Slippage Type Research Articles

Classification of Slippage Following Laparoscopic BariClip Gastroplasty.

Laparoscopic BariClip gastroplasty (LBCG) is a new reversible gastric sleeve-like procedure without gastrectomy proposed to minimize the risk of severe complications. Still one of the possible complications described with LBCG is slippage. The purpose of the current manuscript is to analyze different cases of slippage and propose a classification of this complication. A number of 381 patients who underwent LBCG in 8 different centers were analyzed concerning the risk of slippage. All cases with documented slippage were carefully reviewed in terms of patients' symptomatology (presence of satiety, vomiting), history of weight loss, radiological data, and management of their slippage. A new classification was proposed depending on the anatomy, the symptomatology, and the time of occurrence. We have identified a total of 17 cases (4.46%) of slippage following LBCG. In 11 patients, the slippage was symptomatic with repetitive vomiting and nausea, and in the remaining 6 patients, the slippage was identified by radiological studies for insufficient weight loss, weight regain, or routine radiological follow-up. Depending on the interval time, the slippage was classified as either immediate (in first 7 days) in 6 cases, early (in less than 90 days) in 4 cases, and late (after 3 months) in 7 cases. Evaluation of the radiological studies in these cases identified the following: anterosuperior displacement (type A) in 9 cases, posteroinferior displacement (type B) in 6 cases (one case after 3 months), and lateral displacement (type C) in the remaining 2 cases. The management of the slippage consisted of BariClip removal in 7 cases, repositioning in 5 cases, and conservative treatment in the remaining 5 cases. All patients with conservative treatment were recorded at the beginning of the experience. Slippage is a possible complication after LBCG. This classification of the different types of slippage can benefit the surgeon in the management and treatment of this complication of LBCG.

Comparative study on effectiveness of modified-transforaminal lumbar interbody fusion and posterior lumbar interbody fusion surgery in treatment of mild to moderate lumbar spondylolisthesis in middle-aged and elderly patients

To compare the effectiveness of modified transforaminal lumbar interbody fusion (modified-TLIF) and posterior lumbar interbody fusion (PLIF) for mild to moderate lumbar spondylolisthesis in middle-aged and elderly patients. The clinical data of 106 patients with mild to moderate lumbar spondylolisthesis (Meyerding classification≤Ⅱ degree) who met the selection criteria between January 2015 and January 2017 were retrospectively analysed. All patients were divided into modified-TLIF group (54 cases) and PLIF group (52 cases) according to the different surgical methods. There was no significant difference in preoperative clinical data of gender, age, disease duration, sliding vertebra, Meyerding grade, and slippage type between the two groups ( P>0.05). The intraoperative blood loss, operation time, postoperative drainage volume, postoperative bed time, hospital stay, and complications of the two groups were recorded and compared. The improvement of pain and function were evaluated by the visual analogue scale (VAS) score and Japanese Orthopedic Association (JOA) score at preoperation, 1 week, and 1, 6, 12 months after operation, and last follow-up, respectively. The effect of slip correction was evaluated by slip angle and intervertebral altitude at preoperation and last follow-up, and the effectiveness of fusion was evaluated according to Suk criteria. All patients were followed up, the modified-TLIF group was followed up 25-36 months (mean, 32.7 months), the PLIF group was followed up 24-38 months (mean, 33.3 months). The intraoperative blood loss, operation time, postoperative drainage volume, postoperative bed time, and hospital stay of the modified-TLIF group were significantly less than those of the PLIF group ( P<0.05). The VAS score and JOA score of both groups were significantly improved at each time point after operation ( P<0.05); the scores of the modified-TLIF group were significantly better than those of the PLIF group at 1 and 6 months after operation ( P<0.05). The slip angle and intervertebral altitude of both groups were obviously improved at last follow-up ( P<0.05), and there was no significant difference between the two groups at preoperation and last follow-up ( P>0.05). At last follow-up, the fusion rate of the modified-TLIF group and the PLIF group was 96.3% (52/54) and 98.1% (51/52), respectively, and no significant difference was found between the two groups ( χ 2=0.000, P=1.000). About complications, there was no significant difference between the two groups in nerve injury on the opposite side within a week, incision infection, and pulmonary infection ( P>0.05). No case of nerve injury on the operation side within a week or dural laceration occurred in the modified-TLIF group, while 8 cases (15.4%, P=0.002) and 4 cases (7.7%, P=0.054) occurred in the PLIF group respectively. Modified-TLIF and PLIF are effective in the treatment of mild to moderate lumbar spondylolisthesis in middle-aged and elderly patients. However, modified-TLIF has relatively less trauma, lower blood loss, lower drainage volume, lower incidence of dural laceration and nerve injury, which promotes enhanced recovery after surgery.

