Canal Size Research Articles

Does the Size or Location of Lumbar Disc Herniation Predict the Need for Operative Treatment?

Study Design:Retrospective cohort study.Objective:The goal of this study was to determine whether the absolute size (mm2), relative size (% canal compromise), or location of a single-level, lumbar disc herniation (LDH) on axial and sagittal cuts of magnetic resonance imaging (MRI) were predictive of eventual surgical intervention.Methods:MRIs of 89 patients were reviewed, and patients were split into groups based on type of management received (34 nonoperative vs 55 microdiscectomy). Radiographic characteristics—including size of disc herniation (mm2), size of spinal canal (mm2), location of herniation on axial (central, paracentral, foraminal) and sagittal (disc level, suprapedicle, pedicle, infrapedicle) planes, and type of herniation (bulge, protrusion, extrusion, sequestration)—were measured by 2 independent, orthopedic spine fellows and compared between groups via univariate and multivariate analyses.Results:The operative group showed a significantly higher percentage of canal compromise (39.5% vs 31.1%, P = .001) compared to the nonoperative group. Multiple logistic regression analysis showed higher odds of eventual operative intervention for a disc protrusion (odds ratio [OR] 6.30 [1.99, 19.86], P = .002) or disc extrusion (OR 11.5 [1.63, 81.2], P = .014) for Rater 1 and a higher odds of eventual surgical management for a paracentral location for both Rater 1 and Rater 2 (OR = 3.39 [1.25, 9.22], P = .017, and OR = 5.46 [1.77, 16.8], P = .003, respectively).Conclusions:Disc herniations in a paracentral location were more likely to undergo operative treatment than those more centrally located, on axial MRI views.

Pedigree analysis of lumbar developmental spinal stenosis: Determination of potential inheritance patterns.

Lumbar developmental spinal stenosis (DSS) refers to multilevel pre-existing narrowed spinal canals, which predisposeto neural compromise. The objective of this study is to identify any inheritance pattern of DSS by utilizing pedigree charts. This was a case series of 13 families with a total of 80 subjects having magnetic resonance imaging (MRI) from L1 to S1. Cases (subjects with DSS) or controls (subjects without DSS) were identified by measuring their anteroposterior (AP) vertebral canal diameters. Multilevel model analyses were also performed to evaluate whether there is substantial clustering of observations within the families, and the effect of multilevel DSS. The intraclass correlation coefficient (ICC) and Akaike information criteria (AIC) were compared between models. Correlations between subject demographics and AP vertebral canal diameter were statistically insignificant at all levels. Only vertebral canal cross-sectional area, and axial and sagittal vertebral canal diameter were found to be statistically different between cases and controls at all levels (all p < .05). Both males and females were affected by DSS and there was no skipping of generation, which highly suggested DSS followed an autosomal dominant inheritance pattern. After accounting for multilevel DSS, there was a drop of more than 10 in AIC and some variances were also explained within families. This is the first study that suggests multilevel lumbar DSS to have an autosomal dominant inheritance pattern. Within families with a background of DSS, subjects had a smaller canal size, contributed by shortened axial and sagittal AP vertebral canal diameter, and smaller canal cross-sectional area.

A morphometric analysis of the immature human infraorbital canal

The importance of the infraorbital canal in the growth of the maxilla and associated mid-facial region has significance for innervation of this region as well as the associated dentition, yet little is known about the development of the canal. An analysis of its dimensions and morphology during the late prenatal and early postnatal periods was thus undertaken. The aim of this study was to describe changes in the morphology, size and branching pattern of the infraorbital canal during the late prenatal and early postnatal stages of human growth. Fifty human fetal and neonatal maxillae were analyzed. The sample included 27 late prenatal individuals (30 gestational weeks and birth) and 23 early postnatal individuals (birth and 1year). Maxillae were scanned using a Nikon XTH 225 L micro-CT unit and analyzed using VG studiomax v3.2. Measurements included the maximum width, height and surface area of each foramen associated with the infraorbital canal and the total length of the canal, bilaterally. All the measurements of the canal were greater in the early postnatal group than in the late prenatal group, while the walls and branching pattern of the canal were better developed in the postnatal group. Bone development occurred within the walls as development proceeded. Variations in the branching pattern of the canal were found. The morphology of the infraorbital canal reflected the developmental stage of associated structures such as the dentition, maxillary sinus and orbit.

