Mitochondrial genome sequencing and analysis of the invasive Microstegium vimineum: a resource for systematics, invasion history, and management.

Premise of the Research: Plants remain underrepresented among species with sequenced mitochondrial genomes (mitogenomes), due to the difficulty in assembly with short-read technology. Invasive species lag behind crops and other economically important species in this respect, representing a lack of tools for management and land conservation efforts. Methodology: The mitogenome of Microstegium vimineum, one of the most damaging invasive plant species in North America, was sequenced and analyzed using long-read data, providing a resource for biologists and managers. We conducted analyses of genome content, phylogenomic analyses among grasses and relatives based on mitochondrial coding regions, and an analysis of mitochondrial single nucleotide polymorphism in this invasive grass species. Pivotal Results: The assembly is 478,010 bp in length and characterized by two large, inverted repeats, and a large, direct repeat. However, the genome could not be circularized, arguing against a "master circle" structure. Long-read assemblies with data subsets revealed several alternative genomic conformations, predominantly associated with large repeats. Plastid-like sequences comprise 2.4% of the genome, with further evidence of Class I and Class II transposable element-like sequences. Phylogenetic analysis placed M. vimineum with other Microstegium species, excluding M. nudum, but with weak support. Analysis of polymorphic sites across 112 accessions of M. vimineum from the native and invasive ranges revealed a complex invasion history. Conclusions: We present an in-depth analysis of mitogenome structure, content, phylogenetic relationships, and range-wide genomic variation in M. vimineum's invasive US range. The mitogenome of M. vimineum is typical of other andropogonoid grasses, yet mitochondrial sequence variation across the invasive and native ranges is extensive. Our findings suggest multiple introductions to the US over the last century, with subsequent spread, secondary contact, long-distance dispersal, and possibly post-invasion selection on awn phenotypes. Efforts to produce genomic resources for invasive species, including sequenced mitochondrial genomes, will continue to provide tools for their effective management, and to help predict and prevent future invasions.

Structures of the xyloglucans in the monocotyledon family Araceae (aroids).

MAIN CONCLUSION: The xyloglucans of all aquatic Araceae species examined had unusual structures compared with those of other non-commelinid monocotyledon families previously examined. The aquatic Araceae species Lemna minor was earlier shown to have xyloglucans with a different structure from the fucogalactoxyloglucans of other non-commelinid monocotyledons. We investigated 26 Araceae species (including L. minor), from five of the seven subfamilies. All seven aquatic species examined had xyloglucans that were unusual in having one or two of three features: < 77% XXXG core motif [L. minor (Lemnoideae) and Orontium aquaticum (Orontioideae)]; no fucosylation [L. minor (Lemnoideae), Cryptocoryne aponogetonifolia, and Lagenandra ovata (Aroideae, Rheophytes clade)]; and > 14% oligosaccharide units with S or D side chains [Spirodela polyrhiza and Landoltia punctata (Lemnoideae) and Pistia stratiotes (Aroideae, Dracunculus clade)]. Orontioideae and Lemnoideae are the two most basal subfamilies, with all species being aquatic, and Aroideae is the most derived. Two terrestrial species [Dieffenbachia seguine and Spathicarpa hastifolia (Aroideae, Zantedeschia clade)] also had xyloglucans without fucose indicating this feature was not unique to aquatic species.

Predictors for self-discontinuation of anti-osteoporosis medication: A hospital-based real-world study.

Osteoporotic fractures have a tremendous impact on quality of life and may contribute to fatality, but half of patients may discontinue their anti-osteoporosis medication. The study aimed to investigate the factors associated with the persistence of anti-osteoporosis medication. Between June 2016 and June 2018, we recruited 1195 participants discontinuing prior anti-osteoporosis medication. Telephone interviews were conducted to discern the reasons for discontinuation. Comparisons among groups and risks of self-discontinuation were analyzed. Among 694 patients who have no records of continuing anti-osteoporosis medication, 374 (54%) self-discontinued, 64 (9.2%) discontinued due to physicians' suggestion, and 256 (36.8%) with unintended discontinuation. Among patients with self-discontinuation, 173 (46.3%) forgot to visit outpatient clinics; 92 (24.5%) discontinued because of medication-related factors; 57 (15.2%) thought the severity of osteoporosis had improved and therefore discontinued; 30 (8%) stopped due to economic burden; 22 (5.9%) were lost to follow-up because of newly diagnosed diseases other than osteoporosis. Additionally, older age, male gender, calcium supplement, teriparatide therapy and hip fractures in teriparatide users were associated with adherence to anti-osteoporosis drugs. In conclusion, our results indicate that younger age, female gender, non-use of calcium supplements, and anti-resorptive medication were independent risk factors associated with drug discontinuation. Identifying high-risk patients and providing timely health education are crucial for adherence to anti-osteoporosis medication.

