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The complex biomechanics and morphologies of the femur proximal epiphysis are presented. The nature and fine morphology of the femur head and its structural behavior have been investigated. Isotropic and orthotropic trabecular structures have been associated with oriented compression and tensioned areas of the femur head FEM models. These isotropic/orthotropic trabecular morphologies and their allocations govern the stress and strain distribution in the overall proximal femur region. Finite element models of the femur biofidel were developed using a specific combination of segmentation with computed tomography and solid modeling tools capable of representing bone physiology and structural behavior. This biofidel Finite Element (FEM) model is used to evaluate the change in the physiological distribution of stress in the femoral prosthesis and to evaluate the new design criteria for biopsy. The use of femur proper biofidel modeling while enabling the explanation of physiological stress distribution elucidates the critical mechanical role of the trabecular bone that should be accounted for in the design new innovative more “biologic” prosthetic system. Biomimetics, biomechanics and tissue engineering are three multidisciplinary fields that have been considered in this research to achieve the goal of improving the reliability of prosthetic implants. The authors took these studies to gather the untapped potential of such advanced materials and design technologies by developing finite models of Biofidel elements capable of correctly mimicking the biomechanical behavior of the femur.

Prostheses are widely used in urogenital surgery for many decades and have gained a fundamental role in the management of multiple diseases with good results in terms of functionality, aesthetic outcomes and patients’ satisfaction. It is remarkable that prosthetic device vary in term of mechanical sophistication, costs and surgical implantation techniques ranging from simple device widely used in urological practice like testicular prosthesis to highly sophisticated devices as Inflatable Penile Prosthesis (IPP) and Artificial Urinary Sphincter (AUS). Despite continuous implementations of the devices and improvements of surgical implantation techniques infective complications are still fearful and not uncommon events. Risk of infection depends on patients’ individual features, perioperative strategies, implantation techniques and prosthetic devices. Prevent these complications is imperative because the management of prosthesis infection requires removal of the device in most cases. Centres that plan prosthetic implantations should based on these strategies protocols in order to prevent as far as possible infective complications.

BaCKground: To assess the long-term safety and effectiveness of endovascular aneurysm repair (evar) treatment with unibody endograft deployed on aortic bifurcation (anatomical fixation). MeThods: a retrospective, observational, single-center study of patients treated from 1999 to 2002 with unibody bifurcated endograft. follow-up protocol required clinical and doppler-ultrasound at 1 and 6 months and annually thereafter, computed tomography angiography at 1-, 6- and 12-months and then every year. Primary endpoints included technical and treatment success, survival and freedom from late evar failure; secondary endpoints were freedom from late open conversion (loC), freedom from late re-interventions and endoleaks. resulTs: seventy-three patients, mean age of 73±6 years were enrolled. Median follow-up was 6±0.5 years. Technical success was 98.6% (n.=71/73; causes of failure: 1 open conversion and 1 type ib endoleak). a treatment success of 96% (n.=69/72) was recorded due to endoleaks (n.=2; 1 type ia and 1 type ib) and limb occlusion (n.=1). survival at 1, 5, 10, 15 and 18 years was 90%, 58%, 40%, 32% and 23% respectively. one aneurysm-related death for infection of the endograft was registered. evar failure was 14% (n.=10/71). Three loC were recorded and freedom from reinterventions at 1, 5, 10 and 18 years was 99%, 91%, 86% and 86%. fourteen endoleaks were recorded: ia (n.=6; 42.8%), ia+ib (n.=1; 7.1%), ib (n.=2; 14.2%) and ii (n.=5; 35.6%). four endoleaks were observed, 9 endovascular correction and 1 loC were required. endoleaks free survival of 90% at 1-year and 75% at the end of the study. aneurysm sac shrinkage was observed in 79% (n.=56/71). CONCLUSIONS: This small, retrospective cohort of anatomically fixed EVAR demonstrated long-term safety and effectiveness. The design of the unibody graft did not substantially change and newer generation should guarantee the same performance.

