The assessment of postural control and the influence of a secondary task in people with anterior cruciate ligament reconstructed knees using a Nintendo Wii Balance Board.

PubMed

Howells, Brooke E; Clark, Ross A; Ardern, Clare L; Bryant, Adam L; Feller, Julian A; Whitehead, Timothy S; Webster, Kate E

2013-09-01

Postural control impairments may persist following anterior cruciate ligament (ACL) reconstruction. The effect of a secondary task on postural control has, however, not been determined. The purpose of this case-control study was to compare postural control in patients following ACL reconstruction with healthy individuals with and without a secondary task. 45 patients (30 men and 15 women) participated at least 6 months following primary ACL reconstruction surgery. Participants were individually matched by age, gender and sports activity to healthy controls. Postural control was measured using a Nintendo Wii Balance Board and customised software during static single-leg stance and with the addition of a secondary task. The secondary task required participants to match the movement of an oscillating marker by adducting and abducting their arm. Centre of pressure (CoP) path length in both medial-lateral and anterior-posterior directions, and CoP total path length. When compared with the control group, the anterior-posterior path length significantly increased in the ACL reconstruction patients' operated (12.3%, p=0.02) and non-operated limbs (12.8%, p=0.02) for the single-task condition, and the non-operated limb (11.5%, p=0.006) for the secondary task condition. The addition of a secondary task significantly increased CoP path lengths in all measures (p<0.001), although the magnitude of the increase was similar in both the ACL reconstruction and control groups. ACL reconstruction patients showed a reduced ability in both limbs to control the movement of the body in the anterior-posterior direction. The secondary task affected postural control by comparable amounts in patients after ACL reconstruction and healthy controls. Devices for the objective measurement of postural control, such as the one used in this study, may help clinicians to more accurately identify patients with deficits who may benefit from targeted neuromuscular training programs.

Leaf wax composition and carbon isotopes vary among major conifer groups

NASA Astrophysics Data System (ADS)

Diefendorf, Aaron F.; Leslie, Andrew B.; Wing, Scott L.

2015-12-01

Leaf waxes (e.g. n-alkanes, n-alkanoic acids) and their carbon isotopes (δ13C) are commonly used to track past changes in the carbon cycle, water availability, and plant ecophysiology. Previous studies indicated that conifers have lower n-alkane concentrations than angiosperms and that 13C fractionation during n-alkane synthesis (εn-alkane) is smaller than in angiosperms. These prior studies, however, sampled a limited phylogenetic and geographic subset of conifers, leaving out many important subtropical and Southern Hemisphere groups that were once widespread and common components of fossil assemblages. To expand on previous work, we collected 43 conifer species (and Ginkgo biloba) from the University of California Botanical Garden at Berkeley, sampling all extant conifer families and almost two-thirds of extant genera. We find that Pinaceae, including many North American species used in previous studies, have very low or no n-alkanes. However, other conifer groups have significant concentrations of n-alkanes, especially Southern Hemisphere Araucariaceae and Podocarpaceae (monkey puzzles, Norfolk Island pines, and yellowwoods), and many species of Cupressaceae (junipers and relatives). Within the Cupressaceae, we find total n-alkane concentrations are high in subfamilies Cupressoideae and Callitroideae, but significantly lower in the early diverging taxodioid lineages (including bald cypress and redwood). Individual n-alkane chain lengths have a weak phylogenetic signal, except for n-C29 alkane, but when combined using average chain length (ACL), a strong phylogenetic signal emerges. The strong phylogenetic signal in ACL, observed in the context of a common growth environment for all plants we sampled, suggests that ACL is strongly influenced by factors other than climate. An analysis of εn-alkane indicates a strong phylogenetic signal in which the smallest biosynthetic fractionation occurs in Pinaceae and the largest in Taxaceae (yews and relatives). The relationship between phylogeny and εn-alkane may be related to differences in carbon metabolism among conifer clades. These results have important implications for interpreting n-alkane δ13C values in sedimentary archives, especially outside of North America.

Terrestrial Plant Biomarkers Preserved in Cariaco Basin Sediments: Records of Abrupt Tropical Vegetation Response to Rapid Climate Changes

NASA Astrophysics Data System (ADS)

Hughen, K. A.; Eglinton, T. I.; Makou, M.; Xu, L.; Sylva, S.

2004-12-01

Organic-rich sediments from the anoxic Cariaco Basin, Venezuela, preserve high concentrations of biomarkers for reconstruction of terrestrial environmental conditions. Molecular-level investigations of organic compounds provide a valuable tool for extracting terrestrial signals from these annually laminated marine sediments. Differences in hydrogen isotopic fractionation between C16-18 and C24-30 n-alkanoic acids suggest a marine source for the shorter chain lengths and a terrestrial source for the longer chains. Records of carbon and hydrogen isotopes, as well as average carbon chain length (ACL), from long-chain n-alkanoic acids parallel millennial-scale changes in vegetation and climate between the late Glacial and Preboreal periods, 15,000 to 10,000 years ago. Data from all terrestrial chain lengths were combined to produce single δ D and δ 13C indices through deglaciation, exhibiting enrichment during the late Glacial and Younger Dryas and depletion during the Bolling-Allerod and Preboreal periods. δ D reflects the hydrogen isotopic composition of environmental water used for plant growth, combined with evaporative enrichment within leaf spaces, and as such may act as a proxy for local aridity. Leaf wax δ 13C, which is a proxy for C3 versus C4 metabolic pathways, indicates that C3 plants predominated in the Cariaco watershed during warm/wet Bolling-Allerod and Holocene periods, and C4 plant biomass proliferated during cool/dry Glacial and Younger Dryas intervals. Coupled carbon and hydrogen isotopic measurements together clearly distinguish deglacial climatic periods as wetter with C3 vegetation versus drier with C4 vegetation. High resolution biomarker records reveal the rapidity of vegetation changes in northern South America during the last deglaciation. The leaf wax data reveal that local vegetation biomass, although not necessarily entire assemblages, shifted between arid grassland and wetter forest taxa on timescales of decades. Comparison of ACL versus δ 13C for Cariaco Basin and NW African leaf waxes indicate that biomarkers reflect real changes in local South American vegetation and not contamination from long-distance transport during cold windy climates. The precise temporal relationship between tropical vegetation shifts and climate changes is measured by direct comparison of terrestrial vegetation and climate proxies from the same core. Abrupt deglacial climate shifts in tropical and high-latitude North Atlantic regions were synchronous, whereas changes in tropical vegetation consistently lagged climate shifts by several decades.

A dynamic study of the anterior cruciate ligament of the knee using an open MRI.

PubMed

Guenoun, Daphne; Vaccaro, Julien; Le Corroller, Thomas; Barral, Pierre-Antoine; Lagier, Aude; Pauly, Vanessa; Coquart, Benjamin; Coste, Joel; Champsaur, Pierre

2017-03-01

Recent anatomical and radiological studies of the anterior cruciate ligament (ACL) suggest the ACL length and orientation change during knee flexion, and an open MRI sequencing during knee flexion enables a dynamic ACL analysis. This study's goal is to describe a normal ACL using a 1T open MRI and, in particular, variations in length and insertion angles at different degrees of flexion. Twenty-one volunteers with clinically healthy knees received a dynamic MRI with their knees in hyperextension, neutral position, and flexed at 45° and 90° angles. For each position, two radiologists measured the ACL lengths and angles of the proximal insertion between the ACL's anterior edge and the roof of the inter-condylar notch. Additionally, we measured the ACL's and the tibial plateau's distal angle insertion between their anterior edges and then compared these with the nonparametric Wilcoxon test. The ACL had a significant extension between the 90° flexion and all other positions (hyperextension: 31.75 ± 2.5 mm, neutral position: 32.5 ± 2.6 mm, 45°: 35.6 ± 1.6 mm, 90°: 35.6 ± 1.6 mm). There was also a significant increase of the angle insertion between the proximal 90° flexion and all other positions, as well as between hyperextension and bending to 45° (hyperextension: 2.45° ± 3.7°, neutral: 13.4° ± 9.7°, 45°: 33 25 ± 9.3, 90: 51.85° ± 9.3°). Additionally, there is a significant increase in the distal angle insertion for all positions (hyperextension: 133.2° ± 5.4°, neutral position: 134.95° ± 4.4°, 45°: 138.35° ± 5.9°, 90°: 149.15° ± 8.6°). Our study is the first to exhibit that a dynamic MRI has a significant ACL extension in vivo during bending. This concept opens the way for further studies to improve the diagnosis of traumatic ACL injuries using a dynamic MRI.

Comparison of tunnel variability between trans-portal and outside-in techniques in ACL reconstruction.

PubMed

Sim, Jae-Ang; Kim, Jong-Min; Lee, Sahnghoon; Bae, Ji-Yong; Seon, Jong-Keun

2017-04-01

Although trans-portal and outside-in techniques are commonly used for anatomical ACL reconstruction, there is very little information on variability in tunnel placement between two techniques. A total of 103 patients who received ACL reconstruction using trans-portal (50 patients) and outside-in techniques (53 patients) were included in the study. The ACL tunnel location, length and graft-femoral tunnel angle were analyzed using the 3D CT knee models, and we compared the location and length of the femoral and tibial tunnels, and graft bending angle between the two techniques. The variability in each technique regarding the tunnel location, length and graft tunnel angle using the range values was also compared. There were no differences in the average of femoral tunnel depth and height between the two groups. The ranges of femoral tunnel depth and height showed no difference between two groups (36 and 41 % in trans-portal technique vs. 32 and 41 % in outside-in technique). The average value and ranges of tibial tunnel location also showed similar results in two groups. The outside-in technique showed longer femoral tunnel than the trans-portal technique (34.0 vs. 36.8 mm, p = 0.001). The range of femoral tunnel was also wider in trans-portal technique than in outside-in technique. Although the outside-in technique showed significant acute graft bending angle than trans-portal technique in average values, the trans-portal technique showed wider ranges in graft bending angle than outside-in technique [ranges 73° (SD 13.6) vs. 53° (SD 10.7), respectively]. Although both trans-portal and outside-in techniques in ACL reconstruction can provide relatively consistent in femoral and tibial tunnel locations, trans-portal technique showed high variability in femoral tunnel length and graft bending angles than outside-in technique. Therefore, the outside-in technique in ACL reconstruction is considered as the effective method for surgeons to make more consistent femoral tunnel. III.

Leaf wax n-alkane distributions in and across modern plants: Implications for paleoecology and chemotaxonomy

NASA Astrophysics Data System (ADS)

Bush, Rosemary T.; McInerney, Francesca A.

2013-09-01

Long chain (C21 to C37) n-alkanes are among the most long-lived and widely utilized terrestrial plant biomarkers. Dozens of studies have examined the range and variation of n-alkane chain-length abundances in modern plants from around the world, and n-alkane distributions have been used for a variety of purposes in paleoclimatology and paleoecology as well as chemotaxonomy. However, most of the paleoecological applications of n-alkane distributions have been based on a narrow set of modern data that cannot address intra- and inter-plant variability. Here, we present the results of a study using trees from near Chicago, IL, USA, as well as a meta-analysis of published data on modern plant n-alkane distributions. First, we test the conformity of n-alkane distributions in mature leaves across the canopy of 38 individual plants from 24 species as well as across a single growing season and find no significant differences for either canopy position or time of leaf collection. Second, we compile 2093 observations from 86 sources, including the new data here, to examine the generalities of n-alkane parameters such as carbon preference index (CPI), average chain length (ACL), and chain-length ratios for different plant groups. We show that angiosperms generally produce more n-alkanes than do gymnosperms, supporting previous observations, and furthermore that CPI values show such variation in modern plants that it is prudent to discard the use of CPI as a quantitative indicator of n-alkane degradation in sediments. We also test the hypotheses that certain n-alkane chain lengths predominate in and therefore can be representative of particular plant groups, namely, C23 and C25 in Sphagnum mosses, C27 and C29 in woody plants, and C31 in graminoids (grasses). We find that chain-length distributions are highly variable within plant groups, such that chemotaxonomic distinctions between grasses and woody plants are difficult to make based on n-alkane abundances. In contrast, Sphagnum mosses are marked by their predominance of C23 and C25, chain lengths which are largely absent in terrestrial vascular plants. The results here support the use of C23 as a robust proxy for Sphagnum mosses in paleoecological studies, but not the use of C27, C29, and C31 to separate graminoids and woody plants from one another, as both groups produce highly variable but significant amounts of all three chain lengths. In Africa, C33 and C35 chain lengths appear to distinguish graminoids from some woody plants, but this may be a reflection of the differences in rainforest and savanna environments. Indeed, variation in the abundances of long n-alkane chain lengths may be responding in part to local environmental conditions, and this calls for a more directed examination of the effects of temperature and aridity on plant n-alkane distributions in natural environments.

The Effectiveness of a Functional Knee Brace on Joint-Position Sense in Anterior Cruciate Ligament-Reconstructed Individuals.

PubMed

Sugimoto, Dai; LeBlanc, Jessica C; Wooley, Sarah E; Micheli, Lyle J; Kramer, Dennis E

2016-05-01

It is estimated that approximately 350,000 individuals undergo anterior cruciate ligament (ACL) reconstruction surgery in each year in the US. Although ACL-reconstruction surgery and postoperative rehabilitation are successfully completed, deficits in postural control remain prevalent in ACL-reconstructed individuals. In order to assist the lack of balance ability and reduce the risk of retear of the reconstructed ACL, physicians often provide a functional knee brace on the patients' return to physical activity. However, it is not known whether use of the functional knee brace enhances knee-joint position sense in individuals with ACL reconstruction. Thus, the effect of a functional knee brace on knee-joint position sense in an ACL-reconstructed population needs be critically appraised. After systematically review of previously published literature, 3 studies that investigated the effect of a functional knee brace in ACL-reconstructed individuals using joint-position-sense measures were found. They were rated as level 2b evidence in the Centre of Evidence Based Medicine Level of Evidence chart. Synthesis of the reviewed studies indicated inconsistent evidence of a functional knee brace on joint-position improvement after ACL reconstruction. More research is needed to provide sufficient evidence on the effect of a functional knee brace on joint-position sense after ACL reconstruction. Future studies need to measure joint-position sense in closed-kinetic-chain fashion since ACL injury usually occurs under weight-bearing conditions.

Geochemical characteristics of organic matter in the Andaman Sea sediments: Implications for source, paleovegetation and paleoclimate changes

NASA Astrophysics Data System (ADS)

Hossain, H. M. Z.; Sampei, Y.; Kawahata, H.

2016-12-01

The distribution, source, and redox variation of sedimentary organic matter in the Andaman Sea is significant for understanding its biogeochemical cycle, which we determined the total organic carbon (TOC), total nitrogen (TN), and n-alkanes contents. TOC and TN concentrations varied from 0.61 to 1.18 wt.% (average 0.87 wt.%) and 0.07 to 0.17 wt.% (average 0.13 wt.%), respectively with high TOC in the clay-rich sediments indicate hydrodynamic sorting readily controlled TOC abundances. Bulk C/N ratio (5.51 to 11.92, average 7.89) is attributed to the high inputs of organic matter from planktonic sources and an appreciable amounts of terrestrial derived organic matter. n-Alkane distributions from the Andaman Sea sediment cores are characterized mainly by C17 to C35, with odd-over-even predominance suggest a diverse origin of organic matter. High relative abundances of mid-chain n-alkanes of C23 and C25 recorded in the samples that are characteristically derived from submerges/floating aquatic macrophytes. However, odd long-chain n-alkanes from C27 to C33 with high peaks at C29 and C31 were detected in the samples reflecting a terrigenous origin of organic matter. The average chain length (ACL), carbon preference index (CPI), Paq and Pwax ratio values further suggested that major influence of organic matter from non-emergent aquatic macrophytes together significant proportions of grasses and herbs. Low Pr/Ph and Tm/Ts ratios in most section implying a more reducing to suboxic conditions prevailed during organic matter preservation in the oceanic event. However, high ACL values and low Paq values in the down-core variation could suggest initially cold and dry climates and gradually shifted to warm and humid conditions.

Histological analysis of the tibial anterior cruciate ligament insertion.

PubMed

Oka, Shinya; Schuhmacher, Peter; Brehmer, Axel; Traut, Ulrike; Kirsch, Joachim; Siebold, Rainer

2016-03-01

This study was performed to investigate the morphology of the tibial anterior cruciate ligament (ACL) by histological assessment. The native (undissected) tibial ACL insertion of six fresh-frozen cadaveric knees was cut into four sagittal sections parallel to the long axis of the medial tibial spine. For histological evaluation, the slices were stained with haematoxylin and eosin, Safranin O and Russell-Movat pentachrome. All slices were digitalized and analysed at a magnification of 20×. The anterior tibial ACL insertion was bordered by a bony anterior ridge. The most medial ACL fibres inserted from the medial tibial spine and were adjacent to the articular cartilage of the medial tibial plateau. Parts of the bony insertions of the anterior and posterior horns of the lateral meniscus were in close contact with the lateral part of the tibial ACL insertion. A small fat pad was located just posterior to the functional ACL fibres. The anterior-posterior length of the medial ACL insertion was an average of 10.8 ± 1.1 mm compared with the lateral, which was only 6.2 ± 1.1 mm (p < 0.001). There were no central or posterolateral inserting ACL fibres. The shape of the bony tibial ACL insertion was 'duck-foot-like'. In contrast to previous findings, the functional mid-substance fibres arose from the most posterior part of the 'duck-foot' in a flat and 'c-shaped' way. The most anterior part of the tibial ACL insertion was bordered by a bony anterior ridge and the most medial by the medial tibial spine. No posterolateral fibres nor ACL bundles have been found histologically. This histological investigation may improve our understanding of the tibial ACL insertion and may provide important information for anatomical ACL reconstruction.

Editorial Commentary: The Downstream Effects of Limited Hip Rotation and Femoroacetabular Impingement on the Anterior Cruciate Ligament: Could a Little Hip Stretching Every Day (or Surgery) Keep the Knee Doctor Away?

PubMed

Boykin, Robert E

2018-03-01

Patients with radiographic evidence of femoroacetabular impingement and decreased hip internal rotation have a higher rate of anterior cruciate ligament (ACL) tears. Limited internal rotation of the hip increases strain and potentially resultant fatigue failure of the ACL. Although causation has not been proven, a better understanding of the lower extremity kinetic chain may allow improved ACL prevention strategies through measures (operative or nonoperative) to improve rotation of the hip. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Athletic performance and career longevity following anterior cruciate ligament reconstruction in the National Basketball Association.

PubMed

Kester, Benjamin S; Behery, Omar A; Minhas, Shobhit V; Hsu, Wellington K

2017-10-01

To identify the impact of anterior cruciate ligament (ACL) reconstruction on performance and career longevity for National Basketball Association (NBA) players. Seventy-nine players (80 knees) with acute ACL tears in the NBA between the 1984-2014 seasons, and 112 age, height, weight, and performance-matched controls were identified. Pre- and post-injury performance outcomes including seasons played, games played, games started, minutes per game, points per game, field goals, 3-point shots, rebounds, assists, steals, blocks, turnovers, personal fouls, usage percentage and player efficiency ratings were compared between cases and controls using independent samples t tests and Fisher's exact tests. Sixty-eight of seventy-nine players (86.1 %) returned to play in the NBA following ACL reconstruction. Mean length of post-operative play was 1.84 years shorter than matched controls (P = 0.001). There was a significantly higher rate of attrition from professional basketball for players with a history of ACL reconstruction (P = 0.014). In the first full season following surgery, players started in 15.5 fewer games (P = 0.001), they played in 17.3 fewer games (P < 0.001), and had combined player efficiency ratings 2.35 points lower (P = 0.001) when compared to matched controls. Over the length of their careers, players competed in 22.2 fewer games per season (P = 0.009). There is a high rate of return to sport in the NBA following ACL reconstruction, although playing time, games played, player efficiency ratings and career lengths are significantly impacted in the post-operative period. These data should be used to manage patients' expectations regarding their abilities to return to elite levels of athletic performance.

Histological Analysis of the Tibial Anterior Cruciate Ligament Insertion

PubMed Central

Siebold, Rainer; Oka, Shinya; Traut, Ulrike; Schuhmacher, Peter; Kirsch, Joachim

2017-01-01

Objective: To describe the morphology of the tibial ACL insertion by histological assessment in the sagittal plane. Methods: For histology the native (undissected) tibial ACL insertion of 6 fresh-frozen cadaveric knees was cut into 4 sagittal sections parallel to the long axis of the medial tibial spine. The slices were stained with hematoxylin and eosin, Safranin O and Russell-Movat pentachrome. All slices were digitalized and analyzed at a magnification of ×20. Results: From medial to lateral the anterior-posterior lengths of the ACL insertion were an average of 10.2, 9.3, 7.6 and 5.8 mm. The anterior margin of the tibial ACL insertion raised from an anterior ridge. The most medial ACL fibers rose along with a peak of the anterior part of the medial tibial spine in which the direct insertion was adjacent to the articular cartilage. Parts of the bony insertions of the anterior and posterior horns of the lateral meniscus were in close contact to the lateral ACL insertion. A small fat pad was located just posterior to the tibial ACL insertion. There were no central or posterolateral inserting ACL fibers in the area intercondylaris anterior. Conclusion: The functional intraligamentous midsubstance ACL fibers arose from the most posterior part of its bony tibial insertion in a flat and “C-shape” way. The anterior border of this functional ACL started from a bony ‘anterior ridge’ and the medial border was along with a peak of the medial tibial spine.

Identification of Suitable Reference Genes for Investigating Gene Expression in Anterior Cruciate Ligament Injury by Using Reverse Transcription-Quantitative PCR.

PubMed

Leal, Mariana Ferreira; Astur, Diego Costa; Debieux, Pedro; Arliani, Gustavo Gonçalves; Silveira Franciozi, Carlos Eduardo; Loyola, Leonor Casilla; Andreoli, Carlos Vicente; Smith, Marília Cardoso; Pochini, Alberto de Castro; Ejnisman, Benno; Cohen, Moises

2015-01-01

The anterior cruciate ligament (ACL) is one of the most frequently injured structures during high-impact sporting activities. Gene expression analysis may be a useful tool for understanding ACL tears and healing failure. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) has emerged as an effective method for such studies. However, this technique requires the use of suitable reference genes for data normalization. Here, we evaluated the suitability of six reference genes (18S, ACTB, B2M, GAPDH, HPRT1, and TBP) by using ACL samples of 39 individuals with ACL tears (20 with isolated ACL tears and 19 with ACL tear and combined meniscal injury) and of 13 controls. The stability of the candidate reference genes was determined by using the NormFinder, geNorm, BestKeeper DataAssist, and RefFinder software packages and the comparative ΔCt method. ACTB was the best single reference gene and ACTB+TBP was the best gene pair. The GenEx software showed that the accumulated standard deviation is reduced when a larger number of reference genes is used for gene expression normalization. However, the use of a single reference gene may not be suitable. To identify the optimal combination of reference genes, we evaluated the expression of FN1 and PLOD1. We observed that at least 3 reference genes should be used. ACTB+HPRT1+18S is the best trio for the analyses involving isolated ACL tears and controls. Conversely, ACTB+TBP+18S is the best trio for the analyses involving (1) injured ACL tears and controls, and (2) ACL tears of patients with meniscal tears and controls. Therefore, if the gene expression study aims to compare non-injured ACL, isolated ACL tears and ACL tears from patients with meniscal tear as three independent groups ACTB+TBP+18S+HPRT1 should be used. In conclusion, 3 or more genes should be used as reference genes for analysis of ACL samples of individuals with and without ACL tears.

All-inside, physeal-sparing anterior cruciate ligament reconstruction does not significantly compromise the physis in skeletally immature athletes: a postoperative physeal magnetic resonance imaging analysis.

PubMed

Nawabi, Danyal H; Jones, Kristofer J; Lurie, Brett; Potter, Hollis G; Green, Daniel W; Cordasco, Frank A

2014-12-01

Anterior cruciate ligament (ACL) reconstruction in skeletally immature patients can result in growth disturbance due to iatrogenic physeal injury. Multiple physeal-sparing ACL reconstruction techniques have been described; however, few combine the benefits of anatomic reconstruction using sockets without violation of the femoral or tibial physis. To utilize physeal-specific magnetic resonance imaging (MRI) to quantify the zone of physeal injury after all-inside ACL reconstruction in skeletally immature athletes. Case series; Level of evidence, 4. Twenty-three skeletally immature patients (mean chronologic age 12.6 years; range, 10-15 years) were prospectively evaluated after all-inside ACL reconstruction. The mean bone age was 13.2 years. There were 8 females and 15 males. Fifteen patients underwent an all-epiphyseal (AE) ACL reconstruction and 8 patients had a partial transphyseal (PTP) ACL reconstruction, which spared the femoral physis but crossed the tibial physis. At 6 and 12 months postoperatively, MRI using 3-dimensional fat-suppressed spoiled gradient recalled echo sequences and full-length standing radiographs were performed to assess graft survival, growth arrest, physeal violation, angular deformity, and leg length discrepancy. The mean follow-up for this cohort was 18.5 months (range, 12-39 months). Minimal tibial physeal violation was seen in 10 of 15 patients in the AE group and, by definition, all patients in the PTP group. The mean area of tibial physeal disturbance (±SD) was 57.8 ± 52.2 mm(2) (mean 2.1% of total physeal area) in the AE group compared with 145.1 ± 100.6 mm(2) (mean 5.4% of total physeal area) in the PTP group (P = .003). Minimal compromise of the femoral physis (1.5%) was observed in 1 case in the PTP group and no cases in the AE group. No cases of growth arrest, articular surface violation, or avascular necrosis were noted on MRI. No postoperative angular deformities or significant leg length discrepancies were observed. The study data suggest that all-inside ACL reconstruction is a safe technique for skeletally immature athletes at short-term follow-up. Physeal-specific MRI reveals minimal growth plate compromise that is significantly lower than published thresholds for growth arrest. © 2014 The Author(s).

The relation between knee flexion angle and anterior cruciate ligament femoral tunnel characteristics: a cadaveric study comparing a standard and a far anteromedial portal.

PubMed

Alavekios, Damon; Peterson, Alexander; Patton, John; McGarry, Michelle H; Lee, Thay Q

2014-11-01

The purpose of this study was to compare the anterior cruciate ligament (ACL) femoral tunnel characteristics between 2 common arthroscopic portals used for ACL reconstruction, a standard anteromedial portal and a far anteromedial portal. Seven cadaveric knees were used. A 1.25-mm Kirschner wire was drilled through the center of the ACL femoral footprint and through the distal femur from the standard anteromedial and far anteromedial portals at knee flexion angles of 100°, 120°, and 140°. No formal tunnels were drilled. Each tunnel exit point was marked with a colored pin. After all tunnels were created, the specimens were digitized with a MicroScribe device (Revware, Raleigh, NC) to measure the tunnel length; distance to the posterior femoral cortical wall (posterior cortical margin); and tunnel orientation in the sagittal, coronal, and axial planes. The standard anteromedial portal resulted in a longer tunnel length, a less horizontal tunnel in the coronal plane, and a greater posterior cortical margin compared with the far anteromedial portal at all knee flexion angles. For both portal locations, the tunnel length and posterior cortical margin increased, and the tunnel position became more horizontal in the coronal plane, more anterior in the sagittal plane, and less horizontal in the transverse plane as knee flexion increased. Portal position affects femoral tunnel characteristics, with results favoring the more laterally positioned standard anteromedial portal at all flexion angles. Increasing the knee flexion angle leads to a longer femoral tunnel length and posterior femoral cortical margin with either portal position. Understanding how portal positioning and knee flexion angle affect femoral tunnel orientation and characteristics may lead to improved surgical outcomes after ACL reconstruction. Published by Elsevier Inc.

Mechanism of Activating the Proprioceptive NT-3/TrkC Signalling Pathway by Reverse Intervention for the Anterior Cruciate Ligament–Hamstring Reflex Arc with Electroacupuncture

PubMed Central

Zhang, Lei; Zeng, Yan; Qi, Ji; Guan, Taiyuan; Zhou, Xin; Wang, Guoyou

2018-01-01

The anterior cruciate ligament (ACL) is an important structure maintaining stability of the knee joints. Deficits in physical stability and the proprioceptive capabilities of the knee joints are observed, when the ACL is damaged. Additionally, a unilateral ACL injury can affect bilateral knee proprioception; therefore, proprioception of the ACL may play a key role in stability. Electroacupuncture therapy has a definite effect nerve regeneration. In this study, cynomolgus monkeys were randomly divided into 4 groups: the model control group, intervention of the injured knee with electroacupuncture (IIKE) group, intervention of the bilateral knees with electroacupuncture (IBKE) group, and the blank control group. The unilateral ACL injury model was developed in IIKE and IBKE groups; acupuncture points around the knees underwent intervention similarly in the IIKE and IBKE groups. Then, mRNA and protein expressions of NT-3 and TrkC in the dorsal root ganglion and of growth-associated protein-43 in the ACL increased according to reverse-transcription quantitative polymerase chain reaction and Western blotting results. Decreased incubations and increased amplitudes were found for somatosensory-evoked potentials and motor nerve conduction velocity. The finding indicates that electroacupuncture may play an important role in the recovery of proprioception in the ACL by activating the NT-3/TrkC signalling pathway. PMID:29581981

Remodeling of ACL Allografts is Inhibited by Peracetic Acid Sterilization

PubMed Central

Gonnermann, Johannes; Kamp, Julia; Przybilla, Dorothea; Pruss, Axel

2008-01-01

Sterilization of allografts for anterior cruciate ligament (ACL) reconstruction has become an important prerequisite to prevent disease transmission. However, current sterilization techniques impair the biological or mechanical properties of such treated grafts. Peracetic acid (PAA) has been successfully used to sterilize bone allografts without these disadvantages and does not impair the mechanical properties of soft tissue grafts in vitro. We asked whether PAA sterilization would influence recellularization, restoration of crimp length and pattern, and revascularization of ACL grafts during early healing. We used an in vivo sheep model for open ACL reconstruction. We also correlated the histologic findings with the restoration of anteroposterior stability and structural properties during load-to-failure testing. PAA slowed remodeling activity at 6 and 12 weeks compared to nonsterilized allografts and autografts. The mechanical properties of PAA grafts were also reduced compared to these control groups at both time points. We conclude PAA sterilization currently should not be used to sterilize soft tissue grafts typically used in ACL reconstruction. PMID:18491201

Growth factor controls on the distribution and carbon isotope composition of n-alkanes in leaf wax

NASA Astrophysics Data System (ADS)

Jia, C.; Xie, S.; Huang, X.

2012-12-01

Cuticular wax plays pivotal physiological and ecological roles in the interactions between plants and the environments in which they grow. Plant-derived long-chain alkanes are more resistant to decay than other biochemical polymers. n-Alkane distributions (Carbon Preference Index (CPI) values and Average Chain Length (ACL) values) and carbon isotopic values are used widely in palaeoenvironmental reconstruction. However, there is little information available on how growth stages of the plant might influence the abundance of n-alkanes in the natural environment. In this study, we analyzed n-alkane distributions and carbon isotope data from two tree species (Cinnamomum camphora (L.) Presl. and Liquidambar formosana Hance) collected monthly from 2009 to 2011 in Nanwang Shan, Wuhan, Hubei Province. CPI values for n-alkanes from C. camphora remained stable in autumn and winter but fluctuated dramatically during spring and autumn each year. Positive correlations between CPI values and the relative content of (C27+C29) were observed in both sun and shade leaves of C. camphora from April to July. In L. formosana, CPI values decreased gradually from April to December. A similar trend was observed in all three years suggesting that growth stages rather than temperature or relative humidity affected the CPI values on a seasonal timescale. In the samples of L. formosana ACL values were negatively correlated with CPI values in the growing season (from April to July) and positively correlated with CPI values in the other seasons. The δ13C values of C29 and C31 n-alkanes displayed more negative carbon isotopic values in autumn and winter compared with leaves sampled at the start of the growing season from both trees. The δ13C values of C29 and C31 n-alkanes of L. formosana decreased from April to December. These results demonstrate the importance of elucidating the growing factors that influence the distribution and δ13C values of alkanes in modern leaves prior to using CPI, ACL, and isotopic shifts as indicators of palaeoenvironmental changes on short timescales.

Influence of screw length and diameter on tibial strain energy density distribution after anterior cruciate ligament reconstruction

NASA Astrophysics Data System (ADS)

Yao, Jie; Kuang, Guan-Ming; Wong, Duo Wai-Chi; Niu, Wen-Xin; Zhang, Ming; Fan, Yu-Bo

2014-04-01

Postoperative tunnel enlargement has been frequently reported after anterior cruciate ligament (ACL) reconstruction. Interference screw, as a surgical implant in ACL reconstruction, may influence natural loading transmission and contribute to tunnel enlargement. The aims of this study are (1) to quantify the alteration of strain energy den sity (SED) distribution after the anatomic single-bundle ACL reconstruction; and (2) to characterize the influence of screw length and diameter on the degree of the SED alteration. A validated finite element model of human knee joint was used. The screw length ranging from 20 to 30mm with screw diameter ranging from 7 to 9 mm were investigated. In the post-operative knee, the SED increased steeply at the extra-articular tunnel aperture under compressive and complex loadings, whereas the SED decreased beneath the screw shaft and nearby the intra-articular tunnel aperture. Increasing the screw length could lower the SED deprivation in the proximal part of the bone tunnel; whereas increasing either screw length or diameter could aggravate the SED deprivation in the distal part of the bone tunnel. Decreasing the elastic modulus of the screw could lower the bone SED deprivation around the screw. In consideration of both graft stability and SED alteration, a biodegradable interference screw with a long length is recommended, which could provide a beneficial mechanical environment at the distal part of the tunnel, and meanwhile decrease the bone-graft motion and synovial fluid propagation at the proximal part of the tunnel. These findings together with the clinical and histological factors could help to improve surgical outcome, and serve as a preliminary knowledge for the following study of biodegradable interference screw. [Figure not available: see fulltext.

Flat midsubstance of the anterior cruciate ligament with tibial "C"-shaped insertion site.

PubMed

Siebold, Rainer; Schuhmacher, Peter; Fernandez, Francis; Śmigielski, Robert; Fink, Christian; Brehmer, Axel; Kirsch, Joachim

2015-11-01

This anatomical cadaver study was performed to investigate the flat appearance of the midsubstance shape of the anterior cruciate ligament (ACL) and its tibial "C"-shaped insertion site. The ACL midsubstance and the tibial ACL insertion were dissected in 20 cadaveric knees (n = 6 fresh frozen and n = 14 paraffined). Magnifying spectacles were used for all dissections. Morphometric measurements were performed using callipers and on digital photographs. In all specimens, the midsubstance of the ACL was flat with a mean width of 9.9 mm, thickness of 3.9 mm and cross-sectional area of 38.7 mm(2). The "direct" "C"-shaped tibial insertion runs from along the medial tibial spine to the anterior aspect of the lateral meniscus. The mean width (length) of the "C" was 12.6 mm, its thickness 3.3 mm and area 31.4 mm(2). The centre of the "C" was the bony insertion of the anterior root of the lateral meniscus overlayed by fat and crossed by the ACL. No posterolateral (PL) inserting ACL fibres were found. Together with the larger "indirect" part (area 79.6 mm(2)), the "direct" one formed a "duck-foot"-shaped footprint. The tibial ACL midsubstance and tibial "C"-shaped insertion are flat and are resembling a "ribbon". The centre of the "C" is the bony insertion of the anterior root of the lateral meniscus. There are no central or PL inserting ACL fibres. Anatomical ACL reconstruction may therefore require a flat graft and a "C"-shaped tibial footprint reconstruction with an anteromedial bone tunnel for single bundle and an additional posteromedial bone tunnel for double bundle.

Arthroscopy Up to Date: Anterior Cruciate Ligament Anatomy.

PubMed

Schillhammer, Carl K; Reid, John B; Rister, Jamie; Jani, Sunil S; Marvil, Sean C; Chen, Austin W; Anderson, Chris G; D'Agostino, Sophia; Lubowitz, James H

2016-01-01

To categorize and summarize up-to-date anterior cruciate ligament (ACL) research published in Arthroscopy and The American Journal of Sports Medicine and systematically review each subcategory, beginning with ACL anatomy. After searching for "anterior cruciate ligament" OR "ACL" in Arthroscopy and The American Journal of Sports Medicine from January 2012 through December 2014, we excluded articles more pertinent to ACL augmentation; open growth plates; and meniscal, chondral, or multiligamentous pathology. Studies were subcategorized for data extraction. We included 212 studies that were classified into 8 categories: anatomy; basic science and biomechanics; tunnel position; graft selection; graft fixation; injury risk and rehabilitation; practice patterns and outcomes; and complications. Anatomic risk factors for ACL injury and post-reconstruction graft failure include a narrow intercondylar notch, low native ACL volume, and increased posterior slope. Regarding anatomic footprints, the femoral attachment is 43% of the proximal-to-distal lateral femoral condylar length whereas the posterior border of the tendon is 2.5 mm from the articular margin. The tibial attachment of the ACL is two-fifths of the medial-to-lateral interspinous distance and 15 mm anterior to the posterior cruciate ligament. Anatomic research using radiology and computed tomography to evaluate ACL graft placement shows poor interobserver and intraobserver reliability. With a mind to improving outcomes, surgeons should be aware of anatomic risk factors (stenotic femoral notch, low ligament volume, and increased posterior slope) for ACL graft failure, have a precise understanding of arthroscopic landmarks identifying femoral and tibial footprint locations, and understand that imaging to evaluate graft placement is unreliable. Level III, systematic review of Level III evidence. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Some conifer clades contribute substantial amounts of leaf waxes to sedimentary archives

NASA Astrophysics Data System (ADS)

Diefendorf, A. F.; Wing, S. L.; Leslie, A. B.; Freeman, K. H.

2014-12-01

Leaf waxes (i.e. n-alkanes, n-alkanoic acids) and their carbon isotopes (δ13C) are commonly used to track past changes in the carbon cycle or plant ecophysiology. Previous studies indicated that conifer n-alkane concentrations are lower than in angiosperms and that 13C fractionation during n-alkane synthesis (ɛlipid) is smaller than in angiosperms. These prior studies, however, sampled a limited phylogenetic and geographic subset of conifers, leaving out many important subtropical and Southern Hemisphere groups that were once widespread and common components of fossil assemblages. To expand on previous work, we collected 44 conifer species from the University of California Botanical Garden at Berkeley, capturing all extant conifer families and most extant genera. By collecting all specimens at a common site we attempted to minimize the confounding effects of climate, allowing phylogenetic patterns in the δ13C of leaf waxes to be expressed more strongly. We find that Pinaceae, including many North American species used in previous studies, have very low or no n-alkanes. However, other conifer groups have significant concentrations of n-alkanes, especially the Araucariaceae (Norfolk Island pines), Podocarpaceae (common in the Southern Hemisphere), and many species of Cupressaceae (junipers and relatives). Within the Cupressaceae, we find total n-alkane concentrations are high in subfamilies Cupressoideae and Callitroideae, but significantly lower in the early diverging taxodioid lineages (including bald cypress and redwood). Individual n-alkane chain lengths have a weak phylogenetic signal, except for n-C29 alkane, but when combined using average chain length (ACL), a strong phylogenetic signal emerges. The strong phylogenetic signal in ACL reinforces that it is strongly influenced by factors other than climate. An analysis of ɛlipid indicates a strong phylogenetic signal in which the smallest biosynthetic fractionation occurs in Pinaceae and the largest in Taxaceae (yews and relatives). We are currently exploring potential mechanisms to explain the ɛlipid patterns. These results have important implications for interpreting n-alkane δ13C values in sedimentary archives, especially outside of North America.

Dynamic knee stability and ballistic knee movement after ACL reconstruction: an application on instep soccer kick.

PubMed

Cordeiro, Nuno; Cortes, Nelson; Fernandes, Orlando; Diniz, Ana; Pezarat-Correia, Pedro

2015-04-01

The instep soccer kick is a pre-programmed ballistic movement with a typical agonist-antagonist coordination pattern. The coordination pattern of the kick can provide insight into deficient neuromuscular control. The purpose of this study was to investigate knee kinematics and hamstrings/quadriceps coordination pattern during the knee ballistic extension phase of the instep kick in soccer players after anterior cruciate ligament reconstruction (ACL reconstruction). Seventeen players from the Portuguese Soccer League participated in this study. Eight ACL-reconstructed athletes (experimental group) and 9 healthy individuals (control group) performed three instep kicks. Knee kinematics (flexion and extension angles at football contact and maximum velocity instants) were calculated during the kicks. Rectus femoris (RF), vastus lateralis, vastus medialis, biceps femoralis, and semitendinosus muscle activations were quantified during the knee extension phase. The ACL-reconstructed group had significantly lower knee extension angle (-1.2 ± 1.6, p < 0.021) and increased variability (1.1 ± 1.2, p < 0.012) when compared with the control group. Within the EMG variables, the RF had a significantly greater activity in the ACL-reconstructed group than in the control group (79.9 ± 27.7 % MVC vs. 49.2 ± 20.8 % MVC, respectively, p < 0.034). No other statistically significant differences were found. The findings of this study demonstrate that changes in ACL-reconstructed individuals were observed on knee extension angle and RF muscle activation while performing an instep kick. These findings are in accordance with the knee stability recovery process after ACL reconstruction. No differences were observed in the ballistic control movement pattern between normal and ACL-reconstructed subjects. Performing open kinetic chain exercises using ballistic movements can be beneficial when recovering from ACL reconstruction. The exercises should focus on achieving multi-joint coordination and full knee extension (range of motion). III.

Glycerolipidome responses to freezing- and chilling-induced injuries: examples in Arabidopsis and rice.

PubMed

Zheng, Guowei; Li, Lixia; Li, Weiqi

2016-03-22

Glycerolipids are the principal constituent of cellular membranes; remodelling of glycerolipids plays important roles in temperature adaptation in plants. Temperate plants can endure freezing stress, but even chilling at above-zero temperatures can induce death in tropical species. However, little is known about the differences in glycerolipid response to low temperatures between chilling-sensitive and freezing-tolerant plants. Using ESI-MS/MS-based lipidomic analysis, we compared the glycerolipidome of chilling (4 and 10 °C)-treated rice with that of freezing (-6 and -12 °C)-treated Arabidopsis, both immediately after these low-temperature treatments and after a subsequent recovery culture period. Arabidopsis is a 16:3 plant that harbours both eukaryotic and prokaryotic-type lipid synthesis pathways, while rice is an 18:3 plant that harbours only the eukaryotic lipid synthesis pathway. Arabidopsis contains higher levels of galactolipids than rice and has a higher double bond index (DBI). Arabidopsis contains lower levels of high melting point phosphatidylglycerol (PG) molecules and has a lower average acyl chain length (ACL). Marked phospholipid degradation occurred during the recovery culture period of non-lethal chilling treated rice, but did not occur in non-lethal freezing treated Arabidopsis. Glycerolipids with larger head groups were synthesized more in Arabidopsis than in rice at sub-lethal low-temperatures. Levels of phosphatidic acid (PA) and phosphatidylinositol (PI) rose in both plants after low-temperature treatment. The DBI and ACL of total lipids did not change during low-temperature treatment. A higher DBI and a lower ACL could make the membranes of Arabidopsis more fluid at low temperatures. The ability to synthesize glycerolipids containing a larger head group may correlate with low-temperature tolerance. The low-temperature-induced increase of PA may play a dual role in plant responses to low temperatures: as a lipid signal that initiates tolerance responses, and as a structural molecule that, on extensive in large accumulation, could damage the integrity of membranes. Changes in ACL and DBI are responses of plants to long-term low temperature.

Physeal-Specific MRI Analysis of Growth Plate Disturbance Following All-Inside Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients: Does a Physeal-Sparing Technique Offer any Advantage?

PubMed Central

Nawabi, Danyal H.; Jones, Kristofer J.; Lurie, Brett; Potter, Hollis G.; Green, Daniel W.; Cordasco, Frank A.