OCT based interpretation of the optic nerve head anatomy in young adults with retinal vascular occlusions and ischemic optic neuropathy.

To examine optic nerve head (ONH) anatomy in young adults with central retinal vein occlusion (CRVO), branch retinal vein occlusion (BRVO), central retinal artery occlusion (CRAO), branch retinal artery occlusion (BRAO) or nonarteritic anterior ischemic optic neuropathy (NA-AION) in order to look for associated, potentially predisposing anomalies. Cross-sectional study including 54 patients (ages 16-50 years) diagnosed from 2009 to 2018 with CRVO, BRVO, CRAO, BRAO, or NA-AION. Using Optical Coherence Tomography the presence of optic disc drusen (ODD), prelaminar hyperreflective lines and peripapillary hyperreflective ovoid mass-like structures (PHOMS), and determination of scleral canal size, retinal nerve fiber layer thickness (RNFLT) and macular ganglion cell layer thickness (GCLT) was obtained. Data for retinal vascular occlusion patients were grouped and analyzed together. ODD were found in 13% of all patients, 2% of retinal vascular occlusion patients and 67% of NA-AION patients (p < 0.0001). Prelaminar hyperreflective lines were found in 35% of all patients, 24% of retinal vascular occlusion patients and 89% of NA-AION patients (p = 0.0005). PHOMS were found in 20% of all patients, 13% of retinal vascular occlusion patients and 56% of NA-AION patients (p = 0.012). RNFLT was decreased in ODD patients compared to patients without ODD (p = 0.01). Scleral canal diameter and GCLT was not correlated with ODD, prelaminar hyperreflective lines or PHOMS. ODD, prelaminar hyperreflective lines and PHOMS were more frequent in NA-AION patients compared to retinal vascular occlusion patients. The prevalence of ODD in retinal vascular occlusion patients was similar to the reported prevalence in the general population.

Multimaterial three-dimensional printing in brachytherapy: Prototyping teaching tools for interstitial and intracavitary procedures in cervical cancers

PurposeAs the utilization of brachytherapy procedures continues to decline in clinics, a need for accessible training tools is required to help bridge the gap between resident comfort in brachytherapy training and clinical practice. To improve the quality of intracavitary and interstitial high-dose-rate brachytherapy education, a multimaterial, modular, three-dimensionally printed pelvic phantom prototype simulating normal and cervical pathological conditions has been developed. Methods and MaterialsPatient anatomy was derived from pelvic CT and MRI scans from 50 representative patients diagnosed with localized cervical cancer. Dimensions measured from patients’ uterine body and uterine canal sizes were used to construct a variety of uteri based off of the averages and standard deviations of the subjects in our study. Soft-tissue anatomy was three-dimensionally printed using Agilus blends (shore 30 and 70) and modular components using Vero (shore 85). ResultsThe kit consists of four uteri, a standard bladder, a standard rectum, two embedded gross tumor volumes, and four clip-on gross tumor volume attachments. The three anteverted uteri in the kit are based on the smallest, the average, and the largest dimensions from our patient set, whereas the retroverted uterus assumes average dimensions. ConclusionsThis educational high-dose-rate gynecological pelvic phantom is an accessible and cost-effective way to improve radiation oncology resident training in intracavitary/interstitial brachytherapy cases. Implementation of this phantom in resident education will allow for more thorough and comprehensive physician training through its ability to transform the patient scenario. It is expected that this tool will help improve confidence and efficiency when performing brachytherapy procedures in patients.

IOP-induced regional displacements in the optic nerve head and correlation with peripapillary sclera thickness