Background Prosthetic repair of inguinal hernias is one of the most performed surgical procedures. Nevertheless, high rates of complications affect the surgical treatment. Implant fixation, poor-quality tissue ingrowth and mesh shrinkage seem to be involved in postoperative complications, discomfort and chronic pain following inguinal hernia repair. To address these issues a multilamellar shaped 3D dynamic responsive prosthesis has been developed. This new implant, positioned fixation-free to obliterate the hernia opening, thanks its inherent dynamic compliance during inguinal movements, has demonstrated to induce an enhanced biological response. The ingrowth of newly formed muscle fibers, arteries and veins in a surrounding of viable connective tissue could be evidenced into the implant fabric. This appears to be quite different from the fibrotic plaque, typical biologic response of conventional meshes. In addition to myocytes and vessels, newly ingrown nerves have also been detected in the prosthetic structure. Materials and methods The aim of this investigation was to determine by examining biopsy specimens excised from patients who underwent hernia repair with the 3D dynamic implant, quantity and quality of the neural ingrowth within the implant fabric in the short, medium, and long term post-implantation. Results Newly formed nervous structures were found in biopsy specimens, from multiple spots of nerve clusters evidenced in the short-term along the increased level of neural maturation in the midterm, until the nerves showed complete in all components in the long-term. Conclusion The development of highly specialized nervous tissue in the 3D prosthesis seems to finalize the regenerative biologic response that is expected for the treatment of a degenerative disease, as, in fact, inguinal hernia is. Re-growth of the typical tissue components of the groin evidenced in the 3D dynamic prosthesis seems to effectively revert the degenerative source of inguinal hernia into regeneration of the vanished tissue components of the groin.

Amputation of a sensory peripheral nerve induces severe anatomical and functional changes along the afferent pathway as well as perception alterations and neuropathic pain. In previous studies we showed that electrical stimulation applied to a transected infraorbital nerve protects the somatosensory cortex from the above-mentioned sensory deprivation-related changes. In the present study we focus on the initial tract of the somatosensory pathway and we investigate the way weak electrical stimulation modulates the neuroprotective-neuroregenerative and functional processes of trigeminal ganglia primary sensory neurons by studying the expression of neurotrophins (NTFs) and Glia-Derived Neurotrophic Factors (GDNFs) receptors. Neurostimulation was applied to the proximal stump of a transected left infraorbitary nerve using a neuroprosthetic micro-device 12 h/day for 4 weeks in freely behaving rats. Neurons were studied by in situ hybridization and immunohistochemistry against RET (proto-oncogene tyrosine kinase "rearranged during transfection"), tropornyosin-related kinases (TrkA, TrkB, TrkC) receptors and IB4 (Isolectin B4 from Griffonia simplicifolia). Intra-group (left vs. right ganglia) and inter-group comparisons (between Control, Axotomization and Stimulationafter-axotomization groups) were performed using the mean percentage change of the number of positive cells per section [100*(left-right)/right)]. Intra-group differences were studied by paired t-tests. For inter-group comparisons ANOVA test followed by post hoc LSD test (when P < 0.05) were used. Significance level (01) was set to 0.05 in all cases. Results showed that (i) neurostimulation has heterogeneous effects on primary nociceptive and mechanoceptive/proprioceptive neurons; (ii) neurostimulation affects RET-expressing small and large neurons which include thermo-nociceptors and mechanoceptors, as well as on the IB4- and TrkB-positive populations, which mainly correspond to non-peptidergic thereto-nociceptive cells and mechanoceptors respectively. Our results suggest (i) electrical stimulation differentially affects modality-specific primary sensory neurons (ii) artificial input mainly acts on specific nociceptive and mechanoceptive neurons (iii) neuroprosthetic stimulation could be used to modulate peripheral nerve injuries-induced neuropathic pain. These could have important functional implications in both, the design of effective clinical neurostimulation-based protocols and the development of neuroprosthetic devices, controlling primary sensory neurons through selective neurostimulation.

