Primary constrained-condylar-knee designs outperform posterior-stabilized and cruciate-retaining designs in high-grade varus osteoarthritic knees during short-term follow-up: a pilot study.

INTRODUCTION: High-grade varus osteoarthrosis (OA) is characterized by a pronounced intra-articular varus deformity and associated insufficiency of the lateral ligamentous complex. When performing a total knee arthroplasty (TKA) in such a knee, traditionally the alignment is restored to neutral, and the medial soft tissue structures are released to compensate for the lateral laxity and balance the joint. However, another option would be to leave the medial soft tissues untouched and accept the lateral laxity but to compensate for it using an ML-stabilized constrained-condylar knee (CCK) design. Our aim was to prove our hypothesis that such knees would demonstrate better clinical stability and better functionality as well as subjective outcome scores. MATERIALS AND METHODS: We searched our bicenter database of 912 primary TKAs (from 2016 to 2019) for primary TKA patients with a preoperative varus alignment of > 8°. After inclusion, 60 patients were divided into three groups by implant design: CCK (n = 21), posterior-stabilized (PS) (n = 20) and cruciate-retaining (CR) (n = 19). Oxford Knee Score (OKS), Forgotten Joint Score (FJS), Knee Society Score (KSS), UCLA-activity score, ML instability scores and both radiographic and clinical data were compared between groups. RESULTS: ML stability was significantly better in CCK designs (86% grade 0) compared to CR (37% grade 0) (p = 0.004) but not PS (70% grade 0) designs. No grade II instability was present in CCK and PS implants compared to 16% of CR implants. KSS and UCLA-activity score were higher in CCK designs compared to PS (p = 0.027, p = 0.041) and CR designs (p < 0.001, p = 0.007). OKS and FJS were higher in CCK designs compared to CR (p = 0.025, p = 0.008) but not to PS. CONCLUSION: The use of a CCK design to compensate for the lateral laxity in high-grade varus OA knees allowed to refrain from a medial release. CCK designs displayed improved clinical stability and better functionality as well as subjective outcome scores compared to less-constrained designs.

Simultaneous bilateral opening-wedge high tibial osteotomy with structural allograft impaction results in excellent early recovery and pain reduction similar unilateral osteotomy.

BACKGROUND: Patients suffering from bilateral combined medial osteoarthritis and varus alignment of the knee are eligible for bilateral high tibial osteotomy (HTO) in two-staged surgery. The impact of bilateral HTO surgery on rehabilitation and early outcomes have not yet been reported in the literature, even though these features are decisive in establishing whether a patient is preferably treated in one or two stages. METHODS: A total of 29 patients were followed after simultaneous bilateral HTO surgery. Numeric Rating Scale (NRS), Knee injury and Osteoarthritis Outcome Score - Physical Function Short Form (KOOS-PS) and Lysholm scores were recorded at 3, 6 and 12 months. Results were compared with outcomes of unilateral HTO surgery to asses the additional impact of simultaneous bilateral HTO surgery on the early rehabilitation and recovery of simultaneous bilateral HTO surgery. RESULTS: Three months after surgery, NRS pain scores decreased from 60.5 to 40.9 and subsequently to 30.4 and 24.3 after 6 and 12 months, respectively. KOOS-PS scores improved from 50.0 to 44.3 after 3 months, to 33.9 and 29.8 after 6 and 12 months, respectively. Lysholm scores did not improve after 3 months (45.2-44.2), but significantly improved after 6 and 12 months (66.1 and 75.7, respectively). Compared with unilateral HTO surgery, similar improvements were seen after 6 and 12 months. CONCLUSION: Simultaneous bilateral HTO surgery generates similar clinical outcomes compared with unilateral HTO surgery and moreover it does not excessively prolong time to achieve these outcomes. It is safe and presumably a more effective approach to treat patients suffering bilateral medial osteoarthritis and varus alignment of the knee compared with two-staged surgery.

Impact of blood storage and sample handling on quality of high dimensional flow cytometric data in multicenter clinical research.

Obtaining reliable and reproducible high quality data in multicenter clinical research settings requires design of optimal standard operating procedures. While the need for standardization in sample processing and data analysis is well-recognized, the impact of sample handling in the pre-analytical phase remains underestimated. We evaluated the impact of sample storage time (≈transport time) and temperature, type of anticoagulant, and limited blood volume on reproducibility of flow cytometric studies. EDTA and Na-Heparin samples processed with the EuroFlow bulk lysis protocol, stained and stored at 4 °C showed fairly stable expression of cell surface markers and distribution of the major leukocyte populations for up to 72 h. Additional sample fixation (1% PFA, Fix & Perm) did not have any beneficial effects. Blood samples stored for <24 h at room temperature before processing and staining seemed suitable for reliable immunophenotyping, although losses in absolute cell numbers were observed. The major losses were observed in myeloid cells and monocytes, while lymphocytes seemed less affected. Expression of cell surface markers and population distribution were more stable in Na-Heparin blood than in EDTA blood. However, storage of Na-Heparin samples was associated with faster decrease in leukocyte counts over time. Whole blood fixation strategies (Cyto-Chex, TransFix) improved long-term population distribution, but were detrimental for expression of cellular markers. The main conclusions from this study on healthy donor blood samples were successfully confirmed in EDTA clinical (patient) blood samples with different time delays until processing. Finally, we recognized the need for adjustments in bulk lysis in case of insufficient blood volumes. Despite clear overall conclusions, individual markers and cell populations had different preferred conditions. Therefore, specific guidelines for sample handling should always be adjusted to the clinical application and the main target leukocyte population.

