New methods for early diagnosis of ceramic failure in ceramic on ceramic hip prosthesis

L’accoppiamento articolare in ceramica è sempre più utilizzato in chirurgia protesica dell’anca per le sue eccellenti proprietà tribologiche. Tuttavia la fragilità della ceramica è causa di fallimenti meccanici. Abbiamo quindi condotto una serie di studi al fine di individuare un metodo efficace di diagnosi precoce del fallimento della ceramica. Abbiamo analizzato delle componenti ceramiche espiantate e abbiamo trovato un pattern di usura pre-frattura che faceva supporre una dispersione di particelle di ceramica nello spazio articolare. Per la diagnosi precoce abbiamo validato una metodica basata sulla microanalisi del liquido sinoviale. Per validare la metodica abbiamo eseguito un agoaspirato in 12 protesi ben funzionanti (bianchi) e confrontato i risultati di 39 protesi con segni di rottura con quelli di 7 senza segni di rottura. Per individuare i pazienti a rischio rottura i dati demografici di 26 pazienti con ceramica rotta sono stati confrontati con 49 controlli comparabili in termini demografici, tipo di ceramica e tipo di protesi. Infine è stata condotta una revisione sistematica della letteratura sulla diagnosi della rottura della ceramica. Nell’aspirato la presenza di almeno 11 particelle ceramiche di dimensioni inferiori a 3 micron o di una maggiore di 3 micron per ogni campo di osservazione sono segno di rottura della ceramica. La metodica con agoaspirato ha 100% di sensibilità e 88 % di specificità nel predire rotture della ceramica. Nel gruppo delle ceramiche rotte è stato trovato un maggior numero di malposizionamenti della protesi rispetto ai controlli (p=0,001). Il rumore in protesi con ceramica dovrebbe sollevare il sospetto di fallimento ed indurre ad eseguire una TC e un agoaspirato. Dal confronto con la letteratura la nostra metodica risulta essere la più efficace.Ceramic is increasingly used in total hip replacement for its excellent tribological properties. However, the brittleness of ceramics is of concern and mechanical failures are reported. We conducted a series of studies in order to identify an effective method of early diagnosis of ceramic failure. We have analyzed 20 ceramic components explanted and found a pattern of wear that would suggest a dispersion of ceramic particles in the joint space. We therefore investigated whether isolation, observation at scanning electron microscopy, and chemical identification with microanalysis of particles from synovial fluid could be predictive of ceramic damage. Firstly, the level of ‘‘physiological wear’’ of well functioning hip prostheses was assessed with this method, then the test was validated as diagnostic method for liner fracture. Twelve asymptomatic patients were enrolled to demonstrate the first aim; 39 cases of noisy hip, and 7 cases of pending failure not related to ceramic were enrolled for the second aim. To detect risk factors for ceramic liner fractures we compared 26 ceramic hips revised because of ceramic liner fracture with 49 well-functioning hips. Finally a systematic review was done to compare our results with those reported in the litterature. In the aspirate the presence of at least 11 ceramic particles of size less than 3 microns or the presence of one greater than 3 microns for each field of observation are a sign of ceramic failure. The method with fine needle aspiration has 100% sensitivity and 88% specificity in predicting breakage of the ceramic. A cup anteversion angle out of the optimal range of 15 ̊+/-10 ̊ was found to be a risk factor for ceramic liner fracture. There are no other diagnostic methodologies described in the literature as specific and sensible as the one we have proposed

Influence of occlusal vertical dimension on cervical spine mobility in sports subjects

