Unexpected early loosening of rectangular straight femoral Zweymüller stems with an alumina-reduced surface after total hip arthroplasty-a prospective, double-blind, randomized controlled trial.

BACKGROUND: Alumina particles from the grit blasting of Ti-alloy stems are suspected to contribute to aseptic loosening. An alumina-reduced stem surface was hypothesized to improve osseointegration and show comparable short-term outcomes to those of a standard stem. METHODS: In this prospective, double-blind, randomized trial, 26 standard (STD) and 27 experimental new technology (NT) stems were implanted. The latter were additionally treated by acid etching and ice blasting to remove alumina particles from the grit-blasting process. Follow-up occurred at 12 and 24 months. Bone mineral density (BMD) around the stem was measured by a dual-energy x-ray absorptiometry device (DEXA). Radiographs were reviewed for alterations. Clinical scoring comprised the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Harris Hip Score (HHS). Survival rates were calculated up to 50 months. RESULTS: Lower mean BMD and more severe cortical hypertrophies were found in the NT group. At 12 months, radiolucent lines were observed mostly in the metaphyseal zone for both groups, with a progression tendency in the NT group at 24 months. At 12 months, pain scores and the WOMAC total and physical activity scores were significantly lower in the NT group, without any differences thereafter. The number of NT stem revisions amounted to 6 (24%) and 11 (41%) at 24 and 50 months, respectively. CONCLUSION: In the NT group, unexpected catastrophic failure rates of 41% caused by early aseptic loosening were noted within 50 months. Compared with the STD stems, NT stems lead to poor clinical and radiographic results. LEVEL OF EVIDENCE: II. TRIAL REGISTRATION: NCT05053048.

The impact of different alignment strategies on bone cuts for neutral knee phenotypes in total knee arthroplasty.

PURPOSE: The purpose of this study was to simulate and visualise the influence of the alignment strategy on bone resection in neutral knee phenotypes. It was hypothesised that different amounts of bone resection would be required depending on the alignment strategy chosen. The hypothesis was that by visualising the corresponding bone cuts, it would be possible to assess which of the different alignment strategies required the least change to the soft tissues for the chosen phenotype but still ensured acceptable component alignment and could, therefore, be considered the most ideal alignment strategy. METHODS: Simulations of the different alignment strategies (mechanical, anatomical, restricted kinematic and unrestricted kinematic) regarding their bone resections were performed on four common exemplary neutral knee phenotypes. NEUHKA0° VARFMA 90° VALTMA90°, NEUHKA0° NEUFMA 93° NEUTMA87°, NEUHKA0° VALFMA 96° NEUTMA87° and NEUHKA0° VALFMA 99° VARTMA84°. The phenotype system used categorises knees based on overall limb alignment (i.e. hip knee angle) but also considers joint line obliquity (i.e. TKA and FMA) and has been used globally since its introduction in 2019. These simulations are based on long leg weightbearing radiographs. It is assumed that a change of 1° in the alignment of the joint line corresponds to correspond to 1 mm of distal condyle offset. RESULTS: In the most common neutral phenotype NEUHKA0° NEUFMA 93° NEUTMA87°, with a prevalence of 30%, bone cuts remain below 4 mm regardless of alignment strategy. The greatest changes in the obliquity of the joint line can be expected for the mechanical alignment of the phenotype NEUHKA0° VALFMA 99° VARTMA84° where the medial tibia is raised by 6 mm and the lateral femur is shifted distally by 9 mm. In contrast, the NEUHKA0° VARFMA 90° VALTMA90° phenotype requires no change in joint line obliquity if the mechanical alignment strategy is used. CONCLUSION: Illustrations of alignment strategies help the treating surgeon to estimate the postoperative joint line obliquity. When considering the alignment strategy, it seems reasonable to prefer a strategy where the joint line obliquity is changed as little as possible. Although for the most common neutral knee phenotype the choice of alignment strategy seems to be of negligible importance, in general, even for neutral phenotypes, large differences in bone cuts can be observed depending on the choice of alignment strategy.

The impact of different alignment strategies on bone cuts in total knee arthroplasty for varus knee phenotypes.