The human femur shows a high capacity to withstand external stresses and it is due to the mass distribution, morphology, and orthotropic behaviors of trabecular and cortical bone. Faithful modeling of the femur accounting for bone distribution and material orthotropic behavior is presented. The use of biofidel model is aimed to develop an “in silico” tool that could enable the valuation of biomechanics modification induced by the alteration of the structural and morphological characteristic in prothesized bones. Moreover, a faithful model assists us in the development of new design criteria for innovative prosthetic systems that, following the isostatic loading lines, could restore the physiological and natural stress and strains distribution. In this study a biofidel femur Finite Element Model (FEM) has been developed from Computerized Tomography (CT) scans using specific combination of software’s to correctly represent bone physiology and structural behavior. Proper identification of trabecular bone arrangement and distribution in the proximal diaphysis enabled modeling and definition of material properties. The faithful femur model proposed allows us to correctly account for non-isotropic properties to the proximal end explaining the critical structural role played by trabecular bone that should be taken into account in the design of new innovative prosthetic system.

Despite undisputed improvements, prosthetics hernia repair continues to be affected by unacceptable rates of complications. Postoperative adverse events such as discomfort and chronic pain represent a subject of increasing concern among the surgical community. Poor quality biologic response, stiff scar plates, and mesh shrinkage, a typical effect of conventional static meshes and plugs, are all indicated as the main reasons for many of the complications related to inguinal hernia repair. Even the conventional concept of treatment based upon a supposed reinforcement of the groin consequent to the fibrotic incorporation of meshes, would appear to be inadequate in the light of the latest scientific evidence concerning the degenerative genesis of inguinal hernia. Following these recent studies, a newly conceived 3D dynamically responsive implant has been developed. It concerns a multilamellar shaped prosthesis, intended to be placed fixation-free to obliterate the hernia defect. This 3D structure has already demonstrated to induce a probiotic biological response with development of viable tissue, instead of the fibrotic plaque typical of conventional meshes. Newly formed elastic fibers, neo-angiogenesis, and neo-nerve genesis in a surrounding of well perfused connective tissue are the typical elements of the biologic response in the newly conceived implant. In addition to these elements, muscle fibers have also been detected in the implant structure. The aim of this research was to determine the ingrowth of muscle fibers in the implant by assessing the quantity and quality of muscle development in the short, medium, and long term post-implantation. Histological examination of biopsy samples excised from patients who underwent dynamic hernia repair with the 3D dynamic implant showed the presence of muscular elements that in the short term could be described as multiple spots of myocytes in the early stage of development. Over the mid- to long-term, muscle fibers increased in number and level of maturation, assuming the typical aspect of standard muscle bundles in the final phase. Effectively, long term, myocytes histologically evidenced the distinctive arrangement of the muscle structure, with nuclei and striated elements being similar to normal muscle elements. The development of this highly specialized connective tissue in the 3D dynamic responsive implant seems to document the finalization of an enhanced biologic response leading to the ingrowth of typical tissue components of the groin. Reverting degenerative pathogenesis into effective regeneration recognized in the newly conceived 3D prosthesis would appear to represent a significant concept change in the repair of inguinal hernias.