Introduction: In the scientific literature, a number of studies have reported conflicting results regarding the effects of occlusal vertical dimension (OVD) on sports-related skills. The purpose of this study was to increase OVD in sports subjects so as to specifically investigate the influence on cervical spine mobility. In particular, we measured cervical range of motion (ROM) before and after increasing OVD in individuals, either with or without malocclusion, analyzing both sports and sedentary subjects. Materials and methods: Participants were divided into two groups: a sports group (SG) and a control group (CG), each including 18 subjects. The SG was composed of sports subjects (age: 20.11±3.45 yrs; BMI: 25.39±2.32 kg/m2), whereas the CG consisted of age-matched sedentary subjects (age: 25.78±2.26 yrs; BMI: 24.88±2.87 kg/m2). Cervical range of motion (ROM) was evaluated, by way of an accelerometer (Moover®, Sensor Medica®), before (pre-test) and after (post-test) increasing OVD. Results: The main finding of this study was that sports subjects showed no significant difference, compared to control subjects, in cervical ROM in response to increased OVD. Moreover, we found that sports and sedentary subjects alike showed no significant change in cervical spine mobility as a result of increased OVD, regardless of whether they were affected by malocclusion (class II) or represented subjects with normocclusion (class I). Conclusion: In accord with several studies reported in the literature, the findings of our study indicate that occlusal splints failed to significantly improve the physical-performance endpoint measured, i.e. cervical ROM, in sports subjects as compared to sedentary individuals. Due to the paucity of studies, characterized by conflicting results, there is as yet no compelling scientific evidence as to whether OVD positively impacts sports performance or not. Accordingly, we suggest that further scientific investigation, regarding the relationship between sports performance and OVD, be conducted in the field of sport and exercise sciences

Mouse thyroid gland changes in aging: Implication of galectin-3 and sphingomyelinase

Prevalence of thyroid dysfunction and its impact on cognition in older people has been demonstrated, but many points remain unclarified. In order to study the effect of aging on the thyroid gland, we compared the thyroid gland of very old mice with that of younger ones. We have first investigated the changes of thyroid microstructure and the possibility that molecules involved in thyroid function might be associated with structural changes. Results from this study indicate changes in the height of the thyrocytes and in the amplitude of interfollicular spaces, anomalous expression/localization of thyrotropin, thyrotropin receptor, and thyroglobulin aging. Thyrotropin and thyrotropin receptor are upregulated and are distributed inside the colloid while thyroglobulin fills the interfollicular spaces. In an approach aimed at defining the behavior of molecules that change in different physiopathological conditions of thyroid, such as galectin-3 and sphingomyelinase, we then wondered what was their behavior in the thyroid gland in aging. Importantly, in comparison with the thyroid of young animals, we have found a higher expression of galectin-3 and a delocalization of neutral sphingomyelinase in the thyroid of old animals. A possible relationship between galectin-3, neutral sphingomyelinase, and aging has been discussed

NUTRITION IN IBD PATIENT'S: WHAT ARE THE PROSPECTS?

Summary: Inflammatory Bowel Disease (IBD) is a chronic disorder characterized by a relapsing-remitting course, which alternates between active and quiescent states, ultimately impairing a patients quality of life. The two main types of IBD are Crohn's disease (CD) and Ulcerative Colitis (UC). In physiological conditions the gut is costantly exposed to various antigens, commensal microflora and pathogens and the inflammatory response is finely balanced. It is thought that a vast number of environmental risk factors may be implicated in the development of IBD, including smoking factors, dietary factors, psycological stress, use of non-steroidal anti-inflammatory drugs and oral contraceptives, appendicectomy, breastfeeding, as well as infections. Nutritional support, as a primary therapy, has a crucial role in the management of patients with IBD. The gut microbiota is clearly manipulated by dietary components such as n-3 polyunsatured fatty acids (n-3 PUFA) and coniugated linoleic acid (CLA) which favorably reduce endotoxin load via shifts in the composition and metabolic activity of the microbial community. in particular, the beneficial effect of n-3 PUFAs and fermentable fiber, during the remission/quiescent phase of both CD and UC is Highlighted. In fact, PUFAs are associated with a less grade of inflammation since they are metabolized to 3-series prostagliandins and thromboxanes and 5-series leukotrienes and, in addition, exert antiinflammatory effects when compared with their n-6 PUFA counterparts. In similar action to dietary n-3 PUFA, coniugated linoleic acid (CLA) have been reported to ameliorate intestinal inflammation in animal models of IBD. Currently, is still unclear the role of the fibers in helping the remission of the disease. Data about the consumption of fiber are controversial. On one hand, dietary fibers can act as effective prebiotics by altering the intestinal microbial composition and promoting the growth of beneficial bacterial communities within the large intestine. On the other hand, fibers can promote diarrhea, pain and gas aggravating the clinical sate. Cocnclusion: We suggest that the consumption of fermentable fibers may have a good impact on patient's health

VALIDATION OF A MODIFIED MODEL OF TNBS-INDUCED COLITIS IN RATS. HOW TO INDUCE A CHEMICAL COLITIS IN RATS.