The Butterfly Fragment in Wedge-Shaped Femoral Shaft Fracture: Comparison of Two Different Surgical Methods.

OBJECTIVE: Our study compared the results of wedge-shaped femoral shaft fracture following intramedullary (IM) nailing with or without fixation of the third fragment. METHODS: We retrospectively reviewed patients presenting with femoral shaft fracture with AO/OTA type 32-B from 2011 to 2016. Patients were divided into two groups: closed reduction without touching the third fragment and open reduction with fixation of the third fragment. The fragment ratio, fragment length, nail size, dynamization or not, mRUST scores, union rate, and union time were compared between the two groups. Risk factors of non-union were also investigated, including sex, age, fracture pattern, fracture location, dynamization, nail size, fragment ratio, fragment size, and postoperative fragment displacement. RESULTS: A total of 80 patients met inclusion criteria, 20 patients with wedge-shaped shaft femoral fracture were managed with IM nailing and open reduction with fixation of the third fragment. Sixty patients were treated with IM nail without touching the third fragment. The union rate for the fixation and non-fixation groups were 60.0% and 81.7%, respectively. The mean union time for the fixation group was 19 months vs 14 months for the non-fixation group. Multi-regression analysis showed larger nail size (odds ratio: 2.26) and fixation of the third fragment (odds ratio: 0.18) influenced fracture healing. CONCLUSIONS: Fixation of the third fragment in wedge-shaped shaft femoral fracture results in a longer union time and lower union rate. In the management of femoral fracture with a third fragment, a larger nail size is recommended and fixation should be performed in a closed manner. Fixation of the fragment may achieve better fracture reduction. However, disruption of the vasculature and surrounding structures may further result in nonunion of the fracture site.

Factors Associated with Postoperative Lipiduria and Hypoxemia in Patients Undergoing Surgery for Orthopedic Fractures.

We investigated factors associated with postoperative lipiduria and hypoxemia in patients undergoing surgery for orthopedic fractures. We enrolled patients who presented to our emergency department due to traumatic fractures between 2016 and 2017. We collected urine samples within 24 h after the patients had undergone surgery to determine the presence of lipiduria. Hypoxemia was defined as an SpO2 <95% determined with a pulse oximeter during the hospitalization. Patients' anthropometric data, medical history, and laboratory test results were collected from the electronic medical record. Logistic regression analyses were used to determine the associations of clinical factors with postoperative lipiduria and hypoxemia with multivariate adjustments. A total of 144 patients were analyzed (mean age 51.3 ± 22.9 years, male 50.7%). Diabetes (odd ratio 3.684, 95% CI, 1.256-10.810, p = 0.018) and operation time (odd ratio 1.005, 95% CI, 1.000-1.009, p = 0.029) were independently associated with postoperative lipiduria, while age (odd ratio 1.034, 95% CI, 1.003-1.066, p = 0.029), body mass index (odd ratio 1.100, 95% CI, 1.007-1.203, p = 0.035), and operation time (odd ratio 1.005, 95% CI, 1.000-1.010, p = 0.033) were independently associated with postoperative hypoxemia. We identified several factors independently associated with postoperative lipiduria and hypoxemia in patients with fracture undergoing surgical intervention. Operation time was associated with both postoperative lipiduria and hypoxemia, and we recommend that patients with prolonged operation for fractures should be carefully monitored for clinical signs related to fat embolism syndrome.

Improved outcomes and reduced medical costs through multidisciplinary co-management protocol for geriatric proximal femur fractures: a one-year retrospective study.