2013-01-01

Objectives: The decision to perform anterior cruciate ligament (ACL) reconstruction in skeletally immature patients carries a risk of growth disturbance due to iatrogenic physeal injury. Multiple physeal-sparing techniques have been described but none, to our knowledge combine the benefits of an anatomic reconstruction and socket fixation, without violation of either the femoral or tibial physis at any stage of the procedure. The purpose of this study was to compare the incidence and calculate the area of post-operative physeal disturbances, using a physeal-sensitive magnetic resonance imaging (MRI) sequence*, between all-epiphyseal (AE) and partial transphyseal (PTP) ACL reconstructions in a cohort of skeletally-immature patients. Methods: Twenty-one skeletally immature patients with a mean chronologic age of 12.7 years (range 10 to 16) undergoing all-inside ACL reconstruction were prospectively followed. Fourteen patients had an all-epiphyseal (AE) ACL reconstruction and 7 patients had a partial transphyseal (PTP) ACL reconstruction, which spared the femoral physis but crossed the tibial physis. Hamstring autograft was used in all cases. At a mean of 11.6 months follow-up, all patients were assessed for focal physeal disturbance and graft survival using a three-dimensional (3D) fat suppressed spoiled gradient-recalled echo (SPGR) MRI sequence. Angular deformity and leg length discrepancy were evaluated on full-length standing radiographs. The International Knee Documentation Committee (IKDC) subjective score and Lysholm knee score were also documented. Results: The tibial physis was violated in 13/14 patients in the AE group and all patients in the PTP group. The mean area of post-operative tibial physeal disturbance (± SD) was 42.4 ± 38.6 mm2 (mean 1.7% of total physeal area) in the AE group compared to 216.7 ± 129.1 mm2 (mean 7.3% of total physeal area) in the PTP group (p = 0.003). The femoral physis was violated in one case in both groups resulting in a mean physeal disturbance of 1.5% of the total distal femoral physeal area. No cases of fracture, articular surface violation or avascular necrosis were noted on MRI in either group. Short-term graft survival was 100% amongst the entire cohort. There were no cases of angular deformity in either group with a mean side-side difference in the lateral distal femoral angle of 1.11° ± 1.02° in the AE group and 0.72° ± 0.65° in the PTP group (p = 0.23). No significant leg-length discrepancies were measured in either group. The mean IKDC and Lysholm scores (± SD) were 93.3 ± 5.9 and 97.8 ± 3.8 respectively in the AE group and 87.7 ± 3.5 and 96 ± 5.2 respectively in the PTP group. Conclusion: All-epiphyseal ACL reconstruction caused significantly less focal physeal disturbance than PTP ACL reconstruction, as determined by a 3D physeal-sensitive MRI sequence. Neither technique however resulted in angular deformity or leg-length discrepancy at early follow-up. Both all-inside ACL reconstruction techniques used in this study are safe and effective at early follow-up in skeletally immature patients. Further longitudinal study of this cohort is required to determine any potential advantages of a purely physeal-sparing technique.

Phlebotomine sandfly (Diptera: Psychodidae) diversity and their Leishmania DNA in a hot spot of American Cutaneous Leishmaniasis human cases along the Brazilian border with Peru and Bolivia

PubMed Central

Teles, Carolina Bioni Garcia; dos Santos, Ana Paula de Azevedo; Freitas, Rui Alves; de Oliveira, Arley Faria José; Ogawa, Guilherme Maerschner; Rodrigues, Moreno Souza; Pessoa, Felipe Arley Costa; Medeiros, Jansen Fernandes; Camargo, Luís Marcelo Aranha

2016-01-01

In this study, we identified the phlebotomine sandfly vectors involved in the transmission of American Cutaneous Leishmaniasis (ACL) in Assis Brasil, Acre, Brazil, which is located on the Brazil-Peru-Bolivia frontier. The genotyping of Leishmania in phlebotomines was performed using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. A total of 6,850 sandflies comprising 67 species were captured by using CDC light traps in rural areas of the municipality. Three sandfly species were found in the state of Acre for the first time: Lutzomyia georgii, Lu. complexa and Lu. evangelistai. The predominant species was Lu. auraensis/Lu. ruifreitasi and Lu. davisi (total 59.27%). 32 of 368 pools were positive for the presence of Leishmania DNA (16 pools corresponding to Lu. davisi, and 16 corresponding to Lu. auraensis/Lu. ruifreitasi), with a minimal infection prevalence of 1.85% in Lu. davisi and 2.05% in Lu. auraensis/Lu. ruifreitasi. The Leishmania species found showed maximum identity with L. (Viannia) guyanensis and L. (V.) braziliensis in both phlebotomine species. Based on these results and similar scenarios previously described along the Brazil/Peru/Bolivia tri-border, the studied area must take into consideration the possibility of Lu. davisi and Lu. auraensis/Lu. ruifreitasi as probable vectors of ACL in this municipality. PMID:27304023

Phlebotomine sandfly (Diptera: Psychodidae) diversity and their Leishmania DNA in a hot spot of American Cutaneous Leishmaniasis human cases along the Brazilian border with Peru and Bolivia.

PubMed

Teles, Carolina Bioni Garcia; Santos, Ana Paula de Azevedo Dos; Freitas, Rui Alves; Oliveira, Arley Faria José de; Ogawa, Guilherme Maerschner; Rodrigues, Moreno Souza; Pessoa, Felipe Arley Costa; Medeiros, Jansen Fernandes; Camargo, Luís Marcelo Aranha

2016-06-10

In this study, we identified the phlebotomine sandfly vectors involved in the transmission of American Cutaneous Leishmaniasis (ACL) in Assis Brasil, Acre, Brazil, which is located on the Brazil-Peru-Bolivia frontier. The genotyping of Leishmania in phlebotomines was performed using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. A total of 6,850 sandflies comprising 67 species were captured by using CDC light traps in rural areas of the municipality. Three sandfly species were found in the state of Acre for the first time: Lutzomyia georgii, Lu. complexa and Lu. evangelistai. The predominant species was Lu. auraensis/Lu. ruifreitasi and Lu. davisi (total 59.27%). 32 of 368 pools were positive for the presence of Leishmania DNA (16 pools corresponding to Lu. davisi, and 16 corresponding to Lu. auraensis/Lu. ruifreitasi), with a minimal infection prevalence of 1.85% in Lu. davisi and 2.05% in Lu. auraensis/Lu. ruifreitasi. The Leishmania species found showed maximum identity with L. (Viannia) guyanensis and L. (V.) braziliensis in both phlebotomine species. Based on these results and similar scenarios previously described along the Brazil/Peru/Bolivia tri-border, the studied area must take into consideration the possibility of Lu. davisi and Lu. auraensis/Lu. ruifreitasi as probable vectors of ACL in this municipality.

Can the gracilis be used to replace the anterior cruciate ligament in the knee? A cadaver study.

PubMed

Cavaignac, Etienne; Pailhé, Regis; Murgier, Jérôme; Reina, Nicolas; Lauwers, Frederic; Chiron, Philippe

2014-12-01

The purpose of this study was to evaluate whether a four-strand gracilis-only graft can be used in anterior cruciate ligament (ACL) reconstruction. Cadaver study. This study involved 16 cadaver knees. The length and diameter of the native ACL were measured in each one. The same measurements were performed on a four-strand graft of the gracilis only, the semitendinosus only and both tendons. Student's t-test was used to compare the various conditions. The average diameter of the G4 construct was 0.07 mm greater (1%) than the native ACL (p=0.044). The average cross-sectional area of the G4 construct was 1.2 mm(2) greater (3.9%) than the native ACL (p=0.049). The G4 was on average 38.9 mm longer than the intra-articular portion of the ACL (p<0.001). A four-strand gracilis construct meets the anatomical specifications for use as an ACL reconstruction graft. By using the gracilis only, the morbidity associated with harvesting the gracilis and semitendinosus tendons should be reduced. Further studies must be performed to compare the biomechanical properties of this graft with other graft types and also to evaluate how this four-strand gracilis graft behaves in a clinical setting. Copyright © 2014 Elsevier B.V. All rights reserved.

Predictive formula for the length of tibial tunnel in anterior crucitate ligament reconstruction.

PubMed

Chernchujit, Bancha; Barthel, Thomas

2009-12-01

The anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon bone graft is a common procedure in orthopedics. One challenging problem found is a graft-tunnel mismatch. Previous studies have reported the mathematic formula to predict the tibial angle length and angle to avoid graft-tunnel mismatch but these formulas have shown limited predictability. To propose a predictive formula for the length of tibial tunnel and to examine its predictability. Thirty six patients (26 males, 14 females) with ACL injury were included in this study. The preoperativemedial proximal tibial angle was measured. Intraoperatively, the tibial tunnel length and tibial entry point were measured. The postoperative coronal and saggital angle of tibial tunnel were measured from knee radiograph. The data were analysed by using trigonometry correlation and formulate the predictive formula of tibial tunnel length. We found that tibial tunnel length (T) has trigonometric correlation between the location of tibial tunnel entry point (w), coronal angle of tibial tunnel (b), saggital angle of tibial tunnel (a) and the medial proximal tibial slope (c) by using this formula T = Wcos(c)tan(b)/sin(a) This proposed predictive formula can well predict the length of the tibial tunnel at preoperative period to avoid graft-tunnel mismatch.

Contact area between femoral tunnel and interference screw in anatomic rectangular tunnel ACL reconstruction: a comparison of outside-in and trans-portal inside-out techniques.

PubMed

Hiramatsu, Kunihiko; Mae, Tatsuo; Tachibana, Yuta; Nakagawa, Shigeto; Shino, Konsei

2018-02-01

The purpose of this study was to compare the femoral tunnel length, the femoral graft bending angle at the femoral tunnel aperture, and the contact area between the femoral tunnel wall and an interference screw used for fixation in anatomic rectangular tunnel anterior cruciate ligament (ACL) reconstruction (ART ACLR). The study included 149 patients with primary ACL injury who underwent ART ACLR. Preoperatively, flexion angle of the index knee was checked under general anaesthesia. Those of less than 130° of passive flexion were assigned to the outside-in (OI) technique (78 patients), while the others to the trans-portal inside-out (TP) technique (71 patients). The patients underwent computed tomography with multiplanar reconstruction at 3-5 weeks post-operatively. Femoral tunnel length, graft bending angle, and contact ratio between the IFS and femoral tunnel were assessed. P < 0.05 was considered statistically significant. The femoral tunnel length in the OI technique was significantly longer than that in the TP technique (P < 0.001). The femoral graft bending angle in the OI technique was significantly more acute than that in the TP technique (P < 0.001). The contact ratio in the OI technique was significantly larger than that in the TP technique at every point in the femoral tunnel (P < 0.001). The OI technique resulted in a more acute femoral graft bending angle, longer mean femoral tunnel length, and larger contact ratio than the TP technique after ART ACLR. Retrospective comparative study, Level III.

Morphological size evaluation of the mid-substance insertion areas and the fan-like extension fibers in the femoral ACL footprint.

PubMed

Suruga, Makoto; Horaguchi, Takashi; Iriuchishima, Takanori; Yahagi, Yoshiyuki; Iwama, Genki; Tokuhashi, Yasuaki; Aizawa, Shin

2017-08-01

The purpose of this study was to evaluate the detailed anatomy of the femoral anterior cruciate ligament (ACL) insertion site, with special attention given to the morphology of the mid-substance insertion areas and the fan-like extension fibers. Twenty-three non-paired human cadaver knees were used (7 Males, 16 Females, median age 83, range 69-96). All soft tissues around the knee were resected except the ligaments. The ACL was divided into antero-medial (AM) and postero-lateral (PL) bundles according to the difference in macroscopic tension patterns. The ACL was carefully dissected and two outlines were made of the periphery of each bundle insertion site: those which included and those which excluded the fan-like extension fibers. An accurate lateral view of the femoral condyle was photographed with a digital camera, and the images were downloaded to a personal computer. The area of each bundle, including and excluding the fan-like extension fibers, was measured with Image J software (National Institution of Health). The width and length of the mid-substance insertion sites were also evaluated using same image. The femoral ACL footprint was divided into four regions (mid-substance insertion sites of the AM and PL bundles, and fan-like extensions of the AM and PL bundles). The measured areas of the mid-substance insertion sites of the AM and PL bundles were 35.5 ± 12.5, and 32.4 ± 13.8 mm 2 , respectively. Whole width and length of the mid-substance insertion sites were 5.3 ± 1.4, and 15.5 ± 2.9 mm, respectively. The measured areas of the fan-like extensions of the AM and PL bundles were 27 ± 11.5, and 29.5 ± 12.4 mm 2 , respectively. The femoral ACL footprint was divided into quarters of approximately equal size (mid-substance insertion sites of the AM and PL bundles, and fan-like extensions of the AM and PL bundles). For clinical relevance, to perform highly reproducible anatomical ACL reconstruction, the presence of the fan-like extension fibers should be taken into consideration.

ACL Fibers Near the Lateral Intercondylar Ridge Are the Most Load Bearing During Stability Examinations and Isometric Through Passive Flexion.

PubMed

Nawabi, Danyal H; Tucker, Scott; Schafer, Kevin A; Zuiderbaan, Hendrik Aernout; Nguyen, Joseph T; Wickiewicz, Thomas L; Imhauser, Carl W; Pearle, Andrew D

2016-10-01

The femoral insertion of the anterior cruciate ligament (ACL) has direct and indirect fiber types located within the respective high (anterior) and low (posterior) regions of the femoral footprint. The fibers in the high region of the ACL footprint carry more force and are more isometric than the fibers in the low region of the ACL footprint. Controlled laboratory study. Ten fresh-frozen cadaveric knees were mounted to a robotic manipulator. A 134-N anterior force at 30° and 90° of flexion and combined valgus (8 N·m) and internal (4 N·m) rotation torques at 15° of flexion were applied simulating tests of anterior and rotatory stability. The ACL was sectioned at the femoral footprint by detaching either the higher band of fibers neighboring the lateral intercondylar ridge in the region of the direct insertion or the posterior, crescent-shaped fibers in the region of the indirect insertion, followed by the remainder of the ACL. The kinematics of the ACL-intact knee was replayed, and the reduction in force due to each sectioned portion of insertion fibers was measured. Isometry was assessed at anteromedial, center, and posterolateral locations within the high and low regions of the femoral footprint. With an anterior tibial force at 30° of flexion, the high fibers carried 83.9% of the total anterior ACL load compared with 16.1% in the low fibers (P < .001). The high fibers also carried more anterior force than the low fibers at 90° of flexion (95.2% vs 4.8%; P < .001). Under combined torques at 15° of flexion, the high fibers carried 84.2% of the anterior ACL force compared with 15.8% in the low fibers (P < .001). Virtual ACL fibers placed at the anteromedial portion of the high region of the femoral footprint were the most isometric, with a maximum length change of 3.9 ± 1.5 mm. ACL fibers located high within the femoral footprint bear more force during stability testing and are more isometric during flexion than low fibers. It may be advantageous to create a "higher" femoral tunnel during ACL reconstruction at the lateral intercondylar ridge. © 2016 The Author(s).

EXERCISES THAT FACILITATE OPTIMAL HAMSTRING AND QUADRICEPS CO-ACTIVATION TO HELP DECREASE ACL INJURY RISK IN HEALTHY FEMALES: A SYSTEMATIC REVIEW OF THE LITERATURE.

PubMed Central

Dedinsky, Rachel; Baker, Lindsey; Imbus, Samuel; Bowman, Melissa

2017-01-01

Background Anterior cruciate ligament (ACL) injury is common among females due to many anatomic, hormonal, and neuromuscular risk factors. One modifiable risk factor that places females at increased risk of ACL injury is a poor hamstrings: quadriceps (H:Q) co-activation ratio, which should be 0.6 or greater in order to decrease the stress placed on the ACL. Exercises that produce more quadriceps dominant muscle activation can add to the tension placed upon the ACL, potentially increasing the risk of ACL injury. Hypothesis/Purpose The purpose of this systematic review was to compare quadriceps and hamstring muscle activation during common closed kinetic chain therapeutic exercises in healthy female knees to determine what exercises are able to produce adequate H:Q co-activation ratios. Study Design Systematic Review Methods Multiple online databases were systematically searched and screened for inclusion. Eight articles were identified for inclusion. Data on mean electromyography (EMG) activation of both quadriceps and hamstring muscles, % maximal voluntary isometric contraction (MVIC), and H:Q co-activation ratios were extracted from the studies. Quality assessment was performed on all included studies. Results Exercises analyzed in the studies included variations of the double leg squat, variations of the single leg squat, lateral step-up, Fitter, Stairmaster® (Core Health and Fitness, Vancouver, WA), and slide board. All exercises, except the squat machine with posterior support at the level of the scapula and feet placed 50 cm in front of the hips, produced higher quadriceps muscle activation compared to hamstring muscle activation. Conclusion Overall, two leg squats demonstrate poor H:Q co-activation ratios. Single leg exercises, when performed between 30 and 90 degrees of knee flexion, produce adequate H:Q ratios, thereby potentially reducing the risk of tensile stress on the ACL and ACL injury. Level of Evidence 2a- Systematic Review of Cohort Studies PMID:28217412

Intra-Articular Biocompatibility of Multistranded, Long-Chain Polyethylene Suture Tape in a Canine ACL Model.

PubMed

Smith, Patrick A; Bozynski, Chantelle C; Kuroki, Keiichi; Henrich, Sarah M; Wijdicks, Coen A; Cook, James L

2018-05-31

The purpose of this study was to assess intra-articular use of a nonabsorbable braided suture tape for its biocompatibility when implanted adjacent to the native anterior cruciate ligament (ACL) in a canine model. Establishing biocompatibility of suture tape in the knee is an important foundational step for clinicians considering use of suture tape augmentation for ACL reconstruction or repair. The study hypothesis was that a nonabsorbable braided suture tape would be biocompatible in the knee with no resultant adverse functional consequences, and no significant intra-articular synovial reactions or articular cartilage degeneration attributable to direct exposure to the suture tape, whether intact or transected. Nonabsorbable braided suture tape was arthroscopically implanted adjacent to the native ACL of dogs ( n  = 6). The suture was intact in half of the dogs and was transected in the other half as a "worst-case" scenario. Dogs were assessed for postoperative complications and morbidity. Arthroscopic grading of synovium and cartilage was performed at 4 and 6 months. Histologic assessments were performed at the 6-month endpoint and compared with the ACL partial tear ( n  = 9) and ACL reconstruction ( n  = 5) cohorts as well as historical sham controls. No postoperative complications were noted. No animal developed lameness or clinical dysfunction, and there were no severe inflammatory or immune responses, cartilage erosions, or premature osteoarthritis noted. Arthroscopic assessments revealed no to mild synovitis and no apparent cartilage damage in either group. Histologically, both the intact and transected suture tape groups were associated with significantly ( p  ≤ 0.05) less synovial and articular cartilage pathology compared with the partial ACL transection and patellar bone-tendon-bone ACL autograft reconstruction cohorts, and matched historical sham controls. The hypothesis was accepted as study results support the biocompatibility of suture tape in the canine knee. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Mesenchymal stem cells reside in anterior cruciate ligament remnants in situ.

PubMed

Fu, Weili; Li, Qi; Tang, Xin; Chen, Gang; Zhang, Chenghao; Li, Jian

2016-07-01

It has been reported that the anterior cruciate ligament (ACL) has certain self-healing ability after acute injury or with primary suture repair. Many studies have confirmed that a remnant preservation technique with ACL reconstruction contributes to biological augmentation for ACL healing. However, it remains unclear whether mesenchymal stem cells (MSC) reside in ACL remnants in situ. The aim of this study was to investigate the methods of culture and identification of MSC derived from the remnants of ACL rupture patients and to analyse these MSC's properties. The cells of ACL remnants from the ACL rupture patients were isolated by the methods of enzymatic digestion and cultured in vitro to the third passage under the microscope to observe their morphology and growth status. The third passage of isolated cells was analysed for the identification of immunophenotype, osteogenic, adipogenic and chondrogenic differentiation. On the third to fifth days of in vitro culture, a few cells of long fusiform shape appeared and were adherent to the plastic walls. On the sixth to ninth days, cells clustered and colonies were observed. The third passage cells showed uniform cell morphology and good proliferation, with appearance of the typical surface markers of MSC, CD29, CD44, CD90 and CD105. The surface markers of CD34 and CD45 of haematopoietic stem cells were not expressed. Under appropriate conditions of in vitro culture, isolated cells could be differentiated into osteoblasts that deposit mineralised matrix and express early osteogenic markers, adipocytes that accumulate lipid droplets in cytoplasm and chondrocytes that secrete chondrogenic-specific matrix aggrecan and collagen II. Real-time polymerase chain reaction (PCR) analysis demonstrated that the specific mRNA expression of osteogenesis, adipogenesis and chondrogenesis increased significantly compared with the control groups at day zero. Stem cells derived in situ from the human ACL stump were successfully isolated and characterised. Those isolated cells were identified as MSC according to their adherent ability, morphology, surface markers and multilineage differentiation potential. MSC derived from ACL remnants could be a potential source of seeding cells for ligament regeneration.

Combined effects of tumor necrosis factor-α and interleukin-1β on lysyl oxidase and matrix metalloproteinase expression in human knee synovial fibroblasts in vitro

PubMed Central

Zhang, Yanjun; Jiang, Jiahuan; Xie, Jing; Xu, Chunming; Wang, Chunli; Yin, Lin; Yang, Li; Sung, Kuo-Li Paul

2017-01-01

Previous studies have demonstrated that inflammatory cytokines are associated with matrix metalloproteinases (MMPs) and/or lysyl oxidases (LOXs) produced by anterior cruciate ligament (ACL) fibroblasts, which may contribute to the poor healing ability of the ACL. To evaluate whether the synovium also participates in ACL healing, the inflammatory microenvironment of the knee joint cavity was mimicked following ACL injury, and the combined effects of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) on the expression of MMPs and LOXs in synovial fibroblasts were studied. Cell viability was evaluated using trypan blue staining in the presence of TNF-α and IL-1β, and the expression of LOXs and MMPs was measured by reverse transcription-quantitative polymerase chain reaction. MMP-2 activity was also measured by zymography. The results indicated that the combined effects of TNF-α and IL-1β inhibited LOX expression, while promoting MMP-1, −2 and −3 expression and MMP-2 activity in synovial fibroblasts. These changes may impede healing by altering the balance between the degradative and biosynthetic arms of the ligament tissue remodeling process. Collectively, the present results suggest that the poor healing ability of cruciate ligaments may be due to the sensitivity of the synovium to inflammatory factors. Therefore, the synovium potentially serves a key regulatory role in the joint cavity microenvironment and in the healing process of the ACL, and thus should be considered as a therapeutic target to aid in the treatment of patients with ACL trauma. PMID:29285051

Update on rehabilitation following ACL reconstruction

PubMed Central

Nyland, John; Brand, Emily; Fisher, Brent

2010-01-01

As anterior cruciate ligament (ACL) reconstruction has evolved to less invasive, more anatomical approaches, rehabilitation of the injured athlete has likewise become more progressive and innovative, with a sound understanding of graft and fixation strength and biologic healing-remodeling constraints. This review discusses these innovations including specific considerations before surgery, when planning rehabilitation timetables, and the importance of reestablishing nonimpaired active and passive knee range of motion and biarticular musculotendinous extensibility in positions of function. Concepts of self-efficacy or confidence and reestablishing the “athlete role” are also addressed. Since ACL injury and reinjury are largely related to the influence of structure-form-function on dynamic knee joint stability, the interrelationships between sensorimotor, neuromuscular, and conventional resistance training are also discussed. Although pivot shift “giving way” relates to function loss following ACL injury, anterior translational laxity often does not. Although there is growing evidence that progressive eccentric training may benefit the patient following ACL reconstruction, there is less evidence supporting the use of functional ACL knee braces. Of considerable importance is selecting and achieving a criteria-based progression to sports-specific training, reestablishing osseous homeostasis and improved bone density, blending open and closed kinetic chain exercises at the appropriate time period, and appreciating the influence of the trunk, upper extremities, and sports equipment use on knee loads. We believe that knee dysfunction and functional recovery should be considered from a local, regional, and global perspective. These concepts are consolidated into our approach to prepare patients for return to play including field testing and maintenance training. PMID:24198553

Diagnostic Tools for Acute Anterior Cruciate Ligament Injury: GNRB, Lachman Test, and Telos.

PubMed

Ryu, Seung Min; Na, Ho Dong; Shon, Oog Jin

2018-06-01

The purpose of this study is to compare the accuracy of the GNRB arthrometer (Genourob), Lachman test, and Telos device (GmbH) in acute anterior cruciate ligament (ACL) injuries and to evaluate the accuracy of each diagnostic tool according to the length of time from injury to examination. From September 2015 to September 2016, 40 cases of complete ACL rupture were reviewed. We divided the time from injury to examination into three periods of 10 days each and analyzed the diagnostic tools according to the time frame. An analysis of the area under the curve (AUC) of a receiver operating characteristic curve showed that all diagnostic tools were fairly informative. The GNRB showed a higher AUC than other diagnostic tools. In 10 cases assessed within 10 days after injury, the GNRB showed statistically significant side-to-side difference in laxity (p＜0.001), whereas the Telos test and Lachman test did not show significantly different laxity (p=0.541 and p=0.413, respectively). All diagnostic values of the GNRB were better than other diagnostic tools in acute ACL injuries. The GNRB was more effective in acute ACL injuries examined within 10 days of injury. The GNRB arthrometer can be a useful diagnostic tool for acute ACL injuries.

Updating Recommendations for Rehabilitation after ACL Reconstruction: a Review.

PubMed

Grant, John A

2013-11-01

To review recent evidence in order to update previous systematic reviews on methods of rehabilitation after anterior cruciate ligament (ACL) reconstruction. PubMed, Embase, and the Cochrane Controlled Trials Register were searched for the period January 2006 to December 2010, using terms related to ACL, rehabilitation, and randomized controlled trial (RCT). The search was done in triplicate, and the results reconciled (85 studies identified). Relevant studies in English that were peer-reviewed RCTs or prospective comparative studies evaluating methods of ACL rehabilitation were included (n = 29). Evidence was evaluated by all 3 authors using the CONSORT criteria. The data extracted included number of patients, ACL reconstruction method, randomization method, intervention, length of, and loss to, follow-up, outcomes assessed, bias, and findings. The review included evidence on postoperative bracing, accelerated rehabilitation, home-based rehabilitation, proprioceptive and neuromuscular training, and miscellaneous topics that were investigated by single trials. In 6 studies of postoperative bracing, no study found a clinically significant benefit of bracing or of restricted range of knee motion for pain control, knee laxity, or rehabilitation. Postoperative treatment without the use of a brace was not associated with less favorable outcomes. In 5 studies of accelerated strengthening, beginning eccentric quadriceps strengthening and isokinetic hamstring strengthening 2 weeks after ACL surgery improved or accelerated strength gains. Immediately postoperative weight-bearing, range of knee motion from 0° to 90° of flexion, and strengthening with closed-chain exercises were probably all safe. Home-based rehabilitation was evaluated in 2 studies. One study demonstrated that this intervention was at least as successful as a standard accelerated program over the long term. The other study included very low compliance expectations and other methodologic problems that precluded a useful assessment of benefit. Nine trials of neuromuscular strengthening (including perturbation, vibration, and/or balance training by various means) compared with strength, traditional rehabilitation, or placebo found some small short-term benefits to proprioceptive training and no harm from any of the treatments. Vibration training in addition to other strengthening may lead to faster proprioceptive recovery but the benefits to overall functional outcome are less clear. A study of vitamin C and E supplementation found a correlation between higher presurgery vitamin C levels and greater strength at 3 months, but this strength increase was not related to postsurgical vitamin C supplementation. Hyaluronic acid injection at 8 weeks improved ambulation and peak torque more than other doses or placebo, but poor outcomes in the control group raise questions about the quality of the standard rehabilitation program. Running interval training and continuous active motion had unclear effects. Using the uninjured leg for single-leg cycling prevented the usual loss of aerobic fitness in the postoperative period. Preoperative and postoperative video instruction decreased expectations of pain and increased self-efficacy although it made no difference to performance. The review of rehabilitation interventions after ACL reconstruction suggests that both accelerated and home-based rehabilitation, neuromuscular training programs, hyaluronic acid injection, and single (uninjured) leg cycling may be beneficial. Preoperative and postoperative informational videos may be valuable for psychological well-being. Insufficient evidence was found to recommend bracing.

Disadvantages and advantages of transtibial technique for creating the anterior cruciate ligament femoral socket.

PubMed

Robin, Brett N; Lubowitz, James H

2014-10-01

Anterior cruciate ligament (ACL) femoral socket techniques have distinct advantages and disadvantages when considering the following techniques: transtibial, anteromedial portal, outside-in, and outside-in retroconstruction. There is no one perfect technique and we have an incomplete understanding of anatomical, biomechanical, isometry, stability, and clinical outcomes. Our primary focus is transtibial technique for creating the ACL femoral socket. Advantages include less invasive, isometric graft placement, stable Lachman exam, and minimal graft impingement with the tunnel and notch. Disadvantages include nonanatomic vertical graft placement that can cause rotational instability and positive pivot shift, interference screw divergence, graft-tunnel length mismatch, femoral socket constraint, posterior cruciate ligament impingement, and a short, oblique tibial tunnel that may undermine the medial plateau in an attempt to achieve anatomic ACL reconstruction. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Asymmetry in Femoral Tunnel Socket Length During Anterior Cruciate Ligament Reconstruction With Transportal, Outside-In, and Modified Transtibial Techniques.

PubMed

Osaki, Kanji; Okazaki, Ken; Matsubara, Hirokazu; Kuwashima, Umito; Murakami, Koji; Iwamoto, Yukihide

2015-12-01

To investigate the mismatch between the length at the center and the length on the shortest and longest peripheral sides of the femoral tunnel socket, reamed with the transportal (TP), outside-in (OI), and modified transtibial (TT) techniques, in anterior cruciate ligament (ACL) reconstruction. Femoral tunnel drilling was simulated on 3-dimensional bone models from 40 subjects. The tunnel directions used with the TP, OI, and modified TT techniques were previously described. By use of the resulting angle, a femoral tunnel socket of 9 mm in diameter was drilled from the center of the femoral ACL insertion. The virtual femoral tunnel was extracted, and the length mismatch was measured between the center and the shortest and longest peripheral sides of the tunnel socket. The mean socket length mismatch between the center and the shortest peripheral part of the femoral tunnel socket was 4.2 ± 0.9 mm with the TP technique, 5.2 ± 1.3 mm with the OI technique, and 3.2 ± 0.8 mm with the modified TT technique. The mean socket length mismatch between the center and the longest peripheral part of the femoral tunnel socket was 3.5 ± 0.9 mm with the TP technique, 4.8 ± 1.5 mm with the OI technique, and 3.3 ± 1.2 mm with the modified TT technique. The length mismatch was significantly higher when the tunnel socket was created by the OI technique (P < .01). A length mismatch with the tunnel socket exists after reaming with either the TP, OI, or modified TT technique. In particular, there was a significant increase in length mismatch when the tunnel socket was created by the OI technique, and the length mismatch would easily become greater than 5 mm. The surgeon should recognize this mismatch when it is created and measure the femoral tunnel socket. In anatomic ACL reconstruction, a mismatch between the length at the center and the length at periphery of the femoral tunnel socket occurs, and this is increased particularly when using the OI technique. The discrepancy in tunnel length between its center and its periphery could cause an overestimation of the tunnel length that could result in an error in length during graft preparation. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

ACL Fibers Inserting on the Lateral Intercondylar Ridge Carry the Greatest Loads - Are Modern Anatomic Femoral Tunnel Positions Too Low?

PubMed Central

Nawabi, Danyal H.; Imhauser, Carl; Tucker, Scott; Nguyen, Joseph; Wickiewicz, Thomas L.; Pearle, Andrew

2014-01-01

Objectives: Histological studies have shown that the ACL has a direct and indirect insertion on the femur [1]. The direct insertion is located along the lateral intercondylar ridge and the indirect insertion is located ‘lower’ on the lateral wall of the notch. The trend towards anatomic ACL reconstruction using the anteromedial (AM) portal technique has resulted in ‘lower’ non-isometric femoral tunnel positions and increased graft failures [2]. To our knowledge, the load transfer properties of the direct and indirect ACL insertions have not been studied. This information may help in understanding the increased failures reported with AM portal drilling. The purpose of this study was, 1) to compare the load transferred across the native ACL at the direct and indirect femoral insertions and, 2) to determine the strain behavior of ACL grafts placed at different tunnel locations within the direct and indirect insertions. Methods: Ten fresh-frozen cadaveric knees (mean age, 52.5 years; range, 29-65) were mounted to a six degree of freedom robot. A 134N anterior load at 30 and 90° flexion and a combined valgus (8Nm) and internal (4Nm) rotational moment at 15° flexion were applied. The ACL was subsequently sectioned at the femoral footprint by detaching either the direct or indirect insertion (partially sectioned state), followed by the remainder of the ACL (completely sectioned state) (Figure 1). The kinematics of the intact knee were replayed after each stage of sectioning to determine the loads transferred across the direct and indirect ACL fibers. Loads were expressed as a percentage of the total load borne by the ACL. Strain behaviour was tested by generating 3D models of the femur and tibia from CT scans of each knee. Three tunnel locations (anteromedial bundle [AM], center [C], posterolateral bundle [PL]) each were selected for the direct and indirect insertions and a virtual ACL graft was inserted. The isometry of the virtual graft was calculated through a flexion path of 0 to 90°. Results: Under an anterior tibial load at 30° flexion, the direct insertion carried 83.9% of the total ACL load compared to 16.1% in the indirect insertion (p<0.001). The direct insertion also carried more load at 90° flexion (95.2% vs 4.8%; p<0.001). Under a combined rotatory load at 15° flexion, the direct insertion carried 84.2% of the total ACL load compared to 15.8% in the indirect insertion (p<0.001). A virtual ACL graft placed at the AM position in the direct insertion demonstrated the best strain behaviour with a mean 10.9% change in length. This value was significantly lower (p<0.001) than the isometry at all 3 tunnel positions in the indirect insertion (AM = 18.5%; C = 24.9%; PL = 30.9%). Conclusion: Fibers in the direct insertion of the ACL carry more load than fibers in the indirect insertion. Virtual ACL grafts placed in the ‘higher’ direct location are more isometric than in the ‘lower’ indirect location during range of motion testing. Clinical Relevance: ‘Low’ ACL grafts in the indirect ACL insertion, resulting from AM portal drilling techniques, may experience higher loads in-vivo due to unfavorable biomechanics. With the current shift towards anatomic ACL reconstruction, it may be beneficial to create a ‘higher’ femoral tunnel within the direct insertion at the lateral intercondylar ridge. This position remains anatomical but may also be biomechanically favorable.

Lower Limb Kinematics and Dynamic Postural Stability in Anterior Cruciate Ligament-Reconstructed Female Athletes

PubMed Central

Delahunt, Eamonn; Chawke, Mark; Kelleher, Judy; Murphy, Katie; Prendiville, Anna; Sweeny, Lauren; Patterson, Matt

2013-01-01

Context: Deficits in lower limb kinematics and postural stability are predisposing factors to the development of knee ligamentous injury. The extent to which these deficits are present after anterior cruciate ligament (ACL) reconstruction is still largely unknown. The primary hypothesis of the present study was that female athletes who have undergone ACL reconstruction and who have returned to sport participation would exhibit deficits in dynamic postural stability as well as deficiencies in hip- and knee-joint kinematics when compared with an age-, activity-, and sex-matched uninjured control group. Objective: To investigate dynamic postural stability as quantified by the Star Excursion Balance Test (SEBT) and simultaneous hip- and knee-joint kinematic profiles in female athletes who have undergone ACL reconstruction. Design: Descriptive laboratory study. Setting: University motion-analysis laboratory. Patients or Other Participants: Fourteen female athletes who had previously undergone ACL reconstruction (ACL-R) and 17 age- and sex-matched uninjured controls. Intervention(s): Each participant performed 3 trials of the anterior, posterior-medial, and posterior-lateral directional components of the SEBT. Main Outcome Measure(s): Reach distances for each directional component were quantified and expressed as a percentage of leg length. Simultaneous hip- and knee-joint kinematic profiles were recorded using a motion-analysis system. Results: The ACL-R group had decreased reach distances on the posterior-medial (P < .01) and posterior-lateral (P < .01) directional components of the SEBT. During performance of the directional components of the SEBT, ACL-R participants demonstrated altered hip-joint frontal-, sagittal-, and transverse-plane kinematic profiles (P < .05), as well as altered knee-joint sagittal-plane kinematic profiles (P < .05). Conclusions: Deficits in dynamic postural stability and concomitant altered hip- and knee-joint kinematics are present after ACL reconstruction and return to competitive activity. The extent to which these deficits influence potential future injury is worthy of investigation. PMID:23672381

Improvement in the medial meniscus posterior shift following anterior cruciate ligament reconstruction.

PubMed

Inoue, Hiroto; Furumatsu, Takayuki; Miyazawa, Shinichi; Fujii, Masataka; Kodama, Yuya; Ozaki, Toshifumi

2018-02-01

Anterior cruciate ligament (ACL) reconstruction can reduce the risk of developing osteoarthritic knees. The goals of ACL reconstruction are to restore knee stability and reduce post-traumatic meniscal tears and cartilage degradation. A chronic ACL insufficiency frequently results in medial meniscus (MM) injury at the posterior segment. How ACL reconstruction can reduce the deformation of the MM posterior segment remains unclear. In this study, we evaluated the form of the MM posterior segment and anterior tibial translation before and after ACL reconstruction using open magnetic resonance imaging (MRI). Seventeen patients who underwent ACL reconstructions without MM injuries were included in this study. MM deformation was evaluated using open MRI before surgery and 3 months after surgery. We measured medial meniscal length (MML), medial meniscal height (MMH), medial meniscal posterior body width (MPBW), MM-femoral condyle contact width (M-FCW) and posterior tibiofemoral distance (PTFD) at knee flexion angles of 10° and 90°. There were no significant pre- and postoperative differences during a flexion angle of 10°. At a flexion angle of 90°, MML decreased from 43.7 ± 4.5 to 41.4 ± 4.5 mm (P < 0.001), MMH from 7.5 ± 1.4 to 6.9 ± 1.4 mm (P = 0.006), MPBW from 13.1 ± 2.0 to 12.2 ± 1.9 mm (P < 0.001) and M-FCW from 10.0 ± 1.5 to 8.5 ± 1.5 mm (P < 0.001) after ACL reconstruction. The PTFD increased from 2.1 ± 2.8 to 2.7 ± 2.4 mm after ACL reconstruction (P = 0.015). ACL reconstruction affects the contact pattern between the MM posterior segment and medial femoral condyle and can reduce the deformation of the MM posterior segment in the knee-flexed position by reducing abnormal anterior tibial translation. It possibly prevents secondary injury to the MM posterior segment and cartilage that progresses to knee osteoarthritis. IV.

Effect of knee flexion angle on ground reaction forces, knee moments and muscle co-contraction during an impact-like deceleration landing: implications for the non-contact mechanism of ACL injury.

PubMed

Podraza, Jeffery T; White, Scott C

2010-08-01

Investigating landing kinetics and neuromuscular control strategies during rapid deceleration movements is a prerequisite to understanding the non-contact mechanism of ACL injury. The purpose of this study was to quantify the effect of knee flexion angle on ground reaction forces, net knee joint moments, muscle co-contraction and lower extremity muscles during an impact-like, deceleration task. Ground reaction forces and knee joint moments were determined from video and force plate records of 10 healthy male subjects performing rapid deceleration single leg landings from a 10.5 cm height with different degrees of knee flexion at landing. Muscle co-contraction was based on muscle moments calculated from an EMG-to-moment processing model. Ground reaction forces and co-contraction indices decreased while knee extensor moments increased significantly with increased degrees of knee flexion at landing (all p<0.005). Higher ground reaction forces when landing in an extended knee position suggests they are a contributing factor in non-contact ACL injuries. Increased knee extensor moments and less co-contraction with flexed knee landings suggest that quadriceps overload may not be the primary cause of non-contact ACL injuries. The results bring into question the counterbalancing role of the hamstrings during dynamic movements. The soleus may be a valuable synergist stabilizing the tibia against anterior translation at landing. Movement strategies that lessen the propagation of reaction forces up the kinetic chain may help prevent non-contact ACL injuries. The relative interaction of all involved thigh and lower leg muscles, not just the quadriceps and hamstrings should be considered when interpreting non-contact ACL injury mechanisms. Copyright 2010 Elsevier B.V. All rights reserved.

Anterior Cruciate Ligament Reconstruction Rehabilitation

PubMed Central

Wright, Rick W.; Haas, Amanda K.; Anderson, Joy; Calabrese, Gary; Cavanaugh, John; Hewett, Timothy E.; Lorring, Dawn; McKenzie, Christopher; Preston, Emily; Williams, Glenn; Amendola, Annunziato

2015-01-01

Context: Anterior cruciate ligament (ACL) reconstruction rehabilitation has evolved over the past 20 years. This evolution has been driven by a variety of level 1 and level 2 studies. Evidence Acquisition: The MOON Group is a collection of orthopaedic surgeons who have developed a prospective longitudinal cohort of the ACL reconstruction patients. To standardize the management of these patients, we developed, in conjunction with our physical therapy committee, an evidence-based rehabilitation guideline. Study Design: Clinical review. Level of Evidence: Level 2. Results: This review was based on 2 systematic reviews of level 1 and level 2 studies. Recently, the guideline was updated by a new review. Continuous passive motion did not improve ultimate motion. Early weightbearing decreases patellofemoral pain. Postoperative rehabilitative bracing did not improve swelling, pain range of motion, or safety. Open chain quadriceps activity can begin at 6 weeks. Conclusion: High-level evidence exists to determine appropriate ACL rehabilitation guidelines. Utilizing this protocol follows the best available evidence. PMID:26131301

Variation in n-Alkane Distributions of Modern Plants: Questioning Applications of n-Alkanes in Chemotaxonomy and Paleoecology

NASA Astrophysics Data System (ADS)

Bush, R. T.; McInerney, F. A.

2010-12-01

Long chain n-alkanes (n-C21 to n-C37) are synthesized as part of the epicuticular leaf wax of terrestrial plants and are among the most recognizable and widely used plant biomarkers. n-Alkane distributions have been utilized in previous studies on modern plant chemotaxonomy, testing whether taxa can be identified based on characteristic n-alkane profiles. Dominant n-alkanes (e.g. n-C27 or n-C31) have also been ascribed to major plant groups (e.g. trees or grasses respectively) and have been used in paleoecology studies to reconstruct fluctuations in plant functional types. However, many of these studies have been based on relatively few modern plant data; with the wealth of modern n-alkane studies, a more comprehensive analysis of n-alkanes in modern plants is now possible and can inform the usefulness of n-alkane distributions as paleoecological indicators. The work presented here is a combination of measurements made using plant leaves collected from the Chicago Botanic Garden and a compilation of published literature data from six continents. We categorized plants by type: angiosperms, gymnosperms, woody plants, forbs, grasses, ferns and pteridophytes, and mosses. We then quantified n-alkane distribution parameters such as carbon preference index (CPI), average chain length (ACL), and dispersion (a measure of the spread of the profile over multiple chain lengths) and used these to compare plant groups. Among all plants, one of the emergent correlations is a decrease in dispersion with increasing CPI. Within and among plant groups, n-alkane distributions show a very large range of variation, and the results show little or no correspondence between broad plant groups and a single dominant n-alkane or a ratio of n-alkanes. These findings are true both when data from six continents are combined and when plants from a given region are compared (North America). We also compared the n-alkane distributions of woody angiosperms, woody gymnosperms, and grasses with one another in order to test whether n-C27 and n-C29 represent trees and shrubs while n-C31 represents grasses as previously proposed. The average group profiles are not distinguishable from one another due to their large standard deviations. Although n-C31 is the predominant chain length in many (but not all) grasses, other chain lengths such as n-C29 are also abundant. For grasses as a group one chain length does not dominate significantly over the other. In mosses, while the genus Sphagnum appears to be typified by n-C23 and n-C25 alkanes, the same cannot be said for other moss genera which were more dominated by n-C27 and n-C29. Differences in n-alkane distributions may relate more to environmental changes such as temperature and precipitation than to shifts in dominant plant types.

Effects of mechanical strain on human mesenchymal stem cells and ligament fibroblasts in a textured poly(L-lactide) scaffold for ligament tissue engineering.