Background: there are no standard practice in the induction of colitis by 2,4,6-trinitrobenzene sulfonic (TNBS) acid. Usually, the repeated administration of TNBS is preferred, because it will result in a local Th1 response that has the characteristics of Crohn's disease. material and Methods: A total of 30 rats were randomized into two groups, consisting of a saline control group of ten rats and a TNBS groups of 20 rats. After the animals were anesthesized, 0,5 ml of either 0,9 % saline 8controls) or TNBS 50 mg/Kg dissolved in 50% ethanol were instilled into the colon through a rubber catheter. The experiment was repeated weekly for four weeks, then, the rats were killed at day 40, and the distal colon removed. results: At day 40, the bowel wall basically normal in the control group. In the TNBS group, the bowel lumen became narrow with tickened wall, and the mucosal surface presented adherent membrane with brown black, linear ulcers, proliferous lymphocites tissue, inflammatory granulomas and submucosal neutrophil infiltration. The median score of the severity of the colonic damage was 0 in the control group, and 4,75 (range 4-5) in the TNBS group; the mean weight of the rats was 180+35 g in the TNBS group, while it was 215+25 in the control group. Conclusions: The presented experiment is a cost-effective and safe method to induce Crohn-like colonic damage using a lower dose of TNBS, thus avoiding the risk of a massive loss of rats. This model is rather suitable for the assessment of the effects of potential therapeutic agent

Which stem in total hip arthroplasty for developmental hip dysplasia? A comparative study using a 3D CT-based software for pre-operative surgical planning

Background Stem choice in total hip arthroplasty (THA) for hip dysplasia is still controversial. The aims of the study were to evaluate (1) which stem design provided the highest percentage of adequate reconstructions in THA for dysplasia and (2) any correlation between the reconstructions provided by the stems and the native femoral morphology. Materials and methods 150 CT scans including 200 adult dysplastic hips were randomly selected. Using the 3D CT-based software Hip-Op for surgical planning, the native hip anatomy was studied. Then, a single wedge tapered stem, an anatomical stem and a conical tapered stem were simulated in every hip. An adequate reconstruction of hip biomechanics was obtained when combined anteversion, offset restoration, coronal and sagittal tilt, canal filling and leg lengthening were inside the normal ranges. Results Conical stems achieved the highest percentage of adequate reconstructions (87%, p < 0.0001). The anatomical stem was the worst performer. Single wedge and anatomical stem acceptability was mainly influenced by the combined anteversion. Stem anteversion was correlated with the femoral anteversion (fair correlation), the calcar femorale (fair) and the mediolateral femoral diameter at isthmus (poor). When the femoral anteversion was >= 25 degrees, combined anteversion was very acceptable for the conical stem (99.2%), whereas the rate of acceptable combined anteversion for the single wedge tapered stem was 71.4%, and that for the anatomical stem was 51.6% (p < 0.0001). Conclusions Stem choice in developmental hip dysplasia is mainly driven by appropriate combined anteversion, which is dependent on the coronal and axial femoral morphologies. As a rule of thumb, tapered stems are adequate when femoral anteversion is < 25 degrees; conical stems should be adopted for higher anteversions

Revision Hip Arthroplasty Using a Modular Head–Neck Adapter System and a Ceramic Head: 5-Year Clinical and Radiographic Outcomes