BACKGROUND: To manage the rapidly growing incidence of, and related medical burden resulting from hip fractures in older adults in an aging society, studies involving orthogeriatric co-management treatment models have reported improved outcomes, including reduced medical costs. The treatment gap for osteoporosis was however seldom emphasized in the published treatment protocols. Aiming to improve the existing orthogeriatric protocol, we have established a patient-centered protocol for elderly patient hip fractures, which simultaneously focuses on fracture care and anti-osteoporosis agent prescription in regarding to healthcare quality and medical expense. METHODS: This was a retrospective study comparing patients who enrolled in the multidisciplinary co-managed protocol for geriatric hip fractures and those who did not. The inclusion criteria for this study were: (a) single-sided hip fractures treated from 1 to 2018 to 30 June 2020, (b) patients who were 60-years or older (c) trauma treated within 3 days from time of injury, and (d) minimal follow-up period of 12 months after surgery. RESULTS: From 1 to 2018 to 30 June 2020, 578 patients were included (267 patients in the protocol group vs. 331 patients in the conventional group). The protocol group was associated with significantly reduced lengths of hospital stay (p = 0.041), medical expenditures (p = 0.006), and mortality (p = 0.029) during their acute in-hospital admission period. Early osteoporosis diagnosis and anti-osteoporosis agent prescription were achieved in the protocol group, with a significantly wider coverage for BMD assessment (p < 0.001) and prescriptions for anti-osteoporosis medication (p < 0.001). Yet, there was no significant decline in the one-year refracture rate in the protocol group. CONCLUSIONS: The implementation of a multidisciplinary co-managed care protocol for geriatric proximal femur fractures successfully improved patient outcomes with significantly reduced lengths of stay, medical expenditures, and mortality during the acute in-hospital admission period. The high prescription rate of anti-osteoporosis medication after hip fractures in the protocol group was not associated with a significantly lower re-fracture rate in the 12-month follow-up. However, the association between early anti-osteoporosis agent prescription and reduced long-term medical expenses in this group of patients has provided a direction for future research.

Low Bone Mineral Density and Calcium Levels as Risks for Mortality in Patients with Self-Discontinuation of Anti-Osteoporosis Medication.

Bone mass density (BMD) has been used universally in osteoporosis diagnosis and management. Adherence to anti-osteoporosis medication is related to mortality risk. This study aimed to investigate the relationship between mortality and low BMD of the femoral neck and vertebra among patients self-discontinuing anti-osteoporosis medication. Between June 2016 and June 2018, this single-center retrospective study recruited 596 participants who self-discontinued anti-osteoporosis medication. Patients were categorized into four groups by BMD of the right femoral neck and lumbar spine. Occurrence and causes of mortality were obtained from medical records. Independent risk factors and the five-year survival of various levels of BMD were analyzed by Cox regression and the Kaplan-Meier survival analysis. BMD value and serum calcium level were significantly lower in the mortality group (p < 0.001). Compared to the reference, the adjusted hazard ratio (HR) for all-cause mortality in patients with lower BMD of both the lumbar spine and femoral neck was 3.03. The five-year cumulative survival rate was also significantly lower (25.2%, p < 0.001). A low calcium level was also associated with mortality (HR: 0.87, 95% CI: 0.76-0.99, p = 0.033). In conclusion, lower BMD and calcium levels were associated with higher mortality risk in patients with poor adherence. Hence, patients self-discontinuing anti-osteoporosis medication should be managed accordingly.

Evaluating the necessity of bone augmentation for distal radius fracture fixed with a volar locking plate: a retrospective study.

BACKGROUND: Multiple approaches for fixation of distal radius fractures exist; nonetheless, there is no consensus on the optimal treatment for these injuries. Although using volar locking plates has become increasingly common as a surgical intervention, the usefulness of bone augmentation remains debatable. Therefore, this study aimed to evaluate the necessity of bone augmentation for distal radius fractures fixed with a volar locking plate. METHODS: This retrospective study enrolled patients with a single distal radius fracture treated with a volar locking plate between January 2014 and December 2016. Overall, 105 fractures were included and divided into two groups (non-bone augmentation: group 1, n = 88; bone augmentation: group 2, n = 17). Images were reviewed, and dorsal cortex collapse, volar tilting, and radial height and inclination were measured immediately after surgery and at the 6-month follow-up. RESULTS: Both groups exhibited significant differences in dorsal collapse (p < 0.001 and p = 0.001, respectively) and radial height shortening (p < 0.001 and p = 0.039, respectively); volar tilting and radial inclination did not differ significantly. There was no difference in the degree of dorsal collapse (p = 0.715) and radial height shortening (p = 0.651) between the two groups. Of the 105 fractures, 54 were identified as comminuted type according to the AO classification (A3, C2, and C3), and similar radiographic outcomes were noted. CONCLUSIONS: Volar locking plates for the treatment of distal radius fractures with or without bone augmentation do not affect the radiographic outcomes. In comminuted fractures, additional bone augmentation is unnecessary if intraoperative anatomical reduction and fixation are performed when possible.

