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Although fear in early childhood is an emotion that permits survival of danger, fear of water can block and limit children's adaptive development towards this very fear. Aquatic competence is an important milestone in the improvement of general health in childhood, but there are no scales that measure how fear of water can hinder a child's development in the aquatic environment. This study aimed to design and analyze the validity of a Scale to Measure Fear of the Aquatic Environment (SFAE) to evaluate the perceived fear of the aquatic environment in three- to six-year-old children. Construct validity was also evaluated by verifying its relation to aquatic competence. The exploratory and confirmatory factor analyses support the use of five dimensions of influence on the perception of fear of the aquatic environment: social context, equipment/installations, attitude, experiences, and competence. The correlation pattern also supports construct validity showing negative and significant relations between fear and aquatic competence. The SFAE shows a promising initial validity for its use in the aquatic environment during early childhood., Motricidade, Vol. 16 No. 4 (2020): Motricidade more...

Pedagogical strategies following both the ABI model and the interest pedagogy were implemented in order to vegetal physiology lesson students to promote their motivation, basic competences and research abilities, and to develop in a holistic way the conceptualization of plants as open, complex and cybernetic systems. So, higher levels of motivation and researching abilities were achieved, as expressed by better resolutions of biological questions, along with empowering of the experimental design and the statistical method, in addition to a high expository capacity of both written and verbal results during the public defens of talks in national congresses.RESUMENCon el propósito de promover la motivación, las competencias básicas (interpretativa, argumentativa y propositiva) y las habilidades investigativas, en los estudiantes del curso de fisiología vegetal del programa de biología de la Universidad de Pamplona, se implementaron estrategias pedagógicas siguiendo el modelo ABI y la pedagogía de los intereses, para la comprensión integral del concepto de planta como sistema abierto, complejo y cibernético. Desde el punto de vista conceptual, se logró construir, participativamente, una visión holística de la planta; desde lo pedagógico, se alcanzaron mayores niveles de motivación y de capacidad investigativa, expresada en una mejor resolución de las preguntas biológicas, con empoderamiento del diseño experimental y del método estadístico, alta capacidad expositiva de los resultados tanto escritos como verbales, junto con la defensa pública en ponencias a nivel de semilleros de estudiantes y congresos nacionales. more...

Chlamydia abortus, like other members of the family Chlamydiaceae, have a unique intracellular developmental cycle that is characterized by its chronic nature. Infection of a flock can remain undetected for months, until abortion occurs the following reproductive season but, to date, neither the location nor the mechanisms that maintain this latent phase are fully understood. Studies have shown that IL-10 produced as a response to certain micro-organisms sustains the intracellular survival of pathogens and increases host susceptibility to chlamydial infections. In order to induce a sustained infection C. abortus, transgenic mice that constitutively express IL-10 were infected and the immunological mechanisms that maintain infection in these mice were compared with the mechanisms of a resistant wild-type mouse strain. Viable bacteria could be detected in different tissues of transgenic mice up to 28 days after infection, as analysed by bacterial isolation and immunohistochemistry. Chronic infection in these mice was associated with an impaired recruitment of macrophages, decreased iNOS activity at the site of infection and a more diffuse distribution of inflammatory cells in the liver. This murine model can be of great help for understanding the immunological and bacterial mechanisms that lead to chronic chlamydial infections. more...

Background Besides promising results of metal-on-metal (MOM) hip arthroplasty (HA), frequent failures have been reported even in the short term. Many host, surgical, design, metallurgical, and processing factors have been evoked in the base of these events. We have tried to characterize and to evaluate metallurgical and processing features present in this type of implants. Methods The acetabular and femoral components of 20 MOM HAs collected from a multicenter retrieval program were examined. All the specimens were inspected with naked eye, with confocal microscopy and vertical scanning interferometry, scanning electron microscopy, back-scattered electron imaging, and energy-dispersive X-ray spectroscopy, in 25 zones of each articular component. Results Gas pores, shrinkage voids and holes of detached carbides, carbides on surface, embedded particles, scratches and marks of wear, surface discoloration, surface deposits, and tribochemical reaction layers were widely dispersed through a substantial percentage of the total bearing surface in all the implanted components. Surface cup and head voids, and cup scratches showed significant correlation with the clearance of pair. A higher surface damage of the cup and head was observed mainly in the low clearance prostheses. There was no other significant correlation or difference in the incidence and importance of any of these defects between resurfacing hip arthroplasties and total hip arthroplasties, or according to the pair diameter. Conclusion Some metallurgical features and surface damage were significantly present in the retrieved implants of MoM HAs. It would be desirable to improve the structure and metallurgical characteristics of these implants to avoid those effects and optimize their performance. more...