PubMed

Kreja, Ludwika; Liedert, Astrid; Schlenker, Heiter; Brenner, Rolf E; Fiedler, Jörg; Friemert, Benedikt; Dürselen, Lutz; Ignatius, Anita

2012-10-01

The purpose of this study was to prove the effect of cyclic uniaxial intermittent strain on the mRNA expression of ligament-specific marker genes in human mesenchymal stem cells (MSC) and anterior cruciate ligament-derived fibroblasts (ACL-fibroblasts) seeded onto a novel textured poly(L-lactide) scaffold (PLA scaffold). Cell-seeded scaffolds were mechanically stimulated by cyclic uniaxial stretching. The expression of ligament matrix gene markers: collagen types I and III, fibronectin, tenascin C and decorin, as well as the proteolytic enzymes matrix metalloproteinase MMP-1 and MMP-2 and their tissue specific inhibitors TIMP-1 and TIMP-2 was investigated by analysing the mRNA expression using reverse transcriptase polymerase chain reaction and related to the static control. In ACL-fibroblasts seeded on PLA, mechanical load induced up-regulation of collagen types I and III, fibronectin and tenascin C. No effect of mechanical stimulation on the expression of ligament marker genes was found in undifferentiated MSC seeded on PLA. The results indicated that the new textured PLA scaffold could transfer the mechanical load to the ACL-fibroblasts and improved their ligament phenotype. This scaffold might be suitable as a cell-carrying component of ACL prostheses.

Implant preloading in extension reduces spring length change in dynamic intraligamentary stabilization: a biomechanical study on passive kinematics of the knee.

PubMed

Häberli, Janosch; Voumard, Benjamin; Kösters, Clemens; Delfosse, Daniel; Henle, Philipp; Eggli, Stefan; Zysset, Philippe

2018-06-01

Dynamic intraligamentary stabilization (DIS) is a primary repair technique for acute anterior cruciate ligament (ACL) tears. For internal bracing of the sutured ACL, a metal spring with 8 mm maximum length change is preloaded with 60-80 N and fixed to a high-strength polyethylene braid. The bulky tibial hardware results in bone loss and may cause local discomfort with the necessity of hardware removal. The technique has been previously investigated biomechanically; however, the amount of spring shortening during movement of the knee joint is unknown. Spring shortening is a crucial measure, because it defines the necessary dimensions of the spring and, therefore, the overall size of the implant. Seven Thiel-fixated human cadaveric knee joints were subjected to passive range of motion (flexion/extension, internal/external rotation in 90° flexion, and varus/valgus stress in 0° and 20° flexion) and stability tests (Lachman/KT-1000 testing in 0°, 15°, 30°, 60°, and 90° flexion) in the ACL-intact, ACL-transected, and DIS-repaired state. Kinematic data of femur, tibia, and implant spring were recorded with an optical measurement system (Optotrak) and the positions of the bone tunnels were assessed by computed tomography. Length change of bone tunnel distance as a surrogate for spring shortening was then computed from kinematic data. Tunnel positioning in a circular zone with r = 5 mm was simulated to account for surgical precision and its influence on length change was assessed. Over all range of motion and stability tests, spring shortening was highest (5.0 ± 0.2 mm) during varus stress in 0° knee flexion. During flexion/extension, spring shortening was always highest in full extension (3.8 ± 0.3 mm) for all specimens and all simulations of bone tunnels. Tunnel distance shortening was highest (0.15 mm/°) for posterior femoral and posterior tibial tunnel positioning and lowest (0.03 mm/°) for anterior femoral and anterior tibial tunnel positioning. During passive flexion/extension, the highest spring shortening was consistently measured in full extension with a continuous decrease towards flexion. If preloading of the spring is performed in extension, the spring can be downsized to incorporate a maximum length change of 5 mm resulting in a smaller implant with less bone sacrifice and, therefore, improved conditions in case of revision surgery.

Modified arthroscopic suture fixation of a displaced tibial eminence fracture.

PubMed

Lehman, Ronald A; Murphy, Kevin P; Machen, M Shaun; Kuklo, Timothy R

2003-02-01

This study describes a new arthroscopic method using a whip-stitch technique for treating a displaced type III tibial eminence fracture. A 12-year-old girl who sustained a displaced type III tibial eminence fracture was treated with arthroscopic fixation using the Arthrosew disposable suture device (Surgical Dynamics, Norwalk, CT) to place a whip stitch into the anterior cruciate ligament (ACL). The Arthrex ACL guide (Arthrex, Naples, FL) was used to reduce the avulsed tibial spine fragment. Sutures were then passed through the tibial tunnel and secured over a bony bridge with the knee in 20 degrees of flexion. At 9 months, the patient has a full range of motion with normal Lachman and anterior drawer testing, and she has returned to competitive basketball. Radiographs show complete fracture healing. KT-1000 and isokinetic testing at 9-month follow-up show only minimal side-to-side differences. The Arthrosew device provides a significant advantage in the treatment of type III and IV fractures of the tibial eminence by obtaining arthroscopic fixation within the substance of the ACL, thus obviating arthrotomy and hardware placement. This technique also restores the proper length and tension to the ACL, and provides a simplified, reproducible method of treatment for this injury.

The BCKDH Kinase and Phosphatase Integrate BCAA and Lipid Metabolism via Regulation of ATP-Citrate Lyase.

PubMed

White, Phillip J; McGarrah, Robert W; Grimsrud, Paul A; Tso, Shih-Chia; Yang, Wen-Hsuan; Haldeman, Jonathan M; Grenier-Larouche, Thomas; An, Jie; Lapworth, Amanda L; Astapova, Inna; Hannou, Sarah A; George, Tabitha; Arlotto, Michelle; Olson, Lyra B; Lai, Michelle; Zhang, Guo-Fang; Ilkayeva, Olga; Herman, Mark A; Wynn, R Max; Chuang, David T; Newgard, Christopher B

2018-06-05

Branched-chain amino acids (BCAA) are strongly associated with dysregulated glucose and lipid metabolism, but the underlying mechanisms are poorly understood. We report that inhibition of the kinase (BDK) or overexpression of the phosphatase (PPM1K) that regulates branched-chain ketoacid dehydrogenase (BCKDH), the committed step of BCAA catabolism, lowers circulating BCAA, reduces hepatic steatosis, and improves glucose tolerance in the absence of weight loss in Zucker fatty rats. Phosphoproteomics analysis identified ATP-citrate lyase (ACL) as an alternate substrate of BDK and PPM1K. Hepatic overexpression of BDK increased ACL phosphorylation and activated de novo lipogenesis. BDK and PPM1K transcript levels were increased and repressed, respectively, in response to fructose feeding or expression of the ChREBP-β transcription factor. These studies identify BDK and PPM1K as a ChREBP-regulated node that integrates BCAA and lipid metabolism. Moreover, manipulation of the BDK:PPM1K ratio relieves key metabolic disease phenotypes in a genetic model of severe obesity. Copyright © 2018 Elsevier Inc. All rights reserved.

Factors informing fear of reinjury after anterior cruciate ligament reconstruction.

PubMed

Ross, Cheryl A; Clifford, Amanda; Louw, Quinette A

2017-02-01

Fear of reinjury is associated with cessation of sport after anterior cruciate ligament (ACL) reconstruction despite normal postoperative knee function. The objective of this study is to describe factors informing athletes' experience of fear of reinjury post ACL reconstruction, in athletes who cited fear as the sole reason for not returning to their pre-injury level of sport. Mixed-methods study design of qualitative and a preliminary quantitative component. A conveniently selected private hospital. Ten male and two female athletes, aged between 19 and 45 years, were eligible for the interview from 68 male and 32 female potential participants (age range 17-50) who underwent an ACL reconstruction using any graft type, excluding revision or multi-ligament surgery. To explore factors informing fear of reinjury in participants citing fear of reinjury as the sole reason for not returning to sport, albeit normal knee function. From the participant interview, four themes emerged: undergoing the surgery and recovery again, nature of the pre-injury sport imposing risk of reinjury, personality traits, and social priorities. Clinicians should be aware of factors informing fear of reinjury post ACL reconstruction. Modifiable fears including pain, mode and length of rehabilitation and psychological factors should be considered during rehabilitation to potentially improve the return to sport rate.

Overestimation of femoral tunnel length during anterior cruciate ligament reconstruction using the retrograde outside-in drilling technique.

PubMed

Okazaki, Ken; Osaki, Kanji; Nishikawa, Kazutaka; Matsubara, Hirokazu; Tashiro, Yasutaka; Iwamoto, Yukihide

2016-08-01

When the femoral tunnel socket is reamed in an oblique direction from the wall of inter-condylar notch in anterior cruciate ligament (ACL) reconstruction, the tunnel length can be shorter at the periphery than at the centre. Because surgeons can manipulate the direction of tunnel in the outside-in femoral tunnel drilling technique, this length mismatch would vary depending on the direction of the tunnel. The purpose of this study was to investigate this length mismatch when reamed in various directions. In total of thirteen points were defined as femoral drilling entry points on concentric lines with 0, 1, 2, and 3 cm radius from the lateral epicondyle of a three-dimensional bone model from 40 subjects. Femoral tunnel drilling was simulated on the models by connecting the centre of the ACL footprint with each defined point on the lateral femoral surface. The mismatch length was measured between the centre and the shortest peripheral side of the tunnel socket. When the distance between the drilling entry point on the lateral femoral surface and the lateral epicondyle was increased to anterior proximal direction, there was a significant increase in the mismatch length. The mismatch length became more than 2 mm when the entry point was located more than 2 cm away from the lateral epicondyle. When the drilling entry point is set far away from the lateral epicondyle, a significant increase was observed in tunnel length mismatch between the centre of the tunnel and its shortest peripheral side. Because the tunnel length is measured with a guide pin introduced at the centre of the tunnel before reaming in retrograde outside-in technique, this length mismatch could cause an overestimation of the tunnel length. Surgeons should recognise this mismatch when preparing the length of graft and socket to optimise the graft insertion length into the socket.

Latitudinal distribution of terrestrial lipid biomarkers and n-alkane compound-specific stable carbon isotope ratios in the atmosphere over the western Pacific and Southern Ocean

NASA Astrophysics Data System (ADS)

Bendle, James; Kawamura, Kimitaka; Yamazaki, Koji; Niwai, Takeji

2007-12-01

We investigated the latitudinal changes in atmospheric transport of organic matter to the western Pacific and Southern Ocean (27.58°N-64.70°S). Molecular distributions of lipid compound classes (homologous series of C 15 to C 35n-alkanes, C 8 to C 34n-alkanoic acids, C 12 to C 30n-alkanols) and compound-specific stable isotopes (δ 13C of C 29 and C 31n-alkanes) were measured in marine aerosol filter samples collected during a cruise by the R/V Hakuho Maru. The geographical source areas for each sample were estimated from air-mass back-trajectory computations. Concentrations of TC and lipid compound classes were several orders of magnitude lower than observations from urban sites in Asia. A stronger signature of terrestrial higher plant inputs was apparent in three samples collected under conditions of strong terrestrial winds. Unresolved complex mixtures (UCM) showed increasing values in the North Pacific, highlighting the influence of the plume of polluted air exported from East Asia. n-Alkane average chain length (ACL) distribution had two clusters, with samples showing a relation to latitude between 28°N and 47°S (highest ACL values in the tropics), whilst a subset of southern samples had anomalously high ACL values. Compound-specific carbon isotopic analysis of the C 29 (-25.6‰ to -34.5‰) and C 31n-alkanes (-28.3‰ to -37‰) revealed heavier δ 13C values in the northern latitudes with a transition to lighter values in the Southern Ocean. By comparing the isotopic measurements with back-trajectory analysis it was generally possible to discriminate between different source areas. The terrestrial vegetation source for a subset of the southernmost Southern Ocean is enigmatic; the back-trajectories indicate eastern Antarctica as the only intercepted terrestrial source area. These samples may represent a southern hemisphere background of well mixed and very long range transported higher plant organic material.

Selective contribution of each hamstring muscle to anterior cruciate ligament protection and tibiofemoral joint stability in leg-extension exercise: a simulation study.

PubMed

Biscarini, Andrea; Botti, Fabio Massimo; Pettorossi, Vito Enrico

2013-09-01

A biomechanical model was developed to simulate the selective effect of the co-contraction force provided by each hamstring muscle on the shear and compressive tibiofemoral joint reaction forces, during open kinetic-chain knee-extension exercises. This model accounts for instantaneous values of knee flexion angle [Formula: see text], angular velocity and acceleration, and for changes in magnitude, orientation, and application point of external resistance. The tibiofemoral shear force (TFSF) largely determines the tensile force on anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL). Biceps femoris is the most effective hamstring muscle in decreasing the ACL-loading TFSF developed by quadriceps contractions for [Formula: see text]. In this range, the semimembranosus generates the dominant tibiofemoral compressive force, which enhances joint stability, opposes anterior/posterior tibial translations, and protects cruciate ligaments. The semitendinosus force provides the greatest decreasing gradient of ACL-loading TFSF for [Formula: see text], and the greatest increasing gradient of tibiofemoral compressive force for [Formula: see text]. However, semitendinosus efficacy is strongly limited by its small physiological section. Hamstring muscles behave as a unique muscle in enhancing the PCL-loading TFSF produced by quadriceps contractions for [Formula: see text]. The levels of hamstrings co-activation that suppress the ACL-loading TFSF considerably shift when the knee angular acceleration is changed while maintaining the same level of knee extensor torque by a concurrent adjustment in the magnitude of external resistance. The knowledge of the specific role and the optimal activation level of each hamstring muscle in ACL protection and tibiofemoral stability are fundamental for planning safe and effective rehabilitative knee-extension exercises.

Age-Related Differences in Anterior Cruciate Ligament Remnant Vascular-Derived Cells.

PubMed

Uefuji, Atsuo; Matsumoto, Tomoyuki; Matsushita, Takehiko; Ueha, Takeshi; Zhang, Shurong; Kurosaka, Masahiro; Kuroda, Ryosuke

2014-06-01

The anterior cruciate ligament (ACL) does not heal spontaneously after injury, and patients of different ages respond differently to treatment. CD34+ stem/progenitor cells derived from the ACL remnant and associated tissues contribute to tendon-bone healing, but the relationship between age and the ACL's healing potential has not been clarified. The ACL remnant and associated tissues from adolescent patients have more CD34+ cells, and this population of cells from younger patients exhibits a higher potential for proliferation and differentiation in vitro. Descriptive laboratory study. Ruptured ACL remnants and associated tissues were harvested from 28 patients (mean age, 24.6 ± 1.6 years) who had undergone primary arthroscopic ACL reconstruction. Patients were divided into 3 patient groups by age: 10-19 years (teens group; n = 10), 20-29 years (20s group; n = 10), and ≥30 years (30s group; n = 8). The ACL remnant cells were characterized using fluorescence-activated cell sorting (FACS). Expansion potential was evaluated using population doubling (PD), and multilineage differentiation potential was assessed and compared. The FACS analysis showed numerous CD34+ cells in the teens group compared with the 30s group (mean, 25.4% ± 7.9% vs 16.9% ± 3.9%, respectively; P = .044). The PD results indicated that the teens group had a significantly higher expansion potential than the 30s group at passage 3 (mean, 3.3 ± 0.2 vs 2.8 ± 0.2, respectively; P = .039). Young ACL remnant cells had a higher potential for osteogenic differentiation according to alkaline phosphatase activity (teens group, 169.5 ± 37.9 × 10 ng/mL vs 30s group, 64.9 ± 14.6 × 10 ng/mL; P = .029) and osteocalcin gene expression (teens group, 1.0 ± 0.25 vs 30s group, 0.39 ± 0.01; P = .01). In addition, the teens group displayed a higher differentiation potential to angiogenic lineages (acetylated low-density lipoprotein/Ulex europaeus lectin-stained cell counts) than other groups (teens group, 15.9 ± 1.9 vs 20s group, 8.9 ± 1.3 [P = .04]; teens group, 15.9 ± 1.9 vs 30s group, 7.2 ± 1.5 [P = .008]) and also tube length (teens group, 6939 ± 470 μm vs 30s group, 4119 ± 507 μm; P = .009). The ACL remnants of adolescent patients had more CD34+ cells, and those cells had a higher potential for proliferation and multilineage differentiation in vitro. During remnant-preserving or remnant-transplanted ACL reconstruction, surgeons should consider the patient's age when predicting the healing potential. © 2014 The Author(s).

Biomechanics laboratory-based prediction algorithm to identify female athletes with high knee loads that increase risk of ACL injury

PubMed Central

Myer, Gregory D; Ford, Kevin R; Khoury, Jane; Succop, Paul; Hewett, Timothy E

2014-01-01

Objective Knee abduction moment (KAM) during landing predicts non-contact anterior cruciate ligament (ACL) injury risk with high sensitivity and specificity in female athletes. The purpose of this study was to employ sensitive laboratory (lab-based) tools to determine predictive mechanisms that underlie increased KAM during landing. Methods Female basketball and soccer players (N=744) from a single county public school district were recruited to participate in testing of anthropometrics, maturation, laxity/flexibility, strength and landing biomechanics. Linear regression was used to model KAM, and logistic regression was used to examine high (>25.25 Nm of KAM) versus low KAM as surrogate for ACL injury risk. Results The most parsimonious model included independent predictors (β±1 SE) (1) peak knee abduction angle (1.78±0.05; p<0.001), (2) peak knee extensor moment (0.17±0.01; p<0.001), (3) knee flexion range of motion (0.15±0.03; p<0.01), (4) body mass index (BMI) Z-score (−1.67±0.36; p<0.001) and (5) tibia length (−0.50±0.14; p<0.001) and accounted for 78% of the variance in KAM during landing. The logistic regression model that employed these same variables predicted high KAM status with 85% sensitivity and 93% specificity and a C-statistic of 0.96. Conclusions Increased knee abduction angle, quadriceps recruitment, tibia length and BMI with decreased knee flexion account for 80% of the measured variance in KAM during a drop vertical jump. Clinical relevance Females who demonstrate increased KAM are more responsive and more likely to benefit from neuromuscular training. These findings should significantly enhance the identification of those at increased risk and facilitate neuromuscular training targeted to this important risk factor (high KAM) for ACL injury. PMID:20558526

The effect of knee extensor open kinetic chain resistance training in the ACL-injured knee.

PubMed

Barcellona, Massimo G; Morrissey, Matthew C; Milligan, Peter; Clinton, Melissa; Amis, Andrew A

2015-11-01

To investigate the effect of different loads of knee extensor open kinetic chain resistance training on anterior knee laxity and function in the ACL-injured (ACLI) knee. Fifty-eight ACLI subjects were randomised to one of three (12-week duration) training groups. The STAND group trained according to a standardised rehabilitation protocol. Subjects in the LOW and HIGH group trained as did the STAND group but with the addition of seated knee extensor open kinetic chain resistance training at loads of 2 sets of 20 repetition maximum (RM) and 20 sets of 2RM, respectively. Anterior knee laxity and measurements of physical and subjective function were performed at baseline, 6 and 12 weeks. Thirty-six subjects were tested at both baseline and 12 weeks (STAND n = 13, LOW n = 11, HIGH n = 12). The LOW group demonstrated a reduction in 133 N anterior knee laxity between baseline and 12 weeks testing when compared to the HIGH and the STAND groups (p = 0.009). Specifically, the trained-untrained knee laxity decreased an average of approximately 5 mm in the LOW group while remaining the same in the other two groups. Twelve weeks of knee extensor open kinetic chain resistance training at loads of 2 sets of 20RM led to a reduction in anterior knee laxity in the ACLI knee. This reduction in laxity does not appear to offer any significant short-term functional advantages when compared to a standard rehabilitation protocol. These results indicate that knee laxity can be decreased with resistance training of the thigh muscles. Randomised controlled trial, Level II.

Soft tissue graft interference fit fixation: observations on graft insertion site healing and tunnel remodeling 2 years after ACL reconstruction in sheep.

PubMed

Hunt, Patrick; Rehm, Oliver; Weiler, Andreas

2006-12-01

Using soft tissue grafts for anterior cruciate ligament (ACL) reconstruction, insertion site healing plays a crucial role in the long-term fate of the graft. It has been shown in an experimental animal study that using a soft tissue graft and anatomic graft fixation, a direct ligamentous insertion alike the native ACL developed 24 weeks postoperatively. Yet there are no reports on the long-term insertion site healing of anatomically fixed soft tissue grafts. The objective of this study was to evaluate graft insertion site healing, the intra-tunnel fate of the graft and its osseous replacement 2 years after ACL reconstruction in sheep. The left ACLs of six sheep were replaced by an autologous flexor tendon split graft and anatomically fixed with biodegradable poly-(D, L-lactide) interference screws. Animals received polychromic sequential labeling at different points in time to determine bone apposition per period. For evaluation of the insertion site healing and intra-tunnel changes, MRI scans were taken in vivo. Following sacrifice, radiographic imaging, conventional histology and fluorescence microscopy was undertaken. Most of the specimens showed a wide direct ligamentous insertion. It showed patterns alike the direct ligament insertion seen in intact ACLs. The intra-tunnel part of the graft had completely lost its tendon-like structure and in two cases, it was separated from the graft insertion by a thick bony layer. The biodegradable interference screw was fully degraded in all specimens. Ossification of the former drill tunnels was intense, showing only partial-length tunnel remnants in one femoral and three tibial specimens. As the graft heals to the joint surface and the aperture site is closed with soft tissue, mechanical stress of the intra-tunnel part of the graft is eliminated and the bone tunnel is protected from synovial fluid, resulting in osseous bridging of the tunnel aperture site, accelerated intra-tunnel graft resorption and its osseous replacement.

Characterisation of organic matter source and sediment distribution in Ashtamudi Estuary, southern India

NASA Astrophysics Data System (ADS)

Kumar, Prem; Ankit, Yadav; Mishra, Praveen K.; Jha, Deepak Kumar; Anoop, Ambili

2017-04-01

In the present study we have focussed on the surface sediments of Ashtamudi Estuary (southern India) to understand (i) the fate and sources of organic matter by investigating lipid biomarker (n-alkanes) distribution in modern sediments and vegetation samples and (ii) the processes controlling the sediment distribution into the lake basin using end-member modelling approach. The sediment n-alkanes from the Ashtamudi Estuary exhibit a pronounced odd over even predominance with maxima at C29 and C31 chain length indicative of a dominant terrestrial contribution. A number of n-alkane indices have been calculated to illustrate the variability in space by considering separately the river dominated northern reaches and tidal influenced southern part of Ashtamudi Estuary. The highest terrigenous organic contents were found in sediments from the river and upper bay sites, with smaller contributions to the lower parts of the estuary. The Paq and TAR (terrigenous/aquatic ratio) indices demonstrate maximum aquatic productivity (plankton growth and submerged macrophytes) in the tidal dominated region of the Ashtamudi Estuary. The carbon preference index (CPI) and average chain length (ACL) provide evidence for high petrogenic organic inputs in the tidal zone, whereas dominant biogenic contribution have been observed in the riverine zone. In addition, the end member modeling of the grain size distribution of the surface sediment samples enabled us to decipher significant sedimentological processes affecting the sediment distribution in the estuarine settings. The end-member distribution showing highest loading with the coarser fraction is maximum where estuary debouches into the sea. However, the samples near the mouth of the river shows finer fraction of the end-member.

Terrestrial biomarker records in Seomjin Estuary in the South Sea of Korea: Implication for terrestrial flux and environmental changes

NASA Astrophysics Data System (ADS)

kim, Songyi; hyun, Sangmin; Kim, Wonnyon; Hyeong, Kiseong

2016-04-01

High-resolution records of terrestrial biomarkers, n-alkane compounds, were investigated in two gravity cores (SJP-2 and SJP-4) to evaluate variations in terrestrial organic matter influx. Based on 14C dating, sediments in both cores were deposited during the mid-Holocene; the ages of the bottom sediments of SJP-2 and SJP-4 reached 5,500 Cal yr BP and 5,000 Cal yr BP, respectively. High concentrations of total n-alkanes (nC25-35) in the two cores showed an increasing tendency from 4,500 yr to ca. 2,000 yr. The composition changed at the boundary of 2,500 yr in both cores, suggesting a variation in terrestrial biomarker influx at this time. Several indices including average chain length (ACL), carbon preference index (ICP), and paleo-vegetation index (Paq) showed coincident variations in both cores; ACL exhibited a narrow range of variations with a slight shift at 2,500 yr, CPI showed a decreasing tendency from 4,000 yr to 2,500 yr, and Paq increased during these intervals. Furthermore, the ratios of C23/C31 and C25/C31, indicate a relative abundance of epicuticular wax from vascular plants with coincident variations in both cores, and this also marched well with Paq. CPI excursions suggested that the total n-alkane proxy of the two cores might not only be linked to local climatic variability but also to local oceanographic conditions due to the different sedimentation rates. Variations in paleovegetation and paleoclimate around the study area might be strongly associated with the influx of terrestrial organic compounds derived from vascular plants. Additional 14C dating and isotope study of individual n-alkane biomarkers will provide detailed information on paleoclimatic and paleovegetation changes.

Role of anthropometric data in the prediction of 4-stranded hamstring graft size in anterior cruciate ligament reconstruction.

PubMed

Ho, Sean Wei Loong; Tan, Teong Jin Lester; Lee, Keng Thiam

2016-03-01

To evaluate whether pre-operative anthropometric data can predict the optimal diameter and length of hamstring tendon autograft for anterior cruciate ligament (ACL) reconstruction. This was a cohort study that involved 169 patients who underwent single-bundle ACL reconstruction (single surgeon) with 4-stranded MM Gracilis and MM Semi-Tendinosus autografts. Height, weight, body mass index (BMI), gender, race, age and -smoking status were recorded pre-operatively. Intra-operatively, the diameter and functional length of the 4-stranded autograft was recorded. Multiple regression analysis was used to determine the relationship between the anthropometric measurements and the length and diameter of the implanted autografts. The strongest correlation between 4-stranded hamstring autograft diameter was height and weight. This correlation was stronger in females than males. BMI had a moderate correlation with the diameter of the graft in females. Females had a significantly smaller graft both in diameter and length when compared with males. Linear regression models did not show any significant correlation between hamstring autograft length with height and weight (p>0.05). Simple regression analysis demonstrated that height and weight can be used to predict hamstring graft diameter. The following regression equation was obtained for females: Graft diameter=0.012+0.034*Height+0.026*Weight (R2=0.358, p=0.004) The following regression equation was obtained for males: Graft diameter=5.130+0.012*Height+0.007*Weight (R2=0.086, p=0.002). Pre-operative anthropometric data has a positive correlation with the diameter of 4 stranded hamstring autografts but no significant correlation with the length. This data can be utilised to predict the autograft diameter and may be useful for pre-operative planning and patient counseling for graft selection.

Use of a Bioactive Scaffold to Stimulate ACL Healing Also Minimizes Post-traumatic Osteoarthritis after Surgery

PubMed Central

Murray, Martha M.; Fleming, Braden C.

2013-01-01

Background While ACL reconstruction is the treatment gold standard for ACL injury, it does not reduce the risk of post-traumatic osteoarthritis. Therefore, new treatments that minimize this postoperative complication are of interest. Bio-enhanced ACL repair, in which a bioactive scaffold is used to stimulate healing of an ACL transection, has shown considerable promise in short term studies. The long-term results of this technique and the effects of the bio-enhancement on the articular cartilage have not been previously evaluated in a large animal model. Hypothesis 1) The structural (tensile) properties of the porcine ACL at 6 and 12 months after injury are similar when treated with bio-enhanced ACL repair, bio-enhanced ACL reconstruction, or conventional ACL reconstruction, and all treatments yield results superior to untreated ACL transection. 2) After one year, macroscopic cartilage damage following bio-enhanced ACL repair is similar to bio-enhanced ACL reconstruction and less than conventional ACL reconstruction and untreated ACL transection. Study Design Controlled laboratory study (porcine model) Methods Sixty-two Yucatan mini-pigs underwent ACL transection and randomization to four experimental groups: 1) no treatment, 2) conventional ACL reconstruction, 3) “bio-enhanced” ACL reconstruction using a bioactive scaffold, and 4) “bio-enhanced” ACL repair using a bioactive scaffold. The biomechanical properties of the ligament or graft and macroscopic assessments of the cartilage surfaces were performed after 6 and 12 months of healing. Results The structural properties (i.e., linear stiffness, yield and maximum loads) of the ligament following bio-enhanced ACL repair were not significantly different from bio-enhanced ACL reconstruction or conventional ACL reconstruction, but were significantly greater than untreated ACL transection after 12 months of healing. Macroscopic cartilage damage after bio-enhanced ACL repair was significantly less than untreated ACL transection and bio-enhanced ACL reconstruction, and there was a strong trend (p=.068) that it was less than conventional ACL reconstruction in the porcine model at 12 months. Conclusions Bio-enhanced ACL repair produces a ligament that is biomechanically similar to an ACL graft and provides chondroprotection to the joint following ACL surgery. Clinical Relevance Bio-enhanced ACL repair may provide a new less invasive treatment option that reduces cartilage damage following joint injury. PMID:23857883

Forensic investigation of aliphatic hydrocarbons in the sediments from selected mangrove ecosystems in the west coast of Peninsular Malaysia.

PubMed

Vaezzadeh, Vahab; Zakaria, Mohamad Pauzi; Shau-Hwai, Aileen Tan; Ibrahim, Zelina Zaiton; Mustafa, Shuhaimi; Abootalebi-Jahromi, Fatemeh; Masood, Najat; Magam, Sami Mohsen; Alkhadher, Sadeq Abdullah Abdo

2015-11-15

Peninsular Malaysia has gone through fast development during recent decades resulting in the release of large amounts of petroleum and its products into the environment. Aliphatic hydrocarbons are one of the major components of petroleum. Surface sediment samples were collected from five rivers along the west coast of Peninsular Malaysia and analyzed for aliphatic hydrocarbons. The total concentrations of C10 to C36 n-alkanes ranged from 27,945 to 254,463ng·g(-1)dry weight (dw). Evaluation of various n-alkane indices such as carbon preference index (CPI; 0.35 to 3.10) and average chain length (ACL; 26.74 to 29.23) of C25 to C33 n-alkanes indicated a predominance of petrogenic source n-alkanes in the lower parts of the Rivers, while biogenic origin n-alkanes from vascular plants are more predominant in the upper parts, especially in less polluted areas. Petrogenic sources of n-alkanes are predominantly heavy and degraded oil versus fresh oil inputs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Unit and internal chain profiles of maca amylopectin.

PubMed

Zhang, Ling; Li, Guantian; Yao, Weirong; Zhu, Fan

2018-03-01

Unit chain length distributions of amylopectin and its φ, β-limit dextrins, which reflect amylopectin internal structure from three maca starches, were determined by high-performance anion-exchange chromatography with pulsed amperometric detection after debranching, and the samples were compared with maize starch. The amylopectins exhibited average chain lengths ranging from 16.72 to 17.16, with ranges of total internal chain length, external chain length, and internal chain length of the maca amylopectins at 12.49 to 13.68, 11.24 to 11.89, and 4.27 to 4.48. The average chain length, external chain length, internal chain length, and total internal chain length were comparable in three maca amylopectins. Amylopectins of the three maca genotypes studied here presented no significant differences in their unit chain length profiles, but did show significant differences in their internal chain profiles. Additional genetic variations between different maca genotypes need to be studied to provide unit- and internal chain profiles of maca amylopectin. Copyright © 2017. Published by Elsevier Ltd.

The Role of the Lateral Soft Tissues in Controlling Anterior Translation And Internal Rotation of the Tibia, And An Investigation of Lateral Reconstructions Accompanying ACL Reconstruction

PubMed Central

Williams, Andy; Stephen, Jo; Kittl, Christoph; Inderhaug, Eivint; El-Daou, Hadi; Dodds, Alex; Halewood, Camilla; Amis, Andrew

2017-01-01

Introduction: There is considerable current interest in the role of the lateral soft tissue structures in the context of ACL deficiency (ACLD). Of course the topic is not new but a re-visitation, although with improved experimental techniques available. It was clear that there was a rush to create surgical techniques based on the ‘Anterolateral Ligament’ (ALL) but without investigative ‘due-diligence’ and without consideration that other structures may be important, or more important. Objectives: To study the anatomy and biomechanics of the lateral soft tissues relevant to the ACL and ACL reconstruction techniques investigating isometricity, structures’ contributions to resistance of anterior tibial translation (ATT), internal rotation (IR), and pivot shift (PS). Also we studied the impact of various reconstructions on restoration of kinematics and potential over-constraint and effects on articular surface compression load. Methods: Several studies were undertaken. In all healthy fresh-frozen cadaveric specimens were used. Descriptive anatomy was described. Length changes of suture fixed at structure and reconstruction attachment points on the tibia and femur were measured with linear variable displacement transducers (LVDTs). To investigate structures’ contribution to resist translation and torque a 6-degrees of freedom robot with a universal force-moment sensor was used in a classic ‘cutting study’. The robot replayed the same movement with sequential sectioning of structures recording the decrease in force / torque needed to reach the same movement limit. In this way the structure’s resistance to motion as a percentage of the total could be calculated. In other studies knees were mounted in a test rig where knee kinematics were recorded from 0° to 100° of flexion by use of an optical tracking system. Joint surface compression was measured with Tekscan pressure-sensitive film. Results: The Anterolateral Ligament exists attaching to the tibia mid-way between the LCL attachment to the fibula and Gerdy’s tubercle, and the femur proximal and posterior to the femoral LCL attachment1. However the most isometric structure is the ITB2 from Gerdy’s tubercle to its attachments to the distal lateral femur. The ACL is the primary restraint to resist ATT, but is only the primary restraint to IR / PS close to extension. The ITB, with its attachments to the lateral distal femur, is the most important restraint at all other angles, whilst the ALL / capsule contribute very little restraint to ATT / IR / PS at any angle3. ITB-based tenodeses taken deep to the LCL, irrespective of femoral attachment points, are more isometric1 and restore kinematics more closely to normal compared to an ALL reconstruction. Fixation of the tenodeses with the knee with 0° tibial rotation, and tension of 20 N resulted in no change in tibio-femoral / patello-femoral contact pressures. Fixation with significant external rotation or excess tension (40 N) did increase contact pressures and lead to over-constraint. Conclusion: Despite recent interest the ALL is not as important to the ITB with its femoral attachments in controlling IR / PS. ITB-based tenodeses taken deep to the LCL perform well unless over-tensioned or fixed with tibial ER in the lab. 1 The Anterolateral Ligament: Anatomy, length changes and association with the Segond fracture A. L. Dodds, C. Halewood, C. M. Gupte, A. Williams, and A. A. Amis. Bone Joint J 2014 96-B: 325-331 2 Length change patterns of the lateral extra-articular structures of the knee and related reconstructions.C.Kittl, C Halewood, J Stephen, Gupte C, A Weiler, A. Williams, A.A. Amis. AJSM 2015; 43(2): 354-62 3 The role of the anterolateral structures and the ACL in controlling laxity of the intact and ACL-deficient knee. C Kittl, H El-Daou, KK Athwal, CM Gupte, A Weiler, A Williams, AA Amis. AJSM 2016; 44: 345-354

The Role of the Lateral Soft Tissues in Controlling Anterior Translation And Internal Rotation of the Tibia, and An Investigation of Lateral Reconstructions Accompanying ACL Reconstruction

PubMed Central

Williams, Andy; Stephen, Jo; Kittl, Christoph; Inderhaug, Eivint; El-Daou, Hadi; Dodds, Alex; Halewood, Camilla; Amis, Andrew

2017-01-01

Introduction: There is considerable current interest in the role of the lateral soft tissue structures in the context of ACL deficiency (ACLD). Of course the topic is not new but a re-visitation, although with improved experimental techniques available. It was clear that there was a rush to create surgical techniques based on the ‘Anterolateral Ligament’ (ALL) but without investigative ‘due-diligence’ and without consideration that other structures may be important, or more important. Objectives: To study the anatomy and biomechanics of the lateral soft tissues relevant to the ACL and ACL reconstruction techniques investigating isometricity, structures’ contributions to resistance of anterior tibial translation (ATT), internal rotation (IR), and pivot shift (PS). Also we studied the impact of various reconstructions on restoration of kinematics and potential over-constraint and effects on articular surface compression load. Methods: Several studies were undertaken. In all healthy fresh-frozen cadaveric specimens were used. Descriptive anatomy was described. Length changes of suture fixed at structure and reconstruction attachment points on the tibia and femur were measured with linear variable displacement transducers (LVDTs). To investigate structures’ contribution to resist translation and torque a 6-degrees of freedom robot with a universal force-moment sensor was used in a classic ‘cutting study’. The robot replayed the same movement with sequential sectioning of structures recording the decrease in force / torque needed to reach the same movement limit. In this way the structure’s resistance to motion as a percentage of the total could be calculated. In other studies knees were mounted in a test rig where knee kinematics were recorded from 0° to 100° of flexion by use of an optical tracking system. Joint surface compression was measured with Tekscan pressure-sensitive film. Results: The Anterolateral Ligament exists attaching to the tibia mid-way between the LCL attachment to the fibula and Gerdy’s tubercle, and the femur proximal and posterior to the femoral LCL attachment1. However the most isometric structure is the ITB2 from Gerdy’s tubercle to its attachments to the distal lateral femur. The ACL is the primary restraint to resist ATT, but is only the primary restraint to IR / PS close to extension. The ITB, with its attachments to the lateral distal femur, is the most important restraint at all other angles, whilst the ALL / capsule contribute very little restraint to ATT / IR / PS at any angle3. ITB-based tenodeses taken deep to the LCL, irrespective of femoral attachment points, are more isometric1 and restore kinematics more closely to normal compared to an ALL reconstruction. Fixation of the tenodeses with the knee with 0° tibial rotation, and tension of 20 N resulted in no change in tibio-femoral / patello-femoral contact pressures. Fixation with significant external rotation or excess tension (40 N) did increase contact pressures and lead to over-constraint. Conclusion: Despite recent interest the ALL is not as important to the ITB with its femoral attachments in controlling IR / PS. ITB-based tenodeses taken deep to the LCL perform well unless over-tensioned or fixed with tibial ER in the lab. The Anterolateral Ligament: Anatomy, length changes and association with the Segond fracture A. L. Dodds, C. Halewood, C. M. Gupte, A. Williams, and A. A. Amis. Bone Joint J 2014 96-B: 325-331 Length change patterns of the lateral extra-articular structures of the knee and related reconstructions. C.Kittl, C Halewood, J Stephen, Gupte C, A Weiler, A. Williams, A.A. Amis. AJSM 2015; 43(2): 354-62 The role of the anterolateral structures and the ACL in controlling laxity of the intact and ACL-deficient knee. C Kittl, H El-Daou, KK Athwal, CM Gupte, A Weiler, A Williams, AA Amis. AJSM 2016; 44: 345-354

Clinical Outcome Reporting in Youth ACL Literature Is Widely Variable

PubMed Central

Brusalis, Christopher M.; Lakomkin, Nikita; Suryavanshi, Joash R.; Cruz, Aristides I.; Green, Daniel W.; Jones, Kristofer J.; Fabricant, Peter D.

2017-01-01

Background: Advances in anterior cruciate ligament (ACL) reconstruction procedures in pediatric and adolescent patients have resulted in an increase in recent clinical studies on this topic. However, the consistency with which outcome measures are reported in this demographic is unknown. Purpose: To document outcome reporting patterns of youth ACL reconstruction studies in high-impact journals. Study Design: Systematic review; Level of evidence, 4. Methods: All articles published in 5 high-impact orthopaedic journals from 2010 to 2016 were reviewed to identify those reporting clinical outcomes of young patients who underwent ACL reconstruction. Studies that were nonclinical, reported on patients older than 18 years, or included fewer than 10 patients were excluded. Outcome measures used in all included studies were recorded. Results: Seventeen studies encompassing 772 subjects (mean age, 14.3 years; range, 6.3-18.0 years) were analyzed. Eight studies (47%) reported on Tanner stage of subjects, while 1 study reported skeletal age. Ten studies (59%) clearly documented the presence or absence of surgical complications. Range of motion was reported in 65% of studies. Leg-length discrepancy and angular deformity were each reported in 76% of studies, with 12% quantifying results through radiographic measurements. Ligament testing was variably defined by inclusion of instrumented testing (65%), Lachman test (53%), and pivot-shift test (53%). Fourteen studies (82%) explicitly reported on the rate of ACL rerupture, while 71% reported on the rate of revision surgery. Rate of return to preinjury activity was reported in 8 studies (47%), of which 2 defined criteria for return to sport and 3 defined the level of competitive sport. Patient-reported outcome measures (PROMs) were used variably. For the 3 most commonly reported PROMs (Lysholm, International Knee Documentation Committee, and Tegner), 24% of studies reported all 3 PROMs, 35% of studies reported 2 PROMs, and 6% of studies reported 1 PROM in isolation. A pediatric-specific PROM was reported in 1 of the 17 studies. Conclusion: Studies on pediatric ACL reconstruction published in high-impact journals unreliably defined subjects’ skeletal maturity, inconsistently reported on objective outcome measures, and used disparate adult-validated PROMs to assess subjective outcomes. These findings highlight the need for standardized, pediatric-specific outcome measures to be applied in future studies evaluating ACL reconstruction in children and adolescents. PMID:28840156

Microporous pure beta-tricalcium phosphate implants for press-fit fixation of anterior cruciate ligament grafts: strength and healing in a sheep model.

PubMed

Mayr, Hermann O; Dietrich, Markwart; Fraedrich, Franz; Hube, Robert; Nerlich, Andreas; von Eisenhart-Rothe, Rüdiger; Hein, Werner; Bernstein, Anke

2009-09-01

A sheep study was conducted to test a press-fit technique using microporous pure beta-tricalcium phosphate (beta-TCP) dowels for fixation of the anterior cruciate ligament (ACL) graft. Microporous (5 mum) cylindrical plugs of beta-TCP (diameter, 7 mm; length, 25 mm) with interconnecting pores were used. The material featured a novel configuration of structure and surface geometry. Implants were tested by use of press-fit fixation of ACL grafts with and without bone blocks in 42 sheep over a period of 24 weeks. Biomechanical, radiologic, histologic, and immunohistochemical evaluations were performed. In load-to-failure tests at 6, 12, and 24 weeks after surgery, the intra-articular graft always failed, not the fixation. Grafts showed bony fixation in the tunnel at 6 weeks and primary healing at the junction of the tunnel and joint after 24 weeks. Tricalcium phosphate was resorbed and simultaneously replaced by bone. Remodeling was still incomplete at 24 weeks. In the sheep model microporous beta-TCP implants used with press-fit fixation of ACL grafts permit early functional rehabilitation. After 6 weeks, the graft is fixed by woven bone or bony integration. Implanted microporous tricalcium phosphate is resorbed and replaced by bone. In a sheep model we showed that primary healing of ACL grafts with resorption and bony replacement of the fixating implant can be achieved by means of press-fit fixation with pure beta-TCP.

Anatomical Individualized ACL Reconstruction.

PubMed

Rahnemai-Azar, Amir Ata; Sabzevari, Soheil; Irarrázaval, Sebastián; Chao, Tom; Fu, Freddie H

2016-10-01

The anterior cruciate ligament (ACL) is composed of two bundles, which work together to provide both antero-posterior and rotatory stability of the knee. Understanding the anatomy and function of the ACL plays a key role in management of patients with ACL injury. Anatomic ACL reconstruction aims to restore the function of the native ACL. Femoral and tibial tunnels should be placed in their anatomical location accounting for both the native ACL insertion site and bony landmarks. One main component of anatomical individualized ACL reconstruction is customizing the treatment according to each patient's individual characteristics, considering preoperative and intraoperative evaluation of the native ACL and knee bony anatomy. Anatomical individualized reconstruction surgery should also aim to restore the size of the native ACL insertion as well. Using this concept, while single bundle ACL reconstruction can restore the function of the ACL in some patients, double bundle reconstruction is indicated in others to achieve optimal outcome.

Evaluation of Partial Transection versus Synovial Debridement of the ACL as Novel Canine Models for Management of ACL Injuries.

PubMed

Bozynski, Chantelle C; Kuroki, Keiichi; Stannard, James P; Smith, Patrick A; Stoker, Aaron M; Cook, Cristi R; Cook, James L

2015-10-01

A major hurdle in investigating important clinical questions in knee ligament treatment is a lack of valid translational animal models. This study characterizes the effects of partial transection versus synovial debridement of the anterior (cranial) cruciate ligament (ACL) in dogs. A total of 27 adult purpose-bred research hounds underwent surgery and were assessed over the following 8 weeks. Dogs were randomized into the following three ACL status groups: sham control (n = 9), intact ACL with synovial debridement (exposed ACL) (n = 9), and partial transection of the ACL (partial tear ACL) (n = 9). Dogs in the exposed ACL group and partial tear ACL group had significantly (p < 0.05) more severe lameness, pain, effusion, reduced function, and reduced comfortable range of motion compared with controls, with the partial tear ACL group being most severely affected. More severe ACL and whole-joint pathology, and radiographic scores for osteoarthritis were present in the partial tear ACL group compared with exposed and/or sham control group. On the basis of these findings, biologic components of ACL injury (exposed ACL) played a role in whole-joint inflammation, but the clinical and pathological effects were more severe when both biologic and biomechanical components were present (i.e., partial tear ACL). These novel canine models were successfully developed to evaluate partial transection versus synovial debridement of the ACL and these models will be used to evaluate treatment options for acute management of ACL injuries. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Curve analyses reveal altered knee, hip, and trunk kinematics during drop-jumps long after anterior cruciate ligament rupture.