PURPOSE: The purpose of this study was to visualise the influence of alignment strategy on bone resection in varus knee phenotypes. The hypothesis was that different amounts of bone resection would be required depending on the alignment strategy chosen. Through visualisation of the corresponding bone sections, it was hypothesised, it would be possible to assess which of the different alignment strategies would require the least amount of change to the soft tissues for the chosen phenotype, whilst still ensuring acceptable alignment of the components, and thus could be considered the most ideal alignment strategy. METHODS: Simulations of the different alignment strategies (mechanical, anatomical, constrained kinematic and unconstrained kinematic) in relation to their bone resections were performed on five common exemplary varus knee phenotypes. VARHKA174° VARFMA87° VARTMA84°, VARHKA174° VARFMA90° NEUTMA87°, VARHKA174° NEUFMA93° VARTMA84°, VARHKA177° NEUFMA93° NEUTMA87° and VARHKA177° VALFMA96° VARTMA81°. The phenotype system used categorises knees based on overall limb alignment (i.e. hip knee angle) but also takes into account joint line obliquity (i.e. TKA and FMA) and has been applied in the global orthopaedic community since its introduction in 2019. The simulations are based on long-leg radiographs under load. It is assumed that a change of 1° in the alignment of the joint line corresponds to a displacement of the distal condyle by 1 mm. RESULTS: In the most common phenotype VARHKA174° NEUFMA93° VARTMA84°, a mechanical alignment would result in an asymmetric elevation of the tibial medial joint line by 6 mm and a lateral distalisation of the femoral condyle by 3 mm, an anatomical alignment only by 0 and 3 mm, a restricted by 3 and 3 mm, respectively, whilst a kinematic alignment would result in no change in joint line obliquity. In the similarly common phenotype 2 VARHKA174° VARFMA90° NEUTMA87° with the same HKA, the changes are considerably less with only 3 mm asymmetric height change on one joint side, respectively, and no change in restricted or kinematic alignment. CONCLUSION: This study shows that significantly different amounts of bone resection are required depending on the varus phenotype and the alignment strategy chosen. Based on the simulations performed, it can, therefore, be assumed that an individual decision for the respective phenotype is more important than the dogmatically correct alignment strategy. By including such simulations, the modern orthopaedic surgeon can now avoid biomechanically inferior alignments and still obtain the most natural possible knee alignment for the patient.

Chondrocalcinosis does not affect functional outcome and prosthesis survival in patients after total or unicompartmental knee arthroplasty: a systematic review.

PURPOSE: There are contentious data about the role calcium pyrophosphate (CPP) crystals and chondrocalcinosis (CC) play in the progression of osteoarthritis (OA), as well as in the outcomes after knee arthroplasty. Hence, the purpose of this systematic review was to analyse the clinical and functional outcome, progression of OA and prosthesis survivorship after unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) in patients with CC compared to patients without CC. METHODS: A systematic review of the literature in PubMed, Medline, Embase and Web of Science was performed using the "Preferred Reporting Items for Systematic Reviews and Meta-Analysis" (PRISMA) guidelines. Articles which reported the outcome and survival rates of prosthesis after TKA or UKA in patients with CC were included. RESULTS: A total of 3718 patient knees were included in eight selected publications, with a median sample sizes of 234 knees (range 78-1000) and 954 knees (range 408-1500) for publications including UKA and TKA, respectively. At time of surgery, the mean age was 69 years and the prevalence for CC ranged from 12.6 to 36%. Chondrocalcinosis did not significantly influence the functional and clinical outcome, the implant survival as well as the radiologic progression of OA disease after UKA and TKA. CONCLUSION: The presence of CPP crystals in tissue samples, synovial fluid or evidence of calcifications on preoperative radiographs did not significantly influence the postoperative functional and activity scores. It also had no significant influence on prosthesis survival rate, whether it was a UKA or a TKA. This study shows that the impact of a subclinical form of chondrocalcinosis may not be of clinical relevance in the context of arthroplasty. LEVEL OF EVIDENCE: IV.

Customised, individually made total knee arthroplasty shows promising 1-year clinical and patient reported outcomes.