Learning Spatio Temporal Tactile Features with a ConvLSTM for the Direction Of Slip Detection.

Robotic manipulators have to constantly deal with the complex task of detecting whether a grasp is stable or, in contrast, whether the grasped object is slipping. Recognising the type of slippage—translational, rotational—and its direction is more challenging than detecting only stability, but is simultaneously of greater use as regards correcting the aforementioned grasping issues. In this work, we propose a learning methodology for detecting the direction of a slip (seven categories) using spatio-temporal tactile features learnt from one tactile sensor. Tactile readings are, therefore, pre-processed and fed to a ConvLSTM that learns to detect these directions with just 50 ms of data. We have extensively evaluated the performance of the system and have achieved relatively high results at the detection of the direction of slip on unseen objects with familiar properties (82.56% accuracy).

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Introduction Extra-articular corrective rotational femoral osteotomies enable to completely restore or approximate to the normal the spatial position of the femoral epiphysis and its balance with the acetabulum in patients with most common types of slippage in moderate stable slipped capital femoral epiphysis (SCFE). Aim Evaluation of the effectiveness of a new corrective femoral osteotomy technique that excludes hip subluxation and bayonet deformity of the proximal femur during surgery in children with SCFE. Materials and methods Pre- and postoperative findings of clinical and radiographic examination of 80 patients aged from 11 to 15 years with most common types of moderate stable femoral epiphyseal slippage were analyzed. The technique of corrective femoral osteotomy developed which was applied in 40 patients (40 interventions) differs in spatial position of the rotation axis of the proximal femur and type of bone cut. Results Subluxation and bayonet deformity of the proximal femur in the affected joint were obtained in none of the 24 cases with a maximum anterior rotation of the proximal femur fragment (45°) operated with the new technique while with the Imhauser osteotomy, previously used in group 2, they were seen in eight and 12 out of 24 cases, respectively. Average postoperative follow-up period was four years (range, 2-7 years). Clinical examination and X-ray study after this surgery showed no signs of coxarthrosis in 38 out of 40 cases after two years, and in 9 cases out of 10 after six years. Conclusions New method of corrective femoral osteotomy avoids hip subluxation and bayonet deformity during the surgery of the proximal femur as well as reduces (or completely avoids) lower limb residual shortening. This technique is relatively simple, shorter in time and less invasive than previous modifications. It also prevents femoroacetabular impingement in many clinical cases.

Comparison of accuracy between robot-assisted and fluoroscopy-guided percutaneous pedicle screw placement for treatment of lumbar spondylolisthesis

To explore the clinical application value of the spinal robot-assisted surgical system in mild to moderate lumbar spondylolisthesis and evaluate the accuracy of its implantation. The clinical data of 56 patients with Meyerding grade Ⅰ or Ⅱ lumbar spondylolisthesis who underwent minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) between January 2017 and December 2017 were retrospectively analysed. Among them, 28 cases were preoperatively planned with robotic arm and percutaneous pedicle screw placement according to preoperative planning (group A); the other 28 cases underwent fluoroscopy-guided percutaneous pedicle screw placement (group B). There was no significant difference in gender, age, body mass index, slippage type, Meyerding grade, and surgical segmental distribution between the two groups ( P>0.05). The screw insertion angle was measured by CT, the accuracy of screw implantation was evaluated by Neo's criteria, and the invasion of superior articular process was evaluated by Babu's method. One hundred and twelve screws were implanted in the two groups respectively, 5 screws (4.5%) in group A and 26 screws (23.2%) in group B penetrated the lateral wall of pedicle, and the difference was significant ( χ2=9.157, P=0.002); the accuracy of nail implantation was assessed according to Neo's criteria, the results were 107 screws of degree 0, 3 of degree 1, 2 of degree 2 in group A, and 86 screws of degree 0, 16 of degree 1, 6 of degree 2, 4 of degree 3 in group B, showing significant difference between the two groups ( Z=4.915, P=0.031). In group B, 20 (17.9%) screws penetrated the superior articular process, while in group A, 80 screws were removed from the decompression side, and only 3 (3.8%) screws penetrated the superior articular process. According to Babu's method, the degree of screw penetration into the facet joint was assessed. The results were 77 screws of grade 0, 2 of grade 1, 1 of grade 2 in group A, and 92 screws of grade 0, 13 of grade 1, 4 of grade 2, 3 of grade 3 in group B, showing significant difference between the two groups ( Z=7.814, P=0.029). The screw insertion angles of groups A and B were (23.5±6.6)° and (18.1±7.5)° respectively, showing significant difference ( t=3.100, P=0.003). Compared to fluoroscopy-guided percutaneous pedicle screw placement, robot-assisted percutaneous pedicle screw placement has the advantages such as greater accuracy, lower incidence of screw penetration of the pedicle wall and invasion of the facet joints, and has a better screw insertion angle. Combined with MIS-TLIF, robot-assisted percutaneous pedicle screw placement is an effective minimally invasive treatment for lumbar spondylolisthesis.

