facial profile. To achieve maximal upper airway enlargement without an esthetic disaster, we added counterclockwise rotation of the maxillomandibular complex (MMC) in the routine MMA. In this paper, we have evaluated the objective and subjective outcomes of this technology. In total, 33 severe OSA patients who accepted counterclockwise maxillomandibular advancement (CMMA) were investigated in this study. Genioplasty, uvulopalatopharyngoplasty (UPPP), and turbinate reduction were also performed on selected patients. Polysomnography (PSG) and Epworth sleepiness scale (ESS) were chosen to evaluate the effectiveness of this technology in treating OSA. Patients' facial appearances were evaluated by cephalometric analysis and 5-point Likert scales. After CMMA, the apnea-hypopnea index (AHI) decreased from 59.3±14.6 to 10.2±6.7 (P<0.001), minimum SpO2 (pulse oxygen saturation, %) increased from 74.0±11.7 to 88.8±4.4 (P<0.001), and ESS decreased from 12.5±2.3 to 7.3±2.1. It is encouraging that soft-tissue cephalometric measurements such as facial convexity angle, nasolabial angle, and labiomental fold were not worsening after surgery. The Likert scales revealed that 28 patients (85%) were satisfied or very satisfied with their facial changes. In addition, no patient complained about dental function after surgery. These findings indicate that CMMA is an effective way to achieve a balance between airway enlargement and facial appearance for Chinese patients with severe OSA.

Evaluating the effectiveness of clockwise rotation of the maxillomandibular complex for skeletal class III correction

Evaluating the effectiveness of clockwise rotation of the maxillomandibular complex for skeletal class III correction

Three-dimensional surgical simulation improves the planning for correction of facial prognathism and asymmetry: A qualitative and quantitative study

Traditional planning method for orthognathic surgery has limitations of cephalometric analysis, especially for patients with asymmetry. The aim of this study was to assess surgical plan modification after 3-demensional (3D) simulation. The procedures were to perform traditional surgical planning, construction of 3D model for the initial surgical plan (P1), 3D model of altered surgical plan after simulation (P2), comparison between P1 and P2 models, surgical execution, and postoperative validation using superimposition and root-mean-square difference (RMSD) between postoperative 3D image and P2 simulation model. Surgical plan was modified after 3D simulation in 93% of the cases. Absolute linear changes of landmarks in mediolateral direction (x-axis) were significant and between 1.11 to 1.62 mm. The pitch, yaw, and roll rotation as well as ramus inclination correction also showed significant changes after the 3D planning. Yaw rotation of the maxillomandibular complex (1.88 ± 0.32°) and change of ramus inclination (3.37 ± 3.21°) were most frequently performed for correction of the facial asymmetry. Errors between the postsurgical image and 3D simulation were acceptable, with RMSD 0.63 ± 0.25 mm for the maxilla and 0.85 ± 0.41 mm for the mandible. The information from this study could be used to augment the clinical planning and surgical execution when a conventional approach is applied.

Does Temporomandibular Joint Pathology With or Without Surgical Management Affect the Stability of Counterclockwise Rotation of the Maxillomandibular Complex in Orthognathic Surgery? A Systematic Review and Meta-Analysis.

This study was designed to determine the stability of counterclockwise rotation (CCWR) of the maxillomandibular complex (MMC) in orthognathic surgery with or without surgical correction of coexisting temporomandibular joint (TMJ) pathology. The authors implemented a systematic review and meta-analysis. A search of major databases through PubMed, EMBASE, and Cochrane CENTRAL was performed. Inclusion criteria were studies that analyzed CCWR of the MMC in regard to skeletal stability after orthognathic surgery in patients with or without pre-existing TMJ pathology that was or was not surgically corrected concomitantly. The predictor variables were patients who underwent CCWR of the MMC in the following subgroups: 1) healthy TMJs (presumed healthy based on history, clinical evaluation, and radiographic analysis but without magnetic resonance imaging [MRI] confirmation), 2) no TMJ assessment, 3) untreated TMJ disc displacement (confirmed by MRI), 4) TMJ disc displacement (confirmed by MRI) repositioned using Mitek anchors, and 5) reconstruction with TMJ total joint prosthesis. Outcome variables were surgical relapse for angular and linear measurements. Postsurgical mean changes for the occlusal plane (OP) and linear measurements using a fixed-effects model with a 95% confidence interval were analyzed. A total of 345 patients enrolled in 12 studies were included in this study. There was significant OP relapse and horizontal relapse at the B point and menton for studies with untreated TMJ disc displacement and studies without TMJ assessment (P < .005). There was significant horizontal relapse at the A point for studies with healthy TMJs, without assessment of the TMJs, and with TMJ reconstruction with total joint prostheses (P < .005). There was no significant vertical relapse at the B and A points for all subgroup analyses (P < .005). The result of the meta-analysis suggests that CCWR of the MMC is a stable procedure for patients with healthy TMJs, patients undergoing concomitant TMJ disc repositioning with Mitek anchors, and patients with TMJ patient-fitted total joint prostheses but unstable in the presence of untreated TMJ disc displacements and when TMJ status is not assessed.