INTRODUCTION: Customised individually made (CIM) implants for total knee arthroplasty (TKA) were introduced about 10 years ago. These implants aim to reduce the risk of prosthesis-related issues resulting from anthropometric differences between different knees. The purpose of this study was to analyse the short-term clinical outcome and patient reported outcome measures (PROMs) of a specific CIM implant, the ORIGIN® knee replacement system (Symbios, Yverdon-les-Bains, Switzerland), which was introduced in 2018. MATERIALS AND METHODS: This is a prospective cohort study of patients undergoing primary posterior-stabilised (PS) CIM TKA using the specific ORIGIN® knee replacement system, (Symbios, Yverdon-les-Bains, Switzerland). TKAs were performed from February 2019 to October 2020. Data was collected preoperatively and postoperatively at 4 and 12 months. Outcome measures included the objective part of the Knee Society Score (KSS) with the range of motion (ROM) and the following PROMs: the Knee injury and Osteoarthritis Outcome Score (KOOS), the Forgotten Joint Score (FJS-12), the EuroQol, five dimensions, three levels (EQ-5D-3L) with the EuroQol visual analogue scale (EQ-VAS) and patient satisfaction. Differences in pre- to preoperative data were assessed with paired sample t tests. A p value < 0.05 was considered significant. RESULTS: Twenty-five CIM TKA (20 patients, 8 female) were included. The mean age at surgery was 66 years (SD, 6.9). At 4 and 12 months, significant improvements in the KSS (p < 0.001), the ROM (p < 0.001), all KOOS subscales (p < 0.001), the FJS (p < 0.001) and the EQ-5D-3L (p < 0.026) were found. Satisfaction rate was 91% and 88% at 4 and 12 months, respectively. Intraoperative complications did not occur and no revision surgeries were undertaken. CONCLUSIONS: The present study demonstrated significant improvements in the KSS and specific PROMs 1 year after CIM TKA. This study suggests that CIM TKA is a safe and suitable option, which can yield good clinical outcome and PROMs at least during short-term follow-up.

[Total knee arthroplasty in the young patient-an update]. / Bikondylärer Oberflächenersatz des Kniegelenkes beim jungen Patienten ­ ein Update.

The absolute number of total knee arthroplasties (TKA) continues to rise every year. About 10% of the patients are less than 55 years of age, although it is known that functional results and patient satisfaction are lower combined with an increased likelihood of revision compared to older patients. Higher physical activity and patient expectations are a major challenge in this age group. At the same time, the incidence of posttraumatic/postoperative alterations is high, including ligamentous or bony deficiencies, which can make the surgical procedure challenging. In view of these facts conservative treatments and joint sparing procedures should always be considered first. The potential correction of lower-limb deformities and unicompartmental knee arthroplasties need to be carefully evaluated before considering total knee arthroplasty. Only in advanced cases of osteoarthritis in more than one compartment of the knee of with combined ligamentous instability, can a TKA provide satisfactory results in the young patient. However, the strongest predictor of satisfaction is a realistic expectation.

Dysphagia in the intensive care unit: epidemiology, mechanisms, and clinical management.

Dysphagia may present in all critically ill patients and large-scale clinical data show that e.g. post-extubation dysphagia (PED) is commonly observed in intensive care unit (ICU) patients. Recent data demonstrate that dysphagia is mostly persisting and that its presence is independently associated with adverse patient-centered clinical outcomes. Although several risk factors possibly contributing to dysphagia development were proposed, the underlying exact mechanisms in ICU patients remain incompletely understood and no current consensus exists on how to best approach ICU patients at risk.From a clinical perspective, dysphagia is well-known to be associated with an increased risk of aspiration and aspiration-induced pneumonia, delayed resumption of oral intake/malnutrition, decreased quality of life, prolonged ICU and hospital length of stay, and increased morbidity and mortality. Moreover, the economic burden on public health care systems is high.In light of high mortality rates associated with the presence of dysphagia and the observation that dysphagia is not systematically screened for on most ICUs, this review describes epidemiology, terminology, and potential mechanisms of dysphagia on the ICU. Furthermore, the impact of dysphagia on affected individuals, health care systems, and society is discussed in addition to current and future potential therapeutic approaches.

Defining categories of actionability for secondary findings in next-generation sequencing.

