Sodium Niobate Nanowires Embedded PVA-Hydrogel-Based Triboelectric Nanogenerator for Versatile Energy Harvesting and Self-Powered CO Gas Sensor.

The surging demand for sustainable energy solutions and adaptable electronic devices has led to the exploration of alternative and advanced power sources. Triboelectric Nanogenerators (TENGs) stand out as a promising technology for efficient energy harvesting, but research on fully flexible and environmental friendly TENGs still remain limited. In this study, an innovative approach is introduced utilizing an ionic-solution modified conductive hydrogel embedded with piezoelectric sodium niobate nanowires-based Triboelectric Nanogenerator (NW-TENG), offering intrinsic advantages to healthcare and wearable devices. The synthesized NW-TENG, with a 12.5 cm2 surface area, achieves peak output performance, producing ≈840 V of voltage and 2.3 µC of charge transfer, respectively. The rectified energy powers up 30 LEDs and a stopwatch; while the NW-TENG efficiently charges capacitors from 1µF to 100 µF, reaching 1 V within 4 to 65 s at 6 Hz. Integration with prototype carbon monoxide (CO) gas sensor transform the device into a self-powered gas sensory technology. This study provides a comprehensive understanding of nanowire effects on TENG performance, offering insights for designing highly flexible and environmentally friendly TENGs, and extending applications to portable self-powered gas sensors and wearable devices.

Experimental and Theoretical Insights into Interfacial Properties of 2D Materials for Selective Water Transport Membranes: A Critical Review.

Interfacial properties, such as wettability and friction, play critical roles in nanofluidics and desalination. Understanding the interfacial properties of two-dimensional (2D) materials is crucial in these applications due to the close interaction between liquids and the solid surface. The most important interfacial properties of a solid surface include the water contact angle, which quantifies the extent of interactions between the surface and water, and the water slip length, which determines how much faster water can flow on the surface beyond the predictions of continuum fluid mechanics. This Review seeks to elucidate the mechanism that governs the interfacial properties of diverse 2D materials, including transition metal dichalcogenides (e.g., MoS2), graphene, and hexagonal boron nitride (hBN). Our work consolidates existing experimental and computational insights into 2D material synthesis and modeling and explores their interfacial properties for desalination. We investigated the capabilities of density functional theory and molecular dynamics simulations in analyzing the interfacial properties of 2D materials. Specifically, we highlight how MD simulations have revolutionized our understanding of these properties, paving the way for their effective application in desalination. This Review of the synthesis and interfacial properties of 2D materials unlocks opportunities for further advancement and optimization in desalination.

Pulmonary Manifestations in Patients of Rheumatoid Arthritis and its Correlation with Severity of Disease.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic inflammatory disease of unknown etiology marked by symmetric, peripheral polyarthritis. RA has a prevalence of 1-2% in the general adult population. The mortality rate in patients with RA increases during the course of the disease, with a tendency to accelerate after 15 yearsAim: To study the pulmonary manifestations and their severity using [Disease Activity Score (DAS)-28 score] in patients of RAMaterials and methods: Present study was conducted in the Department of Medicine, Sardar Patel Medical College and Associated Group of Hospitals Bikaner, Bikaner, Rajasthan, India, on 100 patients. This study was a cross-sectional, observational study conducted over 1 year. Consecutive cases of RA patients attending the outpatient department or admitted to the medicine wards were selected according to the inclusion and exclusion criteriaResults: Pulmonary manifestation was present in a total of 38% of cases, while the remaining 62% of cases had no pulmonary manifestation. The presence of comorbidity and C-reactive protein (CRP) was significantly associated with pulmonary manifestation in RA patients. On high-resolution computed tomography (HRCT), the most common finding was interstitial lung disease (ILD) (60.5%), with usual interstitial pneumonia (UIP) as the most common pattern. On performing a pulmonary function test (PFT), 33 patients (86.84%) had an abnormal result, with restrictive as the most common patternConclusion: The patients of RA, especially those with advanced age, long duration of disease, male sex, and associated comorbidity, should be screened for pulmonary complications of RA using X-ray chest and PFT, supplemented by HRCT chest wherever required.

