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In the field of reconstructive surgery, a great challenge is represented by bone injuries beyond the self-repair threshold. Autologous bone grafts may be considered the gold standard. Anyway, such approach is limited by the amount of tissue required for grafting and by donor site morbidity. To overcome these drawbacks, bone tissue engineering represents a promising solution. 3D fully biodegradable and nanocomposite scaffolds for bone tissue regeneration, consisting of poly(ɛ-caprolactone) (PCL) reinforced with hydroxyapatite (HA) nanoparticles, were developed using an additive manufacturing process. The effect of nanoparticles and architecture (i.e., lay-down pattern) on the mechanical/functional and biological properties was discussed.

Experimental/theoretical analyses have already been performed on poly(ε-caprolactone) (PCL) loaded with organic-inorganic fillers (PCL/TiO2 and PCL/ZrO2) to find a correlation between the results from the small punch test and Young's modulus of the materials. PCL loaded with Ti2 (PCL = 12, TiO2 = 88 wt %) and Zr2 (PCL = 12, ZrO2 = 88 wt %) hybrid fillers showed better performances than those obtained for the other particle composition. In this context, the aim of current research is to provide further insight into the mechanical properties of PCL loaded with sol-gel-synthesized organic-inorganic hybrid fillers for bone tissue engineering. For this reason, theoretical analyses were performed by the finite element method. The results from the small punch test and Young's modulus of the materials were newly correlated. The obtained values of Young's modulus (193 MPa for PCL, 378 MPa for PCL/Ti2 and 415 MPa for PCL/Zr2) were higher than those obtained from a previous theoretical modelling (144 MPa for PCL, 282 MPa for PCL/Ti2 and 310 MPa for PCL/Zr2). This correlation will be an important step for the evaluation of Young's modulus, starting from the small punch test data. Experimental/theoretical analyses have already been performed on poly(ε-caprolactone) (PCL) loaded with organic-inorganic fillers (PCL/TiO2and PCL/ZrO2) to find a correlation between the results from the small punch test and Young's modulus of the materials. PCL loaded with Ti2 (PCL = 12, TiO2= 88 wt %) and Zr2 (PCL = 12, ZrO2= 88 wt %) hybrid fillers showed better performances than those obtained for the other particle composition. In this context, the aim of current research is to provide further insight into the mechanical properties of PCL loaded with sol-gel-synthesized organic-inorganic hybrid fillers for bone tissue engineering. For this reason, theoretical analyses were performed by the finite element method. The results from the small punch test and Young's modulus of the materials were newly correlated. The obtained values of Young's modulus (193 MPa for PCL, 378 MPa for PCL/Ti2 and 415 MPa for PCL/Zr2) were higher than those obtained from a previous theoretical modelling (144 MPa for PCL, 282 MPa for PCL/Ti2 and 310 MPa for PCL/Zr2). This correlation will be an important step for the evaluation of Young's modulus, starting from the small punch test data.

Meniscectomy significantly change the kinematics of the knee joint by reducing the contact area between femoral condyles and the tibial plateau, but the shift in the contact area has been poorly described. The aim of our investigation was to measure the shift of the tibiofemoral contact area occurring after meniscectomy. We used laser scans combined to surface texturing for measuring the 3D position and area of the femoral and tibial surfaces involved in the joint. In particular, natural condyles (porcine model) were analysed and the reverse engineering approach was used for the interpretation of the results from compression tests and local force measurements in conjunction with staining techniques. The results suggested that laser scans combined to surface texturing may be considered as a powerful tool to investigate the stained contours of the contact area. Beside the largely documented reduction of contact area and local pressure increase, a shift of the centroid of the contact area toward the intercondylar notch was measured after meniscectomy. As a consequence of the contact area shift and pressure increase, cartilage degeneration close to the intercondylar notch may occur. Meniscectomy significantly change the kinematics of the knee joint by reducing the contact area between femoral condyles and the tibial plateau, but the shift in the contact area has been poorly described. The aim of our investigation was to measure the shift of the tibiofemoral contact area occurring after meniscectomy.We used laser scans combined to surface texturing for measuring the 3D position and area of the femoral and tibial surfaces involved in the joint. In particular, natural condyles (porcine model) were analysed and the reverse engineering approach was used for the interpretation of the results from compression tests and local force measurements in conjunction with staining techniques.The results suggested that laser scans combined to surface texturing may be considered as a powerful tool to investigate the stained contours of the contact area. Beside the largely documented reduction of contact area and local pressure increase, a shift of the centroid of the contact area toward the intercondylar notch was measured after meniscectomy.As a consequence of the contact area shift and pressure increase, cartilage degeneration close to the intercondylar notch may occur.