Next-generation sequencing is increasingly used in clinical practice for the diagnosis of Mendelian diseases. Because of the high likelihood of secondary findings associated with this technique, the process of informing patients is beset with new challenges. One of them is regarding the type of secondary findings that ought to be disclosed to patients. The aim of this research is to propose a practical implementation of the notion of actionability, a common criteria justifying the disclosure of secondary findings but whose interpretation varies greatly among professionals. We distinguish three types of actionability corresponding to (1) well-established medical actions, (2) patient-initiated health-related actions and (3) life-plan decisions. We argue that actionability depends on the characteristics of the mutation or gene and on the values of patients. In discussing the return of secondary findings, it is important that the physician tries to get an impression of the specific situation and values of patients. Regarding variants of uncertain clinical significance in actionable genes, we found that different understandings of autonomy lead to different conclusions and that, for some of them, it may be legitimate to refrain from returning uncertain information.

Correction of hyperglycemia after surgery for diabetic foot infection and its association with clinical outcomes.

OBJECTIVE: Constantly high glycemia levels might influence outcomes in the management of patients undergoing surgery for diabetic foot infections (DFI). In our center for DFI, we performed a case-control study using a multivariate Cox regression model. Patients developing a new DFI could participate in the study several times. RESULTS: Among 1013 different DFI episodes in 586 individual adult patients (type I diabetes 148 episodes [15%], 882 [87%] with osteomyelitis; median antibiotic therapy of 21 days), professional diabetes counselling was provided by a specialized diabetes nurse in 195 episodes (19%). At admission, blood glucose levels were elevated in 110 episodes (11%). Treatments normalized glycemia on postoperative day 3 in 353 episodes (35%) and on day 7 for 321 (32%) episodes. Glycemia levels entirely normalized for 367 episodes (36%) until the end of hospitalization. Overall, treatment of DFI episodes failed in 255 of 1013 cases (25%), requiring surgical revision. By multivariate analysis, neither the provision of diabetes counseling, nor attaining normalizations of daily glycemic levels at day 3, day 7, or overall, influenced the ultimate incidence of clinical failures. Thus, the rapidity or success of achieving normoglycemia do not appear to influence the risk of treatment failure for operated DFI episodes.

Clinical and Radiological Outcomes after Knee Arthroplasty with Patient-Specific versus Off-the-Shelf Knee Implants: A Systematic Review.

Customised, patient-specific implants (PSI) manufactured based on computed tomography data are intended to improve the clinical outcome by restoring more natural knee kinematics as well as providing a better fit and a more precise positioning. The aim of this systematic review is to investigate the effect of these PSI on the clinical and radiological outcome compared to standard, off-the-shelf (OTS) implants. Thirteen comparative studies including a total of 2127 knee implants were identified. No significant differences in clinical outcome assessed with the range of motion, the Knee Society Score (KSS), and the Forgotten Joint Score (FJS-12) were found between PSI and OTS implants. PSI showed fewer outliers from the neutral limb axis and a better implant fit and positioning. Whether these radiological differences lead to long-term advantages in terms of implant survival cannot be answered based on the current data. Patients receiving PSI could be discharged home earlier at the same or at an even lower total cost. The effective overall superiority of PSI has yet to be proven in long-term studies.

Risk Factors for Dysphagia in ICU Patients After Invasive Mechanical Ventilation.

BACKGROUND: Dysphagia is common and independently predicts death in ICU patients. Risk factors for dysphagia are largely unknown, with sparse data available from mostly small cohorts without systematic dysphagia screening. RESEARCH QUESTION: What are the key risk factors for dysphagia in ICU patients after invasive mechanical ventilation? STUDY DESIGN AND METHODS: Post hoc analysis of data from a monocentric prospective observational study (Dysphagia in Mechanically Ventilated ICU Patients [DYnAMICS]) using comprehensive statistical models to identify potential risk factors for postextubation dysphagia. A total of 933 primary admissions of adult medical-surgical ICU patients (median age, 65 years; interquartile range, 54-73; 666 [71%] men) were investigated in a tertiary care academic center. Patients received systematic bedside screening for dysphagia within 3 h postextubation. Dysphagia screening positivity (n = 116) was followed within 24 h by a confirmatory examination. RESULTS: After adjustment for confounders, baseline neurologic disease (OR, 4.45; 95% CI, 2.74-7.24; P < .01), emergency admission (OR, 2.04; 95% CI, 1.15-3.59; P < .01), days on mechanical ventilation (OR, 1.19; 95% CI, 1.06-1.34; P < .01), days on renal replacement therapy (OR, 1.1; 95% CI, 1-1.23; P = .03), and disease severity (Acute Physiology and Chronic Health Evaluation II score within first 24 h; OR, 1.03; 95% CI, 0.99-1.07; P < .01) remained independent risk factors for dysphagia postextubation. Increased BMI reduced the risk for dysphagia (6% per step increase; OR, 0.94; 95% CI, 0.9-0.99; P = .03). INTERPRETATION: In ICU patients, baseline neurologic disease, emergency admission, and duration of invasive mechanical ventilation appeared as prominent independent risk factors for dysphagia. Because all ICU patients after mechanical ventilation should be considered at risk for dysphagia, systematic screening for dysphagia is recommended in respective critically ill patients. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT02333201; URL: www.clinicaltrials.govclinicaltrials.gov.