Support Vector Regression for Mobile Target Localization in Indoor Environments.

Trilateration-based target localization using received signal strength (RSS) in a wireless sensor network (WSN) generally yields inaccurate location estimates due to high fluctuations in RSS measurements in indoor environments. Improving the localization accuracy in RSS-based systems has long been the focus of a substantial amount of research. This paper proposes two range-free algorithms based on RSS measurements, namely support vector regression (SVR) and SVR + Kalman filter (KF). Unlike trilateration, the proposed SVR-based localization scheme can directly estimate target locations using field measurements without relying on the computation of distances. Unlike other state-of-the-art localization and tracking (L&T) schemes such as the generalized regression neural network (GRNN), SVR localization architecture needs only three RSS measurements to locate a mobile target. Furthermore, the SVR based localization scheme was fused with a KF in order to gain further refinement in target location estimates. Rigorous simulations were carried out to test the localization efficacy of the proposed algorithms for noisy radio frequency (RF) channels and a dynamic target motion model. Benefiting from the good generalization ability of SVR, simulation results showed that the presented SVR-based localization algorithms demonstrate superior performance compared to trilateration- and GRNN-based localization schemes in terms of indoor localization performance.

Obesity, Thyroid and OSA: An Intriguing Triangle.

The complex relationship between BMI, thyroid and its effects on OSA raises a question on how patients with suspected OSA should be evaluated. Some studies have described an association between thyroid disorders and OSA. Whether this is a direct effect of thyroid disorders, or it is indirectly related to BMI values is an important point to ponder. The aim of this study was to estimate the prevalence of thyroid disorders in relation to BMI in newly diagnosed patients with OSA (AHI > 5/h on diagnostic Polysomnography) at sleep lab of our tertiary care centre. In addition, we compared baseline characteristics of OSA patients with thyroid parameters. MATERIAL: In this hospital based observational study, recently diagnosed OSA on the basis of PSG showing AHI > 5/ h according to the AASM 2012 scoring rules and age more than 18 years were recruited from OPD and in-patients of SMS Medical College Jaipur. Patients on previous CPAP treatment, mixed or predominantly central sleep apnea, known diabetics and language barriers or cognitive or psychiatric disorders that made informed consent difficult to obtain were excluded. OBSERVATION: During the study period, 65 patients with treatment naïve OSA and a mean age of 52.28±10.92 year, a mean body mass index (BMI) of 34.73±7.20 kg/m2 underwent thyroid function tests. In the OSA patients, the prevalence of newly diagnosed clinical hypothyroidism was 12.3%. In Mild OSA the mean FT3 (ng/ml), FT4 (ng/dl), TSH (mIU/l) and mean AHI score was 3.10±0.71, 1.37±0.58, 3.64±1.37 and 7.74±3.55 respectively. Similarly, mean FT3 (ng/ml), FT4 (ng/dl), TSH (mIU/l) and mean AHI score were 2.97±0.93, 1.46±0.79, 6.33±8.05 and 17.42±88.90 respectively in moderate OSA and 3.32±0.58, 1.23±0.46, 3.55±1.82 and 45.54±21.38 respectively in severe OSA. There was a statistically significant difference between mild moderate and severe OSA regarding thyroid profile as well as BMI with p of <0.05. CONCLUSION: The prevalence of hypothyroidism was common among patients with OSA and the severity of OSA correlated with thyroid function tests and BMI.

Mechanical strength of a nanoporous bicrystalline h-BN nanomembrane in a water submerged state.