PubMed

Hébert-Losier, Kim; Schelin, Lina; Tengman, Eva; Strong, Andrew; Häger, Charlotte K

2018-03-01

Anterior cruciate ligament (ACL) ruptures may lead to knee dysfunctions later in life. Single-leg tasks are often evaluated, but bilateral movements may also be compromised. Our aim was to use curve analyses to examine double-leg drop-jump kinematics in ACL-reconstructed, ACL-deficient, and healthy-knee cohorts. Subjects with unilateral ACL ruptures treated more than two decades ago (17-28years) conservatively with physiotherapy (ACL PT , n=26) or in combination with reconstructive surgery (ACL R , n=28) and healthy-knee controls (n=25) performed 40-cm drop-jumps. Three-dimensional knee, hip, and trunk kinematics were analyzed during Rebound, Flight, and Landing phases. Curves were time-normalized and compared between groups (injured and non-injured legs of ACL PT and ACL R vs. non-dominant and dominant legs of controls) and within groups (between legs) using functional analysis of variance methods. Compared to controls, ACL groups exhibited less knee and hip flexion on both legs during Rebound and greater knee external rotation on their injured leg at the start of Rebound and Landing. ACL R also showed less trunk flexion during Rebound. Between-leg differences were observed in ACL R only, with the injured leg more internally rotated at the hip. Overall, kinematic curves were similar between ACL R and ACL PT . However, compared to controls, deviations spanned a greater proportion of the drop-jump movement at the hip in ACL R and at the knee in ACL PT . Trunk and bilateral leg kinematics during double-leg drop-jumps are still compromised long after ACL-rupture care, independent of treatment. Curve analyses indicate the presence of distinct compensatory mechanisms in ACL PT and ACL R compared to controls. Copyright © 2018 Elsevier B.V. All rights reserved.

Kinematics of anterior cruciate ligament-deficient knees in a Chinese population during stair ascent.

PubMed

Zhao, Chang; Lin, Chuangxin; Wang, Wenhao; Zeng, Chun; Fang, Hang; Pan, Jianying; Cai, Daozhang

2016-08-08

The purpose of this study was to measure the tibiofemoral kinematics of anterior cruciate ligament (ACL) deficiency in a Chinese population and compare the kinematics with published data about a Caucasian population. Unilateral knees of 18 Chinese ACL-deficient (ACL-D) subjects were studied while subjects ascended stairs. Kinematic alteration was compared between ACL-D knees and contralateral ACL-intact (ACL-I) knees. The kinematic alteration of ACL deficiency was also compared between the Chinese population and published data about a Caucasian population. A statistical difference was found in the three-dimensional rotations between ACL-D and ACL-I knees. In the sagittal plane, ACL-I knees had a larger flexion angle than ACL-D knees during 40 to 50 % of the activity during stair ascent (P < 0.027) and throughout the gait cycle. A significant difference in rotational motion between ACL-D and ACL-I knees was also observed in the frontal plane during 40 to 60 % (P < 0.017) of the activity and in the transverse plane during 70 to 80 % (P < 0.028) of the activity. A greater tibial varus was demonstrated in the Chinese population while the published data revealed external tibial rotation and a statistical difference in translation in the Caucasian population. ACL-D knees show different kinematics than ACL-I knees in the Chinese population. ACL-I knees had a larger flexion angle than ACL-D knees in the middle stage of the activity during stair ascent. A significant difference in rotational motion between ACL-D and ACL-I knees was also observed in the frontal plane during the middle phase and in the transverse plane during the terminal phase of the activity. A greater tibial varus was demonstrated in the Caucasian population while the published data revealed external tibial rotation and a statistical difference in translation in the Caucasian population.

Biomechanical Outcomes After Bio-enhanced Anterior Cruciate Ligament Repair and Anterior Cruciate Ligament Reconstruction Are Equal in a Porcine Model

PubMed Central

Vavken, Patrick; Fleming, Braden C.; Mastrangelo, Ashley N.; Machan, Jason T.; Murray, Martha M.

2011-01-01

Purpose The objective of this study was to compare the biomechanical outcomes of a new method of anterior cruciate ligament (ACL) treatment, bio-enhanced ACL repair, with ACL reconstruction in a large animal model. Methods Twenty-four skeletally immature pigs underwent unilateral ACL transection and were randomly allocated to receive bio-enhanced ACL repair with a collagen-platelet composite, allograft (bone–patellar tendon– bone) reconstruction, or no further treatment (n = 8 for each group). The structural properties and anteroposterior laxity of the experimental and contralateral ACL-intact knees were measured 15 weeks postoperatively. All dependent variables were normalized to those of the contralateral knee and compared by use of generalized linear mixed models. Results After 15 weeks, bio-enhanced ACL repair and ACL reconstruction produced superior biomechanical outcomes to ACL transection. However, there were no significant differences between bio-enhanced ACL repair and ACL reconstruction for maximum load (P = .4745), maximum displacement (P = .4217), or linear stiffness (P = .6327). There were no significant differences between the 2 surgical techniques in anteroposterior laxity at 30° (P = .7947), 60° (P = .6270), or 90° (P = .9008). Conclusions Bio-enhanced ACL repair produced biomechanical results that were not different from ACL reconstruction in a skeletally immature, large animal model, although the variability associated with both procedures was large. Both procedures produced significantly improved results over ACL transection, showing that both were effective in this model. Clinical Relevance Bio-enhanced ACL repair may 1 day provide an alternative treatment option for ACL injury. PMID:22261137

Combined organic and inorganic geochemical reconstruction of paleodepositional conditions of a Pliocene sapropel from the eastern Mediterranean Sea

NASA Astrophysics Data System (ADS)

Rinna, J.; Warning, B.; Meyers, P. A.; Brumsack, H.-J.; Rullkötter, J.

2002-06-01

Layers of organic-carbon-rich sapropels in the sediment record of the Mediterranean Sea give evidence of repetitive changes in regional Plio-Pleistocene climate. Results from biomarker molecule and major and trace element analyses of closely spaced samples are used to reconstruct the conditions leading to deposition of a Pliocene sapropel at Ocean Drilling Program (ODP) Site 969 on the Mediterranean Ridge. Organic carbon concentrations increase from 0.2% outside the sapropel and peak to more than 30% within it. Major and trace elemental composition and biomarker-derived parameters indicate elevated productivity, depletion of water-column dissolved-oxygen content, and changes in sediment provenance in response to climatic changes. Budgets of rhenium, thallium, and other trace metals indicate that deep-water exchange between the Mediterranean subbasins and the Atlantic Ocean was not completely interrupted during sapropel formation. Enrichment factors of redox-sensitive and sulfide-forming trace metals as well as the presence of isorenieratene derivatives and high stanol/sterol ratios point to an extended zone of anoxic water masses. Depth profiles of biomarker compositions (sterols, long-chain alkenones, alkandiols and -ketols, fatty acids) indicate great floral diversity during deposition of a single sapropel and highlight the sensitive response of the marine community to variable environmental conditions. Changes in water mass circulation and eolian transport can be reconstructed by use of both lithogenic elements and average chain lengths of n-alkanes (ACL index).

77 FR 7000 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; Gulf of Maine Winter...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-10

... Biological Catches (ABCs), Annual Catch Limits (ACLs), ACL components, and sector Annual Catch Entitlements (ACEs). The ACL components include sub-ACLs for the common pool and sectors. This action is intended to... through 2012. The catch levels specified by FW 44 included OFLs, ABCs, ACLs, and ACL components, including...

Return to Play and Clinical Outcomes after All-Inside, Anterior Cruciate Ligament Reconstruction in Skeletally Immature Athletes

PubMed Central

Nawabi, Danyal H.; McCarthy, Moira; Graziano, Jessica; deMille, Polly; Chiaia, Theresa; Green, Daniel W.; Cordasco, Frank A.

2014-01-01

Objectives: Anterior cruciate ligament (ACL) injuries in skeletally immature athletes are on the rise because of increased participation and level of competition within sports, sports specialization and societal factors. Conservative treatment of these injuries has a poor natural history due to recurrent instability with meniscal and articular cartilage damage. The purpose of this study was to evaluate the results of an all-inside, physeal-sparing ACL reconstruction in skeletally immature athletes, with a focus on return to play. Methods: Forty-two skeletally immature athletes (mean chronologic age 12.7 yrs, [range 10-15]) were prospectively evaluated following an all-inside ACL reconstruction utilizing hamstring autograft. The mean bone age (Greulich and Pyle method) was 13.5 years. There were 10 females and 32 males. Twenty-six patients had an all-epiphyseal (AE) ACL reconstruction and 16 patients had a partial transphyseal (PTP) ACL reconstruction, which spared the femoral physis but crossed the tibial physis. The PTP option was reserved for patients with minimal proximal tibial growth remaining. Fourteen athletes were involved in recreational sport and 28 participated competitively. Lacrosse (36%) and Soccer (32%) were the two most common sports associated with ACL injury in our cohort. All athletes were evaluated with a physical examination, KT-1000 arthrometry, isokinetic testing, validated outcome scores including the International Knee Documentation Committee score (IKDC), the Lysholm score and Marx activity rating scale. Standing radiographs and SPGR MRI analysis was performed at 6, 12 and 24 months post-op depending upon skeletal age. A ‘Return to Play’ performance analysis was also performed where symmetry, alignment control and the ability to decelerate were assessed during progressively challenging movement patterns encountered in sport. Results: At a mean follow-up of 16.7 months (range 12-24), the mean IKDC score was 92.9 ± 7.2, the mean Lysholm score was 97.7 ± 4.6 and the mean Marx activity rating scale score was 12.4 ± 3.5. Lachman and pivot shift testing was negative in all patients. The mean side-to-side difference in the KT-1000 arthrometry was 0.9 ± 0.7 mm, with the maximum difference in the cohort being 2 mm. Isokinetic testing showed a mean deficit of 4.1% in extension torque and 9.2% in flexion torque at a repetition speed of 180 degrees per second. No angular deformities, significant leg length discrepancy or physeal disturbances were observed on postoperative radiographs or MRI. One athlete had a traumatic graft disruption at 12 months and underwent revision ACL reconstruction and one athlete sustained a contralateral ACL rupture at 11 months. The mean time for return to unrestricted competitive activity after successful completion of the ‘Return to Play’ analysis was 12.5 +/- 1.3 months from the time of surgery. Conclusion: An all-inside, physeal-sparing ACL reconstruction technique using hamstring autograft demonstrates excellent subjective and objective clinical outcomes in skeletally immature athletes without growth disturbance. ‘Return to Play’ assessment is an important tool to guide the young athlete and her or his family regarding resumption of competitive sports. In our experience, athletes were on average released for full return to sport after 1 year from ACL reconstruction.

Evaluating Carbon Isotope Signature of Bulk Organic Matter and Plant Wax Derived n-alkanes from Lacustrine Sediments as Climate Proxies along the Western Side of the Andes

NASA Astrophysics Data System (ADS)

Contreras, S.; Werne, J. P.; Araneda, A.; Conejero, C. A.

2015-12-01

Sedimentary carbon isotope values (δ13C) of bulk organic matter and long chain (C25 to C35) n-alkanes are among the most long-lived and widely utilized proxies of organic matter and vegetation source. The carbon distribution (e.g. average carbon chain length, ACL) and isotope signature from long chain n-alkanes had been intensively used on paleoclimate studies because they are less influenced by diagenesis, differential preservation of compound classes, and changes in the sources of organic matter than bulk δ13C values. Recently, studies of modern plant n-alkanes have challenged the use of carbon distribution and carbon isotope signature from sedimentary n-alkanes as reliable indicators of vegetation and climate change. The climate in central-south western South America (SA) is projected to become significantly warmer and drier over the next several decades to centuries in response to anthropogenically driven warming. Paleolimnological studies along western SA are critical to obtain more realistic and reliable regional reconstructions of past climate and environments, including vegetation and water budget variability. Here we discuss bulk δ13C, distribution and δ13C in long chain n-alkanes from a suite of ~40 lake surface sediment (core-top) samples spanning the transition from a Mediterranean climate with a patchwork of cultivated vegetation, pastureland, conifers in central Chile to a rainy temperate climate dominated by broadleaf deciduous and evergreen forest. Data are compared to the latitudinal and orographic climatic trends of the Andes based on the climatology (e.g. precipitation and temperature) of the locations of all lakes involved in this study, using monthly gridded reanalysis products of the Climate Forecast System Reanalysis (CFSR), based on the NCEP global forecast model and meteorological stations available in the region, from January 1979 to December 2010 with a 0.5° horizontal resolution.

Anatomical versus non-anatomical single bundle anterior cruciate ligament reconstruction: a cadaveric study of comparison of knee stability.

PubMed

Lim, Hong-Chul; Yoon, Yong-Cheol; Wang, Joon-Ho; Bae, Ji-Hoon

2012-12-01

The purpose of this study was to compare the initial stability of anatomical and non-anatomical single bundle anterior cruciate ligament (ACL) reconstruction and to determine which would better restore intact knee kinematics. Our hypothesis was that the initial stability of anatomical single bundle ACL reconstruction would be superior to that of non-anatomical single bundle ACL reconstruction. Anterior tibial translation (ATT) and internal rotation of the tibia were measured with a computer navigation system in seven pairs of fresh-frozen cadaveric knees under two testing conditions (manual maximum anterior force, and a manual maximum anterior force combined with an internal rotational force). Tests were performed at 0, 30, 60, and 90 degrees of flexion with the ACL intact, the ACL transected, and after reconstruction of one side of a pair with either anatomical or non-anatomical single bundle ACL reconstruction. Under manual maximal anterior force, both reconstruction techniques showed no significant difference of ATT when compared to ACL intact knee state at 30° of knee flexion (p > 0.05). Under the combined anterior and internal rotatory force, non-anatomical single-bundle ACL reconstruction showed significant difference of ATT compared to those in ACL intact group (p < 0.05). In contrast, central anatomical single bundle ACL reconstruction showed no significant difference of ATT compared to those in ACL intact group (p > 0.05). Internal rotation of the tibia showed no significant difference in the ACL intact, the ACL transected, non-anatomical reconstructed and anatomical reconstructed knees. Anatomical single bundle ACL reconstruction restored the initial stability closer to the native ACL under combined anterior and internal rotational forces when compared to non-anatomical ACL single bundle reconstruction.

Fifteen-Year Survival of Endoscopic Anterior Cruciate Ligament Reconstruction in Patients Aged 18 Years and Younger.

PubMed

Morgan, Matthew D; Salmon, Lucy J; Waller, Alison; Roe, Justin P; Pinczewski, Leo A

2016-02-01

The current body of literature surrounding anterior cruciate ligament (ACL) survival and the variables contributing to further ACL injuries after primary ACL reconstruction in children and adolescents is limited, with no long-term evidence examining the incidence and contributing factors of further ACL injuries in this younger patient population. To determine the long-term survival of the ACL graft and the contralateral ACL (CACL) after primary reconstruction in patients aged ≤18 years and to identify the factors that increase the odds of subsequent ACL injuries. Case series; Level of evidence, 4. Patients having undergone primary ACL reconstruction at age ≤18 years between 1993 and 1998 who were included in a prospective database by a single surgeon were considered for this study. Single-incision endoscopic ACL reconstruction was performed with either an autologous bone-patellar tendon-bone graft or a hamstring tendon graft. At a minimum of 15 years after ACL reconstruction, patients completed a subjective survey involving the International Knee Documentation Committee (IKDC) questionnaire in addition to questions regarding current symptoms, further ACL injuries, family history of ACL injury, and current level of activity. A total of 288 adolescents (age range, 13-18 years) met the inclusion criteria, of whom 242 (84%) were reviewed at a mean of 16 years and 6 months after ACL reconstruction. Of these patients, 75 (31%) sustained a further ACL injury: 27 (11.2%) suffered an ACL graft rupture, 33 suffered a CACL injury (13.6%), and 15 sustained both an ACL graft rupture and a CACL injury (6.2%) over 15 years. Survival of the ACL graft was 95%, 92%, 88%, 85%, and 83% at 1, 2, 5, 10, and 15 years, respectively, and survival of the CACL was 99%, 98%, 90%, 83%, and 81%, respectively. Survival of the ACL graft was less favorable in those with a family history of ACL injury than in those without a family history (69% vs 90%, respectively; hazard ratio [HR], 3.6; P = .001). Survival of the CACL was less favorable in male patients than in female patients (75% vs 88%, respectively; HR, 2.1; P = .03) and in those who returned to competitive team ball sports than in those who did not (78% vs 89%, respectively; HR, 2.3; P = .05). After ACL reconstruction in patients aged ≤18 years, a further ACL injury occurred in 1 in 3 patients over 15 years. The 15-year survival rate of the ACL graft was 83%, and the 15-year survival rate of the CACL was 81%. The ACL graft and CACL were most vulnerable within the first 5 years after index surgery. A family history of ACL rupture significantly increased the risk for ACL graft ruptures, and a CACL injury was more common in male patients and those who returned to team ball sports. High IKDC scores and continued participation in sports were maintained over the long term after ACL reconstruction in the adolescent population. © 2016 The Author(s).

Predictors for additional anterior cruciate ligament reconstruction: data from the Swedish national ACL register.

PubMed

Fältström, Anne; Hägglund, Martin; Magnusson, Henrik; Forssblad, Magnus; Kvist, Joanna

2016-03-01

To identify predictors for additional anterior cruciate ligament (ACL) reconstruction. Patients from the Swedish national ACL register who underwent ACL reconstruction between January 2005 and February 2013 (follow-up duration 6-104 months) were included. Cox regression analyses included the following independent variables regarding primary injury: age, sex, time between injury and primary ACL reconstruction, activity at primary injury, concomitant injuries, injury side, graft type, and pre-surgery KOOS and EQ-5D scores. Among ACL reconstruction procedures, 93% involved hamstring tendon (HT) autografts. Graft type did not predict additional ACL reconstruction. Final regression models only included patients with HT autograft (n = 20,824). Of these, 702 had revision and 591 contralateral ACL reconstructions. The 5-year post-operative rates of revision and contralateral ACL reconstruction were 4.3 and 3.8%, respectively. Significant predictors for additional ACL reconstruction were age (fourfold increased rate for <16-year-old patients vs. >35-year-old patients), time between injury and primary surgery (two to threefold increased rate for ACL reconstruction within 0-90 days vs. >365 days), and playing football at primary injury. This study identified younger age, having ACL reconstruction early after the primary injury, and incurring the primary injury while playing football as the main predictors for revision and contralateral ACL reconstruction. This suggests that the rate of additional ACL reconstruction is increased in a selected group of young patients aiming to return to strenuous sports after primary surgery and should be taken into consideration when discussing primary ACL reconstruction, return to sports, and during post-surgery rehabilitation. II.

Biological enhancement of graft-tunnel healing in anterior cruciate ligament reconstruction

PubMed Central

SACCOMANNO, MARISTELLA F.; CAPASSO, LUIGI; FRESTA, LUCA; MILANO, GIUSEPPE

2016-01-01

The sites where graft healing occurs within the bone tunnel and where the intra-articular ligamentization process takes place are the two most important sites of biological incorporation after anterior cruciate ligament (ACL) reconstruction, since they help to determine the mechanical behavior of the femur-ACL graft-tibia complex. Graft-tunnel healing is a complex process influenced by several factors, such as type of graft, preservation of remnants, bone quality, tunnel length and placement, fixation techniques and mechanical stress. In recent years, numerous experimental and clinical studies have been carried out to evaluate potential strategies designed to enhance and optimize the biological environment of the graft-tunnel interface. Modulation of inflammation, tissue engineering and gene transfer techniques have been applied in order to obtain a direct-type fibrocartilaginous insertion of the ACL graft, similar to that of native ligament, and to accelerate the healing process of tendon grafts within the bone tunnel. Although animal studies have given encouraging results, clinical studies are lacking and their results do not really support the use of the various strategies in clinical practice. Further investigations are therefore needed to optimize delivery techniques, therapeutic concentrations, maintenance of therapeutic effects over time, and to reduce the risk of undesirable effects in clinical practice. PMID:27900311

Risk Factors for Anthroponotic Cutaneous Leishmaniasis at the Household Level in Kabul, Afghanistan

PubMed Central

Reithinger, Richard; Mohsen, Mohammad; Leslie, Toby

2010-01-01

Background Kabul, Afghanistan, is the largest focus of anthroponotic cutaneous leishmaniasis (ACL) in the world. ACL is a protozoan disease transmitted to humans by the bite of phlebotomine sand flies. Although not fatal, ACL can lead to considerable stigmatization of affected populations. Methods Using data from a standardized survey of 872 households in 4 wards of Kabul, Afghanistan, univariate and multivariate logistic regression analyses tested associations between presence of active ACL and ACL scars with 15 household-level variables. Findings Univariate analyses showed that active ACL was positively associated with household member's age, ACL prevalence, and brick wall type, but negatively associated with household number of rooms, bednet use, and proportion of windows with screens. Multivariate analysis showed a positive association between active ACL and household member's age, ACL prevalence, and brick wall type, and a negative association with household proportion of windows with screens. Conclusion Household-level charateristics were shown to be risk factors for ACL. Monitoring a selected number of household characteristics could assist in rapid assessments of household-level variation in risk of ACL. ACL prevention and control programs should consider improving house construction, including smoothing of walls and screening of windows. PMID:20351787

HIGH REPETITION JUMP TRAINING COUPLED WITH BODY WEIGHT SUPPORT IN A PATIENT WITH KNEE PAIN AND PRIOR HISTORY OF ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: A CASE REPORT.

PubMed

Elias, Audrey R C; Kinney, Anthony E; Mizner, Ryan L

2015-12-01

Patients frequently experience long-term deficits in functional activity following anterior cruciate ligament reconstruction, and commonly present with decreased confidence and poor weight acceptance in the surgical knee. Adaptation of neuromuscular behaviors may be possible through plyometric training. Body weight support decreases intensity of landing sufficiently to allow increased training repetition. The purpose of this case report is to report the outcomes of a subject with a previous history of anterior cruciate ligament (ACL) reconstruction treated with high repetition jump training coupled with body weight support (BWS) as a primary intervention strategy. A 23-year old female, who had right ACL reconstruction seven years prior, presented with anterior knee pain and effusion following initiation of a running program. Following visual assessment of poor mechanics in single leg closed chain activities, landing mechanics were assessed using 3-D motion analysis of single leg landing off a 20 cm box. She then participated in an eight-week plyometric training program using a custom-designed body weight support system. The International Knee Documentation Committee Subjective Knee Form (IKDC) and the ACL-Return to Sport Index (ACL-RSI) were administered at the start and end of treatment as well as at follow-up testing. The subject's IKDC and ACL-RSI scores increased with training from 68% and 43% to 90% and 84%, respectively, and were retained at follow-up testing. Peak knee and hip flexion angles during landing increased from 47 ° and 53 ° to 72 ° and 80 ° respectively. Vertical ground reaction forces in landing decreased with training from 3.8 N/kg to 3.2 N/kg. All changes were retained two months following completion of training. The subject experienced meaningful changes in overall function. Retention of mechanical changes suggests that her new landing strategy had become a habitual pattern. Success with high volume plyometric training is possible when using BWS. Clinical investigation into the efficacy of body weight support as a training mechanism is needed. Level 4 - Case Report.

Investigation of the Effects of High-Intensity, Intermittent Exercise and Unanticipation on Trunk and Lower Limb Biomechanics During a Side-Cutting Maneuver Using Statistical Parametric Mapping.

PubMed

Whyte, Enda F; Richter, Chris; OʼConnor, Siobhan; Moran, Kieran A

2018-06-01

Whyte, EF, Richter, C, O'Connor, S, and Moran, KA. Investigation of the effects of high-intensity, intermittent exercise and unanticipation on trunk and lower limb biomechanics during a side-cutting maneuver using statistical parametric mapping. J Strength Cond Res 32(6): 1583-1593, 2018-Anterior cruciate ligament (ACL) injuries frequently occur during side-cutting maneuvers when fatigued or reacting to the sporting environment. Trunk and hip biomechanics are proposed to influence ACL loading during these activities. However, the effects of fatigue and unanticipation on the biomechanics of the kinetic chain may be limited by traditional discrete point analysis. We recruited 28 male, varsity, Gaelic footballers (21.7 ± 2.2 years; 178.7 ± 14.6 m; 81.8 ± 11.4 kg) to perform anticipated and unanticipated side-cutting maneuvers before and after a high-intensity, intermittent exercise protocol (HIIP). Statistical parametric mapping (repeated-measures analysis of varience) identified differences in phases of trunk and stance leg biomechanics during weight acceptance. Unanticipation resulted in less trunk flexion (p < 0.001) and greater side flexion away from the direction of cut (p < 0.001). This led to smaller (internal) knee flexor and greater (internal) knee extensor (p = 0.002-0.007), hip adductor (p = 0.005), and hip external rotator (p = 0.007) moments. The HIIP resulted in increased trunk flexion (p < 0.001) and side flexion away from the direction of cut (p = 0.038), resulting in smaller (internal) knee extensor moments (p = 0.006). One interaction effect was noted demonstrating greater hip extensor moments in the unanticipated condition post-HIIP (p = 0.025). Results demonstrate that unanticipation resulted in trunk kinematics considered an ACL injury risk factor. A subsequent increase in frontal and transverse plane hip loading and sagittal plane knee loading was observed, which may increase ACL strain. Conversely, HIIP-induced trunk kinematic alterations resulted in reduced sagittal plane knee and subsequent ACL loading. Therefore, adequate hip and knee control is important during unanticipated side-cutting maneuvers.

Intercondylar roof impingement pressure after anterior cruciate ligament reconstruction in a porcine model.

PubMed

Iriuchishima, Takanori; Tajima, Goro; Ingham, Sheila J M; Shen, Wei; Horaguchi, Takashi; Saito, Akiyoshi; Smolinski, Patrick; Fu, Freddie H

2009-06-01

Anterior cruciate ligament (ACL) graft impingement against the intercondylar roof has been postulated, but not thoroughly investigated. The roof impingement pressure changes with different tibial and femoral tunnel positions in ACL reconstruction. Anterior tibial translation is also affected by the tunnel positions of ACL reconstruction. The study design included a controlled laboratory study. In 15 pig knees, the impingement pressure between ACL and intercondylar roof was measured using pressure sensitive film before and after ACL single bundle reconstruction. ACL reconstructions were performed in each knee with two different tibial and femoral tunnel position combinations: (1) tibial antero-medial (AM) tunnel to femoral AM tunnel (AM to AM) and (2) tibial postero-lateral (PL) tunnel to femoral High-AM tunnel (PL to High-AM). Anterior tibial translation (ATT) was evaluated after each ACL reconstruction using robotic/universal force-moment sensor testing system. Neither the AM to AM nor the PL to High-AM ACL reconstruction groups showed significant difference when compared with intact ACL in roof impingement pressure. The AM to AM group had a significantly higher failure load than PL to High-AM group. This study showed how different tunnel placements affect the ACL-roof impingement pressure and anterior-posterior laxity in ACL reconstruction. Anatomical ACL reconstruction does not cause roof impingement and it has a biomechanical advantage in ATT when compared with non-anatomical ACL reconstructions in the pig knee. There is no intercondylar roof impingement after anatomical single bundle ACL reconstruction.

Wetland plant waxes from Olduvai Gorge, Tanzania

NASA Astrophysics Data System (ADS)

Tamalavage, A.; Magill, C. R.; Barboni, D.; Ashley, G. M.; Freeman, K. H.

2013-12-01

Olduvai Gorge, northern Tanzania, exposes a Plio-Pleistocene sedimentary record that includes lake and lake-margin sediments and fossil remains of ancient plants and early humans. There are rich paleontological and cultural records at Olduvai Gorge that include thousands of vertebrate fossils and stone tools. Previous studies of plant biomarkers in lake sediments from Olduvai Gorge reveal repeated, abrupt changes in landscape dominance by woodland or grassland vegetation during the early Pleistocene, about 1.8 million years ago. However, the reconstruction of wetland vegetation in the past is limited by a dearth of published lipid signatures for modern wetland species. Here, we present lipid and isotopic data for leaf tissues from eight modern plants (i.e., sedge and Typha species) living in wetlands near Olduvai Gorge. Trends in values for molecular and leaf δ13C and average chain length (ACL) of n-alkanes in plant tissues are similar to values for underlying soils. Compound-specific δ13C values for n-alkanes C25 to C33 range between -36.4 to -23.1‰ for C3 plants and -22.3 to -19.5‰ for C4 plants. Fractionation factors between leaf and lipids, ɛ29 and ɛ33, fall within the range reported in the literature, but they differ more widely within a single plant. For C3 plants, the average difference between ɛ29 and ɛ33 is 6.5 ‰, and the difference between ɛ29 and ɛ33 for C4 plants is less than 2‰. Both plant types show a parabolic relationship between chain length and δ13C values, in which C29 typically has the most depleted value, and typically shift by 3-5‰ between alkane homologs. This pattern has not been previously reported, and could be unique for sedge lipids. If so, these data help constrain the application of plant wax biomarkers from sedges for paleo-vegetation reconstruction in paleoclimate studies and at archaeological sites.

Swelling of biological and semiflexible polyelectrolytes.

PubMed

Dobrynin, Andrey V; Carrillo, Jan-Michael Y

2009-10-21

We have developed a theoretical model of swelling of semiflexible (biological) polyelectrolytes in salt solutions. Our approach is based on separation of length scales which allowed us to split a chain's electrostatic energy into two parts that describe local and remote electrostatic interactions along the polymer backbone. The local part takes into account interactions between charged monomers that are separated by distances along the polymer backbone shorter than the chain's persistence length. These electrostatic interactions renormalize chain persistence length. The second part includes electrostatic interactions between remote charged pairs along the polymer backbone located at distances larger than the chain persistence length. These interactions are responsible for chain swelling. In the framework of this approach we calculated effective chain persistence length and chain size as a function of the Debye screening length, chain degree of ionization, bare persistence length and chain degree of polymerization. Our crossover expression for the effective chain's persistence length is in good quantitative agreement with the experimental data on DNA. We have been able to fit experimental datasets by using two adjustable parameters: DNA ionization degree (α = 0.15-0.17) and a bare persistence length (l(p) = 40-44 nm).

Anterior Cruciate Ligament Injuries in National Football League Athletes From 2010 to 2013: A Descriptive Epidemiology Study.

PubMed

Dodson, Christopher C; Secrist, Eric S; Bhat, Suneel B; Woods, Daniel P; Deluca, Peter F

2016-03-01

There is a high incidence of anterior cruciate ligament (ACL) injuries among National Football League (NFL) athletes; however, the incidence of reinjury in this population is unknown. This retrospective epidemiological study analyzed all publicly disclosed ACL tears occurring in NFL players between 2010 and 2013 to characterize injury trends and determine the incidence of reinjury. Descriptive epidemiological study. A comprehensive online search identified any NFL player who had suffered an ACL injury from 2010 to 2013. Position, playing surface, activity, and date were recorded. Each player was researched for any history of previous ACL injury. The NFL games database from USA Today was used to determine the incidence of ACL injuries on artificial turf and grass fields. Databases from Pro Football Focus and Pro Football Reference were used to determine the injury rate for each position. NFL players suffered 219 ACL injuries between 2010 and 2013. Forty players (18.3%) had a history of previous ACL injury, with 27 (12.3%) retears and 16 (7.3%) tears contralateral to a previous ACL injury. Five players (2.28%) suffered their third ACL tear. Receivers (wide receivers and tight ends) and backs (linebackers, fullbacks, and halfbacks) had significantly greater injury risk than the rest of the NFL players, while perimeter linemen (defensive ends and offensive tackles) had significantly lower injury risk than the rest of the players. Interior linemen (offensive guards, centers, and defensive tackles) had significantly greater injury risk compared with perimeter linemen. ACL injury rates per team games played were 0.050 for grass and 0.053 for turf fields (P > .05). In this retrospective epidemiological study of ACL tears in NFL players, retears and ACL tears contralateral to a previously torn ACL constituted a substantial portion (18.3%) of total ACL injuries. The significant majority of ACL injuries in players with a history of previous ACL injury were retears. Skilled offensive players and linebackers had the greatest injury risk, and significantly more ACL tears occurred among interior linemen than perimeter linemen. The month of August had the highest incidence of ACL injuries, probably because of expanded roster sizes at that point in the NFL season.

The roles of productivity and ecosystem size in determining food chain length in tropical terrestrial ecosystems.

PubMed

Young, Hillary S; McCauley, Douglas J; Dunbar, Robert B; Hutson, Michael S; Ter-Kuile, Ana Miller; Dirzo, Rodolfo

2013-03-01

Many different drivers, including productivity, ecosystem size, and disturbance, have been considered to explain natural variation in the length of food chains. Much remains unknown about the role of these various drivers in determining food chain length, and particularly about the mechanisms by which they may operate in terrestrial ecosystems, which have quite different ecological constraints than aquatic environments, where most food chain length studies have been thus far conducted. In this study, we tested the relative importance of ecosystem size and productivity in influencing food chain length in a terrestrial setting. We determined that (1) there is no effect of ecosystem size or productive space on food chain length; (2) rather, food chain length increases strongly and linearly with productivity; and (3) the observed changes in food chain length are likely achieved through a combination of changes in predator size, predator behavior, and consumer diversity along gradients in productivity. These results lend new insight into the mechanisms by which productivity can drive changes in food chain length, point to potential for systematic differences in the drivers of food web structure between terrestrial and aquatic systems, and challenge us to consider how ecological context may control the drivers that shape food chain length.

The Dutch language anterior cruciate ligament return to sport after injury scale (ACL-RSI) - validity and reliability.

PubMed

Slagers, Anton J; Reininga, Inge H F; van den Akker-Scheek, Inge

2017-02-01

The ACL-Return to Sport after Injury scale (ACL-RSI) measures athletes' emotions, confidence in performance, and risk appraisal in relation to return to sport after ACL reconstruction. Aim of this study was to study the validity and reliability of the Dutch version of the ACL-RSI (ACL-RSI (NL)). Total 150 patients, who were 3-16 months postoperative, completed the ACL-RSI(NL) and 5 other questionnaires regarding psychological readiness to return to sports, knee-specific physical functioning, kinesiophobia, and health-specific locus of control. Construct validity of the ACL-RSI(NL) was determined with factor analysis and by exploring 10 hypotheses regarding correlations between ACL-RSI(NL) and the other questionnaires. For test-retest reliability, 107 patients (5-16 months postoperative) completed the ACL-RSI(NL) again 2 weeks after the first administration. Cronbach's alpha, Intraclass Correlation Coefficient (ICC), SEM, and SDC, were calculated. Bland-Altman analysis was conducted to assess bias between test and retest. Nine hypotheses (90%) were confirmed, indicating good construct validity. The ACL-RSI(NL) showed good internal consistency (Cronbach's alpha 0.94) and test-retest reliability (ICC 0.93). SEM was 5.5 and SDC was 15. A significant bias of 3.2 points between test and retest was found. Therefore, the ACL-RSI(NL) can be used to investigate psychological factors relevant to returning to sport after ACL reconstruction.

Adolescents and female patients are at increased risk for contralateral anterior cruciate ligament reconstruction: a cohort study from the Swedish National Knee Ligament Register based on 17,682 patients.

PubMed

Snaebjörnsson, Thorkell; Hamrin Senorski, Eric; Sundemo, David; Svantesson, Eleonor; Westin, Olof; Musahl, Volker; Alentorn-Geli, Eduard; Samuelsson, Kristian

2017-12-01

The impact of different surgical techniques in index ACL reconstruction for patients undergoing contralateral ACL reconstruction was investigated. The study was based on data from the Swedish National Knee Ligament Register. Patients undergoing index ACL reconstruction and subsequent contralateral ACL reconstruction using hamstring graft under the study period were included. The following variables were evaluated: age at index surgery, gender, concomitant meniscal or cartilage injury registered at index injury, transportal femoral bone tunnel drilling and transtibial femoral bone tunnel drilling. The end-point of primary contralateral ACL surgery was analysed as well as the time-to-event outcomes using survivorship methods including Kaplan-Meier estimation and Cox proportional hazards regression models. A total of 17,682 patients [n = 10,013 males (56.6%) and 7669 females (43.4%)] undergoing primary ACL reconstruction from 1 January 2005 through 31 December 2014 were included in the study. A total of 526 (3.0%) patients [n = 260 males (49.4%) and 266 females (50.6%)] underwent primary contralateral ACL reconstruction after index ACL reconstruction during the study period. Females had a 33.7% greater risk of contralateral ACL surgery [HR 1.337 (95% CI 1.127-1.586); (P = 0 0.001)]. The youngest age group (13-15 years) showed an increased risk of contralateral ACL surgery compared with the reference (36-49) age group [HR 2.771 (95% CI 1.456-5.272); (P = 0.002)]. Decreased risk of contralateral ACL surgery was seen amongst patients with concomitant cartilage injury at index surgery [HR 0.765 (95% CI 0.623-0.939); (P = 0.010)]. No differences in terms of the risk of contralateral ACL surgery were found between anatomic and non-anatomic techniques of primary single-bundle ACL reconstruction, comparing transportal anatomic technique to transtibial non-anatomic, anatomic and partial-anatomic. Age and gender were identified as risk factors for contralateral ACL reconstruction; hence young individuals and females were more prone to undergo contralateral ACL reconstruction. Patients with concomitant cartilage injury at index ACL reconstruction had lower risk for contralateral ACL reconstruction. No significant differences between various ACL reconstruction techniques could be related to increased risk of contralateral ACL reconstruction. Retrospective Cohort Study, Level III.

Influence of knee flexion angle and transverse drill angle on creation of femoral tunnels in double-bundle anterior cruciate ligament reconstruction using the transportal technique: Three-dimensional computed tomography simulation analysis.

PubMed

Choi, Chong Hyuk; Kim, Sung-Jae; Chun, Yong-Min; Kim, Sung-Hwan; Lee, Su-Keon; Eom, Nam-Kyu; Jung, Min

2018-01-01

The purpose of this study was to find appropriate flexion angle and transverse drill angle for optimal femoral tunnels of anteromedial (AM) bundle and posterolateral (PL) bundle in double-bundle ACL reconstruction using transportal technique. Thirty three-dimensional knee models were reconstructed. Knee flexion angles were altered from 100° to 130° at intervals of 10°. Maximum transverse drill angle (MTA), MTA minus 10° and 20° were set up. Twelve different tunnels were determined by four flexion angles and three transverse drill angles for each bundle. Tunnel length, wall breakage, inter-tunnel communication and graft-bending angle were assessed. Mean tunnel length of AM bundle was >30mm at 120° and 130° of flexion in all transverse drill angles. Mean tunnel length of PL bundle was >30mm during every condition. There were ≥1 cases of wall breakage except at 120° and 130° of flexion with MTA for AM bundle. There was no case of wall breakage for PL bundle. Considering inter-tunnel gap of >2mm without communication and obtuse graft-bending angle, 120° of flexion and MTA could be recommended as optimal condition for femoral tunnels of AM and PL bundles. Flexion angle and transverse drill angle had combined effect on femoral tunnel in double-bundle ACL reconstruction using transportal technique. Achieving flexion angle of 120° and transverse drill angle close to the medial femoral condyle could be recommended as optimal condition for femoral tunnels of AM and PL bundles to avoid insufficient tunnel length, wall breakage, inter-tunnel communication and acute graft-bending angle. Copyright © 2017 Elsevier B.V. All rights reserved.

Generation of stem cell-based bioartificial anterior cruciate ligament (ACL) grafts for effective ACL rupture repair.

PubMed

Kouroupis, Dimitrios; Kyrkou, Athena; Triantafyllidi, Eleni; Katsimpoulas, Michalis; Chalepakis, George; Goussia, Anna; Georgoulis, Anastasios; Murphy, Carol; Fotsis, Theodore

2016-09-01

In the present study, we combined stem cell technology with a non-absorbable biomaterial for the reconstruction of the ruptured ACL. Towards this purpose, multipotential stromal cells derived either from subcutaneous human adipose tissue (hAT-MSCs) or from induced pluripotent stem cells (iPSCs) generated from human foreskin fibroblasts (hiPSC-MSCs) were cultured on the biomaterial for 21days in vitro to generate a 3D bioartifical ACL graft. Stem cell differentiation towards bone and ligament at the ends and central part of the biomaterial was selectively induced using either BMP-2/FGF-2 or TGF-β/FGF-2 combinations, respectively. The bioartificial ACL graft was subsequently implanted in a swine ACL rupture model in place of the surgically removed normal ACL. Four months post-implantation, the tissue engineered ACL graft generated an ACL-like tissue exhibiting morphological and biochemical characteristics resembling those of normal ACL. Copyright © 2016 Helmholtz Zentrum München. Published by Elsevier B.V. All rights reserved.

In vitro comparison of human fibroblasts from intact and ruptured ACL for use in tissue engineering.

PubMed

Brune, T; Borel, A; Gilbert, T W; Franceschi, J P; Badylak, S F; Sommer, P

2007-12-17

The present study compares fibroblasts extracted from intact and ruptured human anterior cruciate ligaments (ACL) for creation of a tissue engineered ACL-construct, made of porcine small intestinal submucosal extracellular matrix (SIS-ECM) seeded with these ACL cells. The comparison is based on histological, immunohistochemical and RT-PCR analyses. Differences were observed between cells in a ruptured ACL (rACL) and cells in an intact ACL (iACL), particularly with regard to the expression of integrin subunits and smooth muscle actin (SMA). Despite these differences in the cell source, both cell populations behaved similarly when seeded on an SIS-ECM scaffold, with similar cell morphology, connective tissue organization and composition, SMA and integrin expression. This study shows the usefulness of naturally occurring scaffolds such as SIS-ECM for the study of cell behaviour in vitro, and illustrates the possibility to use autologous cells extracted from ruptured ACL biopsies as a source for tissue engineered ACL constructs.

The effect of isolated valgus moments on ACL strain during single-leg landing: A simulation study

PubMed Central

Shin, Choongsoo S.; Chaudhari, Ajit M.; Andriacchi, Thomas P.

2009-01-01

Valgus moments on the knee joint during single-leg landing have been suggested as a risk factor for anterior cruciate ligament (ACL) injury. The purpose of this study was to test the influence of isolated valgus moment on ACL strain during single-leg landing. Physiologic levels of valgus moments from an in vivo study of single-leg landing were applied to a three-dimensional dynamic knee model, previously developed and tested for ACL strain measurement during simulated landing. The ACL strain, knee valgus angle, tibial rotation, and medial collateral ligament (MCL) strain were calculated and analyzed. The study shows that the peak ACL strain increased nonlinearly with increasing peak valgus moment. Subjects with naturally high valgus moments showed greater sensitivity for increased ACL strain with increased valgus moment, but ACL strain plateaus below reported ACL failure levels when the applied isolated valgus moment rises above the maximum values observed during normal cutting activities. In addition, the tibia was observed to rotate externally as the peak valgus moment increased due to bony and soft-tissue constraints. In conclusion, knee valgus moment increases peak ACL strain during single-leg landing. However, valgus moment alone may not be sufficient to induce an isolated ACL tear without concomitant damage to the MCL, because coupled tibial external rotation and increasing strain in the MCL prevent proportional increases in ACL strain at higher levels of valgus moment. Training that reduces the external valgus moment, however, can reduce the ACL strain and thus may help athletes reduce their overall ACL injury risk. PMID:19100550

Anterior cruciate ligament (ACL) loading in a collegiate athlete during sidestep cutting after ACL reconstruction: A case study.