Isolated and early-onset cerebral fat embolism syndrome in a multiply injured patient: a rare case.

BACKGROUND: Fat embolism syndrome (FES) is a rare complication that can occur between 12 and 72 h after the initial insult. Isolated cerebral FES without pulmonary symptoms is rarer. Early fracture fixation might prevent FES. We report a case of multiple-fracture with FES despite definite fixation three hours post-injury. CASE PRESENTATION: A 54-year-old man presented with multiple fractures: left femoral shaft (AO B2), left distal radius (AO C3), left comminuted patella, right comminuted 1st metatarsal base and left 2nd-4th metatarsal neck. Because he was stable, we gave him early total care and definite fixation, which required seven hours and yielded no complications. After he recovered from anesthesia, however, his eyes deviated right, his right upper arm was paralyzed, his consciousness level was poor, and his Glasgow Coma Scale score was E3VeM4. Chest X-rays showed clear lung fields, and brain computed tomography showed no intracranial hemorrhage. He did, however, have tachycardia, anemia, and thrombocytopenia. Brain magnetic resonance images showed a hyperintensive starfield pattern on diffuse weighted images, which suggested cerebral FES. After supportive care, his consciousness cleared on postoperative day 17, and he recovered full right upper arm muscle power after four months; however, he had a significant cognitive deficit. One-year post-injury, after regular rehabilitation therapy, he was able to independently perform his activities of daily living but still had a residual mild cognitive deficit. CONCLUSION: Early fixation can attenuate but not eliminate the incidence of FES. Early assessment and rehabilitation therapy might be required for patients with cerebral FES and cognitive deficits; however, such deficits are difficult to predict and need long-term follow-ups.

Three-dimensional CT Improves the Reproducibility of Stability Evaluation for Intertrochanteric Fractures.

OBJECTIVES: Femoral intertrochanteric fractures are among the most common fractures in the elderly. There are various classification systems in intertrochanteric fractures. The aim of these classification systems is to help surgeons choose an appropriate treatment. The treatment of femoral intertrochanteric fractures depends on the results of a stability evaluation using imaging studies. However, it is difficult to evaluate the true fracture line using plain X-ray films, especially on the sagittal plane and for intertrochanteric fractures with complex morphologies. The aim of the current study was to determine whether three-dimensional CT (3DCT) improves the reproducibility of stability evaluation for femoral intertrochanteric fractures. METHODS: This was a single-center observational study of intertrochanteric fractures. We retrospectively collected patients in our hospital with intertrochanteric fractures that underwent plain X-ray (anteroposterior, lateral view) CT scans with axial images (2DCT) and 3DCT for an injured hip between 1 December 2011 and 30 November 2015. The exclusion criteria were pathological fractures (due to metastasis or primary bone tumors) and previous intertrochanteric surgery. During this period, 61 patients were enrolled. Two patients were excluded because lateral view X-rays were not available. A total of 59 patients (27 women, 32 men) with an average age of 77 years (range, 55-96 years) were included in our final analysis. The stability evaluation (i.e. stable or unstable) and implant choices (i.e. dynamic hip screws or Gamma nail) were recorded independently by four observers (two attending physicians and two residents). All images were reviewed and classified using the AO/OTA and Evans modified by Jensen (EVJE) classification systems. The session was repeated after a 3-month wash-out period. The inter-observer agreement was evaluated using the Kappa test. RESULTS: The inter-observer agreements, measured by the mean weighted kappa values (expressed as X-ray vs 3DCT) were as follows: For stability evaluation, the mean kappa values for attending physicians and residents were 0.68 versus 0.76 and 0.55 versus 0.56. For implant choices, the mean kappa values for attending physicians and residents were 0.68 versus 0.76 and 0.57 versus 0.65. For AO/OTA classification, the values for attending physicians and residents were 0.67 versus 0.65 and 0.70 versus 0.81. For EVJE classification, the values for attending physicians and residents were 0.66 versus 0.63 and 0.56 versus 0.55. CONCLUSIONS: Three-dimensional CT improved the reproducibility of stability evaluation for femoral intertrochanteric fractures. Preoperative CT scanning may provide a diagnostic benefit for evaluating the stability of intertrochanteric fractures.

