Function-Orientated Structural Analysis of the Proximal Human Femur

In his model of the biomechanics of the proximal human femur, Friedrich Pauwels assumes a resultant force acting on the femoral head that is created by the partial body weight and the force of the abductor muscles inserting at the greater trochanter. This model suggests a tensile force in the region of the greater trochanter. An exact examination of the muscle insertions at the greater trochanter resulted in a contrasting hypothesis assuming a local compression stress in the region of the greater trochanter. The aim of this study was to examine which hypothesis is favored by the internal architecture of the proximal femur. Based on the architectural software Allplan (R), we performed an extended analysis of the trabecular structure within the proximal femur using CT scans of 10 human cadaver femora altogether. According to our results, both the medial and the trochanteric trabecular systems are orientated approximately perpendicular to the arcuate trabecular system {[}angles between systems ranging from 84.6 to 93.0 degrees (mean angle 90.7 degrees) and from 80.9 to 86.5 degrees, (mean angle 84.9 degrees), respectively]; furthermore, the medial trabecular system is orientated perpendicular to the epiphysis of the femoral head (mean of angles: 94.7). The biomechanical interpretation of these results strongly supports the idea of compressive stress in the region of the greater trochanter and makes a predominant tensile force of the abductor muscles highly unlikely. Copyright (C) 2009 S. Karger AG, Base

Physiopathology and biomechanics of hip osteoarthritis

Several factors seem to play a relevant role in the pathogenesis of hip osteoarthritis. Among these, an altered biomechanic and neuromuscular integrity of the hip joint should be considered. This is a review of the recent international literature concerning the role of loads and strengths acting on the hip joint, in order to better understand the pathogenesis and the physiopathology of the hip osteoarthritis. The study of these factors might be important to prevent the development of the osteoarthritis and might suggest the conservative treatment. In particular, the role of the balance among the muscles working in maintaining the equilibrium of the acting strengths is matter of discussion. The articular and neuromuscular dysfunction might induce an altered load distribution in the hip, particularly on the articular cartilage surface, and seems to favour the development of hip osteoarthritis..

Tribological characteristics of a composite total-surface hip replacement

Continuous fiber, woven E glass composite femoral shells having the same elastic properties as bone were fabricated. The shells were then encrusted with filled epoxy wear resistant coatings and run dry against ultrahigh molecular weight polyethylene acetabular cups in 42,000 and 250,000 cycle wear tests on a total hip simulator. The tribological characteristics of these continuous fiber particulate composite femoral shells articulating with ultrahigh molecular weight polyethylene acetabular cups were comparable to those of a vitallium ball articulating with an ultrahigh molecular weight polyethylene acetabular cup

Functional Outcome of Hydrodilatation Versus Intra-Articular Corticosteroid Injection in Patients with Frozen Shoulder.

Background : To compare hydrodilatation with intra-articular injection of corticosteroid in patients with frozen shoulder. Methods: In this comparative study a total of 80 patients with frozen shoulder were divided into two groups. Patients in group A were treated with hydrodilatation under local anaesthesia . The joint capsule was distended by injecting 40 ml of normal saline. Patient was observed for 30 min and then assisted range of motion and supervised active exercises were performed. Group B patients were treated with intra-articular steroid (triamcinolone acetate) 40 mg along with 1 ml of 1 % w/v of lidocaine . The patient was advised to do shoulder exercises from the next day, three times a day along with oral non-narcotic analgesics. Patients were evaluated by recording pre-procedure pain scoring and range of motion and post-procedure scoring at 4 weeks after the procedure. Effectiveness was taken as improvement in the final score of at least 9 (pain improvement of 5 and ROM score of 4) or more at four weeks follow up. Results: Majority (60.62%) were male. Group A patients had mean pre procedure score of 9.87± 4.44 and post procedure score was 22.8± 5.14, while in group B, pre procedure score was 9.78± 4.49 and post procedure score was 21.49± 5.56. Out of 80 patients in group A, the effectiveness was observed in 92.50%, while in group B patients had effectiveness in 73.75%. The chi square test showed the p-value of 0.003, which was quite significant. Conclusion: Hydrodilatation was found to be effective and convenient outpatient department procedure with better functional outcome, at four weeks follow up, than corticosteroid injection alone. &nbsp

