Search results for " Design"

The Retrograde Tibial Nail: presentation and biomechanical evaluation of a new concept in the treatment of distal tibia fractures.

2013

Displaced distal tibia fractures require stable fixation while minimizing secondary damage to the soft tissues by the surgical approach and implants. Antegrade intramedullary nailing has become an alternative to plate osteosynthesis for the treatment of distal metaphyseal fractures over the past two decades. While retrograde intramedullary nailing is a standard procedure in other long bone fractures, only few attempts have been made on retrograde nailing of tibial fractures. The main reasons are difficulties of finding an ideal entry portal and the lack of an ideal implant for retrograde insertion. The Retrograde Tibial Nail (RTN) is a prototype intramedullary implant developed by our group…

A ten-year follow-up of the Reflection cementless acetabular component.

2008

We reviewed the long-term results at ten to 12 years of 118 total hip replacements in 109 patients using a second-generation hemispherical cementless acetabular component (Reflection) designed to address the problem of backside wear. Five patients (five hips) died and six patients (seven hips) were lost to follow-up. The remaining 98 patients (106 hips) had a mean age of 62.9 years (34.0 to 86.2) A rate of revision for aseptic loosening of 0.9%, and predictable results were found with respect to radiological evidence of fixation, lack of pain, walking ability, range of movement and function. One component was revised for aseptic loosening, and of the 101 hips (95.2%) that did not have a rev…

The influence of lateral release on patello-femoral joint loading in knee arthroplasty

1992

Eight fresh, cadaveric knees have been fitted with four different total knee cemented prostheses. Loading forces at the bone implant fixation interface of the patella component have been measured in a knee joint testing rig by four miniaturized force transducers, before and after a lateral release of the patellar retinaculum. The lateral release resulted in a significant local force reduction in the lateral and/or proximal quadrant of the patella resection plane depending on the knee flexion angle, quadriceps tensile force direction, and the patellar prosthesis design.

Biomechanical effectiveness of a distraction-rotation knee brace in medial knee osteoarthritis: preliminary results.

2013

Abstract Background Non-pharmacological therapies are recommended for the care of knee osteoarthritis patients. Unloader knee braces provide an interesting functional approach, which aims to modulate mechanical stress on the symptomatic joint compartment. We aimed to confirm the biomechanical effects and evaluate functional benefits of a new knee brace that combines a valgus effect with knee and tibial external rotation during gait in medial osteoarthritis patients. Methods Twenty patients with unilateral symptomatic medial knee osteoarthritis were included and they performed two test sessions of 3D gait analysis with and without the brace at the initial evaluation (W0) and after 5weeks (W5…

Optimal positioning of the humeral component in the reverse shoulder prosthesis.

2014

Total reverse shoulder arthroplasty is becoming more and more the standard therapeutic practice for glenohumeral arthropathy with massive lesions of the rotator cuff. The biomechanical principle of this prosthesis is represented by the reversion of the normal anatomy of the shoulder joint. This non-anatomical prosthesis leads to a medialization of the rotation centre of the glenohumeral joint and also to a distalization of the humeral head. All that causes a deltoid tension increasing so allowing a larger abduction of the arm. Main complications of the reverse shoulder prosthesis are due to the joint instability, the scapular notching and the wear of the polyethylene insert. The main goal o…

Two different posterior-stabilized mobile-bearing TKA designs: navigator evaluation of intraoperative kinematic differences

2020

Purpose: The purpose of this study was to compare two types of posterior-stabilized (PS) mobile-bearing (MB) total knee arthroplasties (TKAs). The hypothesis was that no major differences were going to be found among the two TKA designs. Methods: Two cohorts of patients who were divided according to implant design (Cohort A, new design gradually reducing radius PS MB TKA; Cohort B, traditional dual-radius PS MB TKA) were analyzed by means of intraoperative navigation. All operations were guided by a non-image-based navigation system that recorded relative femoral and tibial positions in native and implanted knees during the following kinematic tests: passive range of motion (PROM), varus–va…

2021

Vibroarthrography measures joint sounds caused by sliding of the joint surfaces over each other. and can be affected by joint health, load and type of movement. Since both warm-up and muscle fatigue lead to local changes in the knee joint (e.g., temperature increase, lubrication of the joint, muscle activation), these may impact knee joint sounds. Therefore, this study investigates the effects of warm-up and muscle fatiguing exercise on knee joint sounds during an activity of daily living. Seventeen healthy, physically active volunteers (25.7 ± 2 years, 7 males) performed a control and an intervention session with a wash-out phase of one week. The control session consisted of sitting on a c…

The effect of cement fixation on initial micromotion of the femoral component in condylar knee replacement

1992

Four fresh, cadaveric specimens were fitted with total knee replacements and mounted on a knee joint loading and measuring rig. Femoral component micromotion in the sagittal plane was measured with a transducer during flexion and extension of the specimen. Various condylar designs were used without and with cement. Movement followed a characteristic curve pattern and was less with cement fixation particularly for bone of low trabecular strength as determined by bone sample tests for stiffness. Cement fixation appears to be superior to cementless fixation.

Storie di oggetti (e di sogni) perduti. Musei contemporanei per ritrovarsi

2022

What happens to humanity discarded by history? To the broken dreams (of love and life)?What to do with the objects that fill our life as "fragile ruins" of a dream lost forever? The article, looking at various contemporary projects of permanent museums and temporary exhibitions, intends to outline and lead a reflection on the radical paradigm change that intervenes in the exhibition processes and in the strategies of emotional engagement within contemporary museological policies. Conceived as places of encounter and relationship, museums are open to communities and individual stories. In particular, the emotion of lost guided the constitution of collections of objects, in a series of exhibi…

A comparative analysis of the sustainability of rice cultivation technologies using the analytic network process

2010

Sustainability of local farming systems and technologies is a very important issue that faces notorious measurement difficulties. Multi-criteria methods may help researchers to solve empirical problems in the construction of composite sustainability indicators and in ranking agricultural technologies according to their sustainability. This paper shows how a multi-criteria decision-making technique, the Analytic Network Process (ANP), can be fruitfully employed to this end. Contrary to simpler and hierarchical goal-criteria-alternative approaches, in ANP all the elements in the network can be related in any possible way, which means that a network can incorporate feedback and interdependent …