Introduction: A modular head-neck adapter system may help surgeons restore the proximal hip biomechanics in revision hip arthroplasty. However, the clinical and radiographic 5-year outcomes of the system are still scarcely reported. The aim of this study is the assessment of (1) complications and survival rates, (2) clinical and (3) radiological outcomes of the modular head-neck adapter system with a ceramic head in revision hip arthroplasty at 5 years. Methods: 32 revision hip arthroplasties using a modular head-neck adapter system and a ceramic head were retrospectively recorded. Preoperative demographic and implant features were collected. Clinical and radiographic outcomes, failures and reasons for re-revisions were recorded at the last follow-up. Results: A mean follow-up of 59.8 & PLUSMN; 26 months was achieved. The survival rate was 90.6% at 5 years. Post-operative complications occurred in nine cases (28.1%): two dislocations (6.2%), one aseptic cup loosening (3.1%) requiring re-revision, one (3.1%) persistent pelvic pseudotumor requiring embolization. No mechanical failures of the adapter or ceramic head occurred. The mean post-operative HHS score was 84.4 points. Thirteen cases (40.6%) showed optimal radiographic cup osseointegration, and 17 hips (53.1%) showed valid stem osseointegration. The mean post-operative femoral offset was 48.84 mm, larger than the contralateral side (p = 0.02). The post-operative lateralization of the hip joint was 38.09 mm, close to the contralateral side (p = 0.4). Conclusions: In revisions, the modular head-neck adapter system with ceramic head provided good clinical outcomes and acceptable radiographic reconstruction of hip biomechanics, with a survival rate of 87.9% at 5 years

Isolated Femoral or Tibial Component Revision in Total Knee Arthroplasty: A Systematic Review

Objective: The purpose of this systematic review is to assess clinical and radiographic outcomes, complications rates, rates and reasons of re-revision of isolated femoral or tibial component revisions, comparing them with total knee revisions. Methods: A review of the published literature was performed using Medline, Embase and Cochrane libraries. The terms "isolate" and "revision" and "knee arthroplasty" or "knee replacement" were together used as MESH terms. Partial knee replacement, non-English literature, case reports and papers published before 2000 were excluded. Results: Out of 911 papers, six papers met the inclusion criteria. Mean MINORS scores achieved quite low values (13.33 and 13.67). No study encompassed revisions for septic loosening or infection. Total revisions performed for instability and wear achieved better clinical outcomes: in the other cases, partial and total revisions showed no differences in clinical outcomes. Both the cohorts showed similar radiographic features. Lesser bleeding and shorter operative times were observed in partial revisions compared to total revisions. The re-revision rates were similar in most of comparative studies: only one study noticed a significant difference in the failure rate between partial (25% at 3 years) and full (7% at 3.5 years) revisions. Conclusions: The poor quality of the studies precluded sound conclusions. Isolated tibial or femoral component revision is an option when the other component is well-fixed and positioned and in absence of chronic periprosthetic infection; nevertheless, it should be carefully evaluated when the reasons for revision are wear or instability

Software-related recalls in computer-assisted hip and knee arthroplasty

Purpose Computer-assisted arthroplasty supports the surgeons in planning, simulating, and performing the replacement procedure, using robotic or navigation technologies. However, the safety of the technology has not been widely ascertained. Food and Drug Administration (FDA) database was interrogated about software-related recalls in computer-assisted arthroplasty, aiming to assess: (1) the incidence, (2) the root causes, and (3) the actions taken due to recalls.Methods The Medical Device Recalls database was investigated about software-related recalls in computer-assisted hip and knee arthroplasty surgery, between 2017 and 2022. The incidence of the software-related recalls, the root causes according to FDA and manufacturers, and the corrective actions taken by firms were determined.Results Eighteen recall numbers could be identified (1.6%), corresponding to 11 recall events. A total of 4634 units were involved. The FDA determined root causes were: software design (66.6%), design change (22.2%), manufacturing deployment (1, 5.6%), and design manufacturing process (5.6%). Among the manufacturers' reasons for recalls, a specific error was declared in 16 cases (88.9%). In seven cases (43.8%), a coding error about lower limb alignment assessment was identified. Seventeen software-related recalls (94.4%) were classified as class 2; only one case was class 3 (5.6%). Return of the device was the main action taken by firms (8, 44.4%), followed by software update (7, 38.9%).Conclusion Software-related recalls in computer-assisted hip and knee arthroplasty were quite uncommon among all the recalls, deemed non-life threatening and usually due to software design errors. The main actions taken by manufacturers were the return of the device or the software update