Average 4-Year Outcomes of Distal Oblique First Metatarsal Osteotomy for Stage 1 to 3 Hallux Rigidus

Background: Hallux rigidus is the second most frequent pathology of the first ray. Surgical options for degenerative metatarsophalangeal joint disease are either joint destructive or conservative procedures. The hypothesis was that oblique distal shortening osteotomy of the first metatarsal is an effective conservative technique for the management of stage 1 to 3 hallux rigidus. Methods: We conducted a retrospective cohort study of 87 feet with Coughlin and Shurnas’s stage 1-3 hallux rigidus, operated between 2009 and 2019. The cohort consisted in 72 patients (87 feet) with an average age of 57±9 (30/79) years; 22 of 87 (25.3%) feet had the first metatarsal surgery performed in isolation; 65 of 87 (74.7%) had concomitant forefoot procedures, including 31 of 87 (35.6%) with Akin phalangeal osteotomies and 34 of 87 (39.1%) with Moberg phalangeal osteotomies. We evaluated the American Orthopaedic Foot & Ankle Society (AOFAS) Scale, subjective satisfaction, joint amplitudes, shortening rate, and occurrence of postoperative complications with a mean follow-up of 51 months (16/134). Results: The AOFAS score increased from 54.2±11.3 (25/70) preoperatively to 92.2±7.8 (62/100) postoperatively ( P < .001). Patients reported excellent or good outcome in 95.4% of cases. The 40-point self-reported pain subscale score improved from 19.6 (± 10.0) to 37.4 (± 5.4), P < .001. The overall range of motion increased from 61±21 (20/110) degrees to 69±17 (35/120) degrees ( P < .001). The mean first metatarsal shortening rate (SRpo) was 9.6%. Neither the Coughlin grade, the metatarsal index, or the SRpo influenced the AOFAS score. At 6-month follow-up, 15 patients had transfer metatarsalgia compared with 5 at last follow-up without requiring another surgical procedure. The risk was not significantly different according to Coughlin's stage, preoperative metatarsal index, or SRpo. Conclusion: Oblique distal osteotomy of the first metatarsal for stage 1-3 hallux rigidus, often in combination with other first ray procedures, performed well during our follow-up time period, with a high subjective satisfaction rate and few complications. Level of Evidence: Level III, retrospective cohort study.

Feasibility of endoscopic hand suturing on rectal anastomoses in ex vivo porcine models

Prevention of postoperative anastomotic leakage in rectal surgery is still required. This study investigated the feasibility of endoscopic hand suturing (EHS) on rectal anastomosis ex vivo. By using isolated porcine colon, we prepared ten anastomoses 6–10 cm from the virtual anus. Then, we sutured anastomoses intraluminally by EHS, which involved a continuous suturing method in 5 cases and a nodule suturing method with extra corporeal ligation in 5 cases. Completeness of suturing, number of stitches, procedure time and presence of stenosis were investigated. Furthermore, the degree of stenosis was compared between the two suturing methods. In all cases, EHS were successfully completed. The median number of stitches and procedure time was 8 and 5.8 min, respectively. Stenosis was created in all continuous suturing cases whereas none was seen in nodule suturing cases. The shortening rate was significantly greater in the continuous suturing method than in the nodule suturing method. Intraluminal reinforcement of rectal anastomosis by EHS using nodule suturing with extra corporeal ligation is feasible without stenosis, which may be helpful as a countermeasure against possible postoperative anastomotic leakage in rectal surgery.

Angelica sinensis Polysaccharide Alleviates Myocardial Fibrosis and Oxidative Stress in the Heart of Hypertensive Rats

This research is aimed at studying the effect of Angelica sinensis polysaccharide (ASP) extracted from the Lixinshui prescription on cardiac disease induced by hypertension in rats. Rat models of cardiovascular disease were established, and the associated factors were measured. The data showed that ASP treatment increased the ejection fraction and short axis shortening rate, while decreasing the LV end-diastolic diameter, LV end-systolic diameter, LV end-diastolic volume, and LV end-systolic volume in HHD rats. ASP downregulated the expression level of TGF-β1, alpha-smooth muscle actin (α-SMA), collagen I, fibronectin, vimentin, Bax, cleaved caspase-9, and cleaved caspase-3 and upregulated the expression level of Bcl-2 in LV of HHD rats. Meanwhile, ASP increased the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and decreased the level of malondialdehyde (MDA), tissue endogenous hydrogen peroxide (H2O2), and reactive oxygen species (ROS). Our findings indicated that ASP could prevent hypertensive heart disease by inhibiting myocardial fibrosis, suppressing the myocardial apoptosis, and alleviating oxidative stress.