Highlights • A novel surgical technique for reconstructing pelvic defects in hip revision surgery is described. • The Stoppa approach allows for pelvic damage control and reconstruction of bone defect. • The bone reconstruction is made by combining an intrapelvic plating with augmented socket reconstruction., Introduction Failed hip arthroplasty with intrapelvic acetabular migration can be challenging due to the potential damage of intrapelvic structures. Presentation of the case We present a case of a 75 year-old lady with failed hip arthroplasty with loosening of implants and intra-pelvic migration of the cup, antiprotrusio cage mesh, screws and plate. A modified Stoppa approach was performed, a part of the migrated elements were safely removed, the intrapelvic structures were controlled, and the bone defect was reconstructed through the Stoppa approach combined with the lateral window of ilioinguinal approach by means of bone struts and metallic plates, which is a novel technique. Then an extended posterolateral hip approach was done and the acetabulum was reconstructed using porous tantalum augments and morselized allograft. A cemented constrained socket was implanted. After one-year follow-up the patient is able to walk with one crutch without pain. Discussion Due to intrapelvic migration, the implants used in hip arthroplasty may become entrapped between the anatomical structures lodged in the pelvis and cause damage to them. A careful preoperative assessment and planning are mandatory. A migrated socket can be inaccessible through a conventional hip approach and removal could be very difficult and dangerous. Conclusion The Stoppa approach in hip revision surgery can be a complement to traditional approaches to control the intrapelvic structures, remove migrated implants of previous surgery and reconstruct the pelvic defect. more...

**Background:** Anti-thrombotic prophylaxis is routinely used in patients undergoing elective total hip or knee replacement (THR or TKR) to reduce the risk of venous thromboembolism (VTE). In Spain, pharmacological prophylaxis is performed with low-molecular-weight heparin, enoxaparin being the most commonly used. Rivaroxaban is an oral antithrombotic drug that has shown superior efficacy and similar safety profile compared to enoxaparin regimens in randomized clinical trials. The aim of the study was to estimate the budget impact of increasing the use of rivaroxaban with respect to enoxaparin in the prophylaxis of VTE in patients undergoing elective THR or TKR. **Methods:** A budget impact analysis was conducted in order to estimate the economic cost from an increase of rivaroxaban use versus enoxaparin by 10%, 20%, and 30% over the 3 years of the time horizon (2015, 2016, and 2017) for the THR and TKR populations. Data related to rate of thromboembolic events, major bleeding events and use of resources (local or general anesthesia and nurse care after surgery) were obtained from the Xarelto® for VTE Prophylaxis After Hip or Knee Arthroplasty (XAMOS) study, an international, non-interventional, observational, open-label study in unselected patients undergoing THR or TKR surgery in routine practice. The study included a total of 17 701 patients from 252 centers in 37 countries, including Spain, Italy, France and United Kingdom, among others. Two cohorts where considered (patients undergoing THR or TKR) with two arms (patients treated with rivaroxaban or enoxaparin). The Spanish patients enrolled in the XAMOS study were 262 with THR and 538 with TKR. Thromboembolic events, major bleeding rates and health care resources were considered from both the international and the Spanish population. Health care resources including pharmacologic prophylaxis, anesthesia and nurse care costs (Euros 2014) were estimated from the Spanish National Healthcare System (NHS) perspective. The annual cost associated with each cohort was estimated based on the mean cost per patient and the estimated distribution of use of rivaroxaban or enoxaparin in the base case scenario and alternative scenario (increase of rivaroxaban use) over the 3 years. A one-way sensitivity analysis was conducted to evaluate the effect that the uncertainty of the input parameters may have on the results of the impact budget. **Results:** The difference in cost per patient undergoing THR or TKR with rivaroxaban versus enoxaparin was -€140.69 including event rates and resource use from the Spanish XAMOS population, and -€110.54 when considering event rates and resource use from the multinational XAMOS population (including but not limited to European [Spain, France, Italy, United Kingdom, Portugal, etc.], American [Canada, Mexico, Colombia, Venezuela, etc.], Asian [China, etc.] and Australian countries). In the analysis per cohort (THR or TKR), the impact of increasing the use of rivaroxaban in the THR cohort, was -€1106, -€2875, and -€5607 for 2015, 2016, and 2017, considering the data from the Spanish XAMOS population, and -€869, -€2259, and -€4405 considering the data from the multinational population. Considering the TKR cohort, the impact was -€2271, -€5904, and -€11 513, and -€1784, €4639, and -€9046, respectively. **Conclusions:** The present analysis shows that, according to effectiveness data from the XAMOS study (Spanish and multinational cohorts), an increase in the usage of rivaroxaban in VTE prophylaxis would lead to significant direct cost reduction in elective THR and TKR patients. more...