Mechanical insult induced by intraocular pressure (IOP) is likely a driving force in the disease process of glaucoma. This study aimed to evaluate regional displacements in human optic nerve head (ONH) and peripapillary tissue (PPT) in response to acute IOP elevations, and their correlations with morphological characteristics of the posterior eye. Cross-sectional (2D) images of the ONH and PPT in 14 globes of 14 human donors were acquired with high-frequency ultrasound during whole globe inflation from 5 to 30 mm Hg. High-frequency ultrasound has a spatial resolution of tens of micrometers and is capable of imaging through the ONH and PPT thickness. Tissue displacements were calculated using a correlation-based speckle tracking algorithm for a dense matrix of kernels covering the 2D imaging plane. The ONH was manually segmented in the ultrasound B-mode images acquired at 5 mmHg based on echogenicity. The lamina cribrosa (LC) boundaries were visible in eight of the fourteen eyes and the LC region was segmented using a semi-automated superpixel-based method. The ONH had larger radial displacement than the PPT in all tested eyes and the difference increased with increasing IOP. A significant negative correlation was found between ONH-PPT displacement difference and PPT thickness (p < 0.05), while no significant correlations were found between ONH-PPT displacement difference and other morphological parameters including PPT radius of curvature, scleral canal size, LC thickness and anterior LC surface depth. Within the ONH, the radial displacement decreased in the region anterior to and across LC but not in the region posterior to LC. Finite element models using simplified geometry and material properties confirmed the role of LC in reducing the overall ONH radial displacements, but did not predict the displacement gradient change observed experimentally. These results suggested that a thinner PPT may be associated with a larger relative posterior motion of the ONH with respect to the surrounding PPT and the LC may play a major role in preventing excessive posterior displacement of ONH during acute IOP elevations.

Stressed volume around vascular canals explains compressive fatigue life variation of secondary osteonal bone but not plexiform bone

The fatigue life of bone illustrates a large degree of scatter that is likely related to underlying differences in composition and microarchitecture. Vascular canals act as stress concentrations, the magnitude and volume of which may depend on the size and spatial distribution of canals. The purpose of this study was to establish the relationship between vascular canal microarchitecture, stressed volume and the fatigue life of both secondary osteonal and plexiform bovine bone. Twenty-one cortical bone samples were prepared from bovine femora and tibiae and imaged using micro-computed tomography (μCT) to quantify canal diameter, canal separation and canal number. Samples were cyclically loaded in zero-compression to a peak magnitude of 95 MPa, and fatigue life was defined as the number of cycles until fracture. Finite element models were created from μCT images and used to quantify the stressed volume, i.e., the volume of bone stressed higher than a yield stress of 108 MPa. Fatigue life ranged from 162-633,437 cycles with the fatigue life of plexiform bone (n = 15) being more than 4.5 times longer than secondary bone (n = 6). The fatigue life of secondary bone was negatively correlated with canal diameter (r2 = 0.73) and canal separation (r2 = 0.56), while the fatigue life of plexiform bone was negatively correlated with canal separation (r2 = 0.41), but positively correlated with canal number (r2 = 0.36). Stressed volume was related to canal microarchitecture in secondary bone only, where canal diameters and canal separation were larger than approximately 50 μm and 200 μm, respectively. Consequently, stressed volume explained 89% of the fatigue life variance in secondary bone but was not related to the fatigue life of plexiform bone. These findings suggest that the volume of the stress concentration surrounding vascular canals is dictated by canal size and spacing and may play an important role in the fatigue failure of osteonal bone. We suspect that a larger stressed volume is more likely to encounter and facilitate the propagation of pre-existing microcracks, thereby leading to a reduction in fatigue life.

Estimación de la conicidad de los conductos radiculares de primeros molares inferiores primarios utilizando Nano tomografía computarizada (Nano-CT): Estudio in vitro

Objetivo: Estimar la conicidad de conductos radiculares de primeros molares inferiores primarios por medio de Nano tomografía computarizada (Nano-CT).Material y Métodos: La muestra consistió en 10 dientes molares inferiores primarios. Los dientes fueron escaneados por medio de Nano-CT y las imágenes resultantes fueron analizadas con el software On-Demand 3D, considerando entre la evaluación las características anatómicas: la dimensión de los conductos radiculares y área de superficie de los mismos en toda la longitud radicular. Para la medida del mayor y menor diámetro de los conductos radiculares los test estadísticos fueron medidas de tendencia central, con un nivel de significancia de 5%. Resultados: En la raíz distal, mesio vestibular y mesio lingual la dimensión del conducto radicular con mayor promedio de la región cervical (D0) fue de 1.30, 1.00, 1.08 mm, respectivamente. El diámetro a la longitud más profunda (D11) para los mismos conductos fue de 0.29, 0.22, 0.18 mm. Mientras, la medida del área de superficie radicular distal, mesio vestibular y mesio lingual en la línea cervical (D0) fue de 1.43, 0.87, 1.01 mm. El área a la longitud más profunda (D11) fue de 0.09, 0.04, 0.03 mm. Conclusiones: La morfología de las raíces y de los conductos radiculares de primeros molares primarios presentaron una distribución cónica siendo sus diámetros y áreas mayor en la región cervical y disminuyen en la región apical.