Despite improvements in prosthetics and surgical techniques, the rate of complications following inguinal hernia repair remains high. Among these, discomfort and chronic pain have become a source of increasing concern among surgeons. Poor quality of tissue ingrowth, such as thin scar plates or shrinking scars-typical results with conventional static implants and plugs-may contribute to these adverse events. Recently, a new type of 3D dynamically responsive implant was introduced to the market. This device, designed to be placed fixation-free, seems to induce ingrowth of viable and structured tissue instead of regressive fibrotic scarring. To elucidate the differences in biologic response between the conventional static meshes and this 3D dynamically responsive implant, a histological comparison was planned. The aim of this study was to determine the quality of tissue incorporation in both types of implants excised after short, medium, and long periods post-implantation. The results showed large differences in the biologic responses between the two implant types. Histologically, the 3D dynamic implant showed development of tissue elements more similar to natural abdominal wall structures, such as the ingrowth of loose and well-hydrated connective tissue, well-formed vascular structures, elastic fibers, and mature nerves, with negligible or absent inflammatory response. All these characteristics were completely absent in the conventional static implants, where a persistent inflammatory reaction was associated with thin, hardened, and shrunken fibrotic scar formation. Consequently, as herniation is a degenerative process, the 3D dynamic implants, which induce regeneration of the typical groin components, seem to address its pathogenesis.

The use of fully hydrated hydrogels in the body has been well established. The forces a hydrogel generates on swelling when it is placed in a constrained space were investigated with a view to providing a mechanism for fixing a prosthesis in the intramedullary cavity. A cross-linked poly(2-hydroxyethyl methacrylate) [p(HEMA)] hydrogel was investigated as a potential material. In vitro mechanical tests were carried out to determine the stresses generated in the p(HEMA) when it was placed in water and not allowed to swell. Pull out loads of up to 375 N indicated that the system could be used successfully in vivo. Consequently, the material was placed intraosseously at two sites in a rabbit animal model, in the mid-shaft (diaphysis) and the lower end (metaphysis) of the femur. Histological examination showed there was no adverse bone response; bone was growing from the endosteal surface up to and into the hydrogel in the diaphyseal implants and surrounded the hydrogel in the metaphysis. As a result of the shape and size variations in the rabbit femur, in vivo mechanical tests were found to give lower values than those obtained in vitro.

Introduction Issues in ventral hernia repair are represented by the need for mesh fixation and how to assure a sufficient mesh overlap of the defect. Aiming to resolve these problems, this study describes a modified technique for ventral and incisional hernia repair based upon a newly developed mesh with a special design. This new type of implant allows broader coverage of the abdominal wall and results in tension- and fixation-free repair. Materials and methods A unique geometrically shaped mesh consisting of a large central body and radiating arms was used to repair ventral or incisional hernia. The mesh was intended not to be point-fixated. The friction of the straps passing through the tissues was hypothesized to be adequate to maintain the mesh firmly fastened in the abdominal wall, ensuring a wide coverage far from the hernia border. The newly designed mesh was placed in the preperitoneal sublay in 22 patients with ventral or incisional hernia. All straps were passed laterally through the transverse and oblique muscles. In all patients, a defect overlap of at least 8–12 cm was achieved. Results In a midterm follow-up of 18–24 (mean 22) months, three seromas and one infection occurred, which were successfully managed without mesh removal. No hematoma, chronic pain, or recurrence has been reported to date. Conclusions The described arm system of the implant allowed for a much smaller incision and eliminated the complicated maneuvers associated with suturing the mesh. The fixation arms seemed to have ensured the mesh stayed orientated in all patients. A very wide lateral mesh placement was accomplished, assuring sufficient defect overlap when shrinkage occurs.

Long terms results in NY reconstruction with modular uncemented prostheses fixed hinge after resection of bone tumours: a comparison of 2 consecutive designes of the same system

Lower limb modular cemented prostheses after tumour resection: the Rizzoli Experience

Approximately one out of every 750 children are born with some type of an oral cleft (McWilliams, Morris, & Shelton, 1984) Children with clefts of the palate in general have a higher incidence of articulation disorders than do children without clefts. Typical speech problems which tend to occur are hypernasality and multiple articulation errors, often consisting of atypical tongue placement in the mouth or nontypical articulation at sites in the larynx or pharynx. These speech problems can be severe and may require years of expensive, long-term professional treatment to remediate.