Preschool asthma : infant lung function, inflammation and skin barrier function in early life

Background: Asthma is among the most common obstructive respiratory disorders in children, characterized by airway inflammation with features such as wheeze, cough and shortness of breath. Though the etiology behind the disease partly remains unknown, the roots likely origin from early life. Lower lung function, skin barrier impairment, as well as eosinophil inflammation are factors related to asthma development, but are largely unexplored in early life. The overall aim of this doctoral thesis was to explore early risk factors for the development of preschool asthma, related to infant lung function, eosinophil inflammation and skin barrier function in early life. Methods: All four sub studies (I-IV) were based on data prospectively collected from children actively participating in the Preventing Atopic Dermatitis and ALLergies in children (PreventADALL) mother-child cohort (n=2394) recruited from the general population in Sweden and Norway. First, with infant lung function measured in both the awake and sleeping state at three months, we aimed to determine whether lung function by tidal flow-volume (TFV) loops differed according to arousal state (sub study I). Thereafter, we investigated the potential association between infant lung function while awake and preschool asthma at three years (sub study IV). Second, we aimed to explore if infant skin barrier function by transepidermal water loss (TEWL), eczema at three months and mutations in the skin barrier filaggrin (FLG) gene were associated with infant lung function at three months (sub study II) and/or preschool asthma at three years (sub study IV). Third, we aimed to identify if higher levels of inflammation by serum eosinophil-derived neurotoxin (EDN) at one and three years were associated with preschool asthma at three years (sub study III). Lastly, we aimed to assess if the potential associations between infant lung- and skin barrier function as well as early-life eosinophil inflammation and preschool asthma differed by sex (sub study III-IV). Results: Among 91 infants with paired lung function measurements, TFV loop parameters overall differed, with a higher ratio of time to peak tidal expiratory flow to expiratory time, tPTEF/tE, shorter tE but similar tPTEF while awake compared to the sleeping state. Studying 563 children with information on infant lung function while awake and preschool asthma, a fiverespectively three-fold higher odds ratio (OR) of asthma was observed among infants with lower tPTEF/tE (<0.25) and shorter tPTEF (<0.17 s). While the presence of eczema or FLG mutations were not associated with a shorter tPTEF in 899 infants, a high TEWL was. Similarly, a two-fold higher OR of preschool asthma was observed in infants with high TEWL, but not eczema or FLG mutations among 1337 children. Among 1233 children with available serum eosinophil-derived neurotoxin (EDN) levels, EDN levels >26.7 μg/L in late infancy and >20.5 μg/L at preschool age were associated with preschool asthma, increasing the OR by two- and almost five-fold at respective age. Overall, boys had higher rates of preschool asthma compared to girls; >15% versus <9%. Similarly, infant lung function was lower in boys compared to girls; 0.38 versus 0.40 for tPTEF/tE and 0.20 versus 0.21 s for tPTEF, whereas TEWL, eczema and FLG mutations were distributed equally across the sexes. Boys had higher EDN levels in late infancy and at preschool age (32.0 and 20.9 μg/L) compared to girls (24.5 and 19.0 μg/L). The associations to preschool asthma differed by sex, with an eight- and three-fold higher OR in boys with a lower tPTEF/tE respectively shorter tPTEF, and a four-fold higher OR observed in girls with FLG mutations, only, whereas neither eczema nor high TEWL remained significant risk factors. Higher EDN levels in late infancy increased the OR of preschool asthma by four-fold in boys only, whereas at preschool age, higher levels increased the OR in both sexes. Conclusion: Based on our findings, we conclude that lower lung function in the awake state, skin barrier impairment as well as eosinophil inflammation in early life overall may be linked to preschool asthma. However, as the associations to preschool asthma differed by sex, with a higher OR observed in boys with lower lung function, while FLG gene mutations increased the OR in girls, and in late infancy, higher EDN levels remained a significant risk factor in boys, only, our observations point to the importance of potential sex differences