Magnetic resonance imaging findings in intervertebral disc herniation: Comparison of canal compromise and canal size in patients with and without cauda equina syndrome.

Background: Surgical decompressions are typically warranted in patients with magnetic resonance (MR) and clinical evidence of cauda equina syndromes (CESs). However, it is still unclear what MR findings best correlate with such CES. Here, we compared MR-documented canal size and level/extent of compromise in 52 patients with and 56 others without CES attributed to lumbar disc herniation.Methods: This was a retrospective study of 52 patients with and 56 patients without CES attributed to MR- documented lumbar disc herniations (IDHs). The anteroposterior diameters of the spinal canal and the levels of maximal compression were documented and compared utilizing MR scans from both groups.Results: The 52 patients with CES had more extensive narrowing of the canal diameters at the L4-L5 and L5- S1 levels and higher mean canal compression ratios versus 56 patients without CES. The mean percentage of compression in the CES group at L4-L5 and L5-S1 levels (70% and 67.5%, respectively) was less versus L2-L3 and L3-L4 levels (89.7% and 81.8%, respectively).Conclusion: The 52 patients with CES due to IDH had greater canal compromise versus 56 without CES. Further, the percentage of canal compromise was less at L4-L5 and L5-S1 levels compared to other levels in patients with CES.

Cementless femoral stem fixation and leg-length discrepancy after total hip arthroplasty in different proximal femoral morphological types.

Leg-length changes at total hip arthroplasty (THA) may result from too proximal position of the femoral component, i.e. not being sunk deep enough into the femoral canal due to the size and shape of both medullary canal and implant. Some femoral implants are designed to achieve such fixation in the mediolateral dimension, while others also engage the bone anteroposteriorly. Our aim was to examine the relationship between proximal femoral morphology, osseointegration and leg-length equalization at THA. We asked whether the Dorr classification, femoral cortical index and canal flare index on preoperative radiographs had significant impact on THA aseptic loosening rates and post-operative leg-length discrepancy (LLD). Literature review included original articles on proximal femoral morphology with post-operative LLD and other clinical outcomes of THA, published in the last decade. Case reports and biomechanical studies without clinical data were excluded. Higher femoral cortical index and/or canal flare index (corresponding to the Dorr type A) increases the risk of leg lengthening at THA. This is particularly notable in femoral stems with metaphyseal fixation, where high canal flare index has also been linked to osseointegration failure and implant loosening. On the other hand, lower canal flare index (corresponding to the Dorr type C) is more prevalent in the elderly population and increases late periprosthetic fracture rates and stress shielding. Even the most commonly used cementless femoral stems cannot offer optimal fit to intra-/extramedullary geometry or offset restoration in up to 30% of clinical cases. Femoral morphology can have significant impact on post-operative LLD and osseointegration of cementless THA. Quantitative measurements of the proximal femoral canal may improve the choice of a particular implant and fixation method.

Are There Any Risk Factors Associated with the Presence of Cauda Equina Syndrome in Symptomatic Lumbar Disk Herniation?

Risk factors for developing cauda equina syndrome (CES) caused by lumbar disk herniation (LDH) remain controversial and have not been established yet. The aim of the study was to investigate whether there is a relationship among age, sex, body mass index (BMI), or the degree of spinal canal compromise and the presence of CES in patients undergoing lumbar microdiskectomy. Between 2015 and 2019, 506 patients who had an operation for LDH compressing the dural sac were prospectively identified. The "prolapse-to-canal ratio" (PCR) was calculated as a proportion of the cross-sectional area of the disk prolapse compared with the total cross-sectional area of the spinal canal. In total, 35 CES (6.9%) patients were identified. Multivariate logistic regression, adjusted for age, gender, BMI, and PCR, shows that only PCR was associated with the presence of CES (P < 0.001, area under the curve 0.7431). BMI was not associated with an increased risk of CES. This study demonstrates a significant correlation between the size of LDH relative to size of the spinal canal and the presence of CES. A finding of LDH causing >60% obstruction of the spinal canal should be considered a red flag, and such patients need to be watched more closely.