Although the cement in cement technique is a simple method for exchanging cemented stems, it may be technical demanding. The different geometry of different-offset Exeter long stems can be a problem with this technique. We describe a case revision hip surgery as a consequence of neglected bipolar hemiarthroplasty dislocation in which a 44 mm offset long stem was exchanged by a shorter and smaller size 37.5 mm offset stem. The implications of the procedure and the surgical pitfalls are discussed. more...

Porous tantalum is an option of cementless fixation for TKA, but there is no randomized comparison with a cemented implant in a mid-term followup.We asked whether a tibial component fixed by a porous tantalum system might achieve (1) better clinical outcome as reflected by the Knee Society Score (KSS) and WOMAC Osteoarthritis Index, (2) fewer complications and reoperations, and (3) improved radiographic results with respect to aseptic loosening compared with a conventional cemented implant.We randomized 145 patients into two groups, either a porous tantalum cementless tibial component group (Group 1) or cemented conventional tibial component in posterior cruciate retaining TKA group (Group 2). Patients were evaluated preoperatively and 15 days, 6 months, and 5 years after surgery, using the KSS and the WOMAC index. Complications, reoperations, and radiographic failures were tallied.At 5-year followup the KSS mean was 90.4 (range, 68-100; 95% CI, ± 1.6) for Group 1, and 86.5 (range, 56-99; 95% CI, ± 2.4) for Group 2. The effect size, at 95% CI for the difference between means, was 3.88 ± 2.87. The WOMAC mean was 15.1 (range, 0-51; 95% CI, ± 2.6) for the Group 1, and 19.1 (range, 4-61; 95% CI, ± 2.9) for Group 2. The effect size for WOMAC was -4.0 ± 3.9. There were no differences in the frequency of complications or in aseptic loosening between the two groups.Our data suggest there are small differences between the uncemented porous tantalum tibial component and the conventional cemented tibial component. It currently is undetermined whether the differences outweigh the cost of the implant and the results of their long-term performance. more...

The economic burden of periprosthetic infections is enormous, but the number of economic studies dealing with this issue is very scarce. This review tries to know the economic literature existing, assess the value of current data, and recognize the less costly and more effective procedures for prevention, diagnosis and treatment of periprosthetic infections.Forty five studies meeting the inclusion criteria and adhering to the quality criteria used were carefully analyzed to extract the economic data of relevance in evaluating the magnitude of problem and the more cost-effective solutions. However, because the heterogeneity and the low-quality of most of these studies meta-analytical technique has not been possible. Instead, the studies have been reviewed descriptively.Optimizing the antibiotic use in the prevention and treatment of periprosthetic infection, combined with systemic and behavioral changes in the operating room; detecting and treating the high-risk groups; a quick, simple, reliable, safe, and cost-effective diagnosis, and the rationale management of the instituted infection, specifically using the different procedures according to each particular case, could allow to improve outcomes and produce the highest quality of life for patients and the lowest economic impact. Nevertheless, the cost effectiveness of different interventions to prevent and to treat the periprosthetic infection remains unclear. more...