Slip-compensated odometry for tracked vehicle on loose and weak slope

Odometry is widely used to localize wheeled and tracked vehicles because of its simplicity and continuity. Odometric calculations integrate the wheel or track’s rotation speed. The accuracy of position thus calculated, is affected by slippage between the ground and the wheel or track. When traveling on a loose slope, the localization accuracy of the odometry decreases remarkably due to slippage. To improve its accuracy in such environments, terramechanics focus on estimating the interaction between a vehicle and the ground. However, because these formulas are complicated and governed by many terrain-specific parameters, they are difficult to use in unknown environments. In this study, we propose slip estimation methods targeted toward use in unknown environments. We consider four types of slippage, based on the slippage direction and maneuver type. Longitudinal and lateral slippage occurring during straight maneuvering are derived by approximating the terramechanics slip model. In contrast, for turning maneuvers, longitudinal slippage is derived from an empirical equation for the relationship between slip ratio and input velocity, and lateral slippage is obtained from a regression function. We also proposed slip-compensated odometry, which applies the slip model to the kinematics of a skid-steering vehicle. To evaluate the proposed slip model and slip-compensated odometry, we conduct several experiments with a skid-steering tracked vehicle on an indoor sandy slope. Experimental results confirmed that position estimation accuracy was improved by introducing slip-compensated odometry compared to conventional odometry.

Radiographic Detection of Osteoporotic Vertebral Fracture without Collapse

BackgroundOn retrospective basis, we investigated the detection of osteoporotic vertebral fractures (OVFs) without radiologic collapse using a modified Yoshida's classification, which was designed by the authors.MethodsWe observed 82 cases in 76 patients with confirmed OVFs without collapse at the thoracolumbar junction. The following factors were measured: age, gender, body mass index (BMI, kg/m2), bone mineral density (BMD, mg/cm3), type of a modified Yoshida's classification. The correct diagnosis rate for the presence and location of OVFs and the correct diagnosis rate according to the morphological type by a modified Yoshida's classification of the OVFs were analyzed.ResultsThe mean BMI was 21.2; mean BMD, 44.1; and T-score, -4.4. As for the four subtypes of anterior cortical morphological change, there were 14 cases of the protruding type, 12 cases of the indented type, 5 cases of the disrupted type and 8 cases of the prow type. As for the three subtypes of endplate depression, there were 20 cases of upper endplate depression, 12 cases of lower endplate depression and 11 cases of endplate slippage type. According to the examiners, there was a significant difference between being informed before and after the modified Yoshida's classification. For the relationship of examiners and the type of fracture, there was a significant difference between being informed before and after the modified Yoshida's classification, particularly in the protruding type and the upper plate type.ConclusionsA modified Yoshida's classification can be helpful for the diagnosis of OVFs without radiologic collapse in a simple radiograph.

Essential Type of Bank Collapses in the Middle-Lower Yangtze River and Corresponding Preventive Measures

Four types of bank collapses in the middle-lower Yangtze River, that is erosion type, crash type, slippage type and flow-slide type, are pointed out, and characteristics and formation conditions of each one are analyzed. In order to provide a reference for decision-making of calamity reduction and improvement project, some preventive measures on them, including monitoring of river hydrology, morphology near bank, and hydrologicalgeology, and inspection and investigation of outward indication of bank and human activity, are presented by means of analysis on above-mentioned aspects.