Insights into ozone deposition patterns from decade-long ozone flux measurements over a mixed temperate forest.

Long-term fluxes of ozone (O(3)) were measured over a mixed temperate forest using the aerodynamic gradient method. The long-term average O(3) flux (F) was -366 ng m(-2) s(-1) for the period 2000-2010, corresponding to an average O(3) concentration of 48 µg m(-3) and a deposition velocity v(d) of 9 mm s(-1). Average nocturnal ozone deposition amounted to -190 ng m(-2) s(-1), which was about one third of the daytime flux. Also during the winter period substantial O(3) deposition was measured. In addition, total O(3) fluxes were found to differ significantly among canopy wetness categories. During the day, highest deposition fluxes were generally measured for a dry canopy, whereas a rain-wetted canopy constituted the best sink at night. Flux partitioning calculations revealed that the stomatal flux (F(s)) contributed 20% to the total F but the F(s)/F fraction was subject to seasonal and diurnal changes. The annual concentration-based index AOT40 (accumulated dose over a threshold of 40 ppb) and the Phytotoxic Ozone Dose (POD(1) or accumulated stomatal flux above a threshold of 1 nmol m(-2) s(-1)) were related in a curvilinear way. The O(3) deposition was found to be largely controlled by non-stomatal sinks, whose strength was enhanced by high friction velocities (u(*)), optimizing the mechanical mixing of O(3) into the canopy and the trunk space. The long-term geometrical mean of the non-stomatal resistance (R(ns)) was 136 s m(-1) but lower R(ns) values were encountered during the winter half-year due to higher u(*). The R(ns) was also subject to a marked diurnal variability, with low R(ns) in the morning hours, when turbulence took off. We speculate that non-stomatal deposition was largely driven by scavenging of ozone by biogenic volatile organic compounds (BVOCs) and especially NO emitted from the crown or the forest floor.

Bidirectional ammonia exchange above a mixed coniferous forest.

Two canopy compensation point models were used to study the bidirectional exchange of ammonia over a mixed coniferous forest subjected to high nitrogen deposition. The models were tested for 16 time series, average fluxes of which ranged between -270 and +1 ng m(-2)s(-1). The static model consisted of a bidirectional stomatal flux and a unidirectional cuticular flux component. The dynamic model also allowed for desorption of ammonia from the leaf surface and took into account ammonia fluxes from precedent periods. The apoplastic ammonium/hydrogen ion ratio (Gamma), which was derived to estimate the stomatal compensation point (chi(s)), amounted to 3300 in spring and 1375 during the summer/autumn. Empirical descriptions for cuticular resistances (R(w)) in the static model, developed as a function of micrometeorological conditions and codeposition effects, failed to reproduce the measured fluxes. A better match with measurements was obtained using the dynamic model, which succeeded in simulating net-emission during the daytime.

Fluxes of oxidised and reduced nitrogen above a mixed coniferous forest exposed to various nitrogen emission sources.

Concentrations of nitrogen gases (NH(3), NO(2), NO, HONO and HNO(3)) and particles (pNH(4) and pNO(3)) were measured over a mixed coniferous forest impacted by high nitrogen loads. Nitrogen dioxide (NO(2)) represented the main nitrogen form, followed by nitric oxide (NO) and ammonia (NH(3)). A combination of gradient method (NH(3) and NO(x)) and resistance modelling techniques (HNO(3), HONO, pNH(4) and pNO(3)) was used to calculate dry deposition of nitrogen compounds. Net flux of NH(3) amounted to -64 ng N m(-2) s(-1) over the measuring period. Net fluxes of NO(x) were upward (8.5 ng N m(-2) s(-1)) with highest emission in the morning. Fluxes of other gases or aerosols substantially contributed to dry deposition. Total nitrogen deposition was estimated at -48 kg N ha(-1) yr(-1) and consisted for almost 80% of NH(x). Comparison of throughfall nitrogen with total deposition suggested substantial uptake of reduced N (+/-15 kg N ha(-1) yr(-1)) within the canopy.

Influence of common cold and of parenteral administration of influenza virus antigens on bronchoalveolar lavage cells.

We investigated in a pilot study on healthy young subjects whether a common cold or a vaccination with influenza virus antigens within 10 days influenced the number and subsets of inflammatory cells in the bronchoalveolar lavage (BAL) fluid. The total number of BAL-cells was about doubled in the common cold group, yet no consistent changes in overall cell distribution was found. Among BAL-lymphocytes the ratio of helper-inducer over suppressor-cytotoxic lymphocytes (THI/TCS) tended to be increased in both groups, due to a lower percentage of TCS-cells, which was significant in the vaccination group only. In the blood, on the contrary, the THI/TCS ratio was significantly decreased in both groups due to a drop in THI-cells; in addition, the proportions of E-Rosette (+) T-cells and of activated (Ia+) T-cells were slightly increased. In conclusion, only minor changes in inflammatory BAL-cells were observed, which, however, may interfere with the effects of other diseases.