PubMed

Samaan, Michael A; Ringleb, Stacie I; Bawab, Sebastian Y; Greska, Eric K; Weinhandl, Joshua T

2016-08-01

Athletes with anterior cruciate ligament (ACL) injuries usually undergo ACL-reconstruction (ACLR) in order to restore joint stability, so that dynamic maneuvers such as the sidestep cut can be performed. Despite restoration of joint stability after ACLR, many athletes do not return to pre-injury levels and may be at a high risk of a second ACL injury. The purpose of this study was to determine whether or not ACL loading, would increase after ACLR. One female Division I collegiate athlete performed bilateral unanticipated sidestep cuts both before ACL injury and 27months after ACLR. Musculoskeletal simulations were used to calculate ACL loading during the deceleration phase of the sidestep cuts. Twenty-seven months after ACLR, the athlete demonstrated higher total ACL loading in the ipsilateral limb as well as altered joint kinematics, moments, and quadriceps muscle force production. In the contralateral limb, there were no increases in total ACL loading or muscle force production yet altered lower extremity joint kinematics and moments were present after ACLR. Higher total ACL loading in the ipsilateral limb of this athlete may suggest an increased risk of second ACL injury. The results of this study provide an initial step in understanding the effects of ACLR on the risk of second ACL injury in an elite athlete and suggest that it is important to develop a better understanding of this surgical intervention on knee joint loading, in order to reduce the risk of second ACL injury while performing dynamic maneuvers. Copyright © 2016 Elsevier B.V. All rights reserved.

Holocene climatic variations documented by multiple biomarker proxies from Lake Gahai on the Northeastern Tibetan Plateau

NASA Astrophysics Data System (ADS)

He, Y.; Liu, Z.; Zheng, Z.; Zhao, C.; Sun, Y.

2012-12-01

The Northeastern Tibetan Plateau is a high elevation region sensitive to large-scale climate change, thus allows us better understanding the Holocene climate interactions between the mid-latitude westerly and subtropical Asia monsoon circulations. This region is now and in the late Holocene out of the influence of Asian monsoon systems and inconsistency hydrological variations from monsoon controlled region is suggested. However, the boundary and the interactions between the westerly and the Asian monsoon circulations during the whole Holocene have not been well documented. Here we present multiple biomarker alkane and alkenone based records from Lake Gahai in the Qaidam Basin on the northeastern Tibetan Plateau to study the lake level and climate variability over the past 12,000 years. Characterized by marked alkane-based average chain length (ACL) and carbon preference index (CPI) values, our records provide unambiguous evidence of a generally dry climate from 9 to 2 ka (1 ka = 1,000 cal yr BP), and a relatively wet climate after 2 ka and before 9 ka. The occurrence of alkenones during the period of low ACL and CPI values also supports this result. Good match between our records and other earlier paleoclimatic records derived from the same basin was found, suggesting the paleoenvironment record obtained at Lake Gahai is a regional record rather than a local signal, at least in the Qaidam Basin. This generally dry climate between 9 and 2 ka was almost synchronous with the weakening of East Asian and Indian monsoon intensities. However, our data suggest an opposite moisture relation from our region and westerly controlled region. This phenomenon may lie on the interaction between westerly and monsoon systems, probably contributed to the topographic subsidence associated with stronger atmospheric convergence and rising motion on the plateau. Also this discrepancy was likely due to the enhanced evaporation than to the increased monsoon precipitation in the northeastern Tibetan Plateau, which accounts for the high temperatures.

Longitudinal tear of the medial meniscus posterior horn in the anterior cruciate ligament-deficient knee significantly influences anterior stability.

PubMed

Ahn, Jin Hwan; Bae, Tae Soo; Kang, Ki-Ser; Kang, Soo Yong; Lee, Sang Hak

2011-10-01

Longitudinal tears of the medial meniscus posterior horn (MMPH) are commonly associated with a chronic anterior cruciate ligament (ACL) deficiency. Many studies have demonstrated the importance of the medial meniscus in terms of limiting the amount of anterior-posterior tibial translation in response to anterior tibial loads in ACL-deficient knees. An MMPH tear in an ACL-deficient knee increases the anterior-posterior tibial translation and rotatory instability. In addition, MMPH repair will restore the tibial translation to the level before the tear. Controlled laboratory study. Ten human cadaveric knees were tested sequentially using a custom testing system under 5 conditions: intact, ACL deficient, ACL deficient with an MMPH peripheral longitudinal tear, ACL deficient with an MMPH repair, and ACL deficient with a total medial meniscectomy. The knee kinematics were measured at 0°, 15°, 30°, 60°, and 90° of flexion in response to a 134-N anterior and 200-N axial compressive tibial load. The rotatory kinematics were also measured at 15° and 30° of flexion in a combined rotatory load of 5 N·m of internal tibial torque and 10 N·m of valgus torque. Medial meniscus posterior horn longitudinal tears in ACL-deficient knees resulted in a significant increase in anterior-posterior tibial translation at all flexion angles except 90° (P < .05). An MMPH repair in an ACL-deficient knee showed a significant decrease in anterior-posterior tibial translation at all flexion angles except 60° compared with the ACL-deficient/MMPH tear state (P < .05). The total anterior-posterior translation of the ACL-deficient/MMPH repaired knee was not significantly increased compared with the ACL (only)-deficient knee but was increased compared with the ACL-intact knee (P > .05). A total medial meniscectomy in an ACL-deficient knee did not increase the anterior-posterior tibial translation significantly compared with MMPH tears in ACL-deficient knees at all flexion angles (P > .05). In a combined rotatory load, tibial rotation after MMPH tears or a total medial meniscectomy in an ACL-deficient knee were not affected significantly at all flexion angles. This study shows that an MMPH longitudinal tear in an ACL-deficient knee alters the knee kinematics, particularly the anterior-posterior tibial translation. MMPH repair significantly improved anterior-posterior tibial translation in ACL-deficient knees. These findings may help improve the treatment of patients with ACL and MMPH longitudinal tear by suggesting that the medial meniscal repairs should be performed for greater longevity when combined with an ACL reconstruction.

The Location of Anterior Cruciate Ligament Tears: A Prevalence Study Using Magnetic Resonance Imaging

PubMed Central

van der List, Jelle P.; Mintz, Douglas N.; DiFelice, Gregory S.

2017-01-01

Background: Over the past decade, there has been a resurgence of interest in anterior cruciate ligament (ACL) preservation. Proximal and distal avulsion tears have been treated with arthroscopic primary repair, while augmented repair, remnant tensioning, primary repair with biological scaffold, and remnant preservation have been proposed for different types of midsubstance tears. Currently, the incidence of these different tear types is unknown. Purpose: To propose a magnetic resonance imaging (MRI) classification system for different tear types based on clinical relevance and to assess the distribution of these different ACL tear types. Study Design: Case series; Level of evidence, 4. Methods: A retrospective search in an institutional radiographic database was performed for patients who underwent knee MRI at our institution between June 2014 and June 2016. Patients younger than 18 years and those with reports of chronic tears, partial tears, multiligamentous injuries, were excluded. Tear types were graded as proximal avulsion (distal remnant length >90% of total ligament length, type I), proximal (75%-90%, type II), midsubstance (25%-75%, type III), distal (10%-25%, type IV), and distal avulsion (<10%, type V). An orthopaedic surgeon, a radiologist, and a research fellow graded the tear type on 30 MRIs to determine reliability, and the research fellow graded all MRIs. Inter- and intraobserver reliability were measured using kappa statistics. Results: A total of 353 patients (57% male; mean age, 37.1 years; range, 18.1-81.2 years) were included. Interobserver reliability was 0.670 (95% confidence interval, 0.505-0.836), and intraobserver reliability ranged from 0.741 to 0.934. Incidence of type I tears was 16%, type II tears 27%, type III tears 52%, type IV tears 1%, and type V tears 3% (2.5% with bony avulsion). Type I tears were more common in patients older than 35 years compared with those younger than 35 years (23% vs 8%; P < .001). Conclusion: This classification system was reliable in assessing tear location in acute ACL injuries. Type I tears were seen in 16%, type II in 27%, and type III in 52% of patients in our cohort. These data suggest that there may be greater potential application for ACL preservation techniques. PMID:28680889

A comparative study of effect of autograft compared with allograft anterior cruciate ligament reconstruction on expressions of LOXs and MMPs

PubMed Central

Wang, Wei-Ming; Ma, Xiao-Jun; Huang, Shi-Bo; Ren, Liu-Bao

2017-01-01

The present study aimed to compare the effect of autograft or allograft anterior cruciate ligament (ACL) reconstruction on the expressions of lipoxygenases (LOXs) and matrix metalloproteinases (MMPs) in a New Zealand white rabbit model. New Zealand white rabbits were divided randomly into control, sham, autograft and allograft groups. At the 4th and 8th week after operation, biomechanical testing was performed to measure the primary length, cross-sectional area, maximum tensile load and stiffness of ACL, and HE staining was used to observe cell morphology and fibre alignment of ACL. At the 2nd, 4th and 8th week after operation, quantitative real-time PCR (qRT-PCR), Western blotting and immunohistochemistry were applied to detect LOXs and MMPs expressions, and expressions of adenomatous polyposis coli (APC)/Wnt signalling pathway-related proteins. At the 4th and 8th week after operation, the maximum tensile load and stiffness were higher in the autograft group than in the allograft group, and the values at the 8th week were higher than those at the 4th week after operation. The fibroblast proliferation in the allograft group was more significant than that in the autograft group. Compared with the control group, LOXs and MMPs expressions and the positive expression rates of LOXs and MMPs proteins were elevated, and the values in the allograft group were higher than those in the autograft group at all time points. At 8th week after operation, compared with the autograft group, Wnt expression was higher and APC expression was lower in the allograft group. Autograft and allograft ACL reconstruction can promote LOXs and MMPs expressions by activating the APC/Wnt signalling pathway. PMID:28275205

ACL graft constructs: In-vitro fatigue testing highlights the occurrence of irrecoverable lengthening and the need for adequate (pre)conditioning to avert the recurrence of knee instability.

PubMed

Blythe, A; Tasker, T; Zioupos, P

2006-01-01

The performance of ACL grafts in both the short and long term is only as good as the condition of the graft at the time of surgery. If the graft lengthens under load at the two fixation ends incorporation will take longer to occur. Previous studies have shown that the various grafts currently used are strong enough. However, data on strength came primarily from quasistatic single pull to failure tests with, in some cases, modest cycling to precondition the grafts. The present study examined the in-vitro biomechanical behaviour of model ACL grafts, which have been fatigue cycled to failure over a wide range of loads in physiological ambient conditions. Load/deformation curves and the stretch of the grafts was continuously recorded until final rupture. The grafts demonstrated typical creep-rupture like behaviour with elongation (non-recoverable stretch) and loss of stiffness leading to gradual failure. Some of the graft designs were consistently shown to elongate up to 20 mm in length within the first 2000 cycles at moderate physiological loads and a further 10 mm of elongation occurred between the initial preconditioned state and just prior to complete rupture. Not enough attention has been paid previously to the likely long term elongation patterns of ACL grafts post-surgery and even after the usual empirical preconditioning has been performed by the surgeon. Increased graft dimensions may result in recurrent knee instability and may also lead to failure of the graft to incorporate. Preconditioning in-vitro may still be a way to remove some slack and prepare the graft for its operational environment by stiffening in particular the tissue/fixation interface for those grafts that use soft polymer fixation ends.

77 FR 4754 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Snapper-Grouper Fishery off the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-31

... recreational annual catch limits (ACLs) have been met before the end of the fishing year for the past 3 fishing... lb (1,134 kg), round weight; and (3) the South Atlantic Unlimited Snapper-Grouper Permit must have... minimum size limit from 12 inches (30.5 cm), total length (TL) to 13 inches (33 cm), TL, and to increase...

Anatomic double-bundle anterior cruciate ligament reconstruction restores patellofemoral contact areas and pressures more closely than nonanatomic single-bundle reconstruction.

PubMed

Tajima, Goro; Iriuchishima, Takanori; Ingham, Sheila J M; Shen, Wei; van Houten, Albert H; Aerts, Maarten M; Shimamura, Tadashi; Smolinski, Patrick; Fu, Freddie H

2010-10-01

To investigate the effects of anterior cruciate ligament (ACL) deficiency and nonanatomic single-bundle (SB) and anatomic double-bundle (DB) ACL reconstruction on the contact characteristics of the patellofemoral (PF) joint. By use of a materials testing system, 7 fresh-frozen human cadaveric knees were tested. The following states were tested: ACL-intact knee, nonanatomic SB ACL reconstruction, anatomic DB ACL reconstruction, and ACL-deficient knee. Hamstring autografts were used. PF contact pressures and areas were measured with pressure-sensitive film at 30°, 60°, and 90° of knee flexion with a constant 100-N load on the quadriceps tendon. The total contact area of ACL-deficient and nonanatomic SB ACL-reconstructed knees (123.8 ± 63.9 and 149.6 ± 79.3 mm(2), respectively) significantly decreased when compared with those of the intact knee (206.1 ± 83.6 mm(2)) at 30° of knee flexion. The lateral-facet peak pressure of ACL-deficient and nonanatomic SB ACL-reconstructed knees (1.12 ± 0.52 and 1.22 ± 0.54 MPa, respectively) significantly decreased when compared with those of the intact knee (0.68 ± 0.38 MPa) at 90° of knee flexion. Anatomic DB ACL reconstruction restored the contact pressures and areas to values similar to those of the intact knee (no significant difference). ACL deficiency resulted in a significant decrease in the total and medial PF contact areas and in an increase in the lateral PF contact pressure. Anatomic DB ACL reconstruction more closely restored normal PF contact area and pressure than did nonanatomic SB ACL reconstruction. Our findings suggest that the changes in the PF contact area and pressures in ACL deficiency and after nonanatomic SB ACL reconstruction may be one of the causes of PF osteoarthritis or other related PF problems found at long-term follow-up. Anatomic DB ACL reconstruction may reduce the incidence of PF problems by closely restoring the contact area and pressure. Copyright © 2010 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Anterior Cruciate Ligament Injuries in National Football League Athletes From 2010 to 2013

PubMed Central

Dodson, Christopher C.; Secrist, Eric S.; Bhat, Suneel B.; Woods, Daniel P.; Deluca, Peter F.

2016-01-01

Background: There is a high incidence of anterior cruciate ligament (ACL) injuries among National Football League (NFL) athletes; however, the incidence of reinjury in this population is unknown. Purpose: This retrospective epidemiological study analyzed all publicly disclosed ACL tears occurring in NFL players between 2010 and 2013 to characterize injury trends and determine the incidence of reinjury. Study Design: Descriptive epidemiological study. Methods: A comprehensive online search identified any NFL player who had suffered an ACL injury from 2010 to 2013. Position, playing surface, activity, and date were recorded. Each player was researched for any history of previous ACL injury. The NFL games database from USA Today was used to determine the incidence of ACL injuries on artificial turf and grass fields. Databases from Pro Football Focus and Pro Football Reference were used to determine the injury rate for each position. Results: NFL players suffered 219 ACL injuries between 2010 and 2013. Forty players (18.3%) had a history of previous ACL injury, with 27 (12.3%) retears and 16 (7.3%) tears contralateral to a previous ACL injury. Five players (2.28%) suffered their third ACL tear. Receivers (wide receivers and tight ends) and backs (linebackers, fullbacks, and halfbacks) had significantly greater injury risk than the rest of the NFL players, while perimeter linemen (defensive ends and offensive tackles) had significantly lower injury risk than the rest of the players. Interior linemen (offensive guards, centers, and defensive tackles) had significantly greater injury risk compared with perimeter linemen. ACL injury rates per team games played were 0.050 for grass and 0.053 for turf fields (P > .05). Conclusion: In this retrospective epidemiological study of ACL tears in NFL players, retears and ACL tears contralateral to a previously torn ACL constituted a substantial portion (18.3%) of total ACL injuries. The significant majority of ACL injuries in players with a history of previous ACL injury were retears. Skilled offensive players and linebackers had the greatest injury risk, and significantly more ACL tears occurred among interior linemen than perimeter linemen. The month of August had the highest incidence of ACL injuries, probably because of expanded roster sizes at that point in the NFL season. PMID:26998501

Anterior cruciate ligament injury alters preinjury lower extremity biomechanics in the injured and uninjured leg: the JUMP-ACL study.

PubMed

Goerger, Benjamin M; Marshall, Stephen W; Beutler, Anthony I; Blackburn, J Troy; Wilckens, John H; Padua, Darin A

2015-02-01

Information as to how anterior cruciate ligament (ACL) injury and reconstructive surgery (ACLR) alter lower extremity biomechanics may improve rehabilitation and return to play guidelines, reducing the risk for repeat ACL injury. To compare lower extremity biomechanics before ACL injury and after subsequent ACLR for the injured and uninjured leg. Baseline unilateral lower extremity biomechanics were collected on the dominant leg of participants without ACL injury when they entered the Joint Undertaking to Monitor and Prevent ACL (JUMP-ACL) study. Thirty-one participants with subsequent ACL injury, reconstructive surgery and full return to physical activity completed repeat, follow-up biomechanical testing, as did 39 uninjured, matched controls. Not all injured participants suffered injury to the dominant leg, requiring separation of those with ACL injury into two groups: ACLR-injured leg group (n=12) and ACLR-uninjured leg group (n=19). We compared the landing biomechanics of these three groups (ACLR-injured leg, ACLR-uninjured leg, control) before ACL injury (baseline) with biomechanics after ACL injury, surgery and return to physical activity (follow-up). ACL injury and ACLR altered lower extremity biomechanics, as both ACLR groups demonstrated increases in frontal plane movement (increased hip adduction and knee valgus). The ACLR-injured leg group also exhibited decreased sagittal plane loading (decreased anterior tibial shear force, knee extension moment and hip flexion moment). No high-risk biomechanical changes were observed in control group participants. ACL injury and ACLR caused movement pattern alterations of the injured and uninjured leg that have previously shown to increase the risk for future non-contact ACL injury. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Unicondylar arthroplasty in knees with deficient anterior cruciate ligaments.

PubMed

Engh, Gerard A; Ammeen, Deborah J

2014-01-01

Historically, a functional ACL has been a prerequisite for patients undergoing unicondylar knee arthroplasty (UKA). However, this premise has not been rigorously tested. We compared (1) the survivorship free from revision and (2) the failure mechanisms of UKAs in ACL-deficient knees and UKAs in ACL-intact knees performed over the same time interval. Between November 2000 and July 2008, a fixed bearing UKA was performed in 72 patients (81 knees) with intraoperatively confirmed ACL deficiency. Five patients (five knees) with preoperative instability underwent ACL reconstruction and were excluded from analysis. Of the remaining 67 patients (76 knees) without preoperative instability, implant status was known for 68 UKAs in 60 patients. Survivorship and failure mechanisms for these knees were compared to those of 706 UKAs in ACL-intact knees performed during the same time interval by the same surgeon using the same implant system. Minimum followup for the ACL-deficient group was 2.9 years (mean, 6 years; range, 2.9-10 years). Revision rates between UKAs with and without intact ACLs were similar in the absence of clinical instability (p = 0.58). Six-year UKA survivorship was 94% (95% CI: 88%-100%) in ACL-deficient knees and 93% (95% CI: 91%-96%) in ACL-intact knees (p = 0.89). Five knees (7%) in the ACL-deficient group were revised: disease progression (two), loose tibia (one), persistent pain (one), and revised elsewhere/reason unknown (one). Thirty-six knees in the ACL-intact group underwent revision (5%): aseptic loosening (13), revised elsewhere/reason unknown (11), disease progression (three), tibial subsidence/fracture (four), infection (three), pain (one), and lateral compartment overload (one). At 6 years, deficiency of the ACL in patients without clinical knee instability did not impact the survivorship of UKAs compared to UKAs performed in knees with intact ACLs.

Impact of High-Fidelity Simulation and Pharmacist-Specific Didactic Lectures in Addition to ACLS Provider Certification on Pharmacy Resident ACLS Performance.

PubMed

Bartel, Billie J

2014-08-01

This pilot study explored the use of multidisciplinary high-fidelity simulation and additional pharmacist-focused training methods in training postgraduate year 1 (PGY1) pharmacy residents to provide Advanced Cardiovascular Life Support (ACLS) care. Pharmacy resident confidence and comfort level were assessed after completing these training requirements. The ACLS training requirements for pharmacy residents were revised to include didactic instruction on ACLS pharmacology and rhythm recognition and participation in multidisciplinary high-fidelity simulation ACLS experiences in addition to ACLS provider certification. Surveys were administered to participating residents to assess the impact of this additional education on resident confidence and comfort level in cardiopulmonary arrest situations. The new ACLS didactic and simulation training requirements resulted in increased resident confidence and comfort level in all assessed functions. Residents felt more confident in all areas except providing recommendations for dosing and administration of medications and rhythm recognition after completing the simulation scenarios than with ACLS certification training and the didactic components alone. All residents felt the addition of lectures and simulation experiences better prepared them to function as a pharmacist in the ACLS team. Additional ACLS training requirements for pharmacy residents increased overall awareness of pharmacist roles and responsibilities and greatly improved resident confidence and comfort level in performing most essential pharmacist functions during ACLS situations. © The Author(s) 2013.

50 CFR 648.323 - Accountability measures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Administrative Procedure Act. (b) ACL overages-(1) If the ACL is determined to have been exceeded in any given... between ACL and ACT, initially specified at 25 percent, shall be increased by 1 percent for each 1-percent ACL overage in the second fishing year following the fishing year in which the ACL overage occurred...

50 CFR 648.96 - FMP review, specification, and framework adjustment process.

Code of Federal Regulations, 2012 CFR

2012-10-01

... and ACLs. (1) The Councils or the PDT may develop options for setting ABC, ACL, and OFL for each.... The Councils or the PDT may recommend to the SSC that ABC, ACL, and OFL are specified for each.... (ii) ACL recommendations. The Councils shall establish ACLs for each management area that are...

50 CFR 648.323 - Accountability measures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Administrative Procedure Act. (b) ACL overages-(1) If the ACL is determined to have been exceeded in any given... between ACL and ACT, initially specified at 25 percent, shall be increased by 1 percent for each 1-percent ACL overage in the second fishing year following the fishing year in which the ACL overage occurred...

50 CFR 648.96 - FMP review, specification, and framework adjustment process.

Code of Federal Regulations, 2013 CFR

2013-10-01

... and ACLs. (1) The Councils or the PDT may develop options for setting ABC, ACL, and OFL for each.... The Councils or the PDT may recommend to the SSC that ABC, ACL, and OFL are specified for each.... (ii) ACL recommendations. The Councils shall establish ACLs for each management area that are...

50 CFR 648.323 - Accountability measures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Administrative Procedure Act. (b) ACL overages-(1) If the ACL is determined to have been exceeded in any given... between ACL and ACT, initially specified at 25 percent, shall be increased by 1 percent for each 1-percent ACL overage in the second fishing year following the fishing year in which the ACL overage occurred...

50 CFR 648.96 - FMP review, specification, and framework adjustment process.

Code of Federal Regulations, 2014 CFR

2014-10-01

... and ACLs. (1) The Councils or the PDT may develop options for setting ABC, ACL, and OFL for each.... The Councils or the PDT may recommend to the SSC that ABC, ACL, and OFL are specified for each.... (ii) ACL recommendations. The Councils shall establish ACLs for each management area that are...

50 CFR 648.323 - Accountability measures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Administrative Procedure Act. (b) ACL overages-(1) If the ACL is determined to have been exceeded in any given... between ACL and ACT, initially specified at 25 percent, shall be increased by 1 percent for each 1-percent ACL overage in the second fishing year following the fishing year in which the ACL overage occurred...

50 CFR 648.323 - Accountability measures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Administrative Procedure Act. (b) ACL overages-(1) If the ACL is determined to have been exceeded in any given... between ACL and ACT, initially specified at 25 percent, shall be increased by 1 percent for each 1-percent ACL overage in the second fishing year following the fishing year in which the ACL overage occurred...

Healing of the Acutely Injured Anterior Cruciate Ligament: Functional Treatment with the ACL-Jack, a Dynamic Posterior Drawer Brace

PubMed Central

Reischl, Nikolaus; Rönn, Karolin; Magnusson, Robert A.; Gautier, Emanuel; Jakob, Roland P.

2016-01-01

Background. The injured anterior cruciate ligament (ACL) has a limited healing capacity leading to persisting instability. Hypothesis/Purpose. To study if the application of a brace, producing a dynamic posterior drawer force, after acute ACL injury reduces initial instability. Study Design. Cohort study. Methods. Patients treated with the ACL-Jack brace were compared to controls treated with primary ACL reconstruction und controls treated nonsurgically with functional rehabilitation. Measurements included anterior laxity (Rolimeter), clinical scores (Lysholm, Tegner, and IKDC), and MRI evaluation. Patients were followed up to 24 months. Results. Patients treated with the ACL-Jack brace showed a significant improvement of anterior knee laxity comparable to patients treated with ACL reconstruction, whereas laxity persisted after nonsurgical functional rehabilitation. The failure risk (secondary reconstruction necessary) of the ACL-Jack group was however 21% (18 of 86) within 24 months. Clinical scores were similar in all treatment groups. Conclusion. Treatment of acute ACL tears with the ACL-Jack brace leads to improved anterior knee laxity compared to nonsurgical treatment with functional rehabilitation. PMID:28053787

Abnormal Mechanical Loading Induces Cartilage Degeneration by Accelerating Meniscus Hypertrophy and Mineralization After ACL Injuries In Vivo.

PubMed

Du, Guoqing; Zhan, Hongsheng; Ding, Daofang; Wang, Shaowei; Wei, Xiaochun; Wei, Fangyuan; Zhang, Jianzhong; Bilgen, Bahar; Reginato, Anthony M; Fleming, Braden C; Deng, Jin; Wei, Lei

2016-03-01

Although patients with an anterior cruciate ligament (ACL) injury have a high risk of developing posttraumatic osteoarthritis (PTOA), the role of meniscus hypertrophy and mineralization in PTOA after an ACL injury remains unknown. The purpose of this study was to determine if menisci respond to abnormal loading and if an ACL injury results in meniscus hypertrophy and calcification. The hypotheses were that (1) abnormal mechanical loading after an ACL injury induces meniscus hypertrophy and mineralization, which correlates to articular cartilage damage in vivo, and (2) abnormal mechanical loading on bovine meniscus explants induces the overexpression of hypertrophic and mineralization markers in vitro. Controlled laboratory study. In vivo guinea pig study (hypothesis 1): Three-month-old male Hartley guinea pigs (n = 9) underwent ACL transection (ACLT) on the right knee; the left knee served as the control. Calcification in the menisci was evaluated by calcein labeling 1 and 5 days before knee harvesting at 5.5 months. Cartilage and meniscus damage and mineralization were quantified by the Osteoarthritis Research Society International score and meniscus grade, respectively. Indian hedgehog (Ihh), matrix metalloproteinase-13 (MMP-13), collagen type X (Col X), progressive ankylosis homolog (ANKH), ectonucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1), alkaline phosphatase (ALP), inorganic pyrophosphate (PPi), and inorganic phosphate (Pi) concentrations were evaluated by immunohistochemistry and enzyme-linked immunosorbent assay. In vitro bovine meniscus explant study (hypothesis 2): Bovine meniscus explants were subjected to 25% strain at 0.3 Hz for 1, 2, and 3 hours. Cell viability was determined using live/dead staining. The levels of mRNA expression and protein levels were measured using real-time quantitative reverse transcription polymerase chain reaction and Western blot after 24, 48, and 72 hours in culture. The conditioned medium was collected for sulfated glycosaminoglycan (GAG) release and Pi/PPi assay. In vivo guinea pig study: Meniscus size and area as well as intensity of meniscus calcification were significantly increased in the ACLT group compared with the control group. Both calcified area and intensity were correlated with cartilage damage in the ACLT group (meniscus calcified area: r = 0.925, P < .0001; meniscus calcified intensity: r = 0.944, P < .0001). Ihh, MMP-13, Col X, ANKH, ENPP1, and ALP expression were increased in the ACLT group compared with the control group. The Pi level and Pi/PPi ratio increased by 63% and 42%, respectively, in the ACLT group compared with the control group. In vitro bovine meniscus explant study: Cell death was found in the superficial zone of the bovine meniscus explants after loading for 3 hours. The mRNA expression and protein levels of MMP-13, ANKH, ENPP1, and ALP were up-regulated in all 3-hour loaded samples. The Pi/PPi ratio and sulfated GAG content in the culture medium were increased in the 3-hour loaded group. Meniscus hypertrophy and mineralization correlated to cartilage degeneration after ACL injuries. The study data suggest that the suppression of meniscus hypertrophy and calcification may decrease the risk of PTOA after ACL injuries. © 2016 The Author(s).

Abnormal Mechanical Loading Induces Cartilage Degeneration by Accelerating Meniscus Hypertrophy and Mineralization After ACL Injuries In Vivo

PubMed Central

Du, Guoqing; Zhan, Hongsheng; Ding, Daofang; Wang, Shaowei; Wei, Xiaochun; Wei, Fangyuan; Zhang, Jianzhong; Bilgen, Bahar; Reginato, Anthony M.; Fleming, Braden C.; Deng, Jin; Wei, Lei

2016-01-01

Background Although patients with an anterior cruciate ligament (ACL) injury have a high risk of developing posttraumatic osteoarthritis (PTOA), the role of meniscus hypertrophy and mineralization in PTOA after an ACL injury remains unknown. Purpose/Hypothesis The purpose of this study was to determine if menisci respond to abnormal loading and if an ACL injury results in meniscus hypertrophy and calcification. The hypotheses were that (1) abnormal mechanical loading after an ACL injury induces meniscus hypertrophy and mineralization, which correlates to articular cartilage damage in vivo, and (2) abnormal mechanical loading on bovine meniscus explants induces the overexpression of hypertrophic and mineralization markers in vitro. Study Design Controlled laboratory study. Methods In vivo guinea pig study (hypothesis 1): Three-month-old male Hartley guinea pigs (n = 9) underwent ACL transection (ACLT) on the right knee; the left knee served as the control. Calcification in the menisci was evaluated by calcein labeling 1 and 5 days before knee harvesting at 5.5 months. Cartilage and meniscus damage and mineralization were quantified by the Osteoarthritis Research Society International score and meniscus grade, respectively. Indian hedgehog (Ihh), matrix metalloproteinase–13 (MMP-13), collagen type X (Col X), progressive ankylosis homolog (ANKH), ectonucleotide pyrophosphatase/phosphodiesterase–1 (ENPP1), alkaline phosphatase (ALP), inorganic pyrophosphate (PPi), and inorganic phosphate (Pi) concentrations were evaluated by immunohistochemistry and enzyme-linked immunosorbent assay. In vitro bovine meniscus explant study (hypothesis 2): Bovine meniscus explants were subjected to 25% strain at 0.3 Hz for 1, 2, and 3 hours. Cell viability was determined using live/dead staining. The levels of mRNA expression and protein levels were measured using real-time quantitative reverse transcription polymerase chain reaction and Western blot after 24, 48, and 72 hours in culture. The conditioned medium was collected for sulfated glycosaminoglycan (GAG) release and Pi/PPi assay. Results In vivo guinea pig study: Meniscus size and area as well as intensity of meniscus calcification were significantly increased in the ACLT group compared with the control group. Both calcified area and intensity were correlated with cartilage damage in the ACLT group (meniscus calcified area: r = 0.925, P < .0001; meniscus calcified intensity: r = 0.944, P < .0001). Ihh, MMP-13, Col X, ANKH, ENPP1, and ALP expression were increased in the ACLT group compared with the control group. The Pi level and Pi/PPi ratio increased by 63% and 42%, respectively, in the ACLT group compared with the control group. In vitro bovine meniscus explant study: Cell death was found in the superficial zone of the bovine meniscus explants after loading for 3 hours. The mRNA expression and protein levels of MMP-13, ANKH, ENPP1, and ALP were up-regulated in all 3-hour loaded samples. The Pi/PPi ratio and sulfated GAG content in the culture medium were increased in the 3-hour loaded group. Conclusion Meniscus hypertrophy and mineralization correlated to cartilage degeneration after ACL injuries. Clinical Relevance The study data suggest that the suppression of meniscus hypertrophy and calcification may decrease the risk of PTOA after ACL injuries. PMID:26792705

Younger patients are at increased risk for graft rupture and contralateral injury after anterior cruciate ligament reconstruction.

PubMed

Webster, Kate E; Feller, Julian A; Leigh, Warren B; Richmond, Anneka K

2014-03-01

Graft rupture of the same knee or injury to the anterior cruciate ligament (ACL) in the contralateral knee is a devastating outcome after ACL reconstruction surgery. While a number of factors have been identified as potentially increasing the risk of subsequent ACL injury, the literature is far from definitive. To determine the rates of graft rupture and contralateral ACL injury in a large cohort and to investigate patient characteristics that may be associated with these. Case-control study; Level of evidence, 3. A consecutive cohort of 750 patients who had undergone primary ACL reconstruction surgery with a minimum 3-year follow-up were questioned about the incidence of ACL graft rupture, contralateral ACL injury, family history of ACL injury, and current activity level. Patient databases provided details for age, sex, original injury mechanism, meniscus or articular surface injury, and graft diameter. Responses were received from 561 patients (75%) at a mean ± SD follow-up time of 4.8 ± 1.1 years. Anterior cruciate ligament graft ruptures occurred in 25 patients (4.5%), and contralateral ACL injuries occurred in 42 patients (7.5%). The highest incidence of further ACL injury occurred in patients younger than 20 years at the time of surgery. In this group, 29% sustained a subsequent ACL injury to either knee. The odds for sustaining an ACL graft rupture or contralateral injury increased 6- and 3-fold, respectively, for patients younger than 20 years. Returning to cutting/pivoting sports increased the odds of graft rupture by a factor of 3.9 and contralateral rupture by a factor of 5. A positive family history doubled the odds for both graft rupture and contralateral ACL injury. Patients younger than 20 years who undergo ACL reconstruction are at significantly increased risk for both graft rupture and contralateral ACL injury. Whether age per se is a risk factor or age represents a proxy for other factors remains to be determined.

Abnormal tibiofemoral contact stress and its association with altered kinematics following center-center ACL reconstruction: an in vitro study

PubMed Central

Imhauser, Carl; Mauro, Craig; Choi, Daniel; Rosenberg, Eric; Mathew, Stephen; Nguyen, Joseph; Ma, Yan; Wickiewicz, Thomas

2014-01-01

Background Abnormal tibiofemoral contact stress and aberrant kinematics may influence the progression of osteoarthritis in the ACL-deficient and the ACL-reconstructed knee. However, relationships between contact stress and kinematics following ACL reconstruction are poorly understood. Therefore, we posed the following research questions: (1) How do ACL deficiency and reconstruction affect kinematics of and contact stress in the tibiofemoral joint? (2) What kinematic differences are associated with abnormal contact stress following ACL reconstruction? Hypothesis/Purpose Center-center ACL reconstruction will not restore knee kinematics and contact stress. Correlations will exist between abnormal contact stress and aberrant kinematics following ACL reconstruction will exist. Study Design Controlled laboratory study Methods Clinical tests of anterior and rotational stability were simulated on eleven cadaveric knees using an industrial robot. Tests were conducted with the ACL intact, sectioned, and after single bundle ACL reconstruction using a quadrupled hamstring autograft with tunnels drilled through the center of the native footprints. Kinematics were recorded during the tests. Contact stress was continuously recorded from a stress transducer fixed to the tibial plateau and mean contact stress was calculated regionally. Results ACL deficiency resulted in increased mean contact stress in the posterior sectors of the medial and lateral compartments under anterior and rotational loads, respectively. Reconstruction reduced stress in these locations; however contact stress abnormalities remained. On average, kinematics were overconstrained following ACL reconstruction (≤1.8mm and ≤2.6° in all directions). However, combinations of overconstrained and underconstrained motions in ab/adduction and medial-lateral translation in response to combined moments, and axial rotation, anterior-posterior and medial-lateral translation in response to an anterior load were associated with abnormal mean contact stress. Conclusions ACL reconstruction reduces high stresses generated in the posterior compartment of the ACL-deficient knee. Abnormal contact stress following ACL reconstruction is related to multiplanar variations in knee kinematics. Clinical Relevance Clinical measures of multiplanar kinematics may help to better characterize the quality of ACL reconstruction. Such measures may help identify those at increased risk of long-term joint degeneration following this surgery. PMID:23470858

Understanding north-western Mediterranean climate variability: a multi-proxy and multi-sequence approach based on wavelet analysis.

NASA Astrophysics Data System (ADS)

Azuara, Julien; Lebreton, Vincent; Jalali, Bassem; Sicre, Marie-Alexandrine; Sabatier, Pierre; Dezileau, Laurent; Peyron, Odile; Frigola, Jaime; Combourieu-Nebout, Nathalie

2017-04-01

Forcings and physical mechanisms underlying Holocene climate variability still remain poorly understood. Comparison of different paleoclimatic reconstructions using spectral analysis allows to investigate their common periodicities and helps to understand the causes of past climate changes. Wavelet analysis applied on several proxy time series from the Atlantic domain already revealed the first key-issues on the origin of Holocene climate variability. However the differences in duration, resolution and variance between the time-series are important issues for comparing paleoclimatic sequences in the frequency domain. This work compiles 7 paleoclimatic proxy records from 4 time-series from the north-western Mediterranean all ranging from 7000 to 1000 yrs cal BP: -pollen and clay mineral contents from the lagoonal sediment core PB06 recovered in southern France, -Sea Surface Temperatures (SST) derived from alkenones, concentration of terrestrial alkanes and their average chain length (ACL) from core KSGC-31_GolHo-1B recovered in the Gulf of Lion inner-shelf, - δ18O record from speleothems recovered in the Asiul Cave in north-western Spain, -grain size record from the deep basin sediment drift core MD99-2343 north of Minorca island. A comparison of their frequency content is proposed using wavelet analysis and cluster analysis of wavelet power spectra. Common cyclicities are assessed using cross-wavelet analysis. In addition, a new algorithm is used in order to propagate the age model errors within wavelet power spectra. Results are consistents with a non-stationnary Holocene climate variability. The Halstatt cycles (2000-2500 years) depicted in many proxies (ACL, errestrial alkanes and SSTs) demonstrate solar activity influence in the north-western Mediterranean climate. Cluster analysis shows that pollen and ACL proxies, both indicating changes in aridity, are clearly distinct from other proxies and share significant common periodicities around 1000 and 600 years, since the mid-Holocene. The 1000 years period is also evidenced in terrestrial alkanes and Minorca sediment drift grain size, which respectively indicate changes in the Rhône hydrology and changes in the north-western Mediterranean deep water formation. These findings suggests that an original climate driver influences the Gulf of Lion area. Finally, both clay mineral content from PB06, indicative of past storminess and δ18O record from the north western Iberia, related to precipitations, record the well known 1500 years period since the middle Holocene. The presence of this period, widely encountered in the Atlantic, highlights the link between the north-western Mediterranean and the Atlantic climate variability.

50 CFR 648.70 - Surfclam and ocean quahog Annual Catch Limit (ACL).

Code of Federal Regulations, 2013 CFR

2013-10-01

... Limit (ACL). 648.70 Section 648.70 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... Annual Catch Limit (ACL). (a) The MAFMC staff shall recommend to the MAFMC ACLs for the surfclam and... Surfclam and Ocean Quahog FMP. The ACL for ocean quahog will then be allocated to the Maine and non-Maine...

50 CFR 648.233 - Spiny dogfish Accountability Measures (AMs).

Code of Federal Regulations, 2012 CFR

2012-10-01

... vessels issued a spiny dogfish permit under this part. (b) ACL overage evaluation. The ACL will be... determine if the ACL has been exceeded. (c) Overage repayment. In the event that the ACL has been exceeded in a given fishing year, the exact amount in pounds by which the ACL was exceeded shall be deducted...

50 CFR 648.70 - Surfclam and ocean quahog Annual Catch Limit (ACL).

Code of Federal Regulations, 2014 CFR

2014-10-01

... Limit (ACL). 648.70 Section 648.70 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... Annual Catch Limit (ACL). (a) The MAFMC staff shall recommend to the MAFMC ACLs for the surfclam and... Surfclam and Ocean Quahog FMP. The ACL for ocean quahog will then be allocated to the Maine and non-Maine...

50 CFR 648.233 - Spiny dogfish Accountability Measures (AMs).

Code of Federal Regulations, 2013 CFR

2013-10-01

... vessels issued a spiny dogfish permit under this part. (b) ACL overage evaluation. The ACL will be... determine if the ACL has been exceeded. (c) Overage repayment. In the event that the ACL has been exceeded in a given fishing year, the exact amount in pounds by which the ACL was exceeded shall be deducted...

50 CFR 648.70 - Surfclam and ocean quahog Annual Catch Limit (ACL).

Code of Federal Regulations, 2012 CFR

2012-10-01

... Limit (ACL). 648.70 Section 648.70 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... Annual Catch Limit (ACL). (a) The MAFMC staff shall recommend to the MAFMC ACLs for the surfclam and... Surfclam and Ocean Quahog FMP. The ACL for ocean quahog will then be allocated to the Maine and non-Maine...

50 CFR 622.49 - Annual catch limits (ACLs) and accountability measures (AMs).

Code of Federal Regulations, 2012 CFR

2012-10-01

... limit (ACL), the AA will file a notification with the Office of the Federal Register, at or near the...-year ACL was exceeded. The commercial ACL for 2010 and subsequent fishing years is 138,000 lb (62,596 kg). (ii) Recreational sector. If recreational landings, as estimated by the SRD, exceed the ACL, the...

50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

Code of Federal Regulations, 2013 CFR

2013-10-01

... catch limits (ACL), annual catch targets (ACT), DAS allocations, and individual fishing quotas (IFQ... limits (ACL), annual catch targets (ACT), DAS allocations, and individual fishing quotas (IFQ). (a... process specified in § 648.55 and is equal to the overall scallop fishery ACL. The ABC/ACL shall be...

50 CFR 648.233 - Spiny dogfish Accountability Measures (AMs).

Code of Federal Regulations, 2011 CFR

2011-10-01

... vessels issued a spiny dogfish permit under this part. (b) ACL overage evaluation. The ACL will be... determine if the ACL has been exceeded. (c) Overage repayment. In the event that the ACL has been exceeded in a given fishing year, the exact amount in pounds by which the ACL was exceeded shall be deducted...

50 CFR 648.290 - Individual fishing quota program and other restrictions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Limit (ACL). (a) The Tilefish Monitoring Committee shall recommend to the MAFMC an ACL for the...) Periodicity. The tilefish commercial ACL may be established on an annual basis for up to 3 years at a time... the sector ACLs at least every 5 years. (1) If the ACL is exceeded with a frequency greater than 25...

50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

Code of Federal Regulations, 2014 CFR

2014-10-01

... catch limits (ACL), annual catch targets (ACT), DAS allocations, and individual fishing quotas (IFQ... limits (ACL), annual catch targets (ACT), DAS allocations, and individual fishing quotas (IFQ). (a... process specified in § 648.55 and is equal to the overall scallop fishery ACL. The ABC/ACL shall be...

Basic science of anterior cruciate ligament injury and repair

PubMed Central

Kiapour, A. M.; Murray, M. M.

2014-01-01

Injury to the anterior cruciate ligament (ACL) is one of the most devastating and frequent injuries of the knee. Surgical reconstruction is the current standard of care for treatment of ACL injuries in active patients. The widespread adoption of ACL reconstruction over primary repair was based on early perception of the limited healing capacity of the ACL. Although the majority of ACL reconstruction surgeries successfully restore gross joint stability, post-traumatic osteoarthritis is commonplace following these injuries, even with ACL reconstruction. The development of new techniques to limit the long-term clinical sequelae associated with ACL reconstruction has been the main focus of research over the past decades. The improved knowledge of healing, along with recent advances in tissue engineering and regenerative medicine, has resulted in the discovery of novel biologically augmented ACL-repair techniques that have satisfactory outcomes in preclinical studies. This instructional review provides a summary of the latest advances made in ACL repair. Cite this article: Bone Joint Res 2014;3:20–31. PMID:24497504

Comparison of reaction forces on the anterior cruciate and anterolateral ligaments during internal rotation and anterior drawer forces at different flexion angles of the knee joint.