Study Design. Retrospective cost-effectiveness analysis. Objective. To determine the relative cost-effectiveness of anterior cervical discectomy with fusion (ACDF) using a porous tantalum implant compared with autograft with plating, for single-level cervical disc disease with radiculopathy. Summary of Background Data. ACDF with autograft as an interbody spacer is a generally accepted method to treat degenerated cervical discs with radiculopathy. Concerns about donor site morbidity and the structural characteristics of autograft stimulated investigations of alternative materials. Techniques may differ in their operative risks, complications, outcomes, and resource use. Methods. A retrospective review of clinical outcomes and total cost of illness for 5 years postsurgery was performed for 61 consecutive patients enrolled for this study. Twenty-eight patients were treated with single-level ACDF using either a stand-alone, porous tantalum implant, without graft inside the implant, and 33 patients received autograft and plating. A cost-effectiveness analysis comparing the 2 ACDF treatment methods was conducted. This article reports clinical assessments, quality adjusted life years gained, and an incremental cost-effectiveness ratio analysis. Results. Patients in both cohorts reported improved clinical outcomes, including neck disability index, visual analogue scale, Short-Form 36, Odom's clinical assessment, and patient satisfaction at 5 years postindex surgery. The mean cost of illness for the study period, including preoperative through 5 years postoperative assessments, was 6806 € per patient treated with tantalum and 10,143 € per patient receiving autograft and plate. Quality-adjusted life years (QALY) gained were 9.41 and 7.14 for the tantalum and control cohorts, respectively. The cost per QALY for the tantalum group was 723 € and 1420 € for the control group. The incremental cost-effectiveness ratio of ACDF with a porous tantalum implant compared with ACDF with autograft and plate was −1473 € per patient per year for the duration of this study. Conclusion. This cost-effectiveness analysis reports favorable results for ACDF procedures utilizing a tantalum implant. The data reported suggest that using porous tantalum as a stand-alone device is less costly and more effective than autograft and plate in ACDF procedures. more...

AimThe effective results shown in the porous systems of tantalum employed for the use of osseointegrates has been demonstrated by means of animal experimentation. However, there is a total lack of any research studies on the osseointegration of tantalum implants from retrieval of the same after a period of time whereby the material had been implanted within the human body.Materials and MethodsFor this study, five rod implants used for the treatment of avascular necrosis of the femoral head were retrieved following collapse of the femoral head and conversion to total hip arthroplasty. The time of implantation ranged between six weeks and twenty months.ResultsObservation during this study has confirmed the effectiveness of osseointegration within this period of time. New bone was observed around and within the porous system of the on rod devices at retrieval date. The bone ingrowth, however, proved to be slower and less intense than that resulting within animal species during the first few months after implantation.ConclusionsThe results obtained in the quantitative assessment of this process proved to be similar to those results achieved by other authors in previous experimental work studies. more...

The instability in hip arthroplasty, or joint dislocation in its most dramatic form, is a complication that changes the outcome of this procedure, causing a decrease in the quality of life of the patients, and a loss of confidence in their relationship with the surgeon. If we discount failures due to infection, dislocation is the most frequent cause of a short to medium term revision, and the number of cases that require several operations to provide stability to the joint is not insignificant. Despite the frequency and severity of this complication there are few studies with a high level of scientific evidence on this subject. We have attempted to review the published literature and its level of evidence on the pathogenic origin, prophylaxis and treatment of this eventuality. As well as recording and summarizing the findings of each study in this review, we have added the evidence level of the corresponding literature reference. more...

Resumen La inestabilidad en las artroplastias de cadera o la luxacion en su forma mas dramatica, es una complicacion que altera la evolucion de este procedimiento introduciendo una perdida de bienestar en el paciente y una perdida de confianza en su relacion con el cirujano. Si no consideramos los fracasos por infeccion, la luxacion supone la causa mas frecuente de cirugia de revision a corto y medio plazo y no es desdenable el numero de casos que precisan varias intervenciones para aportar estabilidad a la articulacion. A pesar de la frecuencia y gravedad de esta complicacion no son frecuentes estudios con alta evidencia cientifica en este tema. Hemos pretendido recoger la literatura publicada con su grado de evidencia acerca de la etiopatogenia, profilaxis y tratamiento de esta eventualidad. Para ello ademas de anotar y resumir los hallazgos de cada trabajo, hemos anadido el nivel de evidencia tras la cita bibliografica correspondiente. more...

Background and objective We report 2 carriers of the TTRV30M mutation and its plasmatic biochemical marker with clinical symptoms compatible with hereditary TTR amyloidosis. Materials and methods Based on our previously reported casual finding of amyloid TTR in nasal mucosa (2008), we requested biopsy of this tissue to search for amyloid with Congo red staining and TTR immunohistochemical analysis. Results The histological diagnosis was achieved by retrospective analysis of surgical sinonasal biopsy in the first patient and prospective biopsy of inferior nasal concha in the second. Large interstitial deposits of ATTR were observed in both cases. Conclusions We suggest nasal mucosa as a suitable site for tissue biopsy in patients with suspected hereditary TTR amyloidosis. more...