The mechanical properties of three wet commercial bone cements, namely Braxel (from Bioland®), Simplex-P (from Howmedica®) and CMW1-G (from DePuy®) are investigated by means of stress relaxation and dynamic mechanical analysis (DMA). The geometry of loading that was used is the three point bending method (ASTM D790); all the tests were performed in a water chamber by means of temperature sweeps between 17 and 57 °C and spanning four frequency decades. The results show that viscoelastic properties are strongly dependent on specimen conditioning (i.e. water uptake and heat treatment). The results also show that all the cements that were analyzed show mechanical properties which are intermediate between the ones of the cancellous bone and of the metals of which prostheses are normally made. As a consequence, the cement is able to reduce the stress concentrations due to the interfacing of materials which have very different stiffnesses. Moreover, the results of the DMA, particularly the ones concerning the damping factor (tan δ), indicate that at body temperature the bone cements tested show an increased capacity of dissipation, the higher is the loading frequency, thus displaying shock absorbing properties.

Chronic low back pain is a disease that most often affects people between 45 and 64 years. The incidence of low back pain goes from 60 to 90% and the annual incidence is 5%. Often low back pain is accompanied or replaced by an irradiated lower limb pain, configuring the symptomatology of lumboradiculalgia, whose most frequent cause is the disco-radicular conflict. The cause of the onset of pain, even excruciating, in cases of radicular compression of disc origin is not yet clear. Low back pain of disc origin is thought to be caused by direct mechanical compression factors; by indirect mechanical factors ischemia or venous stasis of vasa nervorum; and by type of immune-mediated inflammatory factors (reaction hernia) and/or biochemical evidence related to the disc type (the presence of substances which induce the inflammatory reaction). When a patient is suffering by chronic low back pain, apart from the algic problem, a series of changes in posture will occur, which contribute to worsen low back pain itself. The effects of a polluted posture and, therefore, the muscle retraction manifest in the joints in the form of compression, axial rotation and translation, resulting in modifications of the skeletal morphology (scoliotic attitudes, hyperkyphosis, valgus and varus of the knee, etc.) and possibly evolving into important postural disorders. Currently, the treatment of chronic low back pain and postural secondary disorders is still an open problem. The aim of this preliminary study is: i) to highlight the high incidence of low back pain by providing evidence that there is an anatomical substrate to low back pain originating in the disc; ii) and to assess the effects of the use of oxygen-ozone percutaneous paravertebral intramuscular therapy in synergy with a functional rehabilitation program in a group of patients suffering from chronic low back pain. From the data obtained, the combination of percutaneous paravertebral intramuscular oxygen-ozone therapy with functional rehabilitation is confirmed as an effective and safe method, whose favorable results are evident at the level of lumbar pain symptoms, postural secondary abnormalities, disability in activities of daily living, the mood and tone of the psychological state.

Introduction Over the past years, in order to anchor a prosthetic component to bone, different cements based on self-polymerizing poly(methyl methacrylate) (PMMA) have been widely used as commercial synthetic biomaterials. The aim of this study was to evaluate the influence of a PMMA-based bone cement (Palamed® G40) on the viscoelastic behaviour of spongy bone from proximal human tibial epiphyses, and the assessment of the dynamic-mechanical properties of the natural tissue. Materials and methods The effect of an acrylic bone cement on the dynamic-mechanical performance of spongy bone was assessed by means of dynamic three-point bending tests. All the tests were performed in physiological solution at 37±0.5°C, scanning the frequency from 0.01 to 30 Hz. Samples from proximal human tibial epiphyses were cut along the medial-lateral and anterior-posterior directions considering different regions of the subchondral tibial plate. The dynamic-mechanical properties of specimens infiltrated the PMMA-based bone cement were evaluated in the frequency range investigated. Results The results have highlighted that the viscoelastic properties of spongy bone vary with direction and region, and the PMMA-based bone cement increases the storage modulus (E') of spongy bone of about 100%. However, for bone-cement system, the values of loss factor (tan d) are close to those of the natural structure. Moreover, micro-computed tomography (?CT) has allowed to study the architecture of bone and its interface with the cement. Conclusion The present study has evidenced that bone infiltration allows to enhance the mechanical performances of spongy bone. Furthermore, taking into account the analysis of the viscoelastic properties of the natural structure, future trends will be focused on the possibility to design a prosthetic implant, which emulates the biomechanical behaviour of the natural tissues, or a suitable cement, which improves the mechanical properties of spongy bone.