Due to superior water permeability, structural stability, and adsorption capability, h-BN nanosheets are emerging as an efficient membrane for water desalination. In order to cater to the demand for potable water, large size membranes are required to maintain a high desalination rate from water purification systems. These large size membranes usually contain polycrystals with an offset in their mechanical properties from pristine h-BN nanosheets. In this article, molecular dynamics based simulations were performed in conjunction with a hybrid interatomic potential (reactive force field, TIP3P, and Lennard Jones) to simulate the mechanical strength of nanoporous single and bicrystalline h-BN nanosheets under water submerged conditions. The interaction between the atomic configuration of grain boundary atoms and nanopores in the presence of water molecules helps in investigating the viability of defective h-BN nanomembranes for underwater applications. Higher dislocation density enhances the mechanical strength of nanoporous bicrystalline h-BN nanosheets containing twin nanopores, which makes them a better substitute for water submerged applications as compared to the pristine nanosheets. The mechanical strength of nanoporous single crystalline h-BN nanosheets deteriorates with an increase in the number of nanopores, whereas a contrasting trend was observed with bicrystalline h-BN nanosheets.

Atomistic simulations to study the effect of grain boundaries and hydrogen functionalization on the fracture toughness of bi-crystalline h-BN nanosheets.

The aim of this research article was to investigate the effect of grain boundaries (GBs), and hydrogen functionalisation on the fracture toughness of bi-crystalline hexagonal boron nitride (h-BN) nanosheets. Molecular dynamics based simulations were performed in conjunction with the reactive force field to study the crack tip behaviour in single and bi-crystalline h-BN nanosheets. Atomistic simulations help in predicting a positive effect of the GB plane in the near vicinity of the crack tip. The density of 5|7 dislocation pairs significantly affects the fracture behaviour of bi-crystalline h-BN nanosheets. Additionally, the distance of the GB plane from the crack tip, and limited hydrogen functionalisation of GB atoms, further help in improving the fracture toughness of bi-crystalline h-BN nanosheets. Hydrogen functionalisation helps in inducing out of plane displacement at the GB plane, which helps in arresting or retarding the crack propagation. It can be concluded from the results that instead of deteriorating, geometrical defects such as GBs can also be used to tailor the fracture toughness of h-BN nanosheets. This study on the fracture toughness of bi-crystalline h-BN nanosheets helps in complementing the research on using porous h-BN nanosheets as nanomembranes for water desalination and ion separation.

A Multimodal Approach to Pain Management for Patients with Chronic Back Pain: Outcome Measures at 1 Year.

PURPOSE OF REVIEW: The purpose of this study is to evaluate the effectiveness of a multimodal approach to treating chronic low back pain. RECENT FINDINGS: Chronic non-cancer-related back pain is often a frustrating and poorly managed problem for patients. It poses a significant public health issue worsened by the widespread use of narcotics. In 2016, the CDC released guidelines with noticeably more strict recommendations on prescription of narcotics for pain. Veterans at an interventional pain clinic presenting with chronic back pain refractory to medical and to surgical care were enrolled in an 8-week interdisciplinary pain management program. Pain scores were significantly reduced 1 year after completion of the program. Patients in this study benefitted from lower and sustained pain scores, a reduction in emergency room, and urgent care clinic visits, as well as generally high satisfaction with the interdisciplinary program.

Interstitial Lung Disease in India. Results of a Prospective Registry.