CT morphometric analysis of the cervical spinal canal with special reference to the correlation with the vertebral level

BackgroundNarrowness of the spinal canal is associated with the development of cervical myelopathy. While studies have addressed the sagittal diameter of the cervical spinal canal, few evaluated the correlation between the size of the spinal canal and the vertebral level. We addressed this issue. MethodsOur retrospective study included 102 patients with cranial or spinal disorders. We examined the correlation between the cervical spinal canal diameter (SCD) at C1 to C7 and the inner anteroposterior diameter (IAPD) of the atlas on CT images. ResultsAt C1, the SCD was largest, at C4 it was smallest. While there was a strong correlation between the IAPD and the SCD at C1 (r = 0.8), the correlation between the size of the atlas and the SCD at C4 to C7 was weak (r = 0.2–0.3). We divided our patients into a normal group (n = 34, SCD ≥ 12 mm at any levels) and a stenosis group (n = 68, SCD < 12 mm at all levels). The mean SCD at C2 to C7 was significantly larger in the normal group. There was no significant difference between the two groups with respect to the IAPD and the SCD at C1. ConclusionsThe size of the subaxial spine does not necessarily affect the size of the atlas. The pathophysiology of spinal canal stenosis should be considered separately at the C1- and the subaxial level.

Impact of Surrounding Canal Size on Time to Union After Intramedullary Nailing of Femur Fractures: Are 10-mm Nails All We Need?

To determine whether intramedullary nail (IMN) size and its relation to the canal diameter [nail-canal (NC) diameter] impacts the union rate or time to union in the treatment of femoral shaft fractures. Retrospective review. Two Level 1 and 1 Level 2 trauma centers. Two hundred eighty-seven patients met the criteria and were included in the study. Patients were treated with either an antegrade or retrograde IMN. Comparisons were first performed comparing 10- versus 11- versus 13-mm nails. Patients were then divided into 3 groups based on the difference between the size of the femoral canal at the isthmus and the IMN (NC diameter). Group 1: <1.0 mm, group 2: >1.0 and <2.0 mm, and group 3: >2.0 mm. Nonunion rates, mean time to union. Two hundred eighty-seven patients with a minimum of 12-month follow-up, who were treated with size with IMN for femoral shaft fractures, were assessed for fracture characteristics, time to union, and union rate. When comparing IMN size, no statistical difference was found when comparing time to union or overall union rate. When comparing NC diameter, no significant difference was found in union rate and time to union when comparing between the groups. Similar rate of union and time to union were exhibited regardless of nail size or NC diameter. This can correlate to the standard utilization of a reamed, titanium 10-mm IMN with 5.0-mm interlocking screws in the treatment of femoral shaft fractures, offering potentially less reaming, shorter operative times, and removing unnecessary stock from inventory. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Anatomical Considerations of Intramedullary Humeral Nailing and Lengthening.

Intramedullary lengthening, in cases of extensive humeral shortening, offers the advantages of preventing external-fixator-associated problems. The humeral cavity, as the main parameter in nailing, however, has been neglected in recent literature. It was hypothesized that available implants might be too large and therefore increase the risk of intraoperative fractures. The aim of this cross-sectional study was to describe the humeral canal and how it might affect the choice of implant and the surgical approach. Thirty humeri (15 female, 15 male) from clinical patients and anatomical specimens were studied. Specifically, the medullary cavity width (MCW), cortical thickness (CoT), and the course of the medullary canal were examined. The smallest MCW diameters were found at the distal third of the humeral shaft with mean diameters of 10.15 ± 1.96 mm. CoTs of female humeri were significantly smaller than those of male humeri (p < 0.001). The mean angles of the pro- and recurvatum were 4.01 ± 1.68° and 10.03 ± 2.25°, and the mean valgus bending was 3.37 ± 1.58°. Before implanting a straight lengthening nail into a doubly curved humerus, X-rays and, in selected cases, CT-scans should be performed. The unique size and course of the humeral canal favors an antegrade approach in cases of intramedullary lengthening.