Forest Conservation and Slippage: Evidence from Mexico’s National Payments for Ecosystem Services Program

We investigate a Mexican federal program that compensates landowners for forest protection. We use matched controls from the program applicant pool to establish counterfactual deforestation rates. Deforestation was reduced by 50% in enrolled parcels, but expected average clearing rates without the program were low (0.8% per year), suggesting modest total avoided deforestation benefits. We test for two types of slippage: increased deforestation on other property belonging to program recipients and increased deforestation within markets where there are high levels of program participation. We find evidence of both, with substitution impacts reducing program effectiveness in common properties by about 4% on average. <i>(JEL O13, Q24)</i>

Full and partial boundary slippage effect on squeeze film bearings

Simple experiments were carried out to illustrate the effect of the boundary slippage on the load capacity of a squeeze film. The surface energy of the bearing surface was modified using laser excimer (UV laser). It was found that the load capacity can be reduced if the surfaces are modified to be hydrophobic. The boundary slippage effect on squeeze film was further studied theoretically to get more insight. The paper presents a mathematical model with a critical shear-stress criterion of slippage to describe the squeeze film effect. Three types of slippage, i.e. single zone partial slippage, single zone full slippage, and double zone partial slippage, are modeled. The analytical solution shows that the pressure distribution is a piecewise parabolic curve, where the pressure gradient can be discontinuous at the border of the slip and no-slip regions. Parametric studies illustrate the variations of the pressure and the boundary slippage under different conditions. It is demonstrated that with the increase of the length of the hydrophobic region, the maximum pressure does not increase continuously. Similar to the classical squeeze film bearing, the pressure decreases with the increase in the film thickness or the decrease in the approach velocity. The influences of the critical shear stress are also explored, and are found to significantly affect the squeeze behavior.

Epidemiology and Demographics of Slipped Capital Femoral Epiphysis in Korea: A Multicenter Study by the Korean Pediatric Orthopedic Society

In 1979, slipped capital femoral epiphysis (SCFE) was rarely reported in Korea, although it is the most common hip disorder of adolescence in Western nations. However, because the number of reported cases of SCFE in Korea has increased a great deal since then, we performed a nationwide survey to ascertain its epidemiology and demographics in Korea. We reviewed the discharge databases for the period between January 1989 and December 2003 from 19 university hospitals across Korea. Recorded data included age at onset, sex, past medical history, height, weight, and type of slippage. We compared those data with national census data. The incidence data are reported as cases per 100,000 children between the ages of 10 and 14 years. Data for 231 patients (175 boys and 56 girls) were included in our survey. The average age at onset was 12 years 10 months in boys and 12 years in girls. The average annual incidence was estimated to be at least 0.499 for boys and 0.142 for girls for every 100,000 children between the ages of 10 and 14 years, which was lower than that of Western nations and Japan. The incidence showed a pattern of increments across each period. The mean body mass index was significantly higher in Korean patients with SCFE than in the population of the same age group without it. The incidence of SCFE in preadolescents in Korea has increased markedly since 1979, which may be related to increasing rates of obesity. Therapeutic, level 4.

Fehler bei der Diagnostik und Behandlung der Epiphyseolysis capitis femoris

Expert commissions (Gutachterkommissionen) and arbitration offices (Schlichtungsstellen) in Germany are expert panels for the extrajudical resolution of malpractice claims. The performance of arbitration panel proceedings ("Schlichtungsverfahren") is based on the German medical and insurance jurisdiction. 39 arbitration panel proceedings concerning supposed malpractice in the diagnosis and treatment of slipped capital femoral epiphysis were evaluated in regard to the involved clinics and physicians and, respectively, the medical specialties, type of slippage (acute or chronic), malpractice and the disabilities caused by malpractice. In 28 cases (72 %) the malpractice was confirmed, the average of confirmed failures in all proceedings being about 30 %. The failures could be classified as misdiagnosis followed by inadequate treatment and failures in operative treatment. Minor and moderate permanent disabilities due to malpractice remained in 8 cases, severe permanent disability resulted in 14 cases due to osteonecrosis of the femoral head. The results are discussed with regard to the avoidance of mistakes in diagnosis and treatment and the problems of medical assessment.

Discordancy Tests Based on the Likelihood Ratio for the Bipolar Watson Distribution on the Hypersphere

As the Watson distribution is frequently used for modeling axial data, it is important to investigate the existence of possible outliers in samples from this distribution. Then, we develop for the bipolar Watson distribution defined on the hypersphere, some tests of discordancy of an outlier or several outliers en bloc based on the likelihood ratio, supposing an alternative model of contamination of slippage type. We evaluate the performance of these tests of discordancy of an outlier and we also compare some tests of discordancy of an outlier available for this distribution.