RATIONALE: Interstitial lung disease (ILD) is a heterogeneous group of acute and chronic inflammatory and fibrotic lung diseases. Existing ILD registries have had variable findings. Little is known about the clinical profile of ILDs in India. OBJECTIVES: To characterize new-onset ILDs in India by creating a prospective ILD using multidisciplinary discussion (MDD) to validate diagnoses. METHODS: Adult patients of Indian origin living in India with new-onset ILD (27 centers, 19 Indian cities, March 2012-June 2015) without malignancy or infection were included. All had connective tissue disease (CTD) serologies, spirometry, and high-resolution computed tomography chest. ILD pattern was defined by high-resolution computed tomography images. Three groups independently made diagnoses after review of clinical data including that from prompted case report forms: local site investigators, ILD experts at the National Data Coordinating Center (NDCC; Jaipur, India) with MDD, and experienced ILD experts at the Center for ILD (CILD; Seattle, WA) with MDD. Cohen's κ was used to assess reliability of interobserver agreement. MEASUREMENTS AND MAIN RESULTS: A total of 1,084 patients were recruited. Final diagnosis: hypersensitivity pneumonitis in 47.3% (n = 513; exposure, 48.1% air coolers), CTD-ILD in 13.9%, and idiopathic pulmonary fibrosis in 13.7%. Cohen's κ: 0.351 site investigator/CILD, 0.519 site investigator/NDCC, and 0.618 NDCC/CILD. CONCLUSIONS: Hypersensitivity pneumonitis was the most common new-onset ILD in India, followed by CTD-ILD and idiopathic pulmonary fibrosis; diagnoses varied between site investigators and CILD experts, emphasizing the value of MDD in ILD diagnosis. Prompted case report forms including environmental exposures in prospective registries will likely provide further insight into the etiology and management of ILD worldwide.

Molecular Beam Epitaxy of GaN Nanowires on Epitaxial Graphene.

We demonstrate an all-epitaxial and scalable growth approach to fabricate single-crystalline GaN nanowires on graphene by plasma-assisted molecular beam epitaxy. As substrate, we explore several types of epitaxial graphene layer structures synthesized on SiC. The different structures differ mainly in their total number of graphene layers. Because graphene is found to be etched under active N exposure, the direct growth of GaN nanowires on graphene is only achieved on multilayer graphene structures. The analysis of the nanowire ensembles prepared on multilayer graphene by Raman spectroscopy and transmission electron microscopy reveals the presence of graphene underneath as well as in between nanowires, as desired for the use of this material as contact layer in nanowire-based devices. The nanowires nucleate preferentially at step edges, are vertical, well aligned, epitaxial, and of comparable structural quality as similar structures fabricated on conventional substrates.

Prevalence and severity of asthma among Indian school children aged between 6 and 14 years: associations with parental smoking and traffic pollution.

OBJECTIVE: Phase three of the International Study of Asthma and Allergy in Children (ISAAC) was carried out at various sites in India. The prevalence of asthma symptoms in school children and the effect of environmental tobacco smoke and traffic pollution on the occurrence of asthma were analysed. METHODS: Two groups of school children, aged 6-7 yr and 13-14 yr, participated according to the ISAAC protocol. Schools were randomly selected and responses to the ISAAC questionnaire were recorded. RESULTS: The prevalence of asthma was 5.35% in the 6-7 yr age group and 6.05% in the 13-14 yr age group. The odds ratios (ORs) for the risk of asthma in children with exposure to mild, moderate and heavy traffic pollution compared with minimal traffic pollution were 1.63 (95% CI: 1.43, 1.85), 1.71 (95% CI: 1.49, 1.96) and 1.53 (95% CI: 1.31, 1.78), respectively, in the younger group. Similarly, in the older group, they were 1.19 (95% CI: 1.04, 1.36), 1.51 (95% CI: 1.31, 1.75) and 1.51 (95% CI: 1.29, 1.76). Asthma was associated with maternal smoking [6-7 yr group: OR = 2.72 (2.05, 3.6); 13-14 yr group: OR = 2.14 (1.72, 2.66)] and paternal smoking [6-7 yr group: OR = 1.9 (1.70, 2.11); 13-14 yr group: OR = 1.21 (1.09, 1.34)]. CONCLUSIONS: The prevalence of asthma was lower in the 6-7 than the 13-14 yr age group. Environmental tobacco smoke and traffic pollution were the factors most strongly associated with asthma in Indian children.

Pain in the Elderly.