Dysphagia in the intensive care unit in Switzerland (DICE) - results of a national survey on the current standard of care.

INTRODUCTION: Oropharyngeal dysphagia (OD) is often observed in critically ill patients. In most affected patients OD persists throughout hospital stay and negatively impacts on clinical outcomes. Here we systematically explore routine clinical practice standards for recognition/screening, diagnosis and treatment of OD in accredited Swiss ICUs. METHODS: An online, 23-item questionnaire-based survey was performed to investigate current standards of care for OD in Switzerland (DICE). All (n = 49) accredited Swiss teaching hospitals providing specialist training for adult intensive care medicine were contacted. Senior intensivists were interviewed on how they would screen for, diagnose and treat OD in the ICU. RESULTS: The total response rate was 75.5%, with information available on all tertiary care academic centres. 67.6% (25/37) of institutions stated that they have established standard operating procedures for OD using a mostly sequential diagnostic approach (86.5%, 32/37). In 75.7% (28/37) of institutions, OD confirmation is performed without the use of instrumental techniques such as flexible (or fibre-endoscopic) evaluation of swallowing (FEES). Presumed key risk factors for OD were admission for acute neurological illness, long-term mechanical ventilation, ICU-acquired weakness and pre-existing neurological disease. Reported presumed OD-related complications typically include aspiration-induced pneumonia, increased rates of both reintubation and tracheostomy and increased ICU readmission rates. CONCLUSIONS: Many Swiss ICUs have established standard operating procedures, with most using sequential clinical approaches to assess ICU patients at risk of dysphagia. OD confirmation is mostly performed using non-instrumental techniques. In general, it appears that awareness of OD and ICU educational curricula can be further optimised.

Impact of selection and demography on the diffusion of lactase persistence.

BACKGROUND: The lactase enzyme allows lactose digestion in fresh milk. Its activity strongly decreases after the weaning phase in most humans, but persists at a high frequency in Europe and some nomadic populations. Two hypotheses are usually proposed to explain the particular distribution of the lactase persistence phenotype. The gene-culture coevolution hypothesis supposes a nutritional advantage of lactose digestion in pastoral populations. The calcium assimilation hypothesis suggests that carriers of the lactase persistence allele(s) (LCT*P) are favoured in high-latitude regions, where sunshine is insufficient to allow accurate vitamin-D synthesis. In this work, we test the validity of these two hypotheses on a large worldwide dataset of lactase persistence frequencies by using several complementary approaches. METHODOLOGY: We first analyse the distribution of lactase persistence in various continents in relation to geographic variation, pastoralism levels, and the genetic patterns observed for other independent polymorphisms. Then we use computer simulations and a large database of archaeological dates for the introduction of domestication to explore the evolution of these frequencies in Europe according to different demographic scenarios and selection intensities. CONCLUSIONS: Our results show that gene-culture coevolution is a likely hypothesis in Africa as high LCT*P frequencies are preferentially found in pastoral populations. In Europe, we show that population history played an important role in the diffusion of lactase persistence over the continent. Moreover, selection pressure on lactase persistence has been very high in the North-western part of the continent, by contrast to the South-eastern part where genetic drift alone can explain the observed frequencies. This selection pressure increasing with latitude is highly compatible with the calcium assimilation hypothesis while the gene-culture coevolution hypothesis cannot be ruled out if a positively selected lactase gene was carried at the front of the expansion wave during the Neolithic transition in Europe.