Open reduction of an old and unreduced posterior elbow dislocation

The old unreduced elbow dislocation is not very frequent, but when it is found, it is a challenge for every surgeon. We present a case of 65 years old man who came to the hospital with a dislocated elbow. After the first attempt to reduce, the elbow was mobilized in sling for 2 weeks, but during a small effort, the joint dislocated again. Another two orthopedic reduction were tried, followed by cast immobilization, but the elbow dislocated again. The patient presented in our service after two months from the injury with stiff joint in a vicious position. On imagistic examinations (Rx, CT, MRI), it was found comminuted fracture of coronoid process, posterior dislocation of olecranon and both collateral ligaments were torn. An open reduction was performed during which the joint surface was cleaned up, the anterior capsule was reattached to the coronoid process with an anchor, and then, collateral ligament was restored with the help of autograft, a gracilis muscle (bone fixed with two anchors). Postoperatively, the patient slowly began to mobilize the elbow with splint protection. After a year, the patient returned for follow-up; the function was completely restored and he had no pain.

Working with Uncertainties: An Adaptive Fabrication Workflow for Bamboo Structures

This paper presents and investigates a cyber-physical fabrication workflow, which can respond to the deviations between built- and designed form in real-time with vision augmentation. We apply this method for large scale structures built from natural bamboo poles. Raw bamboo poles obtain evolutionarily optimized fibrous layouts ideally suitable for lightweight and sustainable building construction. Nevertheless, their intrinsically imprecise geometries pose a challenge for reliable, automated construction processes. Despite recent digital advancements, building with bamboo poles is still a labor-intensive task and restricted to building typologies where accuracy is of minor importance. The integration of structural bamboo poles with other building layers is often limited by tolerance issues at the interfaces, especially for large scale structures where deviations accumulate incrementally. To address these challenges, an adaptive fabrication process is developed, in which existing deviations can be compensated by changing the geometry of subsequent joints to iteratively correct the pose of further elements. A vision-based sensing system is employed to three-dimensionally scan the bamboo elements before and during construction. Computer vision algorithms are used to process and interpret the sensory data. The updated conditions are streamed to the computational model which computes tailor-made bending stiff joint geometries that can then be directly fabricated on-the-fly. In this paper, we contextualize our research and investigate the performance domains of the proposed workflow through initial fabrication tests. Several application scenarios are further proposed for full scale vision-augmented bamboo construction systems.

Intra-Operative Soft Tissue Targets For Improved Outcomes In Total Knee Arthroplasty

A poorly balanced, unstable or stiff joint is a leading cause of dissatisfaction and revision after surgery. The quantitative definition of a well-balanced joint, however, remains a source of controversy. This study investigates joint gaps measured by a digitally-controlled ligament tensioning device throughout flexion and its effect on post- operative outcome.Surgeries were performed using the OMNIBotics robot-assisted TKA platform and BalanceBot device. Joint gaps were recorded by the BalanceBot throughout flexion during trialing. Knee Injury and Osteoarthritis Outcome Score (KOOS) was collected at 1-year post-op. Correlations between joint gaps and KOOS outcome were investigated.Knees that reported: a medial gap ≤ lateral gap in extension (p = 0.007, median ∆ = 8.3); an average joint gap of between 1 mm tighter and 1 mm looser than the final insert thickness in midflexion (p = 0.006, median ∆ = 5.5); and an imbalance of less than 1.5 mm in flexion (p = 0.012, median ∆ = 2.8) reported significantly improved pain scores. Patients which satisfied both extension and flexion criteria, or midflexion and flexion criteria reported improved outcomes compared to those which satisfied only one or neither criterion (p = 0.0002, median ∆ = 9.7, p = 0.0019, median ∆ = 8.4 respectively).KOOS Pain scores correlated with joint gap measurements across all flexion angles investigated. Combining joint gap windows, subgroups of patients were found that reported a change in the median KOOS Pain outcome beyond the minimally clinically important difference.

The effect of flexible joint-like elements on the adhesive performance of nature-inspired bent mushroom-like fibers

Many organisms rely on densely packed, tilted and curved fibers of various dimensions to attach to surfaces. While the high elastic modulus of these fibers enables an extremely large number of fibers per unit area, where each fiber stands freely without sticking to its neighbors, the tilt/curvature provides them with the compliance and the directional adhesion properties to attach strongly and efficiently to a surface. Recent studies have revealed that many of such organisms also feature materials with a graded elastic modulus that is tailored towards improving the contact area without sacrificing the fiber density. In particular, for male ladybird beetles, research has shown that the adhesive setae feature a material gradient such that the elastic modulus of the material at the junction between the stalk and the divergent distal end is close to minimum. This soft material acts like a flexible joint, improving the bending compliance of the tip. Here, we mimic this feature using tilted, mushroom-like, stiff fibers comprised of a stiff stalk of elastic modulus 126 MPa, a softer tip of elastic modulus 8.89 MPa, and a joint-like element of elastic modulus 0.45 MPa (very soft), 8.89 MPa (soft), or 126 MPa (stiff) in between. The results from load–drag–pull (LDP) experiments performed along (gripping) and against (releasing) the tilt direction indicate that the soft and the very soft joint fibers performed superior to the stiff joint fibers and maintained directionally dependent performance. The soft joint fibers achieved up to 22 kPa in shear and 110 kPa in pull-off stress in the gripping direction, which are twice and ten times higher than that in the releasing direction, respectively. A model to optimize the elastic modulus of the joint-like elements to enable sliding without peeling of the tips has been proposed.