Role of High-Resolution CT and MRI in Predicting the Degree of Difficulty in Patients undergoing Cochlear Implant Surgery: An Institutional Experience

Abstract Introduction Preoperative imaging is a standard practice for cochlear implant candidacy. We are discussing association between surgical feasibility and various anatomical details of middle and inner ear by both high-resolution computed tomography (HRCT) and 3T magnetic resonance imaging (MRI) in patients with bilateral sensorineural hearing loss (SNHL) and are used as a guide during surgery as well as foresee complications in cochlear implantation. Materials and Methods A total of 56 patients of aged 1 to 5 years (prelingual) and &gt; 1 years (postlingual or perilingual) having bilateral SNHL were included in the study. HRCT temporal bone and MRI head was done in all candidates. Based on the imaging findings of CT and MRI, patients were divided into two categories (normal and abnormal). Demographic and clinical values were compared between two groups. Binary logistic regression analysis was used to identify the predictors of the outcome variable (surgical difficulty). Results Out of 56 patients, 55 underwent cochlear implantation by Veria technique, one patient having Michel’s deformity was denied surgery and was advised brain stem implant. Note that 69.1% patients had no radiological abnormality, while 30.9% patients showed abnormality including acquired disease and malformation. Out of the total study patients, 18% (n = 10) showed various type of congenital inner ear malformation. Large size of the external auditory canal (EAC), high basal turn angle (BTA), and increased distance between tympanic segment of facial canal to EAC (midpoint between level of I-S joint corresponding to EAC and exit of chordae tympanic at level of EAC), all these factors showed inverse relationship with difficulty in surgery, which were found to be statistically significant. Conclusion The imaging in cochlear implant patients is an essential tool for preoperative assessment of candidacy, surgical planning, and avoid intra- and postoperative complications. BTA and distance between tympanic segment of facial nerve and EAC (midpoint between level of I-S joint corresponding to EAC and exit of chordae tympanic at level of EAC) are important predictors for evaluating intra- and postoperative complications.

Variation and genetic parameters of axial resin canal features in clones and families of Pinus radiata

Resin canal features are associated with significant economic losses to appearance grade Pinus radiata timber. This study investigated the variation in resin canal features in young, 2-year-old, P. radiata. Axial resin canal size, density and relative cross-sectional area were determined in twenty families and ten clones from images of microtomed sections, scanned with polarised light to highlight resin canals. Axial resin canal size was generally homogenous with a mean value estimate of 0.02 mm2, and a coefficient of variation of ~ 10%. Estimated mean values for axial resin canal density and relative area were more variable (coefficients of variation ~ 30%) and lower for clones (0.69 canals/mm2 and 1.13%, respectively) than for families (0.90 canals/mm2 and 1.53%, respectively). Narrow-sense heritability (h2) estimates of the studied axial resin canal features in radiata pine at age 2-years-old were ~ 0.30. Modulus of elasticity and longitudinal shrinkage were moderately correlated with axial resin canal density and relative area, while basic density and volumetric shrinkage were independent of axial resin canal features. The study indicated that there could be potential for breeding P. radiata for resin canal features, with the aim to improve the grade yields of appearance grade products.

Bony Hypertrophy in Vascularized Fibular Grafts.

Background: Vascularized fibula graft (VFG) transfer is an established method of repairing large skeletal defects resulting from trauma, tumor resection, or infection. It obviates the process of creeping substitution that conventional bone grafts undergo and therefore exhibits better healing and improved strength. The aim of this study is to evaluate hypertrophy in VFG. Methods: We retrospectively reviewed patients undergoing VFG and studied immediate and late postoperative radiographs. Orthogonal views were measured for width of graft cortex and intramedullary canal, as well as adjacent recipient bone. Changes were measured for total cross sectional area, cortical area, intramedullary area, and graft width. Results: Thirty patients were included in the analysis, with recipient sites including 3 forearm, 4 humerus, 12 tibia, and 11 femur. Mean follow-up was 7.6 years (0.5-24.9 years). Patients' mean age was 31 (16-59 years). Average hypertrophy was 254% in early postoperative period and 340% in the late postoperative period. There was rapid graft hypertrophy in early postoperative period that plateaued with time. The width of the graft increased over time but didn't exceed the width of the adjacent recipient bone. In the later postoperative period, the size of graft intramedullary canal increased. Upper and lower extremity grafts showed similar hypertrophy. Conclusions: Using VFG to treat large skeletal defects is an attractive option in part due to the graft's ability to hypertrophy. We describe an early period of periosteal hypertrophy, followed by endosteal hypertrophy. These processes have relevance to function, mechanical strength, and surgical decision-making.