PubMed

Uğur, Levent

2017-12-01

Having a complicated anatomy, the knee joint has been further detailed and a new formation defined, the anterolateral ligament (ALL), in recent studies. While the importance of this ligament, which previously was associated with Segond fractures, was explained via clinical, radiologic and biomechanical studies, and basically, is thought to be a fixator structures for the tibia against internal rotation stress. Although in recent studies efficient surgical treatment was applied to patients who underwent anterior cruciate ligament (ACL) operation, some patients having a positive pivot test highlights the clinical importance of the ALL. The aim of this study is to evaluate reaction forces of different flexion angles on the tibia during internal rotation and anterior drawer tests on both the ALL and ACL, and to examine theimportance of this ligament in knee biomechanics by a finite element analysis method. In this study, normal anatomy knee joint was modelled using Computed Tomography images from lower extremity length in DICOM format. 0°, 15°,30°,45°,60°,75° and 90° angles of flexion were applied, respectively, to these models and reaction force vectors formed on both ligaments were examined separately and as total vector and size by applying internal rotation and anterior drawer forces on each model. Non-linear analysis was conducted using ANSYS (version 17) with the same limit conditions applied to all models. After all models were examined, in general when comparing reaction forces, those on the ACL were found to be higher. However, when vectoral directions were examined, forces on ALL increased with increased flexion ratio and internal rotation momentum. Beyond 30° flexion, the tensile force on the ALL is increased and compressive overload on the ACL occurs. The ALL plays an important role in stability, especially against internal rotation forces, and an increased knee joint flexion ratio increases the stability contribution ratio. In particular, at 30° and higher angles, ACL reflects an antagonist effect and contributes to knee joint stability for rotational and mediolateral transposition. Copyright © 2017 John Wiley & Sons, Ltd.

Return-to-Sport and Performance After Anterior Cruciate Ligament Reconstruction in National Basketball Association Players

PubMed Central

Harris, Joshua D.; Erickson, Brandon J.; Bach, Bernard R.; Abrams, Geoffrey D.; Cvetanovich, Gregory L.; Forsythe, Brian; McCormick, Frank M.; Gupta, Anil K.; Cole, Brian J.

2013-01-01

Background: Anterior cruciate ligament (ACL) rupture is a significant injury in National Basketball Association (NBA) players. Hypotheses: NBA players undergoing ACL reconstruction (ACLR) have high rates of return to sport (RTS), with RTS the season following surgery, no difference in performance between pre- and postsurgery, and no difference in RTS rate or performance between cases (ACLR) and controls (no ACL tear). Study Design: Case-control. Methods: NBA players undergoing ACLR were evaluated. Matched controls for age, body mass index (BMI), position, and NBA experience were selected during the same years as those undergoing ACLR. RTS and performance were compared between cases and controls. Paired-sample Student t tests, chi-square, and linear regression analyses were performed for comparison of within- and between-group variables. Results: Fifty-eight NBA players underwent ACLR while in the NBA. Mean player age was 25.7 ± 3.5 years. Forty percent of ACL tears occurred in the fourth quarter. Fifty players (86%) RTS in the NBA, and 7 players (12%) RTS in the International Basketball Federation (FIBA) or D-league. Ninety-eight percent of players RTS in the NBA the season following ACLR (11.6 ± 4.1 months from injury). Two players (3.1%) required revision ACLR. Career length following ACLR was 4.3 ± 3.4 years. Performance upon RTS following surgery declined significantly (P < 0.05) regarding games per season; minutes, points, and rebounds per game; and field goal percentage. However, following the index year, controls’ performances declined significantly in games per season; points, rebounds, assists, blocks, and steals per game; and field goal and free throw percentage. Other than games per season, there was no significant difference between cases and controls. Conclusion: There is a high RTS rate in the NBA following ACLR. Nearly all players RTS the season following surgery. Performance significantly declined from preinjury level; however, this was not significantly different from controls. ACL re-tear rate was low. Clinical Relevance: There is a high RTS rate in the NBA after ACLR, with no difference in performance upon RTS compared with controls. PMID:24427434

Return-to-Sport and Performance After Anterior Cruciate Ligament Reconstruction in National Basketball Association Players.

PubMed

Harris, Joshua D; Erickson, Brandon J; Bach, Bernard R; Abrams, Geoffrey D; Cvetanovich, Gregory L; Forsythe, Brian; McCormick, Frank M; Gupta, Anil K; Cole, Brian J

2013-11-01

Anterior cruciate ligament (ACL) rupture is a significant injury in National Basketball Association (NBA) players. NBA players undergoing ACL reconstruction (ACLR) have high rates of return to sport (RTS), with RTS the season following surgery, no difference in performance between pre- and postsurgery, and no difference in RTS rate or performance between cases (ACLR) and controls (no ACL tear). Case-control. NBA players undergoing ACLR were evaluated. Matched controls for age, body mass index (BMI), position, and NBA experience were selected during the same years as those undergoing ACLR. RTS and performance were compared between cases and controls. Paired-sample Student t tests, chi-square, and linear regression analyses were performed for comparison of within- and between-group variables. Fifty-eight NBA players underwent ACLR while in the NBA. Mean player age was 25.7 ± 3.5 years. Forty percent of ACL tears occurred in the fourth quarter. Fifty players (86%) RTS in the NBA, and 7 players (12%) RTS in the International Basketball Federation (FIBA) or D-league. Ninety-eight percent of players RTS in the NBA the season following ACLR (11.6 ± 4.1 months from injury). Two players (3.1%) required revision ACLR. Career length following ACLR was 4.3 ± 3.4 years. Performance upon RTS following surgery declined significantly (P < 0.05) regarding games per season; minutes, points, and rebounds per game; and field goal percentage. However, following the index year, controls' performances declined significantly in games per season; points, rebounds, assists, blocks, and steals per game; and field goal and free throw percentage. Other than games per season, there was no significant difference between cases and controls. There is a high RTS rate in the NBA following ACLR. Nearly all players RTS the season following surgery. Performance significantly declined from preinjury level; however, this was not significantly different from controls. ACL re-tear rate was low. There is a high RTS rate in the NBA after ACLR, with no difference in performance upon RTS compared with controls.

Dependence of Ion Dynamics on the Polymer Chain Length in Poly(ethylene oxide)-Based Polymer Electrolytes.

PubMed

Chattoraj, Joyjit; Knappe, Marisa; Heuer, Andreas

2015-06-04

It is known from experiments that in the polymer electrolyte system, which contains poly(ethylene oxide) chains (PEO), lithium-cations (Li(+)), and bis(trifluoromethanesulfonyl)imide-anions (TFSI(-)), the cation and the anion diffusion and the ionic conductivity exhibit a similar chain-length dependence: with increasing chain length, they start dropping steadily, and later, they saturate to constant values. These results are surprising because Li-cations are strongly correlated with the polymer chains, whereas TFSI-anions do not have such bonding. To understand this phenomenon, we perform molecular dynamics simulations of this system for four different polymer chain lengths. The diffusion results obtained from our simulations display excellent agreement with the experimental data. The cation transport model based on the Rouse dynamics can successfully quantify the Li-diffusion results, which correlates Li diffusion with the polymer center-of-mass motion and the polymer segmental motion. The ionic conductivity as a function of the chain length is then estimated based on the chain-length-dependent ion diffusion, which shows a temperature-dependent deviation for short chain lengths. We argue that in the first regime, counterion correlations modify the conductivity, whereas for the long chains, the system behaves as a strong electrolyte.

50 CFR 622.12 - Annual catch limits (ACLs) and accountability measures (AMs) for Caribbean island management...

Code of Federal Regulations, 2013 CFR

2013-10-01

... ACL, as specified in paragraph (a)(1) of this section for Puerto Rico management area species or... ensure landings do not exceed the applicable ACL. If NMFS determines the ACL for a particular species or... relative to the applicable ACL based on a moving multi-year average of landings, as described in the FMP...

77 FR 10668 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-23

...-ACL (Annual Catch Limit) Harvested for Management Area 2 AGENCY: National Marine Fisheries Service... biological catch, annual catch limit (ACL), optimum yield, domestic harvest and processing, U.S. at-sea...,200 metric tons (mt); the 2012 sub-ACL allocated to Area 2 is 22,146 mt, and 0 mt of the sub-ACL is...

77 FR 32914 - Snapper-Grouper Fishery of the South Atlantic; 2012 Recreational Accountability Measure and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-04

... landings from 2010 and 2011 exceeded the recreational annual catch limit (ACL) for golden tilefish. To... mitigate overages of the ACL if they occur. The final rule for Amendment 17B established ACLs for eight... implemented if these ACLs are reached or exceeded (75 FR 82280, December 30, 2010). The recreational ACL for...

50 CFR 648.22 - Closure of the fishery.

Code of Federal Regulations, 2011 CFR

2011-10-01

... specified for a period of up to 3 years; (2) ACL; ACT including RSA, DAH, DAP; bycatch level of the TALFF... review, may be specified for a period of up to 3 years; (3) ACL; commercial ACT, including RSA, DAH, DAP... less than or equal to the OFL. (ii) ACL. The ACL or Domestic ABC is calculated using the formula ACL...

78 FR 21071 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-09

...-ACL (Annual Catch Limit) Harvested for Management Area 2 AGENCY: National Marine Fisheries Service... limit (ACL), optimum yield, domestic harvest and processing, U.S. at-sea processing, border transfer...); the 2013 sub-ACL allocated to Area 2 is 22,146 mt, and 0 mt of the sub-ACL is set aside for research...

50 CFR 622.41 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

Code of Federal Regulations, 2014 CFR

2014-10-01

..., exceed the commercial ACL, as specified in (a)(1)(iii) of this section, the AA will file a notification... reduce the commercial ACT (commercial quota) and the commercial ACL for that following year by the amount of any commercial ACL overage in the prior fishing year. (iii) The commercial ACL for greater...

50 CFR 622.12 - Annual catch limits (ACLs) and accountability measures (AMs) for Caribbean island management...

Code of Federal Regulations, 2014 CFR

2014-10-01

... ACL, as specified in paragraph (a)(1) of this section for Puerto Rico management area species or... ensure landings do not exceed the applicable ACL. If NMFS determines the ACL for a particular species or... relative to the applicable ACL based on a moving multi-year average of landings, as described in the FMP...

76 FR 14367 - Fisheries in the Western Pacific; Mechanism for Specifying Annual Catch Limits and Accountability...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-16

... have statutory exceptions to the ACL and AM requirements. The intent of the amendment is end and... being exceeded, and to correct or mitigate any overages of the ACL. The ACL and AM mechanism would be... prevent ACLs from being exceeded or to mitigate overages of an ACL, including use of annual catch targets...

50 CFR 622.41 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

Code of Federal Regulations, 2013 CFR

2013-10-01

..., exceed the commercial ACL, as specified in (a)(1)(iii) of this section, the AA will file a notification... reduce the commercial ACT (commercial quota) and the commercial ACL for that following year by the amount of any commercial ACL overage in the prior fishing year. (iii) The commercial ACL for greater...

The Influence of Knee Flexion Angle for Graft Fixation on Rotational Knee Stability During Anterior Cruciate Ligament Reconstruction: A Biomechanical Study.

PubMed

Debandi, Aníbal; Maeyama, Akira; Hoshino, Yuichi; Asai, Shigehiro; Goto, Bunsei; Smolinski, Patrick; Fu, Freddie H

2016-11-01

To evaluate the effect of knee flexion angle for hamstring graft fixation, full extension (FE), or 30°, on acceleration of the knee motion during pivot-shift testing after either anatomic or nonanatomic anterior cruciate ligament (ACL) reconstruction using triaxial accelerometry. Two types of ACL reconstructions (anatomic and nonanatomic) using 2 different angles of knee flexion during graft fixation (FE and 30°) were performed on 12 fresh-frozen human knees making 4 groups: anatomic-FE, anatomic-30°, nonanatomic-FE, and nonanatomic-30°. Manual pivot-shift testing was performed at ACL-intact, ACL-deficient, and ACL-reconstructed conditions. Three-dimensional acceleration of knee motion was recorded using a triaxial accelerometer. The anatomic-30° group showed the smallest overall magnitude of acceleration among the ACL-reconstructed groups (P = .0039). There were no significant differences among the anatomic-FE group, the nonanatomic-FE group, and the nonantomic-30° group (anatomic-FE vs nonanatomic-FE, P = .1093; anatomic-FE vs nonanatomic-30°, P = .8728; and nonanatomic-FE vs nonanatomic-30°, P = .1093). After ACL transection, acceleration was reduced by ACL reconstruction with the exception of the nonanatomic-FE group that did not show a significant difference when compared with the ACL-deficient (P = .4537). The anatomic ACL reconstruction with the graft fixed at 30° of knee flexion better restored rotational knee stability compared with FE. An ACL graft fixed with the knee at FE in anatomic position did not show a significant difference compared with the nonanatomic ACL reconstructions. Knee flexion angle at the time of graft fixation for ACL reconstruction can be considered to maximize the rotational knee stability. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Discrete wavelet-aided delineation of PCG signal events via analysis of an area curve length-based decision statistic.

PubMed

Homaeinezhad, M R; Atyabi, S A; Daneshvar, E; Ghaffari, A; Tahmasebi, M

2010-12-01

The aim of this study is to describe a robust unified framework for segmentation of the phonocardiogram (PCG) signal sounds based on the false-alarm probability (FAP) bounded segmentation of a properly calculated detection measure. To this end, first the original PCG signal is appropriately pre-processed and then, a fixed sample size sliding window is moved on the pre-processed signal. In each slid, the area under the excerpted segment is multiplied by its curve-length to generate the Area Curve Length (ACL) metric to be used as the segmentation decision statistic (DS). Afterwards, histogram parameters of the nonlinearly enhanced DS metric are used for regulation of the α-level Neyman-Pearson classifier for FAP-bounded delineation of the PCG events. The proposed method was applied to all 85 records of Nursing Student Heart Sounds database (NSHSDB) including stenosis, insufficiency, regurgitation, gallop, septal defect, split sound, rumble, murmur, clicks, friction rub and snap disorders with different sampling frequencies. Also, the method was applied to the records obtained from an electronic stethoscope board designed for fulfillment of this study in the presence of high-level power-line noise and external disturbing sounds and as the results, no false positive (FP) or false negative (FN) errors were detected. High noise robustness, acceptable detection-segmentation accuracy of PCG events in various cardiac system conditions, and having no parameters dependency to the acquisition sampling frequency can be mentioned as the principal virtues and abilities of the proposed ACL-based PCG events detection-segmentation algorithm.

Characterization of Acyl-CoA Synthetase Isoforms In Pancreatic Beta Cells: Gene Silencing Shows Participation of ACSL3 and ACSL4 In Insulin Secretion

PubMed Central

Ansari, Israr-ul H.; Longacre, Melissa J.; Stoker, Scott W.; Kendrick, Mindy A.; O’Neill, Lucas M.; Zitur, Laura J.; Fernandez, Luis A.; Ntambi, James M.; MacDonald, Michael J.

2017-01-01

Long-chain acyl-CoA synthetases (ACSLs) convert fatty acids to fatty acyl-CoAs to regulate various physiologic processes. We characterized the ACSL isoforms in a cell line of homogeneous rat beta cells (INS-1 832/13 cells) and human pancreatic islets. ACSL4 and ACSL3 proteins were present in the beta cells and human and rat pancreatic islets and concentrated in insulin secretory granules and less in mitochondria and negligible in other intracellular organelles. ACSL1 and ACSL6 proteins were not seen in INS-1 832/13 cells or pancreatic islets. ACSL5 protein was seen only in INS-1 832/13 cells. With shRNA-mediated gene silencing we developed stable ACSL knockdown cell lines from INS-1 832/13 cells. Glucose-stimulated insulin release was inhibited ~ 50% with ACSL4 and ACSL3 knockdown and unaffected in cell lines with knockdown of ACSL5, ACLS6 and ACSL1. Lentivirus shRNA-mediated gene silencing of ACSL4 and ACSL3 in human pancreatic islets inhibited glucose-stimulated insulin release. ACSL4 and ACSL3 knockdown cells showed inhibition of ACSL enzyme activity more with arachidonate than with palmitate as a substrate, consistent with their preference for unsaturated fatty acids as substrates. ACSL4 knockdown changed the patterns of fatty acids in phosphatidylserines and phosphatidylethanolamines. The results show the involvement of ACLS4 and ACLS3 in insulin secretion. PMID:28193492

No economic benefit of early knee reconstruction over optional delayed reconstruction for ACL tears: registry enriched randomised controlled trial data.

PubMed

Kiadaliri, Aliasghar A; Englund, Martin; Lohmander, L Stefan; Carlsson, Katarina Steen; Frobell, Richard B

2016-05-01

To analyse 5-year cost-effectiveness of early versus optional delayed acute anterior cruciate ligament (ACL) reconstruction. 121 young, active adults with acute ACL injury to a previously uninjured knee were randomised to early ACL reconstruction (n=62, within 10 weeks of injury) or optional delayed ACL reconstruction (n=59; 30 with ACL reconstruction within 6-55 months); all patients received similar structured rehabilitation. Real life data on health care utilisation and sick leave were obtained from regional and national registers. Costs and quality-adjusted life years (QALYs) were discounted at 3%. Full-analysis set (based on study randomisation) and as-treated analysis (according to actual treatment over 5 years) principles were applied. Mean cost of early ACL reconstruction was €4695 higher than optional delayed ACL reconstruction (p=0.19) and provided an additional 0.13 QALYs (p=0.11). Full-analysis set showed incremental net benefit of early versus optional delayed ACL reconstruction was not statistically significantly different from zero at any level. As-treated analysis showed that costs for rehabilitation alone were €13 650 less than early ACL reconstruction (p<0.001). Results were robust to sensitivity analyses. In young active adults with acute ACL injury, a strategy of early ACL reconstruction did not provide extra economic value over a strategy of optional delayed ACL reconstruction over a 5-year period. Results from this and previous reports of the KANON-trial imply that early identification of individuals who would benefit from either early ACL reconstruction or rehabilitation alone might reduce resource consumption and decrease risk of unnecessary overtreatment. ISRCTN84752559. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Analysis of change in gait in the ovine stifle: normal, injured, and anterior cruciate ligament reconstructed.

PubMed

Heard, B J; Beveridge, J E; Atarod, M; O'Brien, E J; Rolian, C; Frank, C B; Hart, D A; Shrive, N G

2017-05-23

Many patients who undergo anterior cruciate ligament (ACL) reconstructive surgery develop post-traumatic osteoarthritis (PTOA). ACL reconstructive surgery may not fully restore pre-injury joint biomechanics, thereby resulting in further joint damage and contributing to the development of PTOA. In an ovine model of idealized ACL reconstruction (ACL-R), it has been shown that signs of PTOA develop within surgical joints by 20 weeks post-surgery. The aim of the present study was to investigate whether altered kinematics contribute to early PTOA development within ACL-R joints of the ovine injury model by comparing the gait of these surgical animals to the gait of a stable normal control group, and an unstable injury group in which the ACL and medial collateral ligament (MCL) had been transected. Fifteen skeletally mature female sheep were allocated evenly into 3 treatment groups: normal control, ACL-R, and ACL/MCL Tx (each group n = 5). Each animal's gait was recorded at baseline, 4 weeks post injury, and 20 weeks post injury. Principal component analysis (PCA) was used to identify the kinematic patterns that may be discriminant between treatment groups. Results from previous studies were referenced to present the amount of gross PTOA-like changes that occurred in the joints. ACL-R and ACL/MCL transected (Tx) animals developed a similar amount of early PTOA-like changes within the surgical joints, but differed significantly in the amount of kinematic change present at 20 weeks post-surgery. We showed that the stifle joint kinematics of ACL/MCL Tx differed significantly from those of CTRL and the majority of ACL-R animals, while no significant differences in joint kinematic changes were found between ACL-R and CTRL animals. These results suggest that the early PTOA-like changes reported in the ACL-R model cannot be attributed exclusively to post-surgical kinematic changes, and therefore biologic components in the post-injury environment must be contributing significantly to PTOA development.

76 FR 66654 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-27

...; Sub-ACL (Annual Catch Limit) Harvested for Management Area 1A AGENCY: National Marine Fisheries... biological catch, annual catch limit (ACL), optimum yield, domestic harvest and processing, U.S. at-sea...,200 metric tons (mt); the 2011 sub-ACL allocated to Area 1A is 26,546 mt, and 0 mt of the sub-ACL is...

Abnormal tibiofemoral contact stress and its association with altered kinematics after center-center anterior cruciate ligament reconstruction: an in vitro study.

PubMed

Imhauser, Carl; Mauro, Craig; Choi, Daniel; Rosenberg, Eric; Mathew, Stephen; Nguyen, Joseph; Ma, Yan; Wickiewicz, Thomas

2013-04-01

Abnormal tibiofemoral contact stress and aberrant kinematics may influence the progression of osteoarthritis in the anterior cruciate ligament (ACL)-deficient and the ACL-reconstructed knee. However, relationships between contact stress and kinematics after ACL reconstruction are poorly understood. Therefore, we posed the following research questions: (1) How do ACL deficiency and reconstruction affect the kinematics of and contact stress in the tibiofemoral joint? (2) What kinematic differences are associated with abnormal contact stress after ACL reconstruction? Center-center ACL reconstruction will not restore knee kinematics and contact stress. Correlations will exist between abnormal contact stress and aberrant kinematics after ACL reconstruction. Controlled laboratory study. Clinical tests of anterior and rotational stability were simulated on 11 cadaveric knees using an industrial robot. Tests were conducted with the ACL intact, sectioned, and after single-bundle ACL reconstruction using a quadrupled hamstring autograft with tunnels drilled through the center of the native footprints. Kinematics were recorded during the tests. Contact stress was continuously recorded from a stress transducer fixed to the tibial plateau, and mean contact stress was calculated regionally. ACL deficiency resulted in increased mean contact stress in the posterior sectors of the medial and lateral compartments under anterior and rotational loads, respectively. Reconstruction reduced stress in these locations; however, contact stress abnormalities remained. On average, kinematics were overconstrained after ACL reconstruction (≤1.8 mm and ≤2.6° in all directions). However, combinations of overconstrained and underconstrained motions in abduction/adduction and medial-lateral translation in response to combined moments, and anterior-posterior translation, medial-lateral translation, and axial rotation in response to an anterior load were associated with abnormal mean contact stress. ACL reconstruction reduces high stresses generated in the posterior compartment of the ACL-deficient knee. Abnormal contact stress after ACL reconstruction is related to multiplanar variations in knee kinematics. Clinical measures of multiplanar kinematics may help to better characterize the quality of ACL reconstruction. Such measures may help identify patients at increased risk of long-term joint degeneration following this surgery.

Effect of Changing the Joint Kinematics of Knees With a Ruptured Anterior Cruciate Ligament on the Molecular Biological Responses and Spontaneous Healing in a Rat Model.

PubMed

Kokubun, Takanori; Kanemura, Naohiko; Murata, Kenji; Moriyama, Hideki; Morita, Sadao; Jinno, Tetsuya; Ihara, Hidetoshi; Takayanagi, Kiyomi

2016-11-01

The poor healing capacity of a completely ruptured anterior cruciate ligament (ACL) has been attributed to an insufficient vascular supply, cellular metabolism, and deficient premature scaffold formation because of the unique intra-articular environment. However, previous studies have focused on intra-articular factors without considering extra-articular factors, including the biomechanical aspects of ACL-deficient knees. Changing the joint kinematics of an ACL-ruptured knee will improve cellular biological responses and lead to spontaneous healing through the mechanotransduction mechanism. Controlled laboratory study. A total of 66 skeletally mature Wistar rats were randomly assigned to a sham-operated group (SO), ACL-transection group (ACL-T), controlled abnormal movement group (CAM), and an intact group (IN). The ACL was completely transected at the midportion in the ACL-T and CAM groups, and the CAM group underwent extra-articular braking to control for abnormal tibial translation. The SO group underwent skin and joint capsule incisions and tibial drilling, without ACL transection and extra-articular braking. The animals were allowed full cage activity until sacrifice at 1, 2, 4, 6, and 8 weeks postoperatively for histological, molecular biological, and biomechanical assessment. All injured ACLs in the ACL-T group were not healed, but those in the CAM group healed spontaneously, showing a typical ligament healing response. Regarding the molecular biological response, there was an upregulation of anabolic factors (ie, transforming growth factor-β) and downregulation of catabolic factors (ie, matrix metalloproteinase). Examination of the mechanical properties at 8 weeks after injury showed that >50% of the strength of the intact ACL had returned. Our results suggest that changing the joint kinematics of knees with a ruptured ACL alters the molecular biological responses and leads to spontaneous healing. These data support our hypothesis that the mechanotransduction mechanism mediates molecular responses and determines whether the ACL will heal. Elucidating the relationship between the mechanotransduction mechanism and healing responses in knees with completely ruptured ACLs may result in the development of novel nonsurgical treatment that enables the ACL to spontaneously heal in patients who are not suitable for reconstruction. © 2016 The Author(s).

High-grade rotatory knee laxity may be predictable in ACL injuries.

PubMed

Musahl, Volker; Burnham, Jeremy; Lian, Jayson; Popchak, Adam; Svantesson, Eleonor; Kuroda, Ryosuke; Zaffagnini, Stefano; Samuelsson, Kristian

2018-06-21

Lateral compartment acceleration and translation have been used to quantify rotatory knee laxity in the setting of anterior cruciate ligament (ACL) injury; however, their relationship remains elusive. The purpose of this study was to examine the correlation between lateral compartment acceleration and translation during pivot shift testing. It was hypothesized that a correlation would exist in ACL-injured and uninjured knees, irrespective of sex, but would be greatest in knees with combined ACL and lateral meniscus tear. Seventy-seven patients (34 females, 25.2 ± 9.0 years) undergoing primary single-bundle ACL reconstruction were prospectively enrolled in a 2-year study across four international centers. Patients underwent preoperative examination under anesthesia of the injured and uninjured knee using Image Analysis software and surface mounted accelerometer. A moderate correlation between lateral compartment acceleration and translation was observed in ACL-injured knees [ρ = 0.36, p < 0.05), but not in uninjured knees (ρ = 0.17, not significant (n.s.)]. A moderate correlation between acceleration and translation was demonstrated in ACL-injured knees with lateral meniscus tears (ρ = 0.53, p < 0.05), but not in knees with isolated ACL-injury (ρ = 0.32, n.s.), ACL and medial meniscus tears (ρ = 0.14, n.s.), or ACL and combined medial and lateral meniscus tears (ρ = 0.40, n.s.). A moderate correlation between acceleration and translation was seen in males (ρ = 0.51, p < 0.05), but not in females (ρ = 0.21, n.s.). Largest correlations were observed in males with ACL and lateral meniscus tears (ρ = 0.75, p < 0.05). Lateral compartment acceleration and translation were moderately correlated in ACL-injured knees, but largely correlated in males with combined ACL and lateral meniscus tears. ACL and lateral meniscus injury in males might, therefore, be suspected when both lateral compartment acceleration and translation are elevated. Surgeons should have a greater degree of suspicion for high-grade rotatory knee laxity in ACL-injured males with concomitant lateral meniscus tears. Future studies should investigate how these two distinct components of rotatory knee laxity-lateral compartment acceleration and translation-are correlated with patient outcomes and affected by ACL surgery. Prospective cohort study; Level of evidence II.

Incidence of Second Anterior Cruciate Ligament Tears and Identification of Associated Risk Factors From 2001 to 2010 Using a Geographic Database

PubMed Central

Schilaty, Nathan D.; Nagelli, Christopher; Bates, Nathaniel A.; Sanders, Thomas L.; Krych, Aaron J.; Stuart, Michael J.; Hewett, Timothy E.

2017-01-01

Background: The reported rate of second anterior cruciate ligament (ACL) injuries (20%-30%), including graft failure and contralateral ACL tears, after ACL reconstruction (ACLR) or nonoperative therapy indicates that multiple factors may predispose patients to subsequent ACL injuries. Purpose: To determine the incidence of second ACL injuries in a population-based cohort over a 10-year observation period (2001-2010) and to identify factors that contribute to the risk of second injuries. Study Design: Descriptive epidemiological study. Methods: International Classification of Diseases, 9th Revision (ICD-9) codes relevant to the diagnosis of an ACL tear and the procedure code for ACLR were utilized to search the Rochester Epidemiology Project, a multidisciplinary county database, between the years of 2001 and 2010. The complete medical records for all cases were reviewed to confirm diagnosis and treatment details. A total of 914 unique patients with 1019 acute, isolated ACL tears were identified. These patients were stratified by primary and secondary tears, sex, age, activity level, side of injury, sex × side of injury, and graft type of reconstruction. Results: Second ACL tears were recorded in 141 (13.8%) of the 914 patients diagnosed with an ACL tear in Olmsted County, Minnesota, USA, from 2001 to 2010; 50.4% of these occurred in the contralateral knee. A noncontact mechanism was responsible for 76.4% of all ACL injuries. A second ACL injury was influenced by factors of sex × age group, treatment type × age group, and treatment type × activity level. Nonparametric analysis of graft disruption × graft type demonstrated that a higher prevalence of second ACL tears occurred with allografts compared with hamstring autografts (P = .0054) and patellar tendon autografts (P = .0001). Conclusion: The incidence of second ACL tears in this population-based cohort was 13.8%, and half occurred to the ACL of the contralateral knee. Statistically, second ACL injuries differed by sex, occurring in female patients younger than 25 years and male patients aged 26 to 45 years. Allografts continued to be associated with a greater risk of second ACL injuries compared with hamstring and patellar tendon autografts. Nonoperative treatment carried more risk of contralateral tears than ACLR. PMID:28840155

ACL-reconstructed and ACL-deficient individuals show differentiated trunk, hip, and knee kinematics during vertical hops more than 20 years post-injury.

PubMed

Markström, Jonas L; Tengman, Eva; Häger, Charlotte K

2018-02-01

Little is known regarding movement strategies in the long term following injury of the anterior cruciate ligament (ACL), and even less about comparisons of reconstructed and deficient knees in relation to healthy controls. The present purpose was to compare trunk, hip, and knee kinematics during a one-leg vertical hop (VH) ~20 years post-ACL injury between persons treated with surgery and physiotherapy (ACL R ), solely physiotherapy (ACL PT ), and controls (CTRL). Between-leg kinematic differences within groups were also investigated. Sixty-six persons who suffered unilateral ACL injury on average 23 ± 2 years ago (32 ACL R , 34 ACL PT ) and 33 controls performed the VH. Peak trunk, hip, and knee angles during Take-off and Landing phases recorded with a 3D motion capture system were analysed with multivariate statistics. Significant group effects during both Take-off and Landing were found, with ACL PT differing from CTRL in Take-off with a combination of less knee flexion and knee internal rotation, and from both ACL R and CTRL in Landing with less hip and knee flexion, knee internal rotation, and greater hip adduction. ACL R also presented different kinematics to ACL PT and CTRL in Take-off with a combination of greater trunk flexion, hip flexion, hip internal rotation, and less knee abduction, and in Landing with greater trunk flexion and hip internal rotation. Further, different kinematics and hop height were found between legs within groups in both Take-off and Landing for both ACL groups, but not for CTRL. Different kinematics for the injured leg for both ACL groups compared to CTRL and between treatment groups, as well as between legs within treatment groups, indicate long-term consequences of injury. Compensatory mechanisms for knee protection seem to prevail over time irrespective of initial treatment, possibly increasing the risk of re-injury and triggering the development of osteoarthritis. Detailed investigation of movement strategies during the VH provides important information and a more comprehensive evaluation of knee function than merely hop height. More attention should also be given to the trunk and hip in clinics when evaluating movement strategies after ACL injury. Prospective cohort study, Level II.

Comparison of hamstring muscle behavior for anterior cruciate ligament (ACL) patient and normal subject during local marching

NASA Astrophysics Data System (ADS)

Amineldin@Aminudin, Nurul Izzaty Bt.; Rambely, A. S.

2014-09-01

This study aims to investigate the hamstring muscle activity after the surgery by carrying out an electromyography experiment on the hamstring and to compare the behavior of the ACL muscle activity between ACL patient and control subject. Electromyography (EMG) is used to study the behavior of muscles during walking activity. Two hamstring muscles involved which are semitendinosus and bicep femoris. The EMG data for both muscles were recorded while the subject did maximum voluntary contraction (MVC) and marching. The study concluded that there were similarities between bicep femoris of the ACL and control subjects. The analysis showed that the biceps femoris muscle of the ACL subject had no abnormality and the pattern is as normal as the control subject. However, ACL patient has poor semitendinosus muscle strength compared to that of control subject because the differences of the forces produced. The force of semitendinosus value for control subject was two times greater than that of the ACL subject as the right semitendinosus muscle of ACL subject was used to replace the anterior cruciate ligament (ACL) that was injured.

Singular eigenstates in the even(odd) length Heisenberg spin chain

NASA Astrophysics Data System (ADS)

Ranjan Giri, Pulak; Deguchi, Tetsuo

2015-05-01

We study the implications of the regularization for the singular solutions on the even(odd) length spin-1/2 XXX chains in some specific down-spin sectors. In particular, the analytic expressions of the Bethe eigenstates for three down-spin sector have been obtained along with their numerical forms in some fixed length chains. For an even-length chain if the singular solutions \\{{{λ }α }\\} are invariant under the sign changes of their rapidities \\{{{λ }α }\\}=\\{-{{λ }α }\\}, then the Bethe ansatz equations are reduced to a system of (M-2)/2((M-3)/2) equations in an even (odd) down-spin sector. For an odd N length chain in the three down-spin sector, it has been analytically shown that there exist singular solutions in any finite length of the spin chain of the form N=3(2k+1) with k=1,2,3,\\cdots . It is also shown that there exist no singular solutions in the four down-spin sector for some odd-length spin-1/2 XXX chains.

Anterior cruciate ligament injury in female and male athletes: the relationship between foot structure and injury.

PubMed

Jenkins, Walter L; Killian, Clyde B; Williams, D S; Loudon, Janice; Raedeke, Suzanne G

2007-01-01

It has been shown that anterior cruciate ligament (ACL) injuries are more prevalent in female athletes than in male athletes. Soccer and basketball are considered high-risk sports for ACL injury in female athletes. Several studies have reported a relationship between ACL injury and measures of foot structure. This study was conducted to investigate the relationship between foot structure and ACL injury rates in female and male soccer and basketball players. One hundred five soccer and basketball players (53 women and 52 men) were recruited and divided into an ACL-normal group (n=89) and an ACL-injured group (n=16). Two measures of foot structure (subtalar joint neutral position and navicular drop test values) were recorded for each subject. An independent t test and a paired t test were used to analyze differences in ACL status, foot structure, and sex. A chi2 analysis determined whether the prevalence of ACL injury was independent of sport. No statistically significant differences were found in the foot structure measures between women and men. Female soccer and basketball players had an ACL injury rate seven times that of male players. Values derived from subtalar joint neutral position measurement and the navicular drop test were not associated with ACL injury in collegiate female and male soccer and basketball players.

Fatigue injury risk in anterior cruciate ligament of target side knee during golf swing.

PubMed

Purevsuren, Tserenchimed; Kwon, Moon Seok; Park, Won Man; Kim, Kyungsoo; Jang, Seung Ho; Lim, Young-Tae; Kim, Yoon Hyuk

2017-02-28

A golf-related ACL injury can be linked with excessive golf play or practice because such over-use by repetitive golf swing motions can increase damage accumulation to the ACL bundles. In this study, joint angular rotations, forces, and moments, as well as the forces and strains on the ACL of the target-side knee joint, were investigated for ten professional golfers using the multi-body lower extremity model. The fatigue life of the ACL was also predicted by assuming the estimated ACL force as a cyclic load. The ACL force and strain reached their maximum values within a short time just after ball-impact in the follow-through phase. The smaller knee flexion, higher internal tibial rotation, increase of the joint compressive force and knee abduction moment in the follow-through phase were shown as to lead an increased ACL loading. The number of cycles to fatigue failure (fatigue life) in the ACL might be several thousands. It is suggested that the excessive training or practice of swing motion without enough rest may be one of factors to lead to damage or injury in the ACL by the fatigue failure. The present technology can provide fundamental information to understand and prevent the ACL injury for golf players. Copyright © 2017. Published by Elsevier Ltd.

A comparison of MRI findings in patients with acute and chronic ACL tears.

PubMed

Dimond, P M; Fadale, P D; Hulstyn, M J; Tung, G A; Greisberg, J

1998-01-01

This retrospective study compared the magnetic resonance imaging (MRI) findings in 87 patients with acute and chronic anterior cruciate ligament (ACL) tears. Sixty patients had acute tears and 27 had chronic tears. The appearance of the torn ligament was examined on MRI, and associated meniscal and osteochondral injuries were described. All findings were verified at arthroscopy. Acute ACL tears (MRI examination was performed within 6 weeks of injury) were typified by the presence of diffuse (58%) or focal (42%) increased signal within the ligament, whereas chronic ACL tears (MRI examination was performed more than 6 months after injury) usually appeared as either a fragmented ligament (44%) or an intact band of low signal with abnormal orientation (30%). Patients with chronic ACL tears had a higher prevalence of medial meniscal tears (78% versus 40%), articular chondromalacia, and an increased posterior cruciate bow ratio (0.47 versus 0.37) in association with chronic ACL tears. A bone bruise was seen in 68% of acute ACL tears but in no case of chronic ACL tear. On MRI, there are salient differences between acute and chronic ACL tears. Chronic ACL tears are associated with a greater prevalence of meniscal and osteochondral injuries. These findings may have implications for future treatment recommendations.

Lessons learned from the last 20 years of ACL-related in vivo-biomechanics research of the knee joint.

PubMed

Pappas, Evangelos; Zampeli, Franceska; Xergia, Sofia A; Georgoulis, Anastasios D

2013-04-01

Technological advances in recent years have allowed the easy and accurate assessment of knee motion during athletic activities. Subsequently, thousands of studies have been published that greatly improved our understanding of the aetiology, surgical reconstruction techniques and prevention of anterior cruciate ligament (ACL) injuries. The purpose of this review is to summarize the evidence from biomechanical studies on ACL-related research. High-impact articles that enhanced understanding of ACL injury aetiology, rehabilitation, prevention and adaptations after reconstruction were selected. The importance of restoring internal tibial rotation after ACL reconstruction has emerged in several studies. Criteria-based, individualized rehabilitation protocols have replaced the traditional time-based protocols. Excessive knee valgus, poor trunk control, excessive quadriceps forces and leg asymmetries have been identified as potential high risk biomechanical factors for ACL tear. Injury prevention programmes have emerged as low cost and effective means of preventing ACL injuries, particularly in female athletes. As a result of biomechanical research, clinicians have a better understanding of ACL injury aetiology, prevention and rehabilitation. Athletes exhibiting neuromuscular deficits predisposing them to ACL injury can be identified and enrolled into prevention programmes. Clinicians should assess ACL-reconstructed patients for excessive internal tibial rotation that may lead to poor outcomes.

Prevention, treatment, and rehabilitation of anterior cruciate ligament injuries in children

PubMed Central

Lang, Pamela J; Sugimoto, Dai; Micheli, Lyle J

2017-01-01

As more children and adolescents participate in competitive organized sports, there has been an increase in the reported incidence of anterior cruciate ligament (ACL) injuries in these age groups. ACL injuries in skeletally immature athletes present a challenge, as reconstruction must preserve the physis of the distal femur and of the proximal tibia to avoid growth disturbances. Historically, a skeletally immature athlete with an ACL injury was treated with a brace and activity modification until skeletal maturity, with ACL reconstruction being performed at that time in the “non-copers” who experienced instability. More recently, evidence has shown that delayed reconstruction may lead to increased damage to the meniscus and articular cartilage. As a result, early reconstruction is favored to protect the meniscus and allow continued physical activity. While adolescents at or those near skeletal maturity may be treated with standard reconstruction techniques, they may result in growth disturbances in younger athletes with significant growth remaining. In response to the growing need for ACL reconstruction techniques in skeletally immature individuals, physeal-sparing and physeal-respecting reconstruction techniques have been developed. In addition to the advancements in surgical technique, ACL injury prevention has also gained attention. This growing interest in ACL prevention is in part related to the high risk of ACL re-tear, either of the ACL graft or of the contralateral ACL, in children and adolescents. Recent reports indicate that well-designed neuromuscular training programs may reduce the risk of primary and subsequent ACL injuries. PMID:28652828

Anterior cruciate ligament allograft transplantation in dogs.

PubMed

Vasseur, P B; Stevenson, S; Gregory, C R; Rodrigo, J J; Pauli, S; Heitter, D; Sharkey, N

1991-08-01

The biomechanical and clinical performance of bone-ligament-bone anterior cruciate ligament (ACL) allografts was studied in eight dogs. Allografts were collected from skeletally mature, healthy dogs using aseptic technique, and stored at -70 degrees for three to five weeks before implantation. The allografts were size-matched to the recipient dogs using ACL length and then rigidly fixed in position with interference screws and Kirschner wires. Three dogs regained a normal gait, and their grafts sustained breaking loads that were 25%, 41%, and 59% of controls. Partial or complete graft failure occurred in the other five dogs at some point in the study. Four had intraligamentous rupture and one had an avulsion fracture of the femoral attachment site. Joint-fluid cytology was normal in all eight dogs. Histologic examination showed persistent lymphoplasmacytic infiltrate. Eventually the allograft cores were incorporated in the host bed. Hyperplasia and fibrosis of the synovial membrane were diffuse and persisted as focal accumulations of mononuclear inflammatory cells.

Sports-specific differences in postsurgical infections after arthroscopically assisted anterior cruciate ligament reconstruction.

PubMed

Krutsch, Werner; Zellner, Johannes; Zeman, Florian; Nerlich, Michael; Koch, Matthias; Pfeifer, Christian; Angele, Peter

2017-12-01

Post-operative infection after arthroscopically assisted anterior cruciate ligament (ACL) reconstruction is a rare but severe complication, particularly for young and active patients. It is unclear whether the prevalence of knee infection is correlated with the type of sports or the level of performance. From 2008 to 2012, the internal single-centre ACL registry of the FIFA Medical Centre of Excellence Regensburg was retrospectively screened for sex, age, time between isolated primary ACL rupture and surgery, surgical technique, rate of infection after ACL reconstruction and the type of sports practised. In total, 4801 ACL reconstructions had been conducted over 5 years, 4579 in amateur and 221 in professional athletes. After application of the exclusion criteria, 1809 athletes with ACL reconstruction were analysed regarding postsurgical infection and the type of sports practised. Professionals and amateurs did not significantly differ with regard to infection rates (n.s.) but in the timing of ACL repair (p < 0.001). Eleven of 1130 football players had developed postsurgical infection after ACL reconstruction (1.0%) in contrast to 557 skiers and snowboarders without infection (p = 0.02). The timing of ACL repair did not differ between the different types of sports (n.s.). Staphylococcus aureus and epidermidis were the predominant detected bacteria. All patients were hospitalised and successfully treated with arthroscopic lavage and antibiotic medication. ACL infections showed sports-related differences. Athletes practising summer outdoor sports such as football had a significantly higher risk of infection after ACL reconstruction than winter sports athletes. No difference was found between professional and amateur athletes. Relevant prevention strategies for postsurgical ACL infections should consider influencing patient factors such as the type of sports activity and attendant circumstances. III.

Intra-ligamentary autologous conditioned plasma and healing response to treat partial ACL ruptures.

PubMed

Koch, Matthias; Matteo, Berardo Di; Eichhorn, Jürgen; Zellner, Johannes; Mayr, Felix; Krutsch, Werner; Achenbach, Leonard; Woehl, Rebecca; Nerlich, Michael; Angele, Peter

2018-05-01

Conservative treatment of partial ACL ruptures is associated with a high failure rate, and often patients undergo ACL reconstruction. ACL preservation by trephination of the ACL origin and application of Autologous Conditioned Plasma (ACP) seems to be an intriguing new treatment option to favour ACL tissue healing and avoid traditional reconstruction. The aim of this study was to describe the mid-term outcomes of this new ACL preserving technique. Twenty-four patients (mean age 41.8 years) affected by partial rupture of one or both ACL bundles were included in the present trial. The partial ACL tears were arthroscopically assessed and classified according to a new five step grading system. All patients were treated by trephination of the femoral ACL stump and intra-ligamentary application of ACP. The postoperative outcome was evaluated by both subjective scores and stability testing up to a mean of 25.1 months' follow-up. Adverse events and failure rate were also documented. Clinical outcome was good to excellent with IKDC subjective 82.7 (SD 11.8), Lysholm 87.6 (SD 8.1), Tegner 5.3 (SD 2.1), Cincinnati 88.7 (SD 14.8). The failure rate (i.e. persisting knee instability assessed clinically or by rolimeter) was 12.5%. At objective measurements, knee joints showed a firm endpoint in Lachman test, negative pivot shift phenomenon and a significant reduction in AP-laxity compared to pre-operative status by rolimeter testing (p = 0.002). Return to sport practice was achieved after mean 4.8 months (SD 4.1). ACL stump trephination and concomitant intra-ligamentary application of ACP revealed promising results at mid-term follow-up to treat partial ACL lesions.