Pleistocene-Holocene crustal deformation in the far-Western Himalaya

We present new Late Pleistocene-Holocene shortening rates across the frontal fold-and-thrust belt, namely as, the Sub-Himalaya (SH) from the far-western Himalayan sector of Jammu. OSL-dated offset/ folded fluvial strath terraces suggest that the intraplate convergence is partitioned among several active structures in the SH. Estimated cumulative Late Pleistocene- Holocene shortening rate in the SH is ~9.5±1.3 mm/yr, which is ~70–75% of the measured geodetic convergence rates. Our study invokes the existence of a ~350–400 km-long out-of-sequence fault-boundary within the SH which accommodates ~5.3±2.3 mm/yr shortening since Late Pleistocene-Holocene. Our study also highlights that ongoing crustal shortening is not accommodated only at the toe of the Himalayan wedge.

Late Quaternary Kinematics and Deformation Rate of the Huoyanshan Structure Derived From Deformed River Terraces in the South Piedmont of the Eastern Chinese Tian Shan

The deformation pattern and strain partitioning in the Eastern Chinese Tian Shan are poorly known because of the lack of quantitative study of the kinematics and deformation rate of the major structure. Here we report a late Quaternary shortening rate for the most active reverse fault-and-fold in the Eastern Chinese Tian Shan. We quantified the kinematics and late Quaternary shortening rate of the Huoyanshan structure based on detailed high-resolution remote sensing image interpretations, field investigations and geological mapping. Six generations of folded terraces along the Tuyugou valley that showed the progressive folding process by the Huoyanshan structure were identified. A kinematic model of curved thrust fault propagation and folding allowed us to describe the terrace deformation pattern and subsurface fault geometry and calculate shortening across this structure. Combined with a regional age control of terrace T4 in the Tuyugou valley, a late Quaternary shortening rate of 2.0–3.2 mm/yr of the Huoyanshan structure was obtained. This is a relatively high shortening rate in the whole Eastern Chinese Tian Shan (roughly east of 88 E). This shortening rate of the Huoyanshan structure highlights that the ongoing India and Eurasia collision has affected the entire Tian Shan but shows two strain partitions: the main strain-absorption belt is located within the Eastern Chinese Tian Shan interior, but strain also occurs at the range-front foreland in the Western Tian Shan.

Structural Style and Kinematic History of the Colombian Eastern Cordillera

Fold-and-thrust belts and their associated structures are among the most common geological features of convergent margins. They provide significant information about crustal shortening and mountain-building processes. In subaerial belts, where the erosional rates are high and the growth strata are mostly eroded, methodologies such as that presented here can provide insights into to their formation. Two 2D cross-sections located in the Eastern Cordillera of Colombia are presented in this research. These sections extend from the Bogota Savanna to The Llanos, parallel to the regional deformation direction. Section construction was carried out using commercial surface data, and seismic information provided by Ecopetrol. Published thermochronometric data, gravel-clast petrography analysis, and paleoflora analysis were used to construct a viable tectono-evolutionary history of the study area. This evolutionary model is presented here in two palinpastic restorations from the Early Paleogene to Recent (∼65 Ma to Present-day). Section 1 and Section 10 accumulated 17.3 km and 19.5 km of shortening, respectively. The section reconstruction displays two major tectonic events – post-rift subsidence during the Early-Mid Paleogene, and positive inversion from the Oligocene to Recent (∼33 Ma to Present-day). This investigation focuses on the compressional period, where the structural analysis evidences an acceleration in the shortening rate, as well as a progressive migration of the deformation from northwest to southeast. This research discusses the extent and limitation of this methodology, as well as the principal structural aspects of the reconstruction.

Population differences in the length, early-life dynamics, and heritability of telomeres among European pied flycatchers