We reviewed 263 consecutive patients with failed acetabular components after total hip arthroplasty that were revised using porous tantalum acetabular components and augments when necessary. The mean follow-up was 73.6 months (range, 60-84 months). The improvement of mean Harris hip score, Western Ontario and McMaster Osteoarthritis Index, and University of California Los Angeles activity scales were statistically significant (P < .001). Subjective assessments showed that 87.3% of patients reported "improvement" and 85.9% were "very or fairly pleased" with the results. At the most recent follow-up, all acetabular components were radiographically stable and none required rerevision for loosening. The acetabular revision was considered successful in 87% of cases. From this study, we conclude that the acetabular component used was reliable in creating a durable composite without failure for a minimum of 5 years. more...

Background Identifying the aetiological agent of atypical pneumonia in human can sometimes be a tedious process, especially in cases where Mycoplasma pneumoniae, Legionella species and Chlamydia pneumoniae are ruled out. In such cases, a correct anamnesis of the patient is basic to clarify which pathogens might have produced the infection. For this reason, health professionals including veterinarians and laboratory personnel working with zoonotic pathogens should keep their doctors informed. Case presentation A human case of atypical pneumonia linked to Chlamydia abortus is reported. A 47-year-old male, a veterinarian researcher into chlamydiae, developed respiratory symptoms, breathing problems and high fever. Serological analyses ruled out the involvement of several respiratory pathogens, such as M. pneumoniae, Legionella pneumophila, Rickettsia conorii and C. pneumoniae, and Chlamydia abortus was identified as the possible aetiological agent of the infection. The isolation of C. abortus from the patient’s sputum and subsequent molecular analysis confirmed the presence of this microorganism. Conclusion As far as we know, although C. abortus has not been previously described as capable of causing pneumonia in humans, this is the first reported case of atypical pneumonia in which C. abortus is thought to have played an aetiological role. more...

Constrained liners are a salvage procedure for treating or preventing recurrent dislocations. The Longevity® constrained liner (Zimmer) has a special design with cut-outs on its circumference for avoiding impingement in certain areas and a metallic constraining ring that has to be impacted. The ring impaction may be technical demanding. We recommend preassembly with the head component prior to seating into the acetabular cup, thus avoiding the soft tissue or cement interference and malposition due to bad angle of incidence of impaction force. more...

Conversion of hip arthrodesis to a THA reportedly provides a reasonable solution, improving function, reducing back and knee pain, and slowing degeneration of neighboring joints associated with a hip fusion. Patients generally are satisfied with conversion despite the fact that range of mobility, muscle strength, leg-length discrepancy (LLD), persistence of limp, and need for assistive walking aids generally are worse than those for conventional primary THA.We compared THA after hip arthrodesis and primary THA to determine whether these procedures would be associated with similar functional scores, maintenance of scores with time, complications and failures, survivorship of the arthroplasty, and patient satisfaction.We retrospectively matched 48 patients undergoing conversion of a fused hip to a THA between January 1980 and January 2000, with 50 patients receiving a primary THA during the same period. We prospectively followed all patients between January 2000 and January 2010. The changes in function and pain after THA were compared between the two cohorts using the Harris hip score (HHS) and the Rosser Index Matrix (RIM). The Oxford hip score (OHS) and the SF-36 also were used to assess quality of life (QOL) during followup. Complications were collected and survivorship of the THA was evaluated. Patient satisfaction was assessed using the Robertsson and Dunbar questionnaire. The minimum followup was 10 years (mean, 17 years; range, 10-29 years).At last followup, hip function and health-related QOL were similar for patients having conversion of hip arthrodesis to THA and for patients having a routine THA. Scores diminished overall in the two groups between 2000 and 2010, but without a difference for the HHS, RIM QOL, and OHS in the study cohort. The rate of complications, THA survival, and patient satisfaction were similar in both groups.Conversion of hip arthrodesis to a THA provides substantial improvement of hip function and health-related QOL, with an acceptable rate of complications, good expectancy of survival for the arthroplasty, and high level of patient satisfaction comparable to those of primary THA.Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. more...