Pain management in the elderly has increasingly become problematic in the USA as the aged population grows. The proportion of the population over 65 continues to climb and may eclipse 20 % in the next decade. In order to effectively diagnosis and treat these patients, a proper history and physical exam remain essential; pain assessment scales such as the Verbal Descriptor Scales (VDS), the Numerical Rating Scales (NRS), and the Visual Analogue Scales (VAS) often but not always prove beneficial. The conditions most frequently afflicting this population include osteoarthritis, diabetic neuropathy, post-herpetic neuralgia, and lower back pain which include spondylosis and radiculopathies. While the normal aging process does not necessarily guarantee symptoms of chronic pain, elderly individuals are far more likely to develop these painful conditions than their younger counterparts. There are many effective treatment modalities available as potential therapeutic interventions for elderly patients, including but not limited to analgesics such as NSAIDs and opioids, as well as multiple interventional pain techniques. This review will discuss chronic pain in the elderly population, including epidemiology, diagnostic tools, the multitude of co-morbidities, and common treatment modalities currently available to physicians.

Design and validation of an assessment tool for open surgical procedures.

BACKGROUND: Laparoscopy is currently the gold standard for cholecystectomy. Recent literature suggests surgical trainees have limited exposure to open cholecystectomy, which may result in suboptimal performance in the event of conversion. Furthermore, most training and assessment models are designed for laparoscopic cholecystectomy, with limited opportunities for open simulator training. The present study's purpose was to design an inexpensive model for open cholecystectomy and to validate a performance assessment tool. METHODS: The simulator comprises a porcine liver and gallbladder in a mock human abdomen with silicon skin. The assessment tool utilizes inexpensive infrared (IR) cameras to provide tracking of participant hand motions. Eleven novice general surgery trainees (<20 cholecystectomies) and five expert surgeons (>100 cholecystectomies) completed an open cholecystectomy using the simulator. Procedures were recorded and assessed by a blinded evaluator using a global rating scale. Tracking data analysis was based on number of movements and total path length. RESULTS: Novices (t = 36.18 min) completed the procedure significantly slower than did experts (t = 19.53 min) (Mann-Whitney test U = 20, p < 0.05) and had significantly more hand movements (Mann-Whitney test U = 20, p < 0.05). Analysis of the total global rating scale scores showed a significant difference between novice (14/35) and expert (24/35) performance in all categories (Mann-Whitney test U = 58, p < 0.05). CONCLUSION: The present model presents a realistic, low-cost tool for training and assessment of procedural skills in open cholecystectomy. The study demonstrated the validity of the IR tracking device as an objective assessment tool for open surgical skills training. Future training should incorporate this low-cost, highly effective training device into surgical curricula.

Comparison of stability and kinematics of the natural knee versus a PS TKA with a 'third condyle'.

PURPOSE: The goal of this study was to compare the kinematics of knees before and after total knee arthroplasty (TKA) that relies on an inter-condylar 'third condyle'. The hypothesis was that the 'third condyle' provides sufficient flexion stability and induces a close to normal femoral rollback, thus granting natural joint kinematics. METHODS: Intra-operative navigation data were collected from 29 consecutive cases that received a cemented TKA (HLS Noetos, Tornier SA, France) designed with an inter-condylar 'third condyle' that engages within the tibial insert beyond 35° flexion. Operations were guided by a non-image-based system (BLU-IGS, Orthokey Italia srl, Italy) that recorded relative femoral and tibial positions in native and implanted knees during: passive range of motion, anterior drawer test at 90° flexion, and varus-valgus stress tests at full extension and at 30° flexion. RESULTS: The total internal tibial rotation during flexion was similar for native (8.2 ± 4.2°) and implanted knees (8.0 ± 5.4°). The lateral femoral condyle was more posterior in implanted knees (1.2 ± 9.4 mm) than in native knees (9.5 ± 3.6 mm) throughout early flexion (p < 0.01), but this difference diminished beyond 100° flexion (n.s.). The implanted knees did not exhibit paradoxical external tibial rotation. Varus-valgus laxity in full extension was lower for implanted knees than for native knees (p = 0.0221), but at 30° flexion was almost identical for both native and implanted knees. Anteroposterior laxity was similar in implanted and native knees. CONCLUSIONS: The 'third condyle' TKA provides similar anteroposterior and mediolateral stability to the natural knee. This feature granted an adequate balance between laxity and constraint to reproduce natural joint kinematics, including smooth femoral rollback, without causing paradoxical external tibial rotation.