Investigation of floristic similarities between Taiwan and terrestrial ecoregions in Asia using GBIF data.

BACKGROUND: Floristic compositions of non-endemic plants of continental islands were related to the neighboring continents because non-endemic plant species had historically migrated to continental islands from source areas. This study attempts to identify source areas of a continental island by means of floristic analysis and to assess possible migration routes on the basis of geographical distribution ranges of plants. Large quantities of angiosperm data records were downloaded from the Global Biodiversity Information Facility (GBIF). Similarity index and cluster analysis were used to identify the floristic similarities among 22 geographical localities of Taiwan (GLTs) and 34 terrestrial ecoregions in Asia. Geographical distribution ranges of non-endemic angiosperm species in Taiwan (NEASTs) were evaluated to mirror the possible migration routes from different source areas to Taiwan. RESULTS: There are 3275 angiosperm species in Taiwan derived from the dataset of GBIF. Among them, 847 are endemic and 2428 are NEASTs. Geographical distribution ranges of the 2428 NEASTs were categorized into 7 distribution groups. They were widely distribution from equator to Siberia (27 species), tropical ecoregions (345 species), tropical and subtropical ecoregions (663 species), tropical to temperate ecoregions (591 species), subtropical ecoregions (265 species), subtropical to temperate ecoregions (387 species), and temperate ecoregions (150 species). Results of similarity indices and cluster analysis demonstrated that high floristic similarities were observed among GLTs at lowland and southern Taiwan and tropical and subtropical ecoregions in Asia. GLTs at high mountains were assumed to have floristic similarity with temperate ecoregions in Asia, whereas the assumption was not supported by our analysis. It is partly because of that angiosperms with tropical and subtropical distributions extend their ranges from low to high elevations in Taiwan. CONCLUSIONS: Subtropical ecoregions at southern China and tropical ecoregions at Indochina were more important than temperate ecoregions on playing source areas of NEASTs. Geographical distribution ranges of NEASTs implied that most of the NEASTs were probably migrated from topical or subtropical ecoregions of Asian continent to Taiwan.

Intraspecific karyotypic polymorphism is highly concordant with allozyme variation in Lysimachia mauritiana (Primulaceae: Myrsinoideae) in Taiwan: implications for the colonization history and dispersal patterns of coastal plants.

BACKGROUND AND AIMS: Investigating intraspecific karyotypic and genetic variations jointly can provide unique insights into how historical, ecological and cytogenetic factors influence microevolution. A coastal herb, Lysimachia mauritiana, exhibits extensive karyotypic polymorphism and displays a complex cytogeographic pattern across the Ryukyus. To explore whether a similar degree of chromosomal variation exists south of the Ryukyus, and in an attempt to ascertain the mechanisms that may have generated the patterns, comprehensive sampling was conducted in Taiwan. METHODS: Karyotypes were analysed at mitotic metaphase for 550 individuals from 42 populations throughout Taiwan Proper and its adjacent islands. In addition, genetic variation was estimated using 12 allozymes (21 loci) of 314 individuals sampled from 12 localities. KEY RESULTS: Four chromosome numbers and eight cytotypes, including four endemic cytotypes, were detected. Cytotype distributions were highly structured geographically, with single cytotypes present in most populations and four major cytotypes dominating the north, east and south of Taiwan and the Penghu Archipelago. Allozyme variation was very low and F-statistics indicated an extremely high level of population differentiation, implying limited gene flow among populations. Cluster analysis of allozyme variation uncovered four geographic groups, each corresponding perfectly to the four dominant cytotypes. The geographic structure of cytotype distribution and allozyme variation probably resulted from severe genetic drift triggered by genetic bottlenecks, suggesting that Taiwanese populations were likely to be derived from four independent founder events. In the few localities with multiple cytotypes, cytogeographic patterns and inferences of chromosomal evolution revealed a trend of northward dispersal, consistent with the course of the Kuroshio Current that has been influential in shaping the coastal biota of the region. CONCLUSIONS: The data elucidate the patterns of colonization and the effects of the Kuroshio Current on the distribution of L. mauritiana in Taiwan. These inferences are highly relevant to other coastal plant species in the region and will stimulate further studies.