The polymerization behaviour of bone cements during total hipreplacements is characterized by a fast and highly non-isothermal bulk reaction.In the first part of this paper the reaction kinetics are analysed bycalorimetric analysis in order to determine the rates of polymerization inisothermal and non-isothermal conditions. A phenomenological kinetic model,accounting for the effects of autoacceleration and vitrification, is presented.This model, integrated with an energy balance, is capable of predicting thetemperature across the prosthesis, the cement and the bone and the degree ofreaction in the cement, during in situ polymerization. The temperatureand the degree of reaction profiles are calculated, as a function of the settingtime, taking into account the system geometry, the thermal diffusivity of bone,prosthesis and cement, and the heat rate generated by the reaction according tothe kinetic model. Material properties, boundary and initial cond!itions are the input data of the heat transfer model. Kinetic and heat transfermodels are coupled and a numerical solution method is used. The model is appliedin order to study the effects of different application procedures on temperatureand degree of reaction profiles across the bone–cement–prosthesissystem.

We present a case of a 56-year old woman with chest lumbar idiopathic scoliosis treated with an oxygen-ozone therapy cycle (10-μg paravertebral and 3-μg subcutaneous infiltrations) for irrepressible pain, as a consequence of a vertebral posterior arthrosis surgery.

Polymer-based composite materials are ideal for applications where high stiffness-to-weight and strength-to-weight ratios are required. From aerospace and aeronautical field to biomedical applications, fiber-reinforced polymers have replaced metals, thus emerging as an interesting alternative. As widely reported, the mechanical behavior of the composite materials involves investigation on micro- and macro-scale, taking into consideration micromechanics, macromechanics and lamination theory. Clinical situations often require repairing connective tissues and the use of composite materials may be suitable for these applications because of the possibility to design tissue substitutes or implants with the required mechanical properties. Accordingly, this review aims at stressing the importance of fiber-reinforced composite materials to make advanced and biomimetic prostheses with tailored mechanical properties, starting from the basic principle design, technologies, and a brief overview of composites applications in several fields. Fiber-reinforced composite materials for artificial tendons, ligaments, and intervertebral discs, as well as for hip stems and mandible models will be reviewed, highlighting the possibility to mimic the mechanical properties of the soft and hard tissues that they replace. © 2011 Società Italiana Biomateriali.

We present a Crawljax based approach to automatically evaluate the accessibility of AJAX applications. Crawljax is a tool able to crawl an AJAX application for inferring a corresponding state-flow graph. Thus, combining Crawljax with a traditional tool for accessibility testing we realized a plugin that provides an automatic generation of accessibility evaluation reports for AJAX applications. The proposed approach has been experimented carrying out a case study that highlighted its effectiveness. Nevertheless, the case study also revealed some shortcomings of the current implementation of Crawljax.

Idiopathic scoliosis (IS) is a largely diffused disease in human population but its pathogenesis is still unknown. There is a relationship between scoliotic phenotype and the patient age, since in the early stage the pathology shows a ratio of 50% between male and female teenagers. During puberty the sex ratio is 8.4/1 (female/male), suggesting a sex-conditioned manifestation of the disease. Genetic inheritance of idiopathic scoliosis is still unclear although some authors claim for its X-linked dominant inheritance. There is large agreement in considering the IS as a sex-conditioned disease, in terms of steroid content and their receptor activity, although no evidence has been found yet. The blood content of 17beta-estradiol in teenagers with IS shows lower levels than teenagers of the same age without IS. Also testosterone and progesterone content are lower in IS girls with respect to the control girls. Furthermore, we extracted DNA from white blood cells of IS patients and their relatives until the third generation in order to examine estrogen receptor alpha polymorphisms, considering this tool a plausible molecular marker for IS prognosis. In this respect, we identified four polymorphisms in the exons encoding for the steroid binding domain and two other in the trans-activation domain. Our results show a clear relationship with clinical manifestation of IS.