Although long-term studies report successful results with total knee arthroplasty (TKA), performed with or without posterior cruciate ligament (PCL) retention, controversy exists as to which is preferable in regard to patient outcome and satisfaction. The possible proprioceptive role of the PCL may account for a more normal feeling of the arthroplasty. Although the PCL has been examined using various histological techniques, immunohistochemical techniques are the most sensitive for neural elements. Therefore an immunohistochemical study was designed to determine the patterns of innervation, the morphological types of the proprioceptors, and their immunohistochemical profile. During TKA, samples were obtained from 22 osteoarthritic PCLs and subjected to immunohistochemical analysis with mouse monoclonal antibodies against neurofilament protein (NFP), S100 protein (S100P), epithelial membrane antigen (EMA), and vimentin (all present in neuromechanoreceptors). Three normal PCLs from cadaveric specimens were also obtained and analyzed for comparison. Five types of sensory corpuscles were observed in both the normal and the arthritic PCLs: simple lamellar, Pacini-like, Ruffini, Krause-like, and morphologically unclassified. Their structure included a central axon, inner core, and capsule in lamellar and Pacini corpuscles and variable intracorpuscular axons and periaxonal cells in the Ruffini and Krause-like corpuscles. The immunohistochemical profile showed the central axon to have NFP immunoreactivity, periaxonal cells to have S100P and vimentin immunoreactivity, and the capsule to have EMA and vimentin immunoreactivity. Nerve fibers and free nerve endings displayed NFP and S100P immunoreactivity. The immunohistochemical profile of the PCL sensory corpuscles is almost identical to that of cutaneous sensory corpuscles. Some prior histological studies of the PCL reported Golgi-like mechanoreceptors, and others found encapsulated corpuscles but no Golgi-like structures. This report determined the innervation of the PCL by the more sensitive immunohistochemical means, revealing four major types of encapsulated mechanoreceptors. The plentiful and varied types of encapsulated mechanoreceptors found in even the arthritic PCL suggests a rich proprioceptive role. It is controversial as to whether preservation of the PCL at TKA improves postoperative proprioception. Our findings tend to support those clinical reports of improved proprioception after PCL-retaining versus PCL-substituting TKAs. The presence of many and varied types of mechanoreceptors may account for the improved stair climbing reported in patients with PCL-retaining TKA and may contribute to patient satisfaction and a more normal feeling after TKA. more...

A prospective study of 116 consecutive Kinemax cemented posterior cruciate ligament-retaining total knee arthroplasties was carried out. Similar surgical technique was used with a single variable: 61 were implanted using intramedullary guides on the tibia and 55 were implanted using extramedullary guides on the tibia. A radiographic study was performed after at least 1 year of follow-up to evaluate postoperative component position and compare the difference in the accuracy of positioning of the femoral and tibial components. Radiographic analysis showed that satisfactory position was achieved using both types of instrumentation. No statistically significant difference was observed in either the coronal or sagittal plane of the femoral component and the sagittal plane positioning of the tibial component. However, the coronal plane positioning of the tibial component revealed a statistically significant difference (P < .01), with intramedullary guides being superior to extramedullary guides. Also observed, was that using either technique, patients with less accurate postoperative positioning tended to be obese, with wide intramedullary canals. Patients with significant extraarticular deformities, marked bowing, and those with prior surgery or fractures may not be suitable for intramedullary guides, and they may require the use of extramedullary guides and intraoperative radiographic control. The ideal indication for the use of intramedullary instrumentation is in the patient who is not obese, with no extraarticular deformity, and with a well-defined, but not excessively wide, tibial medullary canal. Since tibial component malalignment in general, and coronal plane malalignment in particular, may adversely affect the long-term survival of total knee arthroplasties, the use of intramedullary alignment instrumentation is recommended when possible. more...

Acid-sensing ion channels (ASICs) are a family of H(+)-gated voltage-insensitive ion channels that respond to extracellular acidification by regulating transmembrane Ca(2+) flux. Moreover, ASICs can also be gated by mechanical forces and may function as mechanosensors. The cells of the intervertebral disc (IVD) have an unusual acidic and hyperosmotic microenvironment. Changes in the pH and osmolarity determine the viability of IVD cells and the composition of the extracellular matrix, and both are the basis of IVD degeneration. In this study, the expression of ASICs (ASIC1, ASIC2, ASIC3 and ASIC4) mRNAs and proteins in human healthy and degenerated IVD was evaluated by quantitative reverse transcription-quantitative polymerase chain reaction and Western blot. The distribution of ASIC proteins was determined by immunohistochemistry. The mRNAs for all ASICs were detected in normal human IVD, and significantly increased levels were found in degenerated IVD. Western blots demonstrated the presence of proteins with estimated molecular weights of approximately 68-72 kDa. In both the annulus fibrosus (AF) and nucleus pulposus (NP) of normal IVD, ASIC2 is the most frequently expressed ASIC followed by ASIC3, ASIC1 and ASIC4. In the AF of degenerated IVD, there was a significant increase in the number of ASIC1 and ASIC4 positive cells, whereas in the NP, we found significant increase of expression of ASIC1, ASIC2 and ASIC3. These results describe the occurrence and localization of different ASICs in human healthy IVD, and their increased expression in degenerated IVD, thus suggesting that ASICs may be involved in IVD degeneration. more...