[Traumatic response experiences: one year after Typhoon Morakot].

BACKGROUND: Disaster-related mental health problems have been a focus of recent international scholarly interest. Typhoon Morakot caused exceptional destruction in Southern Taiwan, and victims suffered physically, psychologically and financially in its aftermath. PURPOSE: This study investigates the post-traumatic response and coping behaviors of victims one year after Typhoon Morakot. METHODS: Researchers used a phenomenological method with purposive sampling and interviewed 10 Typhoon Morakot victims. Data were collected using deep, semi-structured interviews. All interview sessions were tape-recorded. Researchers used Colaizzi's seven-step phenomenological method to analyze data. RESULTS: Three common themes emerged in subjects following their disaster experiences. The first was residual traumatic response, including fear of continued flooding, fear of future flood recurrence, indifference in responses, and living on alert; The second was insecurity in daily life due to changed surroundings, including anxiety and a heavy sense of loss; The third was conformity in coping behaviors, including shifting attention away from the disaster, turning to a pluralistic support system, having an optimistic outlook on life, and living in the moment. CONCLUSION: Investigating traumatic response experiences and coping behaviors one year after the Typhoon Morakot disaster can help guide healthcare professionals to promote evidence-based health and nursing services. Findings also provide information to healthcare providers essential to improving nursing quality for victims of disasters.

Anteroposterior stability of the knee during the stance phase of gait after anterior cruciate ligament deficiency.

Quadriceps avoidance and higher flexion strategies have been assumed as effects of ACL deficiency on knee joint function during gait. However, the effect of ACL deficiency on anteroposterior stability of the knee during gait is not well defined. In this study, 10 patients with unilateral acute ACL ruptures and the contralateral side intact performed gait on a treadmill. Flexion angles and anteroposterior translation of the ACL injured and the intact controlateral knees were measured at every 10% of the stance phase of the gait (from heel strike to toe-off) using a combined MRI and dual fluoroscopic imaging system (DFIS). The data indicated that during the stance phase of the gait, the ACL-deficient knees showed higher flexion angles compared to the intact contralateral side, consistent with the assumption of a higher flexion gait strategy. However, the data also revealed that the ACL-deficient knees had higher anterior tibial translation compared to the intact contralateral side during the stance phase of the gait. The higher flexion gait strategy was not shown to correlate to a reduction of the anterior tibial translation in ACL deficient knees. These data may provide indications for conservative treatment or surgical reconstruction of the ACL injured knees in restoration of the knee kinematics during daily walking activities.

In vitro and intraoperative laxities after single-bundle and double-bundle anterior cruciate ligament reconstructions.

PURPOSE: The purpose of this study was to objectively evaluate whether double-bundle anterior cruciate ligament (ACL) reconstruction can better restore the normal translational and rotational laxities than the conventional single-bundle ACL reconstruction among the reported biomechanical studies. METHODS: A systematic literature search was conducted to identify in vitro and in vivo (intraoperative) biomechanical studies that compared the laxities (anterior or anteroposterior or rotational) between single- and double-bundle ACL reconstructions. Because of large variability among the loading conditions and testing methods used to determine the rotational laxities among the studies, a meta-analysis of rotational laxities was not feasible. RESULTS: Seven in vitro and three in vivo studies were included in this analysis based on the predefined inclusion criteria. The overall mean differences calculated by the random effects model in anteroposterior laxity between the single-bundle and double-bundle ACL reconstruction techniques at 0°, 30°, 60°, and 90° of flexion were 0.99 mm, 0.38 mm, 0.34 mm, and 0.07 mm, respectively. No statistically significant difference was noted between the 2 treatments at all flexion angles. Among the 9 studies that compared the rotational laxity of single-bundle and double-bundle ACL reconstructions, 4 reported that double-bundle reconstruction can provide better rotational control than single-bundle reconstruction. The other 5 studies could not identify any significant difference between the 2 reconstructions in terms of rotational laxity. CONCLUSIONS: Both single- and double-bundle treatment options for ACL injury result in similar anteroposterior knee joint laxity at time 0. No conclusive evidence on the superiority of 1 reconstruction technique over the other in terms of rotation laxity can be obtained because of several variations in the experimental protocol and the kinematics used to measure the rotational laxity among the studies. LEVEL OF EVIDENCE: Level III, meta-analysis.