Isolation and Characterization of Human Anterior Cruciate Ligament-Derived Vascular Stem Cells

PubMed Central

Matsumoto, Tomoyuki; Ingham, Sheila M.; Mifune, Yutaka; Osawa, Aki; Logar, Alison; Usas, Arvydas; Kuroda, Ryosuke; Kurosaka, Masahiro; Fu, Freddie H.

2012-01-01

The anterior cruciate ligament (ACL) usually fails to heal after rupture mainly due to the inability of the cells within the ACL tissue to establish an adequate healing process, making graft reconstruction surgery a necessity. However, some reports have shown that there is a healing potential of ACL with primary suture repair. Although some reports showed the existence of mesenchymal stem cell-like cells in human ACL tissues, their origin still remains unclear. Recently, blood vessels have been reported to represent a rich supply of stem/progenitor cells with a characteristic expression of CD34 and CD146. In this study, we attempted to validate the hypothesis that CD34- and CD146-expressing vascular cells exist in hACL tissues, have a potential for multi-lineage differentiation, and are recruited to the rupture site to participate in the intrinsic healing of injured ACL. Immunohistochemistry and flow cytometry analysis of hACL tissues demonstrated that it contains significantly more CD34 and CD146-positive cells in the ACL ruptured site compared with the noninjured midsubstance. CD34+CD45− cells isolated from ACL ruptured site showed higher expansionary potentials than CD146+CD45− and CD34−CD146−CD45− cells, and displayed higher differentiation potentials into osteogenic, adipogenic, and angiogenic lineages than the other cell populations. Immunohistochemistry of fetal and adult hACL tissues demonstrated a higher number of CD34 and CD146-positive cells in the ACL septum region compared with the midsubstance. In conclusion, our findings suggest that the ACL septum region contains a population of vascular-derived stem cells that may contribute to ligament regeneration and repair at the site of rupture. PMID:21732814

Low Prevalence of Anterior and Posterior Cruciate Ligament Injuries in Patients With Achondroplasia.

PubMed

Brooks, Jaysson T; Ramji, Alim F; Lyapustina, Tatyana A; Yost, Mary T; Ain, Michael C

2017-01-01

Anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuries and their subsequent reconstructions are common in the general population, but there has been no research regarding ACL or PCL injuries in patients with achondroplasia, the most common skeletal dysplasia. Our goals were to (1) evaluate the prevalence of ACL and PCL injuries in adolescents and adults with achondroplasia, (2) compare this prevalence with that reported for the general population, (3) determine how many patients with ACL or PCL injuries underwent ligament reconstruction as treatment, and (4) determine patient activity levels as they relate to the rate of ACL/PCL injuries and reconstructions. We reviewed medical records of 430 patients with achondroplasia seen in the senior author's clinic from 2002 through 2014. Demographic data were reviewed, as well as any documentation of ACL or PCL injury or reconstruction. We called all 430 patients by telephone, and 148 agreed to participate in our survey, whereas 1 declined. We asked these patients about their history of ACL or PCL injury or reconstruction, as well as current and past physical activity levels. No ACL or PCL injuries were found on chart review. One patient reached by telephone reported an ACL injury that did not require reconstruction. This yielded a theoretical prevalence of 3/430 (0.7%). Of the 148 patients surveyed, 43 (29%) reported low physical activity, 75 (51%) reported moderate physical activity, and 26 (17%) reported high physical activity. There was no significant difference in the rate of ACL injury when stratified by physical activity level (P=0.102). ACL and PCL injuries and reconstructions are extremely rare in patients with achondroplasia, which cannot be completely ascribed to a low level of physical activity. One possible explanation is that patients with achondroplasia, on an average, have a more anterior tibial slope compared with those without achondroplasia, which decreases the force generated within the ACL and may protect against ACL injury. Further research is needed to explore possible causes. Level IV-retrospective review.

Dynamic augmentation restores anterior tibial translation in ACL suture repair: a biomechanical comparison of non-, static and dynamic augmentation techniques.

PubMed

Hoogeslag, Roy A G; Brouwer, Reinoud W; Huis In 't Veld, Rianne; Stephen, Joanna M; Amis, Andrew A

2018-02-03

There is a lack of objective evidence investigating how previous non-augmented ACL suture repair techniques and contemporary augmentation techniques in ACL suture repair restrain anterior tibial translation (ATT) across the arc of flexion, and after cyclic loading of the knee. The purpose of this work was to test the null hypotheses that there would be no statistically significant difference in ATT after non-, static- and dynamic-augmented ACL suture repair, and they will not restore ATT to normal values across the arc of flexion of the knee after cyclic loading. Eleven human cadaveric knees were mounted in a test rig, and knee kinematics from 0° to 90° of flexion were recorded by use of an optical tracking system. Measurements were recorded without load and with 89-N tibial anterior force. The knees were tested in the following states: ACL-intact, ACL-deficient, non-augmented suture repair, static tape augmentation and dynamic augmentation after 10 and 300 loading cycles. Only static tape augmentation and dynamic augmentation restored ATT to values similar to the ACL-intact state directly postoperation, and maintained this after cyclic loading. However, contrary to dynamic augmentation, the ATT after static tape augmentation failed to remain statistically less than for the ACL-deficient state after cyclic loading. Moreover, after cyclic loading, ATT was significantly less with dynamic augmentation when compared to static tape augmentation. In contrast to non-augmented ACL suture repair and static tape augmentation, only dynamic augmentation resulted in restoration of ATT values similar to the ACL-intact knee and decreased ATT values when compared to the ACL-deficient knee immediately post-operation and also after cyclic loading, across the arc of flexion, thus allowing the null hypotheses to be rejected. This may assist healing of the ruptured ACL. Therefore, this study would support further clinical evaluation of dynamic augmentation of ACL repair.

Morphologic Characteristics Help Explain the Gender Difference in Peak Anterior Cruciate Ligament Strain During a Simulated Pivot Landing

PubMed Central

Lipps, David B.; Oh, Youkeun K.; Ashton-Miller, James A.; Wojtys, Edward M.

2015-01-01

Background Gender differences exist in anterior cruciate ligament (ACL) cross-sectional area and lateral tibial slope. Biomechanical principles suggest that the direction of these gender differences should induce larger peak ACL strains in females under dynamic loading. Hypothesis Peak ACL relative strain during a simulated pivot landing is significantly greater in female ACLs than male ACLs. Study Design Controlled laboratory study. Methods Twenty cadaveric knees from height- and weight-matched male and female cadavers were subjected to impulsive 3-dimensional test loads of 2 times body weight in compression, flexion, and internal tibial torque starting at 15° of flexion. Load cells measured the 3-dimensional forces and moments applied to the knee, and forces in the pretensioned quadriceps, hamstring, and gastrocnemius muscle equivalents. A novel, gender-specific, nonlinear spring simulated short-range and longer range quadriceps muscle tensile stiffness. Peak relative strain in the anteromedial bundle of the ACL (AM-ACL) was measured using a differential variable reluctance transducer, while ACL cross-sectional area and lateral tibial slope were measured using magnetic resonance imaging. A repeated-measures Mann-Whitney signed-rank test was used to test the hypothesis. Results Female knees exhibited 95% greater peak AM-ACL relative strain than male knees (6.37% [22.53%] vs 3.26% [11.89%]; P = .004). Anterior cruciate ligament cross-sectional area and lateral tibial slope were significant predictors of peak AM-ACL relative strain (R2 = .59; P = .001). Conclusion Peak AM-ACL relative strain was significantly greater in female than male knees from donors of the same height and weight. This gender difference is attributed to a smaller female ACL cross-sectional area and a greater lateral tibial slope. Clinical Relevance Since female ACLs are systematically exposed to greater strain than their male counterparts, training and injury prevention programs should take this fact into consideration. PMID:21917612

Influence of alkyl chain length compatibility on microemulsion structure and solubilization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, V.K.; O'Connell, J.P.; Shah, D.O.

1980-06-01

The water solubilization capacity of water/oil microemulsions is studied as a function of alkyl chain length of oil (C/sub 8/ to C/sub 16/), surfactant (C/sub 14/ and C/sub 18/ fatty acid soaps), and alcohol (C/sub 4/ to C/sub 7/). Sodium stearate and sodium myristate were used as surfactants. For n-butanol microemulsions the maximum amount of water solubilized in the microemulsion decreased continuously with increasing oil chain length; for n-heptanol it increased continuously. For n-pentanol and n-hexanol systems, water solubilization reached a maximum when the oil chain length plus alcohol chain length was equal to that of the surfactant. The electricmore » resistance and dielectric constant of the microemulsions also are measured as a function of alkyl chain length of the oil. 48 references.« less

The Relationship between Anterior Cruciate Ligament Injury and Osteoarthritis of the Knee

PubMed Central

Simon, David; Saltzman, Bryan M.; Rollins, Meaghan; Bach, Bernard R.; MacDonald, Peter

2015-01-01

Anterior cruciate ligament (ACL) tears are a common injury, particularly in the athletic and youth populations. The known association between ACL injury and subsequent osteoarthritis (OA) of the knee merits a more in-depth understanding of the relationship between the ACL-injured knee and osteoarthritis. ACL injury, especially with concomitant meniscal or other ligamentous pathology, predisposes the knee to an increased risk of osteoarthritis. ACL insufficiency results in deterioration of the normal physiologic knee bending culminating in increased anterior tibial translation and increased internal tibial rotation. This leads to increased mean contact stresses in the posterior medial and lateral compartments under anterior and rotational loading. However, surgical reconstruction of the ACL has not been shown to reduce the risk of future OA development back to baseline and has variability based on operative factors of graft choice, timing of surgery, presence of meniscal and chondral abnormalities, and surgical technique. Known strategies to prevent OA development are applicable to patients with ACL deficiency or after ACL reconstruction and include weight management, avoidance of excessive musculoskeletal loading, and strength training. Reconstruction of the ACL does not necessarily prevent osteoarthritis in many of these patients and may depend on several external variables. PMID:25954533

Anterior cruciate ligament rupture: differences between males and females.

PubMed

Sutton, Karen M; Bullock, James Montgomery

2013-01-01

The rate of anterior cruciate ligament (ACL) rupture is three times higher in female athletes than in male athletes. Intrinsic factors such as increased quadriceps angle and increased posterior tibial slope may predispose girls and women to ACL injury. Compared with males, females have smaller notch widths and smaller ACL cross-sectional area; however, no conclusive correlation between ACL size and notch dimension exists, especially in relation to risk of ACL injury. Female athletes who land with the knees in inadequate flexion and in greater-than-normal valgus and external rotation are at increased risk of ACL injury. No conclusive link has been made between ACL injury and the menstrual cycle. Neuromuscular intervention protocols have been shown to reduce the rate of injury in girls and women. Females are more likely than males to have a narrow A-shaped intercondylar notch, and special surgical considerations are required in such cases. Following ACL reconstruction, female athletes are more likely than male athletes to rupture the contralateral ACL; however, males and females are equally likely to rupture the reconstructed knee. Although self-reported outcomes in the first 2 years following reconstruction are worse for females than for males, longer-term studies demonstrate no difference between males and females.

Relationship Between the Risk of Suffering a First-Time Noncontact ACL Injury and Geometry of the Femoral Notch and ACL: A Prospective Cohort Study With a Nested Case-Control Analysis.

PubMed

Whitney, Darryl C; Sturnick, Daniel R; Vacek, Pamela M; DeSarno, Mike J; Gardner-Morse, Mack; Tourville, Timothy W; Smith, Helen C; Slauterbeck, James R; Johnson, Robert J; Shultz, Sandra J; Hashemi, Javad; Beynnon, Bruce D

2014-08-01

The morphometric characteristics of the anterior cruciate ligament (ACL) and the femoral intercondylar notch within which it resides have been implicated as risk factors for injuries to this important stabilizer of the knee. Prior research has produced equivocal results with differing methodologies, and consequently, it is unclear how these characteristics affect the injury risk in male and female patients. The morphometric characteristics of the ACL and femoral intercondylar notch are individually and independently associated with the risk of suffering a noncontact ACL injury, and these relationships are different in male and female patients. Case-control study; Level of evidence, 3. Magnetic resonance imaging scans of the bilateral knees were obtained on 88 case-control pairs (27 male, 61 female) matched for age, sex, and participation on the same sports team. Patients had suffered a grade III, first-time, noncontact ACL tear. The femoral notch width at 4 locations, the thickness of the bony ridge at the anteromedial outlet of the femoral notch, the femoral notch volume, ACL volume, and ACL cross-sectional area were measured. Multivariate analysis of combined data from male and female patients revealed that decreased ACL volume (odds ratio [OR], 0.829), decreased femoral notch width (OR, 0.700), and increased bony ridge thickness at the anteromedial outlet of the femoral notch (OR, 1.614) were significant independent predictors of an ACL injury. Separate analyses of male and female patients indicated that the femoral notch ridge may be more strongly associated with a risk in female patients, while ACL volume is more strongly associated with a risk in male patients. However, statistical analysis performed with an adjustment for body weight strengthened the association between ACL volume and the risk of injuries in female patients. Morphometric features of both the ACL and femoral notch combine to influence the risk of suffering a noncontact ACL injury. When included together in a multivariate model that adjusts for body weight, the effects of the morphometric measurements are similar in male and female patients. If body weight is not taken into consideration, ACL volume is not associated with a risk in female patients. © 2014 The Author(s).

Structural and Anatomic Restoration of the Anterior Cruciate Ligament Is Associated With Less Cartilage Damage 1 Year After Surgery: Healing Ligament Properties Affect Cartilage Damage

PubMed Central

Kiapour, Ata M.; Fleming, Braden C.; Murray, Martha M.

2017-01-01

Background: Abnormal joint motion has been linked to joint arthrosis after anterior cruciate ligament (ACL) reconstruction. However, the relationships between the graft properties (ie, structural and anatomic) and extent of posttraumatic osteoarthritis are not well defined. Hypotheses: (1) The structural (tensile) and anatomic (area and alignment) properties of the reconstructed graft or repaired ACL correlate with the total cartilage lesion area 1 year after ACL surgery, and (2) side-to-side differences in anterior-posterior (AP) knee laxity correlate with the total cartilage lesion area 1 year postoperatively. Study Design: Controlled laboratory study. Methods: Sixteen minipigs underwent unilateral ACL transection and were randomly treated with ACL reconstruction or bridge-enhanced ACL repair. The tensile properties, cross-sectional area, and multiplanar alignment of the healing ACL or graft, AP knee laxity, and cartilage lesion areas were assessed 1 year after surgery. Results: In the reconstructed group, the normalized graft yield and maximum failure loads, cross-sectional area, sagittal and coronal elevation angles, and side-to-side differences in AP knee laxity at 60° of flexion were associated with the total cartilage lesion area 1 year after surgery (R 2 > 0.5, P < .04). In the repaired group, normalized ACL yield load, linear stiffness, cross-sectional area, and the sagittal and coronal elevation angles were associated with the total cartilage lesion area (R 2 > 0.5, P < .05). Smaller cartilage lesion areas were observed in the surgically treated knees when the structural and anatomic properties of the ligament or graft and AP laxity values were closer to those of the contralateral ACL-intact knee. Reconstructed grafts had a significantly larger normalized cross-sectional area and sagittal elevation angle (more vertical) when compared with repaired ACLs (P < .02). Conclusion: The tensile properties, cross-sectional area, and multiplanar alignment of the healing ACLs or grafts and AP knee laxity in reconstructed knees were associated with the extent of tibiofemoral cartilage damage after ACL surgery. Clinical Relevance: These data highlight the need for novel ACL injury treatments that can restore the structural and anatomic properties of the torn ACL to those of the native ACL in an effort to minimize the risk of early-onset posttraumatic osteoarthritis. PMID:28875154

Biomechanical Evaluation of Knee Joint Laxities and Graft Forces After Anterior Cruciate Ligament Reconstruction by Anteromedial Portal, Outside-In, and Transtibial Techniques

PubMed Central

Sim, Jae Ang; Gadikota, Hemanth R.; Li, Jing-Sheng; Li, Guoan; Gill, Thomas J.

2013-01-01

Background Recently, anatomic anterior cruciate ligament (ACL) reconstruction is emphasized to improve joint laxity and to potentially avert initiation of cartilage degeneration. There is a paucity of information on the efficacy of ACL reconstructions by currently practiced tunnel creation techniques in restoring normal joint laxity. Study Design Controlled laboratory study. Hypothesis Anterior cruciate ligament reconstruction by the anteromedial (AM) portal technique, outside-in (OI) technique, and modified transtibial (TT) technique can equally restore the normal knee joint laxity and ACL forces. Methods Eight fresh-frozen human cadaveric knee specimens were tested using a robotic testing system under an anterior tibial load (134 N) at 0°, 30°, 60°, and 90° of flexion and combined torques (10-N·m valgus and 5-N·m internal tibial torques) at 0° and 30° of flexion. Knee joint kinematics, ACL, and ACL graft forces were measured in each knee specimen under 5 different conditions (ACL-intact knee, ACL-deficient knee, ACL-reconstructed knee by AM portal technique, ACL-reconstructed knee by OI technique, and ACL-reconstructed knee by TT technique). Results Under anterior tibial load, no significant difference was observed between the 3 reconstructions in terms of restoring anterior tibial translation (P > .05). However, none of the 3 ACL reconstruction techniques could completely restore the normal anterior tibial translations (P <.05). Under combined tibial torques, both AM portal and OI techniques closely restored the normal knee anterior tibial translation (P > .05) at 0° of flexion but could not do so at 30° of flexion (P <.05). The ACL reconstruction by the TT technique was unable to restore normal anterior tibial translations at both 0° and 30° of flexion under combined tibial torques (P <.05). Forces experienced by the ACL grafts in the 3 reconstruction techniques were lower than those experienced by normal ACL under both the loading conditions. Conclusion Anterior cruciate ligament reconstructions by AM portal, OI, and modified TT techniques are biomechanically comparable with each other in restoring normal knee joint laxity and in situ ACL forces. Clinical Relevance Anterior cruciate ligament reconstructions by AM portal, OI, and modified TT techniques result in similar knee joint laxities. Technical perils and pearls should be carefully considered before choosing a tunnel creating technique. PMID:21908717

Quantification of bone marrow water and lipid composition in anterior cruciate ligament-injured and osteoarthritic knees using three-dimensional magnetic resonance spectroscopic imaging.

PubMed

Tufts, Lauren S; Shet, Keerthi; Liang, Fei; Majumdar, Sharmila; Li, Xiaojuan

2016-06-01

To quantitatively evaluate longitudinal changes in water and lipid in knee bone marrow with and without bone marrow edema-like lesions (BMELs) in subjects with acutely ruptured anterior cruciate ligaments (ACLs) or osteoarthritis (OA) using three-dimensional magnetic resonance spectroscopic imaging (3D MRSI). Ten ACL and 10 OA subjects who presented with BMEL and seven BMEL-free controls were scanned at 3T. All ACL and OA subjects had one-year follow-up scans. 3D MRSI was acquired in BMEL and adjacent bone marrow, and water content (WC) and unsaturated lipid index (UI) were calculated in each region of interest. At baseline, ACL BMEL WC was significantly higher than ACL non-BMEL, OA BMEL, and control WC; ACL non-BMEL WC, ACL BMEL UI, and OA BMEL WC were significantly higher than control. ACL BMEL WC decreased significantly one year post-reconstruction; UI decreased non-significantly (p=0.09). No significant changes in OA BMEL or ACL and OA non-BMEL WC and UI were observed. 3D MRSI is a powerful method of quantitatively assessing the biochemical composition of bone marrow in OA and ACL-injured knees, which may serve as imaging markers to improve comprehension of primary and secondary OA pathology. Copyright © 2016 Elsevier Inc. All rights reserved.

Side-Chain Effects on the Thermoelectric Properties of Fluorene-Based Copolymers.

PubMed

Liang, Ansheng; Zhou, Xiaoyan; Zhou, Wenqiao; Wan, Tao; Wang, Luhai; Pan, Chengjun; Wang, Lei

2017-09-01

Three conjugated polymers with alkyl chains of different lengths are designed and synthesized, and their structure-property relationship as organic thermoelectric materials is systematically elucidated. All three polymers show similar photophysical properties, thermal properties, and mechanical properties; however, their thermoelectric performance is influenced by the length of their side chains. The length of the alkyl chain significantly influences the electrical conductivity of the conjugated polymers, and polymers with a short alkyl chain exhibit better conductivity than those with a long alkyl chain. The length of the alkyl chain has little effect on the Seebeck coefficient. Only a slight increase in the Seebeck coefficient is observed with the increasing length of the alkyl chain. The purpose of this study is to provide comprehensive insight into fine-tuning the thermoelectric properties of conjugated polymers as a function of side-chain engineering, thereby providing a novel perspective into the design of high-performance thermoelectric conjugated polymers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vertical stiffness is not related to anterior cruciate ligament elongation in professional rugby union players.

PubMed

Serpell, Benjamin G; Scarvell, Jennie M; Pickering, Mark R; Ball, Nick B; Perriman, Diana; Warmenhoven, John; Smith, Paul N

2016-01-01

Novel research surrounding anterior cruciate ligament (ACL) injury is necessary because ACL injury rates have remained unchanged for several decades. An area of ACL risk mitigation which has not been well researched relates to vertical stiffness. The relationship between increased vertical stiffness and increased ground reaction force suggests that vertical stiffness may be related to ACL injury risk. However, given that increased dynamic knee joint stability has been shown to be associated with vertical stiffness, it is possible that modification of vertical stiffness could help to protect against injury. We aimed to determine whether vertical stiffness is related to measures known to load, or which represent loading of, the ACL. This was a cross-sectional observational study of 11 professional Australian rugby players. Knee kinematics and ACL elongation were measured from a 4-dimensional model of a hopping task which simulated the change of direction manoeuvre typically observed when non-contact ACL injury occurs. The model was generated from a CT scan of the participant's knee registered frame by frame to fluoroscopy images of the hopping task. Vertical stiffness was calculated from force plate data. There was no association found between vertical stiffness and anterior tibial translation (ATT) or ACL elongation (r=-0.05; p=0.89, and r=-0.07; p=0.83, respectively). ATT was related to ACL elongation (r=0.93; p=0.0001). Vertical stiffness was not associated with ACL loading in this cohort of elite rugby players but a novel method for measuring ACL elongation in vivo was found to have good construct validity.

Bone-to-bone Fixation Enhances Functional Healing of the Porcine Anterior Cruciate Ligament Using a Collagen-Platelet Composite

PubMed Central

Murray, Martha M.; Magarian, Elise; Zurakowski, David; Fleming, Braden C.

2010-01-01

Purpose The purpose of this study was to determine if providing bony stabilization between the tibia and femur would improve the structural properties of an “enhanced” ACL repair using a collagen-platelet composite when compared to the traditional (Marshall) suture technique. Methods Twelve pigs underwent unilateral ACL transection and were treated with sutures connecting the bony femoral ACL attachment site to the distal ACL stump (LIGAMENT group), or to the tibia via a bone tunnel (TIBIA group). A collagen-platelet composite was placed around the sutures to enhance the biologic repair in both groups. Anteroposterior (AP) knee laxity and the graft structural properties were measured after 15 weeks of healing in both the ACL-repaired and contralateral ACL-intact joints. Results Enhanced ACL repair with bone-to-bone fixation significantly improved yield load and linear stiffness of the ACL repairs (p<0.05) after 15 weeks of healing. However, laxity values of the knees were similar in both groups of repaired knees (p>0.10). Conclusions Using an enhanced ACL suture repair technique that includes bone-to-bone fixation to protect the repair in the initial healing stages resulted in an ACL with improved structural properties after 15 weeks in the porcine model. Clinical Relevance The healing response of an ACL suture repair using a collagen-platelet composite can be enhanced by providing bony stabilization between the tibia and femur to protect the graft during the initial healing process in a translational model. PMID:20810092

50 CFR 648.123 - Scup accountability measures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... remainder of the period. (1) Commercial ACL overage evaluation. The commercial sector ACL will be evaluated... discards will be evaluated in determining if the commercial sector ACL has been exceeded. (2) Commercial... the commercial sector ACL is exceeded. Any current year landings in excess of the commercial quota in...

50 CFR 648.123 - Scup accountability measures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... remainder of the period. (1) Commercial ACL overage evaluation. The commercial sector ACL will be evaluated... discards will be evaluated in determining if the commercial sector ACL has been exceeded. (2) Commercial... the commercial sector ACL is exceeded. Any current year landings in excess of the commercial quota in...

50 CFR 648.103 - Summer flounder accountability measures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... sector ACL to be exceeded, or if the commercial fisheries in all states have been closed. The Regional... commercial fisheries in one or more states have been reopened without causing the sector ACL to be exceeded... in that state. (1) Commercial ACL overage evaluation. The commercial sector ACL will be evaluated...

50 CFR 648.103 - Minimum fish sizes.

Code of Federal Regulations, 2011 CFR

2011-10-01

... determines that the inaction of one or more states will cause the commercial sector ACL to be exceeded, or if... more states have been reopened without causing the sector ACL to be exceeded. (b) State commercial...) Commercial ACL overage evaluation. The commercial sector ACL will be evaluated based on a single-year...

50 CFR 648.55 - Framework adjustments to management measures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... establish OFL, ABC, ACL, ACT, DAS allocations, rotational area management programs, percentage allocations... measures will be adjusted. (c) OFL, ABC, ACL, ACT, and AMs. The Council shall specify OFL, ABC, ACL, ACT... derive specifications for ABC, ACL, and ACT, as specified in paragraphs (c)(2) through (c)(5) of this...

50 CFR 648.82 - Effort-control program for NE multispecies limited access vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... ACL for a particular stock to be exceeded. If such catch resulted in the overall ACL for a particular... amount of the overage of the overall ACL for that stock multiplied by the common pool's share of the overall ACL for that stock calculated...

50 CFR 648.123 - Scup accountability measures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... remainder of the period. (1) Commercial ACL overage evaluation. The commercial sector ACL will be evaluated... discards will be evaluated in determining if the commercial sector ACL has been exceeded. (2) Commercial... the commercial sector ACL is exceeded. Any current year landings in excess of the commercial quota in...

50 CFR 648.55 - Framework adjustments to management measures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... establish OFL, ABC, ACL, ACT, DAS allocations, rotational area management programs, percentage allocations... measures will be adjusted. (c) OFL, ABC, ACL, ACT, and AMs. The Council shall specify OFL, ABC, ACL, ACT... derive specifications for ABC, ACL, and ACT, as specified in paragraphs (c)(2) through (c)(5) of this...

50 CFR 648.103 - Summer flounder accountability measures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... sector ACL to be exceeded, or if the commercial fisheries in all states have been closed. The Regional... commercial fisheries in one or more states have been reopened without causing the sector ACL to be exceeded... in that state. (1) Commercial ACL overage evaluation. The commercial sector ACL will be evaluated...

50 CFR 648.55 - Framework adjustments to management measures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... establish OFL, ABC, ACL, ACT, DAS allocations, rotational area management programs, percentage allocations... measures will be adjusted. (c) OFL, ABC, ACL, ACT, and AMs. The Council shall specify OFL, ABC, ACL, ACT... derive specifications for ABC, ACL, and ACT, as specified in paragraphs (c)(2) through (c)(5) of this...

50 CFR 648.55 - Framework adjustments to management measures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... establish OFL, ABC, ACL, ACT, DAS allocations, rotational area management programs, percentage allocations... measures will be adjusted. (c) OFL, ABC, ACL, ACT, and AMs. The Council shall specify OFL, ABC, ACL, ACT... derive specifications for ABC, ACL, and ACT, as specified in paragraphs (a)(2) through (5) of this...

50 CFR 648.103 - Summer flounder accountability measures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... sector ACL to be exceeded, or if the commercial fisheries in all states have been closed. The Regional... commercial fisheries in one or more states have been reopened without causing the sector ACL to be exceeded... in that state. (1) Commercial ACL overage evaluation. The commercial sector ACL will be evaluated...

Opening of DNA chain due to force applied on different locations.

PubMed

Singh, Amar; Modi, Tushar; Singh, Navin

2016-09-01

We consider a homogeneous DNA molecule and investigate the effect of random force applied on the unzipping profile of the molecule. How the critical force varies as a function of the chain length or number of base pairs is the objective of this study. In general, the ratio of the critical forces that is applied on the middle of the chain to that which is applied on one of the ends is two. Our study shows that this ratio depends on the length of the chain. This means that the force which is applied to a point can be experienced by a section of the chain. Beyond a length, the base pairs have no information about the applied force. In the case when the chain length is shorter than this length, this ratio may vary. Only in the case when the chain length exceeds a critical length, this ratio is found to be two. Based on the de Gennes formulation, we developed a method to calculate these forces at zero temperature. The exact results at zero temperature match numerical calculations.

Constraints on food chain length arising from regional metacommunity dynamics

PubMed Central

Calcagno, Vincent; Massol, François; Mouquet, Nicolas; Jarne, Philippe; David, Patrice

2011-01-01

Classical ecological theory has proposed several determinants of food chain length, but the role of metacommunity dynamics has not yet been fully considered. By modelling patchy predator–prey metacommunities with extinction–colonization dynamics, we identify two distinct constraints on food chain length. First, finite colonization rates limit predator occupancy to a subset of prey-occupied sites. Second, intrinsic extinction rates accumulate along trophic chains. We show how both processes concur to decrease maximal and average food chain length in metacommunities. This decrease is mitigated if predators track their prey during colonization (habitat selection) and can be reinforced by top-down control of prey vital rates (especially extinction). Moreover, top-down control of colonization and habitat selection can interact to produce a counterintuitive positive relationship between perturbation rate and food chain length. Our results show how novel limits to food chain length emerge in spatially structured communities. We discuss the connections between these constraints and the ones commonly discussed, and suggest ways to test for metacommunity effects in food webs. PMID:21367786

Electrostatic contribution to the persistence length of a semiflexible dipolar chain.

PubMed

Podgornik, Rudi

2004-09-01

We investigate the electrostatic contribution to the persistence length of a semiflexible polymer chain whose segments interact via a screened Debye-Hückel dipolar interaction potential. We derive the expressions for the renormalized persistence length on the level of a 1/D-expansion method already successfully used in other contexts of polyelectrolye physics. We investigate different limiting forms of the renormalized persistence length of the dipolar chain and show that, in, general, it depends less strongly on the screening length than in the context of a monopolar chain. We show that for a dipolar chain the electrostatic persistence length in the same regime of the parameter phase space as the original Odijk-Skolnick-Fixman (OSF) form for a monopolar chain depends logarithmically on the screening length rather than quadratically. This can be understood solely on the basis of a swifter decay of the dipolar interactions with separation compared to the monopolar electrostatic interactions. We comment also on the general contribution of higher multipoles to the electrostatic renormalization of the bending rigidity.

ACL reconstruction - discharge

MedlinePlus

Anterior cruciate ligament reconstruction - discharge; ACL reconstruction - discharge ... had surgery to reconstruct your anterior cruciate ligament (ACL). The surgeon drilled holes in the bones of ...

Cloning and biochemical characterization of a novel lipolytic gene from activated sludge metagenome, and its gene product

PubMed Central

2010-01-01

In this study, a putative esterase, designated EstMY, was isolated from an activated sludge metagenomic library. The lipolytic gene was subcloned and expressed in Escherichia coli BL21 using the pET expression system. The gene estMY contained a 1,083 bp open reading frame (ORF) encoding a polypeptide of 360 amino acids with a molecular mass of 38 kDa. Sequence analysis indicated that it showed 71% and 52% amino acid identity to esterase/lipase from marine metagenome (ACL67845) and Burkholderia ubonensis Bu (ZP_02382719), respectively; and several conserved regions were identified, including the putative active site, GDSAG, a catalytic triad (Ser203, Asp301, and His327) and a HGGG conserved motif (starting from His133). The EstMY was determined to hydrolyse p-nitrophenyl (NP) esters of fatty acids with short chain lengths (≤C8). This EstMY exhibited the highest activity at 35°C and pH 8.5 respectively, by hydrolysis of p-NP caprylate. It also exhibited the same level of activity over wide temperature and pH spectra and in the presence of metal ions or detergents. The high level of stability of esterase EstMY with unique substrate specificities makes it highly valuable for downstream biotechnological applications. PMID:21054894

Bio-enhanced repair of the anterior cruciate ligament

PubMed Central

Proffen, Benedikt L.; Sieker, Jakob T.; Murray, Martha

2015-01-01

Suture repair of the ACL has been widely abandoned in favor of ACL reconstruction, largely due to the high rates of failure and unreliability of the outcomes following suture repair. However, there have been recent basic science studies which suggest that combining a suture repair with a biologic adjunct may improve the results of suture repair of the ACL, with several studies in large animal models showing equivalent strength of an ACL treated with bio-enhanced repaired with that of an ACL graft at 3, 6 and 12 months after surgery. In addition, the groups treated with bio-enhanced repair had significantly less osteoarthritis when compared with the animals undergoing ACL reconstruction. These findings have led to a renewed interest in bio-enhanced primary repair as a way to make repair of the ACL a viable option for a select group of patients in the future. PMID:25595694

Three-Dimensional Engineered Bone–Ligament–Bone Constructs for Anterior Cruciate Ligament Replacement

PubMed Central

Ma, Jinjin; Smietana, Michael J.; Kostrominova, Tatiana Y.; Wojtys, Edward M.; Larkin, Lisa M.

2012-01-01

The anterior cruciate ligament (ACL), a major stabilizer of the knee, is commonly injured. Because of its intrinsic poor healing ability, a torn ACL is usually reconstructed by a graft. We developed a multi-phasic, or bone–ligament–bone, tissue-engineered construct for ACL grafts using bone marrow stromal cells and sheep as a model system. After 6 months in vivo, the constructs increased in cross section and exhibited a well-organized microstructure, native bone integration, a functional enthesis, vascularization, innervation, increased collagen content, and structural alignment. The constructs increased in stiffness to 52% of the tangent modulus and 95% of the geometric stiffness of native ACL. The viscoelastic response of the explants was virtually indistinguishable from that of adult ACL. These results suggest that our constructs after implantation can obtain physiologically relevant structural and functional characteristics comparable to those of adult ACL. They present a viable option for ACL replacement. PMID:21902608

50 CFR 648.163 - Bluefish Accountability Measures (AMs).

Code of Federal Regulations, 2014 CFR

2014-10-01

...) ACL overage evaluation. The ACL will be evaluated based on a single-year examination of total catch (landings and dead discards). Both landings and dead discards will be evaluated in determining if the ACL... cause the ACL specified in § 648.160(a) to be exceeded, or if the commercial fisheries in all states...

50 CFR 648.163 - Bluefish Accountability Measures (AMs).

Code of Federal Regulations, 2012 CFR

2012-10-01

...) ACL overage evaluation. The ACL will be evaluated based on a single-year examination of total catch (landings and dead discards). Both landings and dead discards will be evaluated in determining if the ACL... cause the ACL specified in § 648.160(a) to be exceeded, or if the commercial fisheries in all states...

50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Summer flounder Annual Catch Limit (ACL... Management Measures for the Summer Flounder Fisheries § 648.100 Summer flounder Annual Catch Limit (ACL). (a... frequent or more specific ACL performance review criteria as part of a stock rebuilding plan following a...

50 CFR 648.120 - Scup Annual Catch Limit (ACL).

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Scup Annual Catch Limit (ACL). 648.120... Measures for the Scup Fishery § 648.120 Scup Annual Catch Limit (ACL). (a) The Scup Monitoring Committee... more specific ACL performance review criteria as part of a stock rebuilding plan following a...

50 CFR 648.163 - Gear restrictions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Bluefish Accountability Measures (AMs). (a) ACL overage evaluation. The ACL will be evaluated based on a... be evaluated in determining if the ACL has been exceeded. (b) Commercial sector EEZ closure. NMFS... inaction of one or more states will cause the ACL specified in § 648.160(a) to be exceeded, or if the...

50 CFR 648.120 - Scup Annual Catch Limit (ACL).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Scup Annual Catch Limit (ACL). 648.120... Measures for the Scup Fishery § 648.120 Scup Annual Catch Limit (ACL). (a) The Scup Monitoring Committee... more specific ACL performance review criteria as part of a stock rebuilding plan following a...

50 CFR 648.96 - FMP review, specification, and framework adjustment process.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Councils or the PDT may develop options for setting ABC, ACL, and OFL for each monkfish stock, as necessary... recommend to the SSC that ABC, ACL, and OFL are specified for each monkfish stock for multiple years as... not limited to, OFLs, ACLs, and management uncertainty. (ii) ACL recommendations. The Councils shall...

50 CFR 648.160 - Catch quotas and other restrictions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Limit (ACL). (a) The Bluefish Monitoring Committee shall recommend to the MAFMC an ACL for the bluefish fishery, which shall be equal to the ABC recommended by the SSC. (1) Periodicity. The bluefish fishery ACL... Monitoring Committee shall conduct a detailed review of fishery performance relative to the ACL at least...

50 CFR 648.120 - Scup Annual Catch Limit (ACL).

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Scup Annual Catch Limit (ACL). 648.120... Measures for the Scup Fishery § 648.120 Scup Annual Catch Limit (ACL). (a) The Scup Monitoring Committee... more specific ACL performance review criteria as part of a stock rebuilding plan following a...

50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Tilefish Annual Catch Limit (ACL). 648... Measures for the Tilefish Fishery § 648.290 Tilefish Annual Catch Limit (ACL). (a) The Tilefish Monitoring Committee shall recommend to the MAFMC an ACL for the commercial tilefish fishery, which shall be equal to...

50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Summer flounder Annual Catch Limit (ACL... Management Measures for the Summer Flounder Fisheries § 648.100 Summer flounder Annual Catch Limit (ACL). (a... frequent or more specific ACL performance review criteria as part of a stock rebuilding plan following a...

50 CFR 648.160 - Bluefish Annual Catch Limit (ACL).

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Bluefish Annual Catch Limit (ACL). 648... Measures for the Atlantic Bluefish Fishery § 648.160 Bluefish Annual Catch Limit (ACL). (a) The Bluefish Monitoring Committee shall recommend to the MAFMC an ACL for the bluefish fishery, which shall be equal to...

50 CFR 648.160 - Bluefish Annual Catch Limit (ACL).

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Bluefish Annual Catch Limit (ACL). 648... Measures for the Atlantic Bluefish Fishery § 648.160 Bluefish Annual Catch Limit (ACL). (a) The Bluefish Monitoring Committee shall recommend to the MAFMC an ACL for the bluefish fishery, which shall be equal to...

50 CFR 648.160 - Bluefish Annual Catch Limit (ACL).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Bluefish Annual Catch Limit (ACL). 648... Measures for the Atlantic Bluefish Fishery § 648.160 Bluefish Annual Catch Limit (ACL). (a) The Bluefish Monitoring Committee shall recommend to the MAFMC an ACL for the bluefish fishery, which shall be equal to...

50 CFR 648.163 - Bluefish Accountability Measures (AMs).

Code of Federal Regulations, 2013 CFR

2013-10-01

...) ACL overage evaluation. The ACL will be evaluated based on a single-year examination of total catch (landings and dead discards). Both landings and dead discards will be evaluated in determining if the ACL... cause the ACL specified in § 648.160(a) to be exceeded, or if the commercial fisheries in all states...

50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Tilefish Annual Catch Limit (ACL). 648... Measures for the Tilefish Fishery § 648.290 Tilefish Annual Catch Limit (ACL). (a) The Tilefish Monitoring Committee shall recommend to the MAFMC an ACL for the commercial tilefish fishery, which shall be equal to...

50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Tilefish Annual Catch Limit (ACL). 648... Measures for the Tilefish Fishery § 648.290 Tilefish Annual Catch Limit (ACL). (a) The Tilefish Monitoring Committee shall recommend to the MAFMC an ACL for the commercial tilefish fishery, which shall be equal to...

50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Summer flounder Annual Catch Limit (ACL... Management Measures for the Summer Flounder Fisheries § 648.100 Summer flounder Annual Catch Limit (ACL). (a... frequent or more specific ACL performance review criteria as part of a stock rebuilding plan following a...

50 CFR 648.233 - Spiny dogfish Accountability Measures (AMs).

Code of Federal Regulations, 2014 CFR

2014-10-01

... dogfish permit under this part. (b) ACL overage evaluation. The ACL will be evaluated based on a single-year examination of total catch (including both landings and dead discards) to determine if the ACL has been exceeded. (c) Overage repayment. In the event that the ACL has been exceeded in a given fishing...

50 CFR 648.70 - Annual individual allocations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... text is set forth as follows: § 648.70 Surfclam and ocean quahog Annual Catch Limit (ACL). (a) The... established consistent with the guidelines contained in the Atlantic Surfclam and Ocean Quahog FMP. The ACL... ACLs at least every 5 years. (1) If the surfclam or the ocean quahog ACL is exceeded with a frequency...

Anticardiolipin antibodies in patients from Malaysia with systemic lupus erythematosus.

PubMed

Jones, H W; Ireland, R; Senaldi, G; Wang, F; Khamashta, M; Bellingham, A J; Veerapan, K; Hughes, G R; Vergani, D

1991-03-01

Systemic lupus erythematosus (SLE) is highly prevalent in Malaysia, which has a mixed population of Malays, Chinese, and Indians. A quantitative enzyme linked immunosorbent assay (ELISA) was used to determine anticardiolipin antibody (aCL) levels (total immunoglobulin, IgG, and IgM) in 200 patients with SLE (164 Chinese, 26 Malay, and 10 Indian) attending the University Hospital of Kuala Lumpur, Malaysia, and 103 matched controls. Only 33 (16.5%) of the patients had raised aCL levels; 26 had raised IgG aCL, five IgM aCL, and two both IgG and IgM aCL. There was a low prevalence of raised levels of aCL in the population studied, which was seen in conjunction with a rare occurrence of thrombosis. The classical association of high aCL levels with thrombocytopenia and recurrent abortions was noted, though not with cerebral disease. The low prevalence of aCL in this study population of mixed racial origin contrasts with findings in European patients with SLE and lends support to the influence of local factors, be they genetic or environmental, on the clinical manifestations of this disease.

Athymic Rat Model for Evaluation of Engineered Anterior Cruciate Ligament Grafts

PubMed Central

Leong, Natalie L.; Kabir, Nima; Arshi, Armin; Nazemi, Azadeh; Wu, Ben M.; McAllister, David R.; Petrigliano, Frank A.

2015-01-01

Anterior cruciate ligament (ACL) rupture is a common ligamentous injury that often requires surgery because the ACL does not heal well without intervention. Current treatment strategies include ligament reconstruction with either autograft or allograft, which each have their associated limitations. Thus, there is interest in designing a tissue-engineered graft for use in ACL reconstruction. We describe the fabrication of an electrospun polymer graft for use in ACL tissue engineering. This polycaprolactone graft is biocompatible, biodegradable, porous, and is comprised of aligned fibers. Because an animal model is necessary to evaluate such a graft, this paper describes an intra-articular athymic rat model of ACL reconstruction that can be used to evaluate engineered grafts, including those seeded with xenogeneic cells. Representative histology and biomechanical testing results at 16 weeks postoperatively are presented, with grafts tested immediately post-implantation and contralateral native ACLs serving as controls. The present study provides a reproducible animal model with which to evaluate tissue engineered ACL grafts, and demonstrates the potential of a regenerative medicine approach to treatment of ACL rupture. PMID:25867958

Dimensionality of the Knee Numeric-Entity Evaluation Score (KNEES-ACL): a condition-specific questionnaire.

PubMed

Comins, J D; Krogsgaard, M R; Kreiner, S; Brodersen, J

2013-10-01

The benefit of anterior cruciate ligament (ACL) reconstruction has been questioned based on patient-reported outcome measures (PROMs). Valid interpretation of such results requires confirmation of the psychometric properties of the PROM. Rasch analysis is the gold standard for validation of PROMs, yet PROMs used for ACL reconstruction have not been validated using Rasch analysis. We used Rasch analysis to investigate the psychometric properties of the Knee Numeric-Entity Evaluation Score (KNEES-ACL), a newly developed PROM for patients treated for ACL deficiency. Two-hundred forty-two patients pre- and post-ACL reconstruction completed the pilot PROM. Rasch models were used to assess the psychometric properties (e.g., unidimensionality, local response dependency, and differential item functioning). Forty-one items distributed across seven unidimensional constructs measuring impairment, functional limitations, and psychosocial consequences were confirmed to fit Rasch models. Fourteen items were removed because of statistical lack of fit and inadequate face validity. Local response dependency and differential item functioning were identified and adjusted. The KNEES-ACL is the first Rasch-validated condition-specific PROM constructed for patients with ACL deficiency and patients with ACL reconstruction. Thus, this instrument can be used for within- and between-group comparisons. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The common mechanisms of anterior cruciate ligament injuries in judo: a retrospective analysis.