Our working hypothesis was that minimally invasive surgery was superior to conventional surgery for total hip arthroplasty procedure. We compared THR results in the minimally invasive posterior approach with THR results in the conventional posterior approach.Prospective, randomised trial. Fifty patients were selected and then divided into two groups based on treatment (minimally invasive posterior approach or conventional posterior approach).Perioperative bleeding, postoperative pain, time of recovery, component orientation, complications and functional results. One year follow-up.No differences were found in blood loss, surgical time, component orientation, rate of complications or functional result. The minimally invasive lateral approach produced less postoperative pain and a faster recovery, with a shorter hospital stay and earlier walking-start, and a positive economic impact with 5% of the total process cost saved.Minimally invasive surgery permits less postoperative pain, faster recovery and a positive economic saving, without differences in the rest of the items studied. more...

Porous tantalum is reportedly a good substitute for structural bone graft in several applications. So far, its use has not been reported in tibial tuberosity anteriorization (TTA) for treatment of isolated degenerative chondral lesions of the patellofemoral joint.We asked whether the use of this material would produce similar standardized functional scores, pain (VAS), fusion rates, complications, and patient satisfaction to those for bone graft.We performed a randomized, controlled trial in 101 patients (108 knees) scheduled for TTA comparing a porous tantalum implant (57 knees) with an autologous local tibial bone graft (51 knees). The minimum followup was 5 years (mean, 6.2 years; range, 5-8 years).At the last followup, clinical scores, fusion rates, and maintenance of the anteriorization either were better or similar for the TTA using the tantalum implant depending on the respective parameter. The operative technique was easier and shorter with the tantalum device. Complication and failure rates were greater using bone graft. Patient satisfaction was greater using the tantalum implant.Porous tantalum provided a reasonable alternative to bone graft in TTA.Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. more...

Efficacy of osteointegration of tantalum porous systems has been demonstrated through animal experimentation. However, there is a lack of studies that evaluate osteointegration of implants retrieved after a period of implantation in humans. For this study, eight rod implants used for the treatment of avascular necrosis of the femoral head were retrieved following collapse of the femoral head and conversion to total hip arthroplasty. The time of implantation ranged between six weeks and twenty three months. Observation during this study has confirmed effectiveness of osseointegration within this period of time. New bone was observed around and within the porous system of the on rod devices at retrieval date. Bone in growth however, proved to be of a slower and less intense degree than that resulting within animal species during first months after implantation. Nevertheless, the results obtained in the quantitative evaluation of this process proved to be similar to those results achieved by other authors in previous experimental studies. more...

We reviewed 263 consecutive patients with failed acetabular components after total hip arthroplasty that were revised using porous tantalum acetabular components and augments when necessary. The mean follow-up was 73.6 months (range, 60-84 months). The improvement of mean Harris hip score, Western Ontario and McMaster Osteoarthritis Index, and University of California Los Angeles activity scales were statistically significant (P.001). Subjective assessments showed that 87.3% of patients reported "improvement" and 85.9% were "very or fairly pleased" with the results. At the most recent follow-up, all acetabular components were radiographically stable and none required rerevision for loosening. The acetabular revision was considered successful in 87% of cases. From this study, we conclude that the acetabular component used was reliable in creating a durable composite without failure for a minimum of 5 years. more...