Influencia de la vía de abordaje y de posición de la cúpula acetabular en la luxación de la artroplastia total de cadera: estudio caso-control

Tanto la vía de acceso quirúrgica como la posición de los componentes se han relacionado con la presencia de una luxación en las artroplastias primarias de cadera. Hemos estudiado la presencia de esta complicación en una serie de 758 artroplastias no cementadas modelo Bihapro. Encontramos 21 luxaciones. Por otro lado se seleccionó de forma aleatoria un grupo de control de 42 pacientes que no habían presentado luxación. Se diseñó un estudio de casos y controles que englobaba por tanto a 63 pacientes que tenían implantada una artroplastia de este modelo. En el grupo de casos observamos que el porcentaje de luxación fue sensiblemente mayor en el sexo masculino con un 66,7%, en comparación con el sexo femenino que fue de un 42,8% aunque esta diferencia no fue estadísticamente significativa. No se observaron diferencias en la frecuencia de luxaciones en relación con la vía anterior o lateral, pero sin embargo en la vía posterior la luxación se produjo en un solo caso (4,8% de todas las luxaciones) con una incidencia claramente menor que en los abordajes anterior y lateral, siendo esta diferencia estadísticamente significativa (p=0,005). También observamos diferencias estadísticamente significativas en cuanto a un mayor porcentaje de luxaciones cuando la inclinación del componente acetabular era mayor de 50º (76,2%), o cuando la anteversión del cotilo era mayor o igual a 20º (54,4%). La vía de abordaje posterior con reconstrucción capsular y muscular presenta un menor porcentaje de luxación después de una artroplastia primaria en comparación con la anterior o lateral. Una inclinación mayor de 50º o una anteversión mayor de 20º favorecen la presencia de una luxación.The surgical approach and the cup position have been related with the dislocations of total hip arthroplasty. We have studied the presence of this complication in 758 Bihapro™ cementless arthroplasties. We got a case group of 21 dislocations; then we selected a control group of 42 patients without luxation to design a case-control study. The case group had a higher rate of dislocation in males (66.7 % versus 42.8 % in females) although this difference was not statistically significant. We didn’t observe any difference in the frequency of luxations relating to the anterior or lateral surgical approach, however in the posterior approach the dislocation appeared only in one case (4.8 % of the all dislocations) with statistically differences (p=0.005). We also observed statistically significant differences of luxations when the acetabular cup inclination was higher than 50º (76.2 %), or when the cup anteversion was equal or higher than 20º (52.4 %). The posterior surgical approach with capsular and muscular suture presented a lower rate of dislocation after a primary arthroplasty compared with the anterior or lateral approachs. An inclination bigger than 50º or an anteversion bigger than 20º seems to be a risk factor of luxation

Eosinophil-derived neurotoxin levels in early childhood and association with preschool asthma – A prospective observational study

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Hyaluronic acid as a treatment for ankle osteoarthritis

Viscosupplementation refers to the concept of synovial fluid replacement with intra-articular injections of hyaluronic acid (HA) for the relief of pain associated with osteoarthritis (OA). Intra-articular viscosupplementation was approved by the Food and Drug Administration (FDA) in 1997. It is currently indicated only for the treatment of pain associated with knee OA. However, OA can occur in several of the weight-bearing joints of the foot and ankle. Ankle OA produces chronic disability that directly impacts the quality of life. There is only limited published literature relating to the use of HA in the ankle. This paper will review the authors’ experience, indications, clinical outcomes, and complications of viscosupplementation therapy in patients with ankle OA