Telomere length and shortening rate are increasingly used as biomarkers for long-term costs in ecological and evolutionary studies because of their relationships with survival and fitness. Telomere length can be heritable, but both early-life conditions and later-life stressors can create variation in telomere shortening rate. Studies on between-population telomere length and dynamics are mostly lacking, despite the expectation that populations exposed to varying environmental constraints would present divergent telomere length patterns. Pied flycatcher (Ficedula hypoleuca) is a passerine bird spending the non-breeding period in sub-Saharan Africa but breeding across Eurasia (from Spain to western Siberia). Populations show marked differences in migration distance, genetics, breeding parameters, and egg components. We studied the large-scale variation of telomere length, early-life dynamics and heritability in the pied flycatcher by comparing six European populations across a north-south gradient (Finland, Estonia, England and Spain). There were clear population differences in telomere length, with English birds having the longest telomeres, followed by Spanish and lastly by Estonian and Finnish birds. Early-life telomere shortening rate tended to vary between populations, and faster nestling growth affected telomeres more negatively in northern than southern populations. The heritability of telomere length was moderate (h2 = 0.34 - 0.40), with stronger heritability to paternal than maternal telomere length. There was also evidence indicating that the level of paternal heritability could differ between populations. While the sources of between-population differences in telomere-related biology remain to be identified (i.e. genetics, environmental factors), our study illustrates the need to expand telomere studies at the between-population level.

Multi-method luminescence dating of old fluvial sediments from northern Tian Shan, China

At the eastern tip of Anjihai anticline on the northern piedmont of Tian Shan (northwest China), deformed fluvial deposits have recorded active folding since the Pleistocene, but the absence of accurate ages makes it difficult to evaluate the anticline’s shortening rate. Geological studies ascribed the fluvial strata to the early Pleistocene, which poses potential challenges for luminescence dating. In this study, multi-methods luminescence dating was applied to a fluvial sand sample taken from the sandy bed of the deformed basal strata. Single grain post-Infrared Infrared Stimulated Luminescence (pIRIR) and multiple-aliquot-regenerative (MAR) dose along with multiple-elevated-temperature pIRIR (MET-pIRIR) procedures were applied to determine the paleodose of the sample. The methodological uncertainties, such as thermal transfer and initial sensitivity change, were treated by increasing the test dose and performing dose recovery test. With consideration of the potential partial bleaching and anomalous fading, various statistical metrics were applied to the De values determined by using the single grain pIRIR225, single grain pIRIR290 and MAR-MET-pIRIR290 signals. The minimum age model (MAM) De values are 11% – 17% lower than the central age model (CAM) De values in general, and the MAM De values determined by the single grain pIRIR procedures are underestimated by more than 40% when compared with those determined by MAR-MET-pIRIR290 procedure. The MAM MAR-MET-pIRIR290 De of 811 ± 44 Gy results in a burial age of 284 ka for the basal deformed fluvial strata, which is much younger than the proposed early Pleistocene age.

Incremental shortening calculation of the mixed-shear fault-bend folds

&lt;p&gt;Shear fault-bend folds are characterized by a long back-limb that dips more gently than the fault ramp [1]. During the folding growth, the back limb rotates and widens progressively through a combination of limb rotation and kink-band migration. Two end-member models of shear fault-bend folding theories, including simple-shear fault-bend folding (C=0.5) and pure-shear fault-bend folding (C=1), have been developed and widely applied. Mixtures of pure and simple shear (0.5&lt;C&lt;1) are possible and have been found in the natural. Few quantitative methods to limit the shear-index (C) of the shear fault-bend folds so far. The incremental shortening can be calculated based on a simplified equation that assumes the linear relationship between the shortening and the limb rotation angle of the back limb [2]. However, the relationship of these two parameters is nonlinear according to the shear fault-bend folding theory [1]. Calculation results of the linear model have large uncertainty.&lt;/p&gt;&lt;p&gt;Here, we develop a method to calculate the shear-index (C), providing an idea to improve the mixed-shear fault-bend fold models, and establishing a formula to calculate the incremental shortening based on the nonlinear relationship between the back-limb dip angle and the shortening. It is a more general method to calculate the incremental shortening of the shear fault-bend folds.&lt;/p&gt;&lt;p&gt;This model has been applied to the Tugulu anticline in the northern foreland of Chinese Tian Shan, which is a mixed-shear fault-bend fold based on previous studies [3]. Through an analysis of deformed fluvial terraces and growth strata, we develop the shortening history of the Tugulu anticline along the Hutubi River using our developed nonlinear model. Our results show that the Tugulu anticline has a shear-index of ~0.91 and a steady shortening rate of ~1.5mm/yr over the last 500ka.&lt;/p&gt;&lt;p&gt;References:&lt;/p&gt;&lt;ul&gt;&lt;li&gt;[1] Suppe et al. (2004) AAPG Memoir 82: 303-323.&lt;/li&gt; &lt;li&gt;[2] Yue et al. ( 2011) AAPG Memoir 94: 153&amp;#8211;186.&lt;/li&gt; &lt;li&gt;[3] Qiu et al. ( 2019) Tectonophysics 772:228209.&lt;/li&gt; &lt;/ul&gt;