An abundance of data exists documenting the association of H. pylori eradication with the reduction in duodenal ulcer recurrence.To evaluate the validity of using H. pylori eradication as a surrogate marker for the reduction in duodenal ulcer recurrence using rigorously controlled studies.Three controlled clinical trials were conducted in patients with uncomplicated, active duodenal ulcers. Patients were treated with various combinations of omeprazole and amoxycillin. Ulcer healing and H. pylori eradication were assessed. For patients whose duodenal ulcer healed, duodenal ulcer recurrence was determined over a 6-month period in patients with H. pylori eradication and those remaining positive for H. pylori at least 4 weeks after treatment. To support the data obtained from these clinical trials, a search of the medical literature was conducted to identify additional human clinical trials in which duodenal ulcer recurrence rates were measured and categorized by H. pylori status at least 1 month post-treatment.In 11 controlled trials, the overall 6-18-month duodenal ulcer recurrence rate was 54% among patients remaining positive for H. pylori at least 4 weeks after treatment compared to 6% among patients with H. pylori eradication following treatment. This finding was corroborated by the uncontrolled trials, in which the duodenal ulcer recurrence rate was 64% among patients found to be H. pylori-positive and 6% for patients found to be H. pylori-negative at least 4 weeks after treatment. A time course of duodenal ulcer recurrence rates using pooled data from both controlled and uncontrolled studies demonstrated that duodenal ulcer recurrence rates for H. pylori-negative patients persisted for up to 4 years following treatment. Duodenal ulcer recurrence rates for H. pylori-positive patients increased for the first year, then levelled off. A comparison of the duodenal ulcer recurrence rates for different treatment regimens revealed that eradication regimens based on omeprazole plus antibiotics and bismuth plus antibiotics exhibited similar duodenal ulcer recurrence rates for H. pylori-positive and -negative patients.Regardless of treatment regimens, H. pylori eradication produced a consistent and significant reduction in duodenal ulcer recurrence. Therefore H. pylori eradication, 4 weeks post-therapy, can be used as a surrogate marker for reduced duodenal ulcer recurrence in investigational clinical trials.

The development of a completely biodegradable composite artificial tendon prosthesis that mimics the structure and stress-strain response of natural tendon is presented. The artificial tendon is a composite of water-swollen poly(2-hydroxyethylmethacrylate)/poly(caprolactone) blend hydrogel matrix reinforced with poly(lactic acid) fibres. © 1992 Chapman & Hall. The development of a completely biodegradable composite artificial tendon prosthesis that mimics the structure and stress-strain response of natural tendon is presented. The artificial tendon is a composite of water-swollen poly(2-hydroxyethylmethacrylate)/poly(caprolactone) blend hydrogel matrix reinforced with poly(lactic acid) fibres. © 1992 Chapman & Hall.

Patients with non–insulin dependent diabetes mellitus (NIDDM) have a higher risk of atherosclerotic cardiovascular disease than nondiabetic subjects. In seven patients with both hypercholesterolemia and NIDDM controlled by chlorpropamide, lovastatin (20 mg b.i.d. for 6 weeks) lowered low-density lipoprotein cholesterol by 28%, total cholesterol by 24%, and apolipoprotein B by 24%. Lovastatin levels for a 4-hour period (measured as 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitory activity) were similar to those measured previously in nondiabetic patients. Lovastatin did not alter chlorpropamide kinetics or glycemic profiles. No patient had an elevation in serum transaminases or creatinine phosphokinase, and no patient had any other laboratory or clinical drug-related adverse experience during the study. Lovastatin was as effective in reducing low-density lipoprotein cholesterol in patients with NIDDM as in nondiabetic subjects. Diabetic control was unaltered, and no evidence of alteration in lovastatin or chlorpropamide blood levels was noted. Clinical Pharmacology and Therapeutics (1990) 48, 467–472; doi:10.1038/clpt.1990.176

The metallic plates, pins and screws currently used in orthopaedics for internal fixation have elastic moduli much higher than that of the hones to which they are connected. This difference in rigidity prevents healing through proliferation of primary callus early in the healing process and in the later process of healing, bone atrophy and osteoporosis occur.

The mechanical characterization of rabbit Achilles' tendon and anterior cruciate ligament is presented. Both static and dynamic mechanical tests have been performed on fresh explanted tissues. Experimental results are presented and discussed in terms of a relationship between structural architecture and mechanical properties. The differences in collagen fibre configuration and composition between tendon and ligament influence the tensile and viscoelastic properties. In particular, tendons and ligaments showed a gradual transition from a rubber-like to a glassy-like behaviour during the loading process due to the straightening of collagen fibres.

The mechanical properties of three wet commercial bone cements, namely Braxel (from Bioland), Simplex-P (from Howmedica) and CMW1-G (from DePuy) are investigated by means of stress relaxation and dynamic mechanical analysis (DMA). The geometry of loading that was used is the three point bending method (ASTM D790); all the tests were performed in a water chamber by means of temperature sweeps between 17 and 57 degrees C and spanning four frequency decades. The results show that viscoelastic properties are strongly dependent on specimen conditioning (i.e. water uptake and heat treatment). The results also show that all the cements that were analyzed show mechanical properties which are intermediate between the ones of the cancellous bone and of the metals of which prostheses are normally made. As a consequence, the cement is able to reduce the stress concentrations due to the interfacing of materials which have very different stiffnesses. Moreover, the results of the DMA, particularly the ones concerning the damping factor (tan delta), indicate that at body temperature the bone cements tested show an increased capacity of dissipation, the higher is the loading frequency, thus displaying shock absorbing properties.