To determine whether a biphasic calcium phosphate (BCP) ceramic supplemented with fresh autologous bone marrow (BMA) can give rise to adequate bone to achieve a vertebral fusion mass.A prospective nonrandomized, radiographic study on 35 patients with posterolateral fusion using rigid transpedicular instrumentation for degenerative lumbar disease. At least 2-year follow-up. On the left side: autologous bone graft obtained from decompression. On the right side: a mixture of BCP and fresh autogenous bone marrow from the right iliac crest. Single-level fusion in 22 patients and two or more levels in 13. Patients assessed with x-rays and computed tomography by an orthopedic surgeon and an independent radiologist. Fusion mass was considered "good" when there was a continuous block of bone without radiolucent areas. No intersegmental bony bridging fusion was considered "poor" mass. McNemar, Fisher, and kappa tests were used for statistical analysis.The interobserver agreement (kappa) had an average of 0.75 for the fusion masses. The interobserver average in the radiologic evaluation of ceramic resorption was 0.68. No differences between smokers and nonsmokers were found. Plain radiography findings: good left fusion masses (autologous bone) in 31 patients and poor in 4; good right masses (BMA plus BCP) in 31 patients and poor in 4 (P0.05). Computed tomography evaluation: good left fusion masses in 28 patients and poor in 7; good right fusion masses in 31 patients and poor in 4 (P0.05). One patient was reoperated, allowing biopsies to be performed: compact bone tissue was observed around hydroxyapatite in the right fusion mass.The differences detected between right-side and left-side masses are not statistically significant. This indicates that, BMA and BCP, when mixed, behave like composite grafts and are able to generate sufficient bone mass for arthrodesis when a rigid instrumentation is used. However, a larger number of cases and longer follow-up are needed to generalize the indication. more...

Different bearing surfaces, including alumina-on-alumina, have been used to avoid osteolysis. We prospectively followed 288 patients (319 hips) in which an alumina-on-alumina cup was used with a hydroxyapatite stem. The patients' mean age was 52.7 (range, 14-70 years), and the minimum followup was 3 years (mean, 4.7 years; range, 3-8 years). At final followup, five cups (including one with an alumina liner fracture) and two stems underwent revision. The cumulative probability of not having a revision of one or both components for any cause was 97% (95% confidence interval, 94.7%-99.1%). No patient spontaneously reported any noises from the hip and none reported noises when specifically questioned. All patients who had not undergone revision had good clinical results, but five of these patients had radiographic cup loosening at last followup. These data suggest alumina-on-alumina prostheses had reasonable outcomes after 5 years. One acetabular component fractured from trauma. We observed no linear femoral head penetration. Continued followup will be required to determine if reduction in wear between the alumina-on-alumina bearings results in less osteolysis and loosening.Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. more...

Yttria-stabilized tetragonal zirconia may undergo extensive transformation to the monoclinic phase under mechanical and/or hydrothermal stress, with degradation of mechanical and tribologic properties. We hypothesized progressive phase transformation of zirconia in service in vivo is directly related to the time of implantation and to patient-related factors. The subsequent decrease in fracture toughness and increase in surface roughness and wear are related to the increased monoclinic content. We performed a study on 47 yttria-stabilized tetragonal zirconia femoral heads retrieved from failed total hip arthroplasties after 2 to 10 years implantation. Age, weight, and activity of the patients were retrieved from clinical records. Monoclinic content, fracture toughness, surface roughness, and wear were measured. Strong correlations were found between monoclinic content in the weightbearing surface and time of implantation (r = 0.97) and between increase in monoclinic content and decrease in fracture toughness (r = -0.92), increase in surface roughness (r = 0.88), and increase in surface wear (r = 0.89). No correlation was observed between the increase in monoclinic content and the age, weight, or activity of the patients. Aging of zirconia in vivo is then a function of time in service, and the loss of surface properties is caused by the corresponding increase in monoclinic content. more...

Hypothetically, hydroxyapatite-coated anatomic-shaped femoral stems and hemispheric acetabular cups should improve biologic fixation of the implant and strength transmission to the bone, improving unsatisfactory results of the first cementless hip prosthesis focused on the stress-shielding phenomenon at the femur and failure of the threaded acetabular cups. A consecutive series of 312 patients who had primary Anatomique Benoist Giraud hip prostheses unilaterally implanted were followed up. We analyzed the clinical and radiographic results and report the outcomes 7-10 years after implantation. Two hundred thirty-two patients were assessed at 7-10 years. The survival rate for the implant was 96.8%; 77.2% of patients had no pain, 72.4% maintained total mobility, and 62.9% were able to walk without restrictions. However, radiologic assessment shows that problems improved but did not disappear. More than 55% of femurs had signs of proximal stress-shielding develop. More important, substantial polyethylene wear was observed in at least 62% of the acetabular inserts at 7-10 years followup. more...

Surgical field illumination and visualization is the key for total hip arthroplasty through a mini-incision approach. An easy, quick, and inexpensive method is described, using a conventional endoscopic light-source temporally fixed to conventional hip surgery retractors. more...