The Arp2/3 complex and the formin, Diaphanous, are both required to regulate the size of germline ring canals in the developing egg chamber

Intercellular bridges are an essential structural feature found in both germline and somatic cells throughout the animal kingdom. Because of their large size, the germline intercellular bridges, or ring canals, in the developing fruit fly egg chamber are an excellent model to study the formation, stabilization, and growth of these structures. Within the egg chamber, the germline ring canals connect 15 supporting nurse cells to the developing oocyte, facilitating the transfer of materials required for successful oogenesis. The ring canals are derived from a stalled actomyosin contractile ring; once formed, additional actin and actin-binding proteins are recruited to the ring to support the 20-fold growth that accompanies oogenesis. These behaviors provide a unique model system to study the actin regulators that control incomplete cytokinesis, intercellular bridge formation, and growth. By temporally controlling their expression in the germline, we have demonstrated that the Arp2/3 complex and the formin, Diaphanous (Dia), coordinately regulate ring canal size and growth throughout oogenesis. Dia is required for successful incomplete cytokinesis and the initial stabilization of the germline ring canals. Once ring canals have formed, the Arp2/3 complex and Dia cooperate to determine ring canal size and maintain stability. Our data suggest that nurse cells must maintain a precise balance between the activity of these two nucleators during oogenesis.

MRI AND ULTRASOUND CRITERIA FOR THE DIAGNOSIS OF A SPORTS HERNIA IN FOOTBALL PLAYERS

The aim of the study is to specify diagnostic MRI and ultrasound criteria for a sports hernia in order to verify its diagnosis in football players. Materials and methods: The study included 50 professional and amateur football players aged 15 to 34 from 2016 to 2019. The criteria for inclusion in the study were: the presence of groin pain in football players, which prevented them from continuing to actively participate in sports activities. Results: The findings of the study revealed that during MRI the two factors, which had the strongest influence, were "increased MR signal intensity on PDfs observed from the structures of the inguinal canal" and "increased MR signal intensity on PDfs observed from bone marrow of superior ramus of the pubic bone". During ultrasound of the inguinal area, the main criterion for a sports hernia diagnosis was "increased size of the inguinal canal". The verification of the diagnosis was carried out on the basis of the presence of a protrusion in the posterior wall of the inguinal canal. For a sports hernia diagnosis the MRI sensitivity is 91.67% (95% CI 77.5 - 98.2), specificity -78.57% (95% CI 49.2 - 95.3) and the sensitivity of ultrasound is 88.89% (95% CI 73.9 - 96.9), the specificity - 50% (95% CI 23.0 - 77). Conclusions: The combination of MRI and ultrasound makes it possible to accurately detect the presence of a sports hernia in the football player. Based on the findings of our study, we formulated MRI and ultrasound criteria for a sports hernia diagnosis.

Microbial reduction after using different root canal irrigation–activation techniques

AimThe aim was to clinically evaluate the microbial reduction after using different irrigation–activation techniques including needle irrigation, passive ultrasonic irrigation (PUI) and EndoVac.Materials and MethodsTwenty-four patients with single rooted, single-canal teeth with primary endodontic infection were selected for this study then randomly assigned into three groups according to the final irrigation–activation method. Group 1 (control group) needle irrigation, group 2 (PUI irrigation) and group 3 (EndoVac irrigation). The first microbial sample (S1) was taken after access cavity preparation under complete aseptic condition then the second microbial sample (S2) after chemomechanical preparation using ProTaper Universal rotary system up to F3 or F4 or F5 according to canal size. Finally, the third microbial sample (S3) was taken after irrigation–activation, the three samples were cultured on blood agar aerobic and anaerobic, incubated for 24–48 h at 37°C, the growing colonies were counted and recorded as colony forming units.ResultsPUI group showed the highest microbial reduction, while the needle group showed the lowest microbial reduction with statistically significant difference with both PUI group and EndoVac group. While no statistically significant difference was recorded between PUI and EndoVac groups.ConclusionIrrigation–activation increases the efficacy of irrigation concerning the microbial reduction and PUI is the most recommended method of activation.