Anatomic-like polyethylene insert could improve knee kinematics after total knee arthroplasty--a computational assessment.

BACKGROUNDS: Deficiencies in contemporary posterior crucitate retaining knee included inadequate femoral rollback and insufficient tibial rotation. Current study attempted to restore normal femoral rollback and tibial rotation to facilitate in knee flexion/extension and to achieve appropriate posture at deep knee bending after total knee arthroplasy by mimicking the morphology of convexly lateral tibial plateau of intact knee. METHODS: Computational simulation was utilized to analyze motion of three-dimensional knee models, including intact, traditionally symmetrical posterior crucitate retaining and newly anatomic-like posterior crucitate retaining knees. Solid bones, attachments of ligaments and tendons of simulation models were reconstructed by magnetic resonance images of the subject. According to the representative literature, the distal femur was modeled to rotate about the specific axes and the motion of the proximal tibial was unconstrained except for the flexion/extension. Movements of the medial/lateral condyles and tibial rotation were recorded and analyzed. FINDINGS: The newly anatomic-like posterior crucitate retaining knee improved the posterior movement of lateral condyle and tibial internal rotation significantly during full range of flexion. Compared with traditionally symmetrical posterior crucitate retaining knee, the improvements displayed by newly developed posterior crucitate retaining knee in posterior movement of lateral condyle and tibial internal rotation were 11.2mm and 9.3° at full flexion, respectively. INTERPRETATION: The newly anatomic-like posterior crucitate retaining knee demonstrated that mimicking the morphology of convexly lateral tibial plateau can be expected to restore normal knee kinematics.

Deposited metamaterial thin film with negative refractive index and permeability in the visible regime.

Thin films are fabricated from arrays of silver nanorods with thicknesses of 160 nm and 200 nm, to function as a metamaterial. The negative refractive index and negative permeability are retrieved from measured reflection and transmission coefficients using walk-off interferometer in the visible regime. A negative-index-material thin film with negative permittivity or (and) permeability can be produced by glancing angle deposition.

The effect of graft fixation sequence on force distribution in double-bundle anterior cruciate ligament reconstruction.

PURPOSE: This paper investigated the effect of graft fixation sequence on knee joint biomechanics after a double-bundle ACL reconstruction. METHOD: Two independently published biomechanical studies that investigated the biomechanics of double-bundle ACL reconstructions using similar robotic testing systems were compared. In each study, ten human cadaveric knees were tested under three different conditions: intact, ACL deficient, and ACL reconstructed using a double-bundle technique with the anteromedial (AM) graft fixed at 60° of flexion and the posterolateral (PL) graft fixed at full extension. In one study (Study A), the AM graft was fixed first; while in another study (Study B), the PL graft was fixed first. Knee kinematics, in situ forces of the ACL and the ACL grafts were measured under two loading conditions: an anterior tibial load of 134 N and a combined tibial torques (10 N·m valgus and 5 N·m internal tibial torques) in both studies. RESULT: When AM graft was fixed first, the in situ force of the AM graft was lower than the native AM bundle at all flexion angles. The in situ force in the PL graft, however, was higher than the native PL bundle at all flexion angles. When the PL graft was fixed first, the in situ force of the AM graft was higher than the native AM bundle, while the in situ forces of the PL graft were lower than the native PL bundle at all flexion angles. Both studies demonstrated that the double-bundle ACL reconstructions can closely restore the normal knee joint kinematics. CONCLUSION: Even though the grafts were fixed using similar initial tensions and at same flexion angles, the sequence of fixing the two grafts in a double-bundle ACL reconstruction could alter the in situ forces in the grafts and affect the knee kinematics. These data imply that in clinical application of a double-bundle ACL reconstruction, the sequence of graft fixation should be an important surgical parameter.