Moderate varus/valgus malalignment after total knee arthroplasty has little effect on knee function or muscle strength: 91 patients assessed after 1 year

Background and purpose — Postoperative muscle strength and component alignment are important factors affecting functional results after total knee arthroplasty (TKA). We are not aware of any studies that have investigated the relationship between them. We therefore investigated whether coronal malalignment of the mechanical axis and/or of individual implant components would affect knee muscle strength and function 1 year after TKA surgery.Patients and methods — We included 120 consecutive osteoarthritis (OA) patients admitted for TKA. Preoperative active range of motion (ROM) of the knee, patient age, sex, and BMI were recorded and the Knee Society score (KSS) and knee joint extensor/flexor muscle strength were assessed. At 1-year follow-up, the mechanical and coronal component alignment was measured from a postoperative long standing radiograph, and ROM, KSS, and muscle strength measurements were taken in 91 patients. Functional outcome and muscle strength measurements were compared between normally aligned and malaligned TKA groups.Results — 29 of 91 TKAs were malaligned, i.e. they deviated more than 3° from the neutral mechanical axis. 18 femoral components and 15 tibial components were malaligned. Before surgery, the malaligned and normally aligned groups were similar regarding sex distribution, BMI, ROM, KSS, and muscle strength. At the 1-year follow-up, the differences between the groups regarding knee joint function and muscle strength were small, not statistically significant, and barely clinically relevant.Interpretation — Moderate varus/valgus malalignment of the mechanical axis or of individual components has no relevant clinical effect on function or muscle strength 1 year after TKA surgery.Failure to restore limb alignment in total knee arthroplasty (TKA) increases the risk of revision (Jeffery et al. 1991, Ritter et al. 1994 and 2011, Berend et al. 2004), but the effect of accurate postoperative alignment on TKA function is controversial (Lotke and Ecker 1977, Choong et al. 2009, Fang et al. 2009, Longstaff et al. 2009, Huang et al. 2012).Huang et al. (2012) reported that TKAs with a coronal alignment within 3° from the neutral axis had better function and quality of life at 5-year follow-up than TKAs that deviated more than 3° from neutral alignment. Other studies comparing computer-assisted TKA with conventional TKA surgery have not been able to correlate malalignment with inferior functional outcomes (Spencer et al. 2007, Kamat et al. 2009, Kim et al. 2009, Burnett and Barrack 2013).Patients with greater preoperative muscle strength have been reported to have faster recovery and better functional outcome after TKA (Mizner et al. 2005, Yoshida et al. 2008). However, full recovery of muscle strength after TKA is uncommon (Berth et al. 2002, Valtonen et al. 2009, Maffiuletti et al. 2010, Vahtrik et al. 2012).It is plausible that failure to restore the mechanical axis restoration results in inferior muscle function. Sogabe et al. (2009) found different cross-sectional areas in the quadriceps muscles with different knee alignments. They suggested that knees with varus or valgus deformation should have poorer muscle function compared to normally aligned knees. However, we have not been able find any studies investigating muscle strength after TKA in relation to component alignment and mechanical axis restoration.We investigated whether coronal malalignment of the mechanical axis and/or of individual implant components would affect knee muscle strength and function 1 year after TKA surgery.     

The Rheometric Analysis of the Polymer Modifier’s Properties in the Environment of Hydrated Cement

This paper investigates the effect of polymer modifiers (re-dispersible powder, multifunctional additives, methylhydroxyethylcellulose) on the rheological behavior of emulsions, saturated of calcium hydrosilicates to simulate a hydrating cement structure. The subjects of the study were modified emulsions which had varied concentrations of each additive and they were examined comparatively to a base emulsion. Tests were performed with a CR-rheometer (“Himpribor-1”, Tula, Russia) applying the Searle measuring principle at various shear rates to characterize viscosity properties. The performance of modified mixtures within the operating period was analyzed by using two parameters—effective viscosity (η) and the proportion of structural failure (|m|). The test results showed that the most important factor influencing rheological characteristics is the addition of methylhydroxyethylcellulose additive—the higher additive amount in the emulsion, the higher the viscosity. Furthermore it was noted in the work that adding olefin sulfonate sodium salt causes reduced viscosities as well as lower shear moduli. If ethylhydroxyethylcellulose and ethylene vinyl acetate additives are used in the same mixture together, the rate of structural failure |m| can be relatively similar and low regardless of whether the mixture has large or small viscosity values.     