Experimental Measurement of the Shank Torque As a Function of the Stiffness and Frictional Characteristics of the Bolted Joint

During tightening, the amount of torque given by the difference between the tightening torque, which is directly applied by the torque wrench, and the underhead torque, flows through the screw shank towards the threaded portion. This torque combines with the axial preload to bring about the overall stress state of the screw at tightening. Upon release of the torque wrench, a certain amount of the shank torque is released due to the elastic springback of the screw-plates system. In the literature [1], this phenomenon is just briefly treated by a few authors: they generally agree that approximately a half of the initial shank torque is released just a few seconds after torque wrench removal. This indication is given regardless of the frictional [2] and stiffness [3] parameters, which govern the joint. The present contribution aims at assessing, if there is any effect of the following parameters on the amount of shank torque being released after wrench removal: (i) the ratio between the torsional stiffness of the screw and of the plates, (ii) the friction coefficients in the underhead and in the thread. The experimentation has been run on a M20 8.8 class socket head screw, which has been instrumented by a double array of strain gauges, to simultaneously measure both the axial preload and the torque acting on its shank. Two different types of joined members have been examined: a cylindrical sleeve whose diameter is twice the screw diameter (compliant joint) and a rectangular plate whose transverse dimensions are more than ten times larger than the screw diameter (stiff joint). The underhead and thread friction coefficients have been controlled by properly selecting lubrication conditions. The main outcome of the work is that the torsional stiffness of the joined members does have an impact on the residual shank torque. A simple mathematical model has also been implemented, in order to predict the residual shank torque during the design phase.

Dynamic Simulation of the Six Axis Machining Robot for Trajectory Planning in CATIA-LMS

Nowadays six axis machining robots are widely used in many fields of industry. Compared to machine tools, industrial robots offer a cheaper yet more flexible alternative to the machine-tools in the cleaning and pre-machining applications of aluminum castings. But the low stiffness has limited the application of industrial robots to the machining tasks with very low precision requirement. This paper presents a practical approach to improve the robot-machining accuracy by developing an off line simulation tool. Firstly we will complete the dynamic simulation of the 6-axis stiff model in CATIA-LMS for trajectory planning. Secondly we will set flexible joints and balancing system for the industry machining robot in LMS. Finally we will make some compare with the position trajectories generated by flexible joint and stiff joint, and then adjust the parameters under the references of the simulation result before the industry machining.

First Test Results of a Haptic Tele-Operation System to Enhance Stability of Telescopic Handlers

According to a recent report of ILO (International Labour Organization), more than two million people die or loose the working capability every year because of accidents or work-related diseases. A large portion of these accidents are related to the execution of motion and transportation tasks involving heavy duty machines. The insufficient degree of interaction between the human operator and the machine may be regarded as one of the major causes of this phenomenon. The main goal of the tele-operation system presented in this paper is to both preserving slave (machine) stability, by reducing the inputs of slave actuators when certain unsafe working conditions occur, and improving the level of interaction at master (operator) side. Different control schemes are proposed in the paper, including several combinations of master and slave control strategies. The effectiveness of the algorithms is analyzed by presenting some experimental results, based on the use of a two degrees-of-freedom force feedback input device (with one active actuator and one passive stiff joint) coupled with a simulator of a telescopic handler.

CHAPTER XXI

The abbess of Andoüillets, which if you look into the large set of provincial maps now publishing at Paris, you will find situated amongst the hills which divide Burgundy from Savoy, being in danger of an. Anchylosis or stiff joint (the ...

Arthrogryposis multiplex congenita - a rare congenital stiff joints syndrome

Introduction: Arthrogryposis multiplex congenita is not a disease but a term describing multiple congenital contractures. Etiological factors include neurological and primary myogenic diseases. This rare syndrome is present at birth and is characterized by reduced mobility of many joints. The contractures involve two or more joints with ankylosis. The accompanying musculature is hypoplastic, but multiple pterygia are also present. Arthrogryposis multiplex congenita is a heterogeneous group of disorders with the incidence rate of 6.2/100000 liveborn infants. The true incidence cannot be established, because many cases result in spontaneous miscarriages or stillbirth. More than 90% of cases are associated with birth defects. The cause of this syndrome is unknown. Many forms are not hereditary, though there are hereditary forms as well. Case report. This paper presents a case with arthrogryposis multiplex congenita. The pregnancy was not controlled regularly. During the pregnancy, oligohydramnion was detected. Due to contractures, labor ended is cesarean section. The child was born in the 34th week of gestation. Flexion and extension joint contractures were observed. Active and passive mobility of the afflicted joints was reduced. There was a limited motor function in the shoulder, elbow and wrist joints with a slight internal rotation of the shoulder joint and lower arm joints during pronation. The hips were subluxated; the feet were in equinovarus position and the fingers in ulnar deviation with partial syndactyly of the 4th and 5th fingers on the left hand. The infant had abnormal dermatoglyphics. The neck was short, and the 2nd and 3rd cervical vertebrae were fused. There was also a slight left-sided thoracic scoliosis. Trismus was present due to the existing ankylosis of the temporomandibular joint. The karyotype was normal. The serum creatinine phosphokinase was slightly elevated. The electromyographic picture indicate non-specific signs of myopathy. Discussion and conclusion. This is a case report of a "stiff joint syndrome". Due to the fact that data from the family history were unavailable, we could not establish the type of syndrome. However, heredity, growth and development at later age, as well as IQ, might significantly help in definite differentiation of this syndrome. In pregnancy, oligohydramnion should indicate more detailed ultrasonographic examination, as ankylosed joints can be detected in utero. .