Clinical profile of pneumonia and its association with rain wetting in patients admitted at a tertiary care institute during pandemic of influenza A (H1N1) pdm09 virus infection.

BACKGROUND: Influenza pneumonia often occurs as epidemics in the Asian countries and have significant impact on the health of world population. METHODS: We studied the association of rain-wetting with occurrence of pneumonia during the outbreak of the influenza A (H1N1) pdm09 virus infection. All patients admitted with community-acquired pneumonia during the period 13th September to 10th October 2010 were recruited in the present study. The diagnosis of influenza was established by real-time polymerase chain reaction (RT-PCR). The demographic data and clinical profile of the patients were recorded with a special consideration to record of possible risk factors. RESULTS: Of the 123 patients studied, 39 (32%) patients had tested positive for influenza A (H1N1) pdm09; 12 (10%) tested positive for influenza A and remaining 72 (58%) patients were negative for influenza virus. Pattern of illness was almost identical in H1N1-positive and-negative groups. History of rain-wetting was present in 48 patients (39%) preceding the onset of illness. Getting wet in the rain was significantly higher in patients with pneumonia than control subjects [odds ratio 2.53, 95% confidence intervals (CI) 1.301-4.91; p=0.009)]. The number of pneumonia patients was also higher on rainy days and the numbers started declining a week later. CONCLUSION: More pneumonia patients are admitted during the periods of greater rainfall and rain-wetting may be an important risk factor for the occurrence of pneumonia.

Cross-species amplification of microsatellite markers in Mycteria leucocephala Pennant 1769: molted feathers as successful DNA source.

DNA from molted feathers is being increasingly used for genetic studies on birds. However, the DNA obtained from such non-invasive sources is often not of enough quantity and quality for isolation of new microsatellite markers. The present study examined the potential of shed feathers of near threatened Painted Stork as a source of its DNA for cross-species amplification of microsatellites. Thirty-one shed feathers of varying conditions ('good' and 'deteriorated') and sizes ('large', 'intermediate' and 'small') collected in a north Indian population were used to isolate DNA by a standard isopropanol method and 11 microsatellite markers already developed in the Wood Stork were screened for amplification. Nine plucked feathers from two dead Painted Storks were also used to compare the DNA yield and amplification success. The DNA yield of feathers varied significantly in relation to the calamus size and condition. Among molted feathers, 'good' and 'large' samples provided more DNA than 'deteriorated' and 'small' ones, respectively. 'Large' plucked feathers yielded more DNA than 'large' molted feathers. DNA was almost degraded in all the samples and ratio of absorbance at 260/280 nm varied from 1.0 to 1.8, indicating impurity in many samples. Independent of DNA yields, all microsatellites were cross-amplified in all kinds of feathers, with > 80% success in different feather categories. It is concluded that the shed feathers can be successfully used to isolate DNA in the Painted Stork and for cross-species amplification of microsatellites.

Electrospun Polymeric Nanofibers: Current Trends in Synthesis, Surface Modification, and Biomedical Applications.