Commentary on: Influence of the Pectoralis Major Muscle Sling in Chest Wall-Based Flap Suspension After Vertical Mammaplasty: Ten-Year Follow-Up

Reduction mammaplasty continues to remain a rewarding procedure with high satisfaction rates among patients of all Body Mass Indes, due to improvement in quality life.1-3 When an inferior pedicle or one of its variations is utilized, loss of upper pole fullness, pseudo-ptosis (bottoming out), and upwards rotation of nipple-areola complex (star gazing deformity) are the most feared concerns. This occurs due to the effect of gravity and lack of lower pole support that lead to downward movement of the breast parenchyma infero-laterally. The authors in this article have demonstrated a technical pearl that can minimize one of the long-term concerns in breast reduction, bottoming out.4 By better supporting the lower pole, one can minimize all other sequale of bottoming out. Even though the number of patients is limited in this study, the design of it is unique and helps the readers understand the descent of the …

Stronger net posterior cortical forces and asymmetric microtubule arrays produce simultaneous centration and rotation of the pronuclear complex in the early Caenorhabditis elegans embryo.

Positioning of microtubule-organizing centers (MTOCs) incorporates biochemical and mechanical cues for proper alignment of the mitotic spindle and cell division site. Current experimental and theoretical studies in the early Caenorhabditis elegans embryo assume remarkable changes in the origin and polarity of forces acting on the MTOCs. These changes must occur over a few minutes, between initial centration and rotation of the pronuclear complex and entry into mitosis, and the models do not replicate in vivo timing of centration and rotation. Here we propose a model that incorporates asymmetry in the microtubule arrays generated by each MTOC, which we demonstrate with in vivo measurements, and a similar asymmetric force profile to that required for posterior-directed spindle displacement during mitosis. We find that these asymmetries are capable of and important for recapitulating the simultaneous centration and rotation of the pronuclear complex observed in vivo. The combination of theoretical and experimental evidence provided here offers a unified framework for the spatial organization and forces needed for pronuclear centration, rotation, and spindle displacement in the early C. elegans embryo.

The Implication of Anterior Communicating Complex Rotation and 3-Dimensional Computerized Tomography Angiography Findings in Surgical Approach to Anterior Communicating Artery Aneurysms

To investigate the usefulness of 3-dimensional computerized tomography angiography (3D-CTA) in the microsurgical management of anterior communicating artery (AcomA) aneurysms. Twenty-six consecutive patients with AcomA aneurysms (22 ruptured) underwent microsurgical clipping. Detailed angioanatomic assessment of the AcomA complex and operative approach was based on the 3D-CTA. The 3D-CTA showed a dominant proximal anterior cerebral artery (A1) segment in 61% and symmetric A1s in 39% of aneurysms. Dominant A1 segments presented with rotation of the AcomA complex toward the contralateral side in 63%, toward the ipsilateral side in 25%, and without rotation in 12%. With symmetric A1s, the AcomA was parallel to the coronal plane in 90% and a right-sided approach was carried out in these patients. In rotated AcomA complexes, the virtual 3D views were compared to determine the side of the approach. For superior projecting aneurysms, we determined that the approach from the side in which the A1-distal anterior cerebral artery (posterior communicating) angle was posterior was more favorable. For posterior projecting aneurysms, the approach from the side where the A1-distal anterior cerebral artery (posterior communicating) angle was more anterior was more favorable. For anteroinferior projecting aneurysms, an approach from the dominant A1 side was chosen regardless of AcomA complex rotation. Postoperative 3D-CTA showed complete exclusion of 24 aneurysms (>92%) and 2 small remnants (<2 mm). Outcome was excellent or good (modified Rankin score 0-2) in 88% of patients. Rotation of the AcomA complex and dome projection are important angioanatomic elements in determining the surgical exposure and side of the approach. This study illustrates the role of 3D-CTA in the management of these difficult lesions by individualizing the surgical approach.

The centre of rotation of the shoulder complex and the effect of normalisation

Shoulder motions consist of a composite movement of three joints and one pseudo-joint, which together dictate the humerothoracic motion. The purpose of this work was to quantify the location of the centre of rotation (CoR) of the shoulder complex as a whole. Dynamic motion of 12 participants was recorded using optical motion tracking during coronal, scapular and sagittal plane elevation. The instantaneous CoR was found for each angle of elevation using helical axes projected onto the three planes of motion. The location of an average CoR for each plane was evaluated using digitised and anthropometric measures for normalisation. When conducting motion in the coronal, scapular, and sagittal planes, respectively, the coefficients for locating the CoRs of the shoulder complex are −61%, −61%, and −65% of the anterior–posterior dimension – the vector between the midpoint of the incisura jugularis and the xiphoid process and the midpoint of the seventh cervical vertebra and the eighth thoracic vertebra; 0%, −1%, and −2% of the superior–inferior dimension – the vector between the midpoint of the acromioclavicular joints and the midpoint of the anterior superior iliac spines; and 57%, 57%, and 78% of the medial–lateral dimension −0.129 times the height of the participant. Knowing the location of the CoR of the shoulder complex as a whole enables improved participant positioning for evaluation and rehabilitation activities that involve movement of the hand with a fixed radius, such as those that employ isokinetic dynamometers.