Degeneration of mammalian PNS and CNS axons is accelerated by incubation with protein synthesis inhibitors

Protein synthesis inhibitors (PSIs) increase the rate of degeneration, as measured by compound action potential (CAP) conduction, in segments of rat PNS and CNS axons. Sciatic axonal segments maintained in vitro in Krebs at 37-38 degrees C generate CAPs for 24 h compared to 8 h for axons exposed to Krebs containing two PSIs, 100 microM anisomycin and/or 35 microM cycloheximide. Spinal axonal segments at 37-38 degrees C generate CAPs for 3 h compared to 2 h for axons exposed to Krebs containing PSIs. While cooling (6-9 degrees C) slows degeneration rate, cooled sciatic axons exposed to PSIs exhibit lower peak CAPs compared to cooled control segments (P<0.005).     

Patients with Acute Lacunar Infarction Have Benefit from Intravenous Thrombolysis

Introduction: Usefulness of intravenous thrombolysis in patients with acute lacunar cerebral infarction is questionable. The aim of this study was to evaluate the efficacy and safety of intravenous thrombolysis in patients with lacunar infarction in comparison with patients with nonlacunar infarction as well as with patients with lacunar infarction who were not treated with intravenous thrombolysis. Materials and methods: In the first part of the study, among patients with acute ischemic stroke treated with intravenous thrombolysis, characteristics and outcomes of 46 patients with lacunar and 221 patients with nonlacunar infarction were compared. In the second part, 46 patients with lacunar infarction treated with intravenous thrombolysis were compared with 45 lacunar infarction patients who were not treated with intravenous thrombolysis. Results: Patients with lacunar infarction had a lower National Institutes of Health Stroke Scale score (9.2 versus 13.9, P < .001), a greater Alberta Stroke Program Early computed tomography (CT) score (9.7 versus 9.2, P?=?.002), a lower prevalence of atrial fibrillation (6.5% versus 41.2%, P < .001), and significantly more frequently an excellent outcome after 3 months (76.1% versus 36.2%, P < .001) compared with patients with nonlacunar infarction. Among patients with lacunar infarction, an excellent outcome at discharge was significantly more frequent in the intravenous thrombolysis group (41.3% versus 15.6%, P?=?.01), and the length of hospitalization was significantly shorter (9.5 days versus 14.3 days, P?=?.002). There was no hemorrhagic transformation among patients with lacunar infarction treated with intravenous thrombolysis. Conclusion: Intravenous thrombolysis has proven to be effective and safe in patients with lacunar infarction and should always be applied if there are no absolute contraindications.     

Lanthanum and Manganese Co-Doping Effects on Structural,Morphological, and Magnetic Properties of Sol-Gel Derived BiFeO3

In this work, lanthanum and manganese co-substitution effects on different properties of bismuth ferrite solid solutions Bi_1-xLa_xFe_0.85Mn_0.15O₃ (x from 0 to 1) prepared by a sol-gel synthetic approach have been investigated. It was observed that the structural, morphological, and magnetic properties of obtained specimens are influenced by the amount of introduced La³⁺ ions. Surprisingly, only the compound with a composition of BiFe_0.85Mn_0.15O₃ was not monophasic, and the presence of neighboring phases was determined from X-ray diffraction analysis and Mössbauer measurements. Structural transitions from orthorhombic to cubic and back to orthorhombic were also observed depending on the La³⁺ amount. Antiferromagnetic behaviour was observed for all of the samples, with the highest magnetisation values for Bi_0.5La_0.5Fe_0.85Mn_0.15O₃. Additionally, structural attributes and morphological features were evaluated by Raman spectroscopy and scanning electron microscopy (SEM), respectively.     

Clinical and genetic heterogeneity of erythrokeratoderma variabilis

The skin disease erythrokeratoderma variabilis (EKV) has been shown to be associated with mutations in GJB3 and GJB4 encoding connexin (Cx)31 and Cx30.3, respectively. Gap junctions composed of Cx proteins are intracellular channels providing a mechanism of synchronized cellular response facilitating metabolic and electronic functions of the cell. In the skin, Cx31 and Cx30.3 are expressed in the stratum granulosum of the epidermis with a suggested role in late keratinocyte differentiation. Molecular investigations of GJB3 and GJB4 were performed in five pedigrees and three sporadic cases of EKV. Mutational analyzes revealed disease-associated Cx31 or Cx30.3 mutations in only three probands of which two were novel mutations and one was a recurrent mutation. These genetic studies further demonstrate the heterogeneous nature of the erythrokeratodermas as not all individuals that were clinically diagnosed with EKV harbor Cx31 or Cx30.3 mutations.