Electrospun polymeric nanofibers are essential in various fields for various applications because of their unique properties. Their features are similar to extracellular matrices, which suggests them for applications in healthcare fields, such as antimicrobials, tissue engineering, drug delivery, wound healing, bone regeneration, and biosensors. This review focuses on the synthesis of electrospun polymeric nanofibers, their surface modification, and their biomedical applications. Nanofibers can be fabricated from both natural and synthetic polymers and their composites. Even though they mimic extracellular matrices, their surface features (physicochemical characteristics) are not always capable of fulfilling the purpose of the target application. Therefore, they need to be improved via surface modification techniques. Both needle-based and needleless electrospinning are thoroughly discussed. Various techniques and setups employed in each method are also reviewed. Furthermore, pre- and postspinning modification approaches for electrospun nanofibers, including instrument design and the modification features for targeted biomedical applications, are also extensively discussed. In this way, the remarkable potential of electrospun polymeric nanofibers can be highlighted to reveal future research directions in this dynamic field.

Within-team debriefing versus instructor-led debriefing for simulation-based education: a randomized controlled trial.

OBJECTIVE: To compare the effectiveness of an interprofessional within-team debriefing with that of an instructor-led debriefing on team performance during a simulated crisis. BACKGROUND: Although instructor-led simulation debriefing is considered the "gold standard" in team-based simulation education, cost and logistics are limiting factors for its implementation. Within-team debriefing, led by the individuals of the team itself rather than an external instructor, has the potential to address these limitations. METHODS: One hundred twenty subjects were grouped into 40 operating room teams consisting of 1 anesthesia trainee, 1 surgical trainee, and 1 staff circulating operating room nurse. All teams managed a simulated crisis scenario (pretest). Teams were then randomized to either a within-team debriefing group or an instructor-led debriefing group. In the within-team debriefing group, the teams reviewed the video of their scenario by themselves. The teams in the instructor-led debriefing group reviewed their scenario guided by a trained instructor. Immediately after debriefing, all teams managed a different intraoperative crisis scenario (posttest). All sessions were videotaped. Blinded expert examiners used the validated Team Emergency Assessment Measure scale to assess crisis resource management performance of all teams in random order. RESULT: Team performance significantly improved from pretest to posttest (P = 0.008) regardless of the type of debriefing. There was no significant difference in the degree of improvement between within-team debriefing and instructor-led debriefing (P = 0.52). CONCLUSIONS: Within-team debriefing results in measurable improvements in team performance in simulated crisis scenarios. This form of debriefing may be as effective as instructor-led team debriefing, which could improve resource utilization and feasibility of team-based simulation (NCT01067378).

Tibial tubercle osteotomy or quadriceps snip in two-stage revision for prosthetic knee infection? A randomized prospective study.

BACKGROUND: Although 7% to 38% of revision total knee arthroplasties (RTKAs) are attributable to prosthetic knee infections, controversy exists regarding the best surgical approach while reducing the risk of extensor mechanism complications and the reinfection rate. QUESTIONS/PURPOSES: We compared The Knee Society Score(©) (KSS), incidences of complications, maximum knee flexion, residual extension lag, and reinfection rate in patients with prosthetic knee infections treated with two-stage RTKAs using either the tibial tubercle osteotomy (TTO) or the quadriceps snip (QS) for exposure at the time of reimplantation. METHODS: We prospectively followed 81 patients with chronic prosthetic knee infections treated between 1997 and 2004. Patients were randomized to receive a TTO or QS for exposure at the time of reimplantation. All patients had the same rehabilitation protocol. The minimum followup was 8 years (mean, 12 years; range, 8-15 years). RESULTS: Patients in the TTO group had a higher mean KSS than the QS group (88 versus 70, respectively). Mean maximum knee flexion was greater in the TTO group (113° versus 94°); with a lower incidence of extension lag (45% versus 13%). We observed no differences in reinfection rate between groups. CONCLUSIONS: We found the TTO combined with an early rehabilitation protocol associated with superior KSS did not impair extensor mechanism function or increase the reinfection rate. We believe a two-stage RTKA with TTO is a reasonable approach for treating prosthetic knee infections. LEVEL OF EVIDENCE: Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.