Syndrome du droit inférieur reculé : exploration chirurgicale et concepts physiopathologiques

Progressive overcorrection after inferior rectus recession may occur in 10%-40% of cases, whatever the surgical indication, whatever the technique. The clinical features are hypertropia, inferior rectus underaction, and lid retraction. The anatomy of the inferior rectus during surgical exploration is described in 11 cases initially operated on for different types of strabismus. Several types of slippage and several types of excessive fibrosis in the area of the inferior rectus are described. Our surgical data are compared to the pathophysiological hypothesis described in the literature. Preventive measures and curative treatment are discussed. Even a better understanding of the physiopathogenesis of overcorrection after inferior rectus recession could not prevent its occurrence, despite upgraded surgical technique. There is no consensual opinion on how to prevent and cure these overcorrections. Associating oculomotor surgery and lid surgery is an interesting direction for new research.

On detection of outliers in symmetric normal models

Extensions of recent results for detection of mean slippage type outliers from i.i.d. multivariate normal and elliptically symmetric distributions are made to symmetric case, that is, when the observations are equicorrelated. The main tool used is Wijsman's (1967) representation theorem. The results obtained can be viewed as a robustness property of the use of Mardia's multivariate kurtosis as a locally optimal test statistic to detect outliers against equicorrelated distributions.

On a conjecture concerning the least favorable configuration of a two-stage selection procedure

A two-stage procedure 𝓅with screening in the first stage to find the population with the largest mean out of k ≧ 2 normal populations with unknown means and a common variance is under concern. It was proposed and previousiy studied by Cohen (1959), Alam (1970) and Tamhane and Bechhofer (1977, 1979) using the indifference-zone approach. The conjecture that the least favourable parameter configuration for the probability of a correct selection is of the slippage type remained unproved for k ≧ 3. Miescke and Sehr (1980) proved the conjecture for k=3. The problem was further discussed by Gupta and Miescke (1982). A general proof for rhe conjecture will be given in this paper.

Optimum two-stage selection procedures for Weibull populations

Let π 1,…, π k be Weibull populations with a common known shape parameter, and with unknown scale parameters. The goal is to find the population with the largest scale parameter. From each population, Type II-censored observations are available at two stages, where censoring at stage 1 (2) occurs at the q-th ( r-th) failure. Two-stage procedures with screening at the first stage are considered which are optimum permutation invariant in terms of the risk with respect to a large class of loss functions. For the procedure with a fixed subset size at stage 1, the least favorable parameter configuration under the indifference zone approach is of the slip-page type, which makes it feasible to control the infimum of the probability of a correct selection. Some extensions of the results are discussed at the end.

DETECTION AND TESTING OF DIFFEFENT TYPES OF OUTLIER IN LINEAR STRAUCTURAL RELATIONASHIPS

SummaryThe linear structural model provides one way of modelling a linear relationship between two random variables. It is well known that problems of unidentifiability arise for unreplicated observations and normal error structure. As in all data sets, outliers can arise and methods are needed for detecting and testing them. An outlier‐generating model of mean–slippage type can be used to characterise four different forms of outlier manifestation. It is interesting to find that the unidentifiability problem provides no obstacle for detecting or testing the outliers for three of the four forms. Detection principles, and specific discordancy tests, are derived and illustrated by application to some data on physical measurements of Pacific squid.

On subsonic propagation of the edge of shear displacement with friction along a boundary separating elastic materials

Analysis of the stress and velocity fields at the edge of a cut (and in particular of a transverse shear crack), gives rise to the problem studied here, of the asymptotics of dynamic solutions near a moving point represented by the point at which the boundary conditions at the inner boundary of a piecewise homogeneous, linearly ealstic body, change. The sets of boundary conditions of slippage type with dry and viscous friction (or without friction) and adherence with (or without) restrictions on the magnitude of shear stress of static friction type, are considered. It is shown that homogeneous solutions of the problems with similar mixed boundary conditions have nonoscillatory character and the singularity index depends on the velocity, friction coefficients and other material parameters. Velocity ranges are noted within which the stresses are singular or continuous. Results are given of the computations of the angular dependence of the shear stress at different rates of motion of the transverse shear crack edge, and the effect of changing the direction of the maximum stress is studied.

A Quick and Simple Technique for General Slippage Problems

Abstract In a recent article we described some quick and simple tests for the k-sample slippage problem. Those tests were designed for the alternative that precisely one population had slipped. In this article we present a method of testing which has power for all slippage alternatives and which makes a diagnosis of the type of slippage that has occurred. Critical values are obtained either from a table (in the case of small samples), from graphs or from asymptotic approximations, which turn out to be very accurate.