PubMed

Koshida, S; Deguchi, T; Miyashita, K; Iwai, K; Urabe, Y

2010-09-01

Although high prevalence of anterior cruciate ligament injuries (ACL) in judokas has been reported, there has been very little research concerning events preceding the injury. To determine the common situations and mechanisms of ACL injury in judo. A total of 43 cases of ACL injuries that had occurred during judo competition or practice were investigated, using questionnaires with interviews conducted by a single certified athletic trainer who has 20 years of judo experience to obtain information regarding the situation and mechanism in which the ACL injury occurred. The number of ACL injuries when the participant's grip style was different from the style of the opponent (ie, kenka-yotsu style) (28 cases) was significantly greater than when the participant's grip style was the same as that of the opponent (ie, ai-yotsu style) (15 cases; p<0.001). The number of ACL injuries was significantly higher when the participant was attacked by the opponent than when counterattacked or when attempting the attack (p<0.001). In addition, being attacked with osoto-gari was revealed as the leading cause of ACL injury incidence among the participants (16.8%). Grip style may be associated with ACL injury occurrence in judo. In addition, direct contact due to the opponent's attack may be a common mechanism for ACL injuries in judo.

Biologic Approaches for the Treatment of Partial Tears of the Anterior Cruciate Ligament

PubMed Central

Dallo, Ignacio; Chahla, Jorge; Mitchell, Justin J.; Pascual-Garrido, Cecilia; Feagin, John A.; LaPrade, Robert F.

2017-01-01

Background: Anterior cruciate ligament reconstruction (ACLR) has been established as the gold standard for treatment of complete ruptures of the anterior cruciate ligament (ACL) in active, symptomatic individuals. In contrast, treatment of partial tears of the ACL remains controversial. Biologically augmented ACL-repair techniques are expanding in an attempt to regenerate and improve healing and outcomes of both the native ACL and the reconstructed graft tissue. Purpose: To review the biologic treatment options for partial tears of the ACL. Study Design: Review. Methods: A literature review was performed that included searches of PubMed, Medline, and Cochrane databases using the following keywords: partial tear of the ACL, ACL repair, bone marrow concentrate, growth factors/healing enhancement, platelet-rich plasma (PRP), stem cell therapy. Results: The use of novel biologic ACL repair techniques, including growth factors, PRP, stem cells, and bioscaffolds, have been reported to result in promising preclinical and short-term clinical outcomes. Conclusion: The potential benefits of these biological augmentation approaches for partial ACL tears are improved healing, better proprioception, and a faster return to sport and activities of daily living when compared with standard reconstruction procedures. However, long-term studies with larger cohorts of patients and with technique validation are necessary to assess the real effect of these approaches. PMID:28210653

Anterior cruciate ligament injury about 20 years post-treatment: A kinematic analysis of one-leg hop.

PubMed

Tengman, E; Grip, H; Stensdotter, Ak; Häger, C K

2015-12-01

Reduced dynamic knee stability, often evaluated with one-leg hops (OLHs), is reported after anterior cruciate ligament (ACL) injury. This may lead to long-standing altered movement patterns, which are less investigated. 3D kinematics during OLH were explored in 70 persons 23 ± 2 years after ACL injury; 33 were treated with physiotherapy in combination with ACL reconstruction (ACL(R)) and 37 with physiotherapy alone (ACL(PT)). Comparisons were made to 33 matched controls. We analyzed (a) maximal knee joint angles and range of motion (flexion, abduction, rotation); (b) medio-lateral position of the center of mass (COM) in relation to knee and ankle joint centers, during take-off and landing phases. Unlike controls, ACL-injured displayed leg asymmetries: less knee flexion and less internal rotation at take-off and landing and more lateral COM related to knee and ankle joint of the injured leg at landing. Compared to controls, ACL(R) had larger external rotation of the injured leg at landing. ACL(PT) showed less knee flexion and larger external rotation at take-off and landing, and larger knee abduction at Landing. COM was more medial in relation to the knee at take-off and less laterally placed relative to the ankle at landing. ACL injury results in long-term kinematic alterations during OLH, which are less evident for ACL(R). © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Diagnostic value of medical history and physical examination of anterior cruciate ligament injury: comparison between primary care physician and orthopaedic surgeon.

PubMed

Geraets, Stijn E W; Meuffels, Duncan E; van Meer, Belle L; Breedveldt Boer, Hans P; Bierma-Zeinstra, Sita M A; Reijman, Max

2015-04-01

Well-designed validity studies on the clinical diagnosis of anterior cruciate ligament (ACL) injury are scarce. Our purpose is to assess the diagnostic value of ACL-specific medical history assessment and physical examination between primary and secondary care medical specialists. Medical history assessment and physical examination were performed by both an orthopaedic surgeon and a primary care physician, both blinded to all clinical information, in a secondary care population. A knee arthroscopy was used as reference standard. A total of 60 participants were divided into an index group with an arthroscopically proven complete ACL rupture and a control group with an arthroscopically proven intact ACL. The orthopaedic surgeon recognized 94 % of the participants with an ACL rupture through a positive medical history combined with a positive physical examination; of the participants with an intact ACL, 16 % were misclassified by the orthopaedic surgeon. The primary care physician recognized 62 % of the participants with an ACL rupture and misclassified 23 % of the participants with an intact ACL. Physical examination appeared to have no additional value for the primary care physician. Combined medical history and physical examination have strong diagnostic value in ACL rupture diagnostics performed by an orthopaedic surgeon, whereas for the primary care physician, only medical history appeared to be of value. For current practice, this could mean that only orthopaedic surgeons can perform an ACL physical examination with accuracy. III.

Risk Factors for Anterior Cruciate Ligament Injury in Competitive Adolescent Alpine Skiers

PubMed Central

Westin, Maria; Harringe, Marita L.; Engström, Björn; Alricsson, Marie; Werner, Suzanne

2018-01-01

Background: There is a high risk for anterior cruciate ligament (ACL) injuries in alpine skiers. To reduce or try to prevent these injuries, intrinsic and extrinsic risk factors need to be identified. Purpose: To identify possible intrinsic and extrinsic ACL injury risk factors among competitive adolescent alpine skiers. Study Design: Case-control study; Level of evidence, 3. Methods: Between 2006 and 2009, a cohort of 339 alpine ski students (176 male, 163 female) from Swedish ski high schools were prospectively observed in terms of ACL injuries. First-time ACL injuries were recorded. In September, prior to each ski season, the skiers were clinically examined according to a specific knee protocol. Results: Overall, 11 male and 14 female skiers sustained a total of 25 first-episode ACL injuries. The majority of injuries occurred in the left knee (P < .05). Skiers who had participated in alpine skiing for >13 years (hazard ratio, 0.83; 95% CI, 0.68-1.00; P < .05) had a reduced risk of sustaining an ACL injury. Eighteen ACL injuries occurred during training, 12 in the technical discipline of giant slalom, and 8 in slalom. Fourteen skiers reported not to be fatigued at all at the time of injury, and 8 skiers reported that they were somewhat fatigued. Conclusion: ACL injuries occurred more often in the left knee than the right. This should be taken into consideration in the design of ACL injury prevention programs. Those who reported a higher number of active years in alpine skiing showed a reduced risk of sustaining an ACL injury. No other factor among those studied could be identified as an independent risk factor for ACL injury. PMID:29780835

Vertical stiffness is not related to anterior cruciate ligament elongation in professional rugby union players

PubMed Central

Serpell, Benjamin G; Scarvell, Jennie M; Pickering, Mark R; Ball, Nick B; Perriman, Diana; Warmenhoven, John; Smith, Paul N

2016-01-01

Background Novel research surrounding anterior cruciate ligament (ACL) injury is necessary because ACL injury rates have remained unchanged for several decades. An area of ACL risk mitigation which has not been well researched relates to vertical stiffness. The relationship between increased vertical stiffness and increased ground reaction force suggests that vertical stiffness may be related to ACL injury risk. However, given that increased dynamic knee joint stability has been shown to be associated with vertical stiffness, it is possible that modification of vertical stiffness could help to protect against injury. We aimed to determine whether vertical stiffness is related to measures known to load, or which represent loading of, the ACL. Methods This was a cross-sectional observational study of 11 professional Australian rugby players. Knee kinematics and ACL elongation were measured from a 4-dimensional model of a hopping task which simulated the change of direction manoeuvre typically observed when non-contact ACL injury occurs. The model was generated from a CT scan of the participant's knee registered frame by frame to fluoroscopy images of the hopping task. Vertical stiffness was calculated from force plate data. Results There was no association found between vertical stiffness and anterior tibial translation (ATT) or ACL elongation (r=−0.05; p=0.89, and r=−0.07; p=0.83, respectively). ATT was related to ACL elongation (r=0.93; p=0.0001). Conclusions Vertical stiffness was not associated with ACL loading in this cohort of elite rugby players but a novel method for measuring ACL elongation in vivo was found to have good construct validity. PMID:27900192

Quantitative comparison of the pivot shift test results before and after anterior cruciate ligament reconstruction by using the three-dimensional electromagnetic measurement system.

PubMed

Nagai, Kanto; Hoshino, Yuichi; Nishizawa, Yuichiro; Araki, Daisuke; Matsushita, Takehiko; Matsumoto, Tomoyuki; Takayama, Koji; Nagamune, Kouki; Kurosaka, Masahiro; Kuroda, Ryosuke

2015-10-01

Tibial acceleration during the pivot shift test is a potential quantitative parameter to evaluate rotational laxity of anterior cruciate ligament (ACL) insufficiency. However, clinical application of this measurement has not been fully examined. This study aimed to measure and compare tibial acceleration before and after ACL reconstruction (ACLR) in ACL-injured patients. We hypothesized tibial acceleration would be reduced by ACLR and tibial acceleration would be consistent in the same knee at different time points. Seventy ACL-injured patients who underwent ACLR were enrolled. Tibial acceleration during the pivot shift test was measured using an electromagnetic measurement system before ALCR and at the second-look arthroscopy 1 year post-operatively. Tibial acceleration was compared to clinical grading and between ACL-injured/ACL-reconstructed and contralateral knees. Pre-operative tibial acceleration was increased stepwise with the increase in clinical grading (P < 0.01). Tibial acceleration in ACL-injured knee (1.9 ± 1.2 m/s(2)) was larger than that in the contralateral knee (0.8 ± 0.3 m/s(2), P < 0.01), and reduced to 0.9 ± 0.3 m/s(2) post-operatively (P < 0.01). There was no difference between ACL-reconstructed and contralateral knee (n.s.). Tibial acceleration in contralateral knees was consistent pre- and post-operatively (n.s.). Tibial acceleration measurement demonstrated increased rotational laxity in ACL-injured knees and its reduction by ALCR. Additionally, consistent measurements were obtained in ACL-intact knees at different time points. Therefore, tibial acceleration during the pivot shift test could provide quantitative evaluation of rotational stability before and after ACL reconstruction. III.

The Cost-Effectiveness of Anterior Cruciate Ligament Reconstruction in Competitive Athletes.

PubMed

Stewart, Bruce A; Momaya, Amit M; Silverstein, Marc D; Lintner, David

2017-01-01

Competitive athletes value the ability to return to competitive play after the treatment of anterior cruciate ligament (ACL) injuries. ACL reconstruction has high success rates for return to play, but some studies indicate that patients may do well with nonoperative physical therapy treatment. To evaluate the cost-effectiveness of the treatment of acute ACL tears with either initial surgical reconstruction or physical therapy in competitive athletes. Economic and decision analysis; Level of evidence, 2. The incremental cost, incremental effectiveness, and incremental cost-effectiveness ratio (ICER) of ACL reconstruction compared with physical therapy were calculated from a cost-effectiveness analysis of ACL reconstruction compared with physical therapy for the initial management of acute ACL injuries in competitive athletes. The ACL reconstruction strategy and the physical therapy strategy were represented as Markov models. Costs and quality-adjusted life-years (QALYs) were evaluated over a 6-year time horizon and were analyzed from a societal perspective. Quality of life and probabilities of clinical outcomes were obtained from the peer-reviewed literature, and costs were compiled from a large academic hospital in the United States. One-way, 2-way, and probabilistic sensitivity analyses were used to assess the effect of uncertainty in variables on the ICER of ACL reconstruction. The ICER of ACL reconstruction compared with physical therapy was $22,702 per QALY gained. The ICER was most sensitive to the quality of life of returning to play or not returning to play, costs, and duration of follow-up but relatively insensitive to the rates and costs of complications, probabilities of return to play for both operative and nonoperative treatments, and discount rate. ACL reconstruction is a cost-effective strategy for competitive athletes with an ACL injury.

Tibiofemoral joint contact area and pressure after single- and double-bundle anterior cruciate ligament reconstruction.

PubMed

Morimoto, Yusuke; Ferretti, Mario; Ekdahl, Max; Smolinski, Patrick; Fu, Freddie H

2009-01-01

The purpose of this study was to compare the tibiofemoral contact area and pressure after single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) reconstruction by use of 2 femoral and 2 tibial tunnels in intact cadaveric knees. Tibiofemoral contact area and mean and maximum pressures were measured by pressure-sensitive film (Fujifilm, Valhalla, NY) inserted between the tibia and femur. The knee was subjected to a 1,000-N axial load by use of a uniaxial testing machine at 0 degrees , 15 degrees , 30 degrees , and 45 degrees of flexion. Three conditions were evaluated: (1) intact ACL, (2) SB ACL reconstruction (n = 10 knees), and (3) DB ACL reconstruction (n = 9 knees). When compared with the intact knee, DB ACL reconstruction showed no significant difference in tibiofemoral contact area and mean and maximum pressures. SB ACL reconstruction had a significantly smaller contact area on the lateral and medial tibiofemoral joints at 30 degrees and 15 degrees of flexion. SB ACL reconstruction also had significantly higher mean pressures at 15 degrees of flexion on the medial tibiofemoral joint and at 0 degrees and 15 degrees of flexion on the lateral tibiofemoral joint, as well as significantly higher maximum pressures at 15 degrees of flexion on the lateral tibiofemoral joint. SB ACL reconstruction resulted in a significantly smaller tibiofemoral contact area and higher pressures. DB ACL more closely restores the normal contact area and pressure mainly at low flexion angles. Our findings suggest that the changes in the contact area and pressures after SB ACL reconstruction may be one of the causes of osteoarthritis on long-term follow-up. DB ACL reconstruction may reduce the incidence of osteoarthritis by closely restoring contact area and pressure.

Knee extension torque variability after exercise in ACL reconstructed knees.

PubMed

Goetschius, John; Kuenze, Christopher M; Hart, Joseph M

2015-08-01

The purpose of this study was to compare knee extension torque variability in patients with ACL reconstructed knees before and after exercise. Thirty two patients with an ACL reconstructed knee (ACL-R group) and 32 healthy controls (control group) completed measures of maximal isometric knee extension torque (90° flexion) at baseline and following a 30-min exercise protocol (post-exercise). Exercise included 30-min of repeated cycles of inclined treadmill walking and hopping tasks. Dependent variables were the coefficient of variation (CV) and raw-change in CV (ΔCV): CV = (torque standard deviation/torque mean x 100), ΔCV = (post-exercise - baseline). There was a group-by-time interaction (p = 0.03) on CV. The ACL-R group demonstrated greater CV than the control group at baseline (ACL-R = 1.07 ± 0.55, control = 0.79 ± 0.42, p = 0.03) and post-exercise (ACL-R = 1.60 ± 0.91, control = 0.94 ± 0.41, p = 0.001). ΔCV was greater (p = 0.03) in the ACL-R group (0.52 ± 0.82) than control group (0.15 ± 0.46). CV significantly increased from baseline to post-exercise (p = 0.001) in the ACL-R group, while the control group did not (p = 0.06). The ACL-R group demonstrated greater knee extension torque variability than the control group. Exercise increased torque variability more in the ACL-R group than control group. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Increased Platelet Concentration does not Improve Functional Graft Healing in Bio-Enhanced ACL Reconstruction

PubMed Central

Fleming, Braden C.; Proffen, Benedikt L.; Vavken, Patrick; Shalvoy, Matthew R.; Machan, Jason T.; Murray, Martha M.

2014-01-01

Purpose The use of an extra-cellular matrix scaffold (ECM) combined with platelets to enhance healing of an ACL graft (“bio-enhanced ACL reconstruction”) has shown promise in animal models. However, the effects of platelet concentration on graft healing remains unknown. The objectives of this study were to determine if increasing the platelet concentration in the ECM scaffold would; 1) improve the graft biomechanical properties, and 2) decrease cartilage damage after surgery. Methods Fifty-five adolescent minipigs were randomized to 5 treatment groups; untreated ACL transection (n=10), conventional ACL reconstruction (n=15), and bio-enhanced ACL reconstruction using 1X (n=10), 3X (n=10) or 5X (n=10) platelet-rich plasma. The graft biomechanical properties, anteroposterior (AP) knee laxity, graft histology and macroscopic cartilage integrity were measured at 15 weeks. Results The mean linear stiffness of the bio-enhanced ACL reconstruction procedure using the 1X preparation was significantly greater than traditional reconstruction while the 3X and 5X preparations were not. The failure loads of all the ACL reconstructed groups were equivalent but significantly greater than untreated ACL transection. There were no significant differences in the ligament maturity index or AP laxity between reconstructed knees. Macroscopic cartilage damage was relatively minor, though significantly less when the ECM-platelet composite was used. Conclusions Only the 1X platelet concentration improved healing over traditional ACL reconstruction. Increasing the platelet concentration from 1X to 5X in the ECM scaffold did not further improve the graft mechanical properties. The use of an ECM-platelet composite decreased the amount of cartilage damage seen after ACL surgery. PMID:24633008

Biologic agents for anterior cruciate ligament healing: A systematic review

PubMed Central

Di Matteo, Berardo; Loibl, Markus; Andriolo, Luca; Filardo, Giuseppe; Zellner, Johannes; Koch, Matthias; Angele, Peter

2016-01-01

AIM To systematically review the currently available literature concerning the application of biologic agents such as platelet-rich plasma (PRP) and stem cells to promote anterior cruciate ligament (ACL) healing. METHODS A systematic review of the literature was performed on the use of biologic agents (i.e., PRP or stem cells) to favor ACL healing during reconstruction or repair. The following inclusion criteria for relevant articles were used: Clinical reports of any level of evidence, written in English language, on the use of PRP or stem cells during ACL reconstruction/repair. Exclusion criteria were articles written in other languages, reviews, or studies analyzing other applications of PRP/stem cells in knee surgery not related to promoting ACL healing. RESULTS The database search identified 394 records that were screened. A total of 23 studies were included in the final analysis: In one paper stem cells were applied for ACL healing, in one paper there was a concomitant application of PRP and stem cells, whereas in the remaining 21 papers PRP was used. Based on the ACL injury pattern, two papers investigated biologic agents in ACL partial tears whereas 21 papers in ACL reconstruction. Looking at the quality of the available literature, 17 out of 21 studies dealing with ACL reconstruction were randomized controlled trials. Both studies on ACL repair were case series. CONCLUSION There is a paucity of clinical trials investigating the role of stem cells in promoting ACL healing both in case of partial and complete tears. The role of PRP is still controversial and the only advantage emerging from the literature is related to a better graft maturation over time, without documenting beneficial effects in terms of clinical outcome, bone-graft integration and prevention of bony tunnel enlargement. PMID:27672573

Increased platelet concentration does not improve functional graft healing in bio-enhanced ACL reconstruction.

PubMed

Fleming, Braden C; Proffen, Benedikt L; Vavken, Patrick; Shalvoy, Matthew R; Machan, Jason T; Murray, Martha M

2015-04-01

The use of an extracellular matrix scaffold (ECM) combined with platelets to enhance healing of an anterior cruciate ligament (ACL) graft ("bio-enhanced ACL reconstruction") has shown promise in animal models. However, the effects of platelet concentration on graft healing remain unknown. The objectives of this study were to determine whether increasing the platelet concentration in the ECM scaffold would (1) improve the graft biomechanical properties and (2) decrease cartilage damage after surgery. Fifty-five adolescent minipigs were randomized to five treatment groups: untreated ACL transection (n = 10), conventional ACL reconstruction (n = 15) and bio-enhanced ACL reconstruction using 1× (n = 10), 3× (n = 10) or 5× (n = 10) platelet-rich plasma. The graft biomechanical properties, anteroposterior (AP) knee laxity, graft histology and macroscopic cartilage integrity were measured at 15 weeks. The mean linear stiffness of the bio-enhanced ACL reconstruction procedure using the 1× preparation was significantly greater than traditional reconstruction, while the 3× and 5× preparations were not. The failure loads of all the ACL-reconstructed groups were equivalent but significantly greater than untreated ACL transection. There were no significant differences in the Ligament Maturity Index or AP laxity between reconstructed knees. Macroscopic cartilage damage was relatively minor, though significantly less when the ECM-platelet composite was used. Only the 1× platelet concentration improved healing over traditional ACL reconstruction. Increasing the platelet concentration from 1× to 5× in the ECM scaffold did not further improve the graft mechanical properties. The use of an ECM-platelet composite decreased the amount of cartilage damage seen after ACL surgery.

Anterior cruciate ligament injury/reinjury in alpine ski racing: a narrative review

PubMed Central

Jordan, Matthew J; Aagaard, Per; Herzog, Walter

2017-01-01

The purpose of the present review was to: 1) provide an overview of the current understanding on the epidemiology, etiology, risk factors, and prevention methods for anterior cruciate ligament (ACL) injury in alpine ski racing; and 2) provide an overview of what is known pertaining to ACL reinjury and return to sport after ACL injury in alpine ski racing. Given that most of the scientific studies on ACL injuries in alpine ski racing have been descriptive, and that very few studies contributed higher level scientific evidence, a nonsystematic narrative review was employed. Three scholarly databases were searched for articles on ACL injury or knee injury in alpine ski racing. Studies were classified according to their relevance in relation to epidemiology, etiology, risk factors, and return to sport/reinjury prevention. Alpine ski racers (skiers) were found to be at high risk for knee injuries, and ACL tears were the most frequent diagnosis. Three primary ACL injury mechanism were identified that involved tibial internal rotation and anteriorly directed shear forces from ski equipment and the environment. While trunk muscle strength imbalance and genetics were found to be predictive of ACL injuries in development-level skiers, there was limited scientific data on ACL injury risk factors among elite skiers. Based on expert opinion, research on injury risk factors should focus on equipment design, course settings/speed, and athlete factors (eg, fitness). While skiers seem to make a successful recovery following ACL injury, there may be persistent neuromuscular deficits. Future research efforts should be directed toward prospective studies on ACL injury/reinjury prevention in both male and female skiers and toward the effects of knee injury on long-term health outcomes, such as the early development of osteoarthritis. International collaborations may be necessary to generate sufficient statistical power for ACL injury/reinjury prevention research in alpine ski racing. PMID:28435336

MRI signal intensity of anterior cruciate ligament graft after transtibial versus anteromedial portal technique (TRANSIG): design of a randomized controlled clinical trial.

PubMed

Ruiter, Simeon J S; Brouwer, Reinoud W; Meys, Tim W G M; Slump, Cornelis H; van Raay, Jos J A M

2016-08-10

There are two primary surgical techniques to reconstruct the anterior cruciate ligament (ACL), transtibial (TT) technique and anteromedial portal (AMP) technique. Currently, there is no consensus which surgical technique elicits the best clinical and functional outcomes. MRI-derived measures of the signal intensity (SI) of the ACL graft have been described as an independent predictor of graft properties. The purpose of this study is to compare the MRI derived SI measurements of the ACL graft one year after ACL reconstruction, in order to compare the outcomes of both the AMP and TT ACL reconstruction technique. Thirty-six patients will be included in a randomized controlled trial. Patients who are admitted for primary unilateral ACL reconstruction will be included in the study. Exclusion criteria are a history of previous surgery on the ipsilateral knee, re-rupture of the ipsilateral ACL graft, associated ligamentous injuries or meniscal tear of the ipsilateral knee, unhealthy contralateral knee, contra-indications for MRI and a preference for one of the two surgical techniques and/or orthopaedic surgeon. Primary outcome is MRI Signal intensity ratio (SIR) of the ACL graft. Secondary outcome measures are the International Knee Documentation Committee (IKDC) Knee Examination Form,the Knee injury and Osteoarthritis Outcome Scores (KOOS) and the Anterior Cruciate Ligament OsteoArthritis Score (ACLOAS). Differences between MRI SIR assessment with the current MRI protocol (proton density weighted imaging protocol) and the additional T2*-weighted gradient-echo protocol will be assessed. There is no consensus regarding the TT or AMP ACL reconstruction technique. SI measurements with MRI have been used in other clinical studies for evaluation of the ACL graft and maturation after ACL reconstruction compared to clinical and functional outcomes. This randomized controlled trial has been designed to compare the TT technique with the AMP technique with the use of MRI SI of the graft after ACL reconstruction. Netherlands Trial Registry NTR5410 (registered on August 24, 2015).

Differences in kinematics of single leg squatting between anterior cruciate ligament-injured patients and healthy controls.

PubMed

Yamazaki, J; Muneta, T; Ju, Y J; Sekiya, I

2010-01-01

Seventy to eighty percent of all anterior cruciate ligament (ACL) injuries are due to non-contact injury mechanisms. It has been reported that the majority of injuries due to single leg landing come from valgus positioning of the lower leg. Preventing valgus positioning during single leg landing is expected to help reduce the number of ACL injuries. We found that many ACL-deficient patients cannot perform stable single leg squatting. Therefore, we performed 3D motion analysis of the single-legged half squat for ACL-injured patients to evaluate its significance as a risk factor for ACL injuries. We evaluated the relative angles between the body, thigh, and lower leg using an electromagnetic device during single leg half squatting performed by 63 ACL-injured patients (32 males, 31 females) the day before ACL reconstruction and by 26 healthy control subjects with no knee problems. The uninjured leg of ACL-injured male subjects demonstrated significantly less external knee rotation than that of the dominant leg of the male control. The uninjured leg of ACL-injured female subjects demonstrated significantly more external hip rotation and knee flexion and less hip flexion than that of the dominant leg of the female control. Comparing injured and uninjured legs, the injured leg of male subjects demonstrated significantly less external knee and hip rotation, less knee flexion, and more knee varus than that of the uninjured leg of male subjects. The injured leg of female subjects demonstrated more knee varus than that of the uninjured leg of female subjects. Regarding gender differences, female subjects demonstrated significantly more external hip rotation and knee valgus than male subjects did in both the injured and uninjured legs (P < 0.05). The current kinematic study exhibited biomechanical characteristics of female ACL-injured subjects compared with that of control groups. Kinematic correction during single leg half squat would reduce ACL reinjury in female ACL-injured subjects.

Restricted Hip Rotation Is Correlated With an Increased Risk for Anterior Cruciate Ligament Injury.

PubMed

VandenBerg, Curtis; Crawford, Eileen A; Sibilsky Enselman, Elizabeth; Robbins, Christopher B; Wojtys, Edward M; Bedi, Asheesh

2017-02-01

The primary purpose was to compare ipsilateral hip internal rotation (IR) in male and female athletes with or without an anterior cruciate ligament (ACL) tear. A secondary purpose was to compare radiographic markers of femoroacetabular impingement (FAI) in patients with or without an ACL tear. In this prospective case-control study, based on a power analysis, a convenience sample of 25 ACL-injured and 25 control patients matched by age and gender were examined over 14 months. The ACL injury group included preoperative patients 12-40 years old with an ACL rupture within the previous 3 months with no prior lower extremity injuries, ligamentous laxity, or arthralgias. Controls included patients presenting with an upper extremity complaint with no history of knee injury. In the outpatient clinic, hip axial rotation range of motion was measured with a goniometer on physical examination and hip radiographs were evaluated for morphologic variations consistent with FAI. Univariate analysis of variance was used to examine differences between groups. Each group had 13 males and 12 females, average ages of 22.8 ± 7.2 years (ACL group) versus 24.5 ± 7.9 years (controls; P = .439). The average sum of hip rotation (internal plus external) in patients with an ACL tear was 60.3 ± 12.4° compared with 72.6 ± 17.2° in controls (P = .006). ACL-injured patients had decreased hip IR compared with controls, with respective mean measurements of 23.4 ± 7.6° versus 30.4 ± 10.4° (P = .009). For every 10° increase in hip IR, the odds of having an ACL tear decreased by a factor of 0.419 (P = .015). Risk of ACL injury is associated with restricted hip IR, and as hip IR increases, the odds of having an ACL tear decreases. In addition, ACL injury is associated with FAI in a generalized population of male and female athletes, although causality cannot be determined and most ACL-injured patients do not exhibit hip complaints. Level II, prognostic, prospective cohort study. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Addition of autologous mesenchymal stem cells to whole blood for bioenhanced ACL repair has no benefit in the porcine model.

PubMed

Proffen, Benedikt L; Vavken, Patrick; Haslauer, Carla M; Fleming, Braden C; Harris, Chad E; Machan, Jason T; Murray, Martha M

2015-02-01

Coculture of mesenchymal stem cells (MSCs) from the retropatellar fat pad and peripheral blood has been shown to stimulate anterior cruciate ligament (ACL) fibroblast proliferation and collagen production in vitro. Current techniques of bioenhanced ACL repair in animal studies involve adding a biologic scaffold, in this case an extracellular matrix-based scaffold saturated with autologous whole blood, to a simple suture repair of the ligament. Whether the enrichment of whole blood with MSCs would further improve the in vivo results of bioenhanced ACL repair was investigated. The addition of MSCs derived from adipose tissue or peripheral blood to the blood-extracellular matrix composite, which is used in bioenhanced ACL repair to stimulate healing, would improve the biomechanical properties of a bioenhanced ACL repair after 15 weeks of healing. Controlled laboratory study. Twenty-four adolescent Yucatan mini-pigs underwent ACL transection followed by (1) bioenhanced ACL repair, (2) bioenhanced ACL repair with the addition of autologous adipose-derived MSCs, and (3) bioenhanced ACL repair with the addition of autologous peripheral blood derived MSCs. After 15 weeks of healing, the structural properties of the ACL (yield load, failure load, and linear stiffness) were measured. Cell and vascular density were measured in the repaired ACL via histology, and its tissue structure was qualitatively evaluated using the advanced Ligament Maturity Index. After 15 weeks of healing, there were no significant improvements in the biomechanical or histological properties with the addition of adipose-derived MSCs. The only significant change with the addition of peripheral blood MSCs was an increase in knee anteroposterior laxity when measured at 30° of flexion. These findings suggest that the addition of adipose or peripheral blood MSCs to whole blood before saturation of an extracellular matrix carrier with the blood did not improve the functional results of bioenhanced ACL repair after 15 weeks of healing in the pig model. Whole blood represents a practical biologic additive to ligament repair, and any other additive (including stem cells) should be demonstrated to be superior to this baseline before clinical use is considered. © 2014 The Author(s).

Translation and cross-cultural adaptation of the anterior cruciate ligament-return to sport after injury (ACL-RSI) scale into Turkish.

PubMed

Harput, Gulcan; Tok, Damla; Ulusoy, Burak; Eraslan, Leyla; Yildiz, Taha Ibrahim; Turgut, Elif; Demirci, Serdar; Duzgun, Irem; Tunay, Volga Bayrakci; Baltaci, Gul; Ergun, Nevin

2017-01-01

To translate and culturally adapt the anterior cruciate ligament-return to sport after injury (ACL-RSI) scale into Turkish (ACL-RSI-Tr) and examine and evaluate the psychometric properties of the Turkish version in individuals who have undergone anterior cruciate ligament (ACL) reconstruction. The ACL-RSI was forward- and back-translated, culturally adapted and validated on ninety-three Turkish individuals who had undergone ACL reconstruction (5 females, 88 males; age 28.7 ± 8.6 years; body mass 80.1 ± 13.9 kg; height 178.8 ± 6.9 cm; body mass index 25.0 ± 3.7 kg/m 2 ). All patients completed the translated ACL-RSI, Tampa Scale of Kinesiophobia (TSK), Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentary Committee (IKDC) and Lysholm questionnaires. We then analysed the internal consistency, reliability and validity of the newly formed ACL-RSI-Tr scale. The ACL-RSI-Tr showed good internal consistency (Cronbach's alpha 0.86) and test-retest reliability (ICC 0.92) and was significantly correlated with the KOOS 'quality of life' (r = 0.58, p < 0.002), 'symptoms and stiffness' (r = 0.35, p = 0.001), 'pain' (r = 0.49, p < 0.001), 'sports' (r = 0.44, p < 0.001) and 'daily life' (r = 0.42, p < 0.001) subscales. The ACL-RSI-Tr also correlated significantly with the TSK (r = - 0.45, p < 0.001), Lysholm (r = 0.45, p < 0.001) and IKDC (r = 0.44, p < 0.001) scores. The Turkish version of the ACL-RSI scale was valid, discriminant, consistent and reliable in patients who had undergone ACL reconstruction. This score could be useful to evaluate the effect of psychological factors on return to sport following ACL surgery. Diagnostic study, Level I.

Strain Response of the Anterior Cruciate Ligament to Uniplanar and Multiplanar Loads During Simulated Landings: Implications for Injury Mechanism.

PubMed

Kiapour, Ata M; Demetropoulos, Constantine K; Kiapour, Ali; Quatman, Carmen E; Wordeman, Samuel C; Goel, Vijay K; Hewett, Timothy E

2016-08-01

Despite basic characterization of the loading factors that strain the anterior cruciate ligament (ACL), the interrelationship(s) and additive nature of these loads that occur during noncontact ACL injuries remain incompletely characterized. In the presence of an impulsive axial compression, simulating vertical ground-reaction force during landing (1) both knee abduction and internal tibial rotation moments would result in increased peak ACL strain, and (2) a combined multiplanar loading condition, including both knee abduction and internal tibial rotation moments, would increase the peak ACL strain to levels greater than those under uniplanar loading modes alone. Controlled laboratory study. A cadaveric model of landing was used to simulate dynamic landings during a jump in 17 cadaveric lower extremities (age, 45 ± 7 years; 9 female and 8 male). Peak ACL strain was measured in situ and characterized under impulsive axial compression and simulated muscle forces (baseline) followed by addition of anterior tibial shear, knee abduction, and internal tibial rotation loads in both uni- and multiplanar modes, simulating a broad range of landing conditions. The associations between knee rotational kinematics and peak ACL strain levels were further investigated to determine the potential noncontact injury mechanism. Externally applied loads, under both uni- and multiplanar conditions, resulted in consistent increases in peak ACL strain compared with the baseline during simulated landings (by up to 3.5-fold; P ≤ .032). Combined multiplanar loading resulted in the greatest increases in peak ACL strain (P < .001). Degrees of knee abduction rotation (R(2) = 0.45; β = 0.42) and internal tibial rotation (R(2) = 0.32; β = 0.23) were both significantly correlated with peak ACL strain (P < .001). However, changes in knee abduction rotation had a significantly greater effect size on peak ACL strain levels than did internal tibial rotation (by ~2-fold; P < .001). In the presence of impulsive axial compression, the combination of anterior tibial shear force, knee abduction, and internal tibial rotation moments significantly increases ACL strain, which could result in ACL failure. These findings support multiplanar knee valgus collapse as one the primary mechanisms of noncontact ACL injuries during landing. Intervention programs that address multiple planes of loading may decrease the risk of ACL injury and the devastating consequences of posttraumatic knee osteoarthritis. © 2016 The Author(s).

Posteromedial Meniscocapsular Lesions Increase Tibiofemoral Joint Laxity With Anterior Cruciate Ligament Deficiency, and Their Repair Reduces Laxity.

PubMed

Stephen, Joanna M; Halewood, Camilla; Kittl, Christoph; Bollen, Steve R; Williams, Andy; Amis, Andrew A

2016-02-01

Injury to the posteromedial meniscocapsular junction has been identified after anterior cruciate ligament (ACL) rupture; however, there is a lack of objective evidence investigating how this affects knee kinematics or whether increased laxity can be restored by repair. Such injury is often overlooked at surgery, with possible compromise to results. (1) Sectioning the posteromedial meniscocapsular junction in an ACL-deficient knee will result in increased anterior tibial translation and rotation. (2) Isolated ACL reconstruction in the presence of a posteromedial meniscocapsular junction lesion will not restore intact knee laxity. (3) Repair of the posteromedial capsule at the time of ACL reconstruction will reduce tibial translation and rotation to normal. (4) These changes will be clinically detectable. Controlled laboratory study. Nine cadaveric knees were mounted in a test rig where knee kinematics were recorded from 0° to 100° of flexion by use of an optical tracking system. Measurements were recorded with the following loads: 90-N anterior-posterior tibial forces, 5-N·m internal-external tibial rotation torques, and combined 90-N anterior force and 5-N·m external rotation torque. Manual Rolimeter readings of anterior translation were taken at 30° and 90°. The knees were tested in the following conditions: intact, ACL deficient, ACL deficient and posteromedial meniscocapsular junction sectioned, ACL deficient and posteromedial meniscocapsular junction repaired, ACL patellar tendon reconstruction with posteromedial meniscocapsular junction repair, and ACL reconstructed and capsular lesion re-created. Statistical analysis used repeated-measures analysis of variance and post hoc paired t tests with Bonferroni correction. Tibial anterior translation and external rotation were both significantly increased compared with the ACL-deficient knee after posterior meniscocapsular sectioning (P < .05). These parameters were restored after ACL reconstruction and meniscocapsular lesion repair (P > .05). Anterior and external rotational laxities were significantly increased after sectioning of the posteromedial meniscocapsular junction in an ACL-deficient knee. These were not restored after ACL reconstruction alone but were restored with ACL reconstruction combined with posterior meniscocapsular repair. Tibial anterior translation changes were clinically detectable by use of the Rolimeter. This study suggests that unrepaired posteromedial meniscocapsular lesions will allow abnormal meniscal and tibiofemoral laxity to persist postoperatively, predisposing the knee to meniscal and articular damage. © 2015 The Author(s).

Reprint of "Stable hydrogen and carbon isotopic compositions of long-chain (C21-C33) n-alkanes and n-alkenes in insects"

NASA Astrophysics Data System (ADS)

Chikaraishi, Yoshito; Kaneko, Masanori; Ohkouchi, Naohiko

2013-06-01

We report the molecular and stable isotopic (δD and δ13C) compositions of long-chain n-alkanes in common insects including the cabbage butterfly, swallowtail, wasp, hornet, grasshopper, and ladybug. Insect n-alkanes are potential candidates of the contamination of soil and sedimentary n-alkanes that are believed to be derived from vascular plant waxes. Long-chain n-alkanes (range C21-33; maximum C23-C29) are found to be abundant in the insects (31-781 μg/dry g), with a carbon preference index (CPI) of 5.1-31.5 and an average chain length (ACL) of 24.9-29.3. The isotopic compositions (mean ± 1σ, n = 33) of the n-alkanes are -195 ± 16‰ for hydrogen and -30.6 ± 2.4‰ for carbon. The insect n-alkanes are depleted in D by approximately 30-40‰ compared with wax n-alkanes from C3 (-155 ± 25‰) and C4 vascular plants (-167 ± 13‰), whereas their δ13C values fall between those of C3 (-36.2 ± 2.4‰) and C4 plants (-20.3 ± 2.4‰). Thus, the contribution of insect-derived n-alkanes to soil and sediment could potentially shift δD records of n-alkanes toward more negative values and potentially muddle the assumed original C3/C4 balance in the δ13C records of the soil and sedimentary n-alkanes. n-Alkenes are also found in three insects (swallowtail, wasp and hornet). They are more depleted in D relative to the same carbon numbered n-alkanes (δDn-alkene - δDn-alkane = -17 ± 16‰), but the δ13C values are almost identical to those of the n-alkanes (δ13Cn-alkene - δ13Cn-alkane = 0.1 ± 0.2‰). These results suggest that these n-alkenes are desaturated products of the same carbon numbered n-alkanes.

Stable hydrogen and carbon isotopic compositions of long-chain (C21-C33) n-alkanes and n-alkenes in insects

NASA Astrophysics Data System (ADS)

Chikaraishi, Yoshito; Kaneko, Masanori; Ohkouchi, Naohiko

2012-10-01

We report the molecular and stable isotopic (δD and δ13C) compositions of long-chain n-alkanes in common insects including the cabbage butterfly, swallowtail, wasp, hornet, grasshopper, and ladybug. Insect n-alkanes are potential candidates of the contamination of soil and sedimentary n-alkanes that are believed to be derived from vascular plant waxes. Long-chain n-alkanes (range C21-33; maximum C23-C29) are found to be abundant in the insects (31-781 μg/dry g), with a carbon preference index (CPI) of 5.1-31.5 and an average chain length (ACL) of 24.9-29.3. The isotopic compositions (mean ± 1σ, n = 33) of the n-alkanes are -195 ± 16‰ for hydrogen and -30.6 ± 2.4‰ for carbon. The insect n-alkanes are depleted in D by approximately 30-40‰ compared with wax n-alkanes from C3 (-155 ± 25‰) and C4 vascular plants (-167 ± 13‰), whereas their δ13C values fall between those of C3 (-36.2 ± 2.4‰) and C4 plants (-20.3 ± 2.4‰). Thus, the contribution of insect-derived n-alkanes to soil and sediment could potentially shift δD records of n-alkanes toward more negative values and potentially muddle the assumed original C3/C4 balance in the δ13C records of the soil and sedimentary n-alkanes. n-Alkenes are also found in three insects (swallowtail, wasp and hornet). They are more depleted in D relative to the same carbon numbered n-alkanes (δDn-alkene - δDn-alkane = -17 ± 16‰), but the δ13C values are almost identical to those of the n-alkanes (δ13Cn-alkene - δ13Cn-alkane = 0.1 ± 0.2‰). These results suggest that these n-alkenes are desaturated products of the same carbon numbered n-alkanes.

Diagnostic Value of Knee Arthrometry in the Prediction of Anterior Cruciate Ligament Strain During Landing

PubMed Central

Kiapour, Ata M.; Wordeman, Samuel C.; Paterno, Mark V.; Quatman, Carmen E.; Levine, Jason W.; Goel, Vijay K.; Demetropoulos, Constantine K.; Hewett, Timothy E.

2014-01-01

Background Previous studies have indicated that higher knee joint laxity may be indicative of an increased risk of anterior cruciate ligament (ACL) injuries. Despite the frequent clinical use of knee arthrometry in the evaluation of knee laxity, little data exist to correlate instrumented laxity measures and ACL strain during dynamic high-risk activities. Purpose/Hypotheses The purpose of this study was to evaluate the relationships between ACL strain and anterior knee laxity measurements using arthrometry during both a drawer test and simulated bipedal landing (as an identified high-risk injurious task). We hypothesized that a high correlation exists between dynamic ACL strain and passive arthrometry displacement. The secondary hypothesis was that anterior knee laxity quantified by knee arthrometry is a valid predictor of injury risk such that specimens with greater anterior knee laxity would demonstrate increased levels of peak ACL strain during landing. Study Design Controlled laboratory study. Methods Twenty cadaveric lower limbs (mean age, 46 ± 6 years; 10 female and 10 male) were tested using a CompuKT knee arthrometer to measure knee joint laxity. Each specimen was tested under 4 continuous cycles of anterior-posterior shear force (±134 N) applied to the tibial tubercle. To quantify ACL strain, a differential variable reluctance transducer (DVRT) was arthroscopically placed on the ACL (anteromedial bundle), and specimens were retested. Subsequently, bipedal landing from 30 cm was simulated in a subset of 14 specimens (mean age, 45 ± 6 years; 6 female and 8 male) using a novel custom-designed drop stand. Changes in joint laxity and ACL strain under applied anterior shear force were statistically analyzed using paired sample t tests and analysis of variance. Multiple linear regression analyses were conducted to determine the relationship between anterior shear force, anterior tibial translation, and ACL strain. Results During simulated drawer tests, 134 N of applied anterior shear load produced a mean peak anterior tibial translation of 3.1 ± 1.1 mm and a mean peak ACL strain of 4.9% ± 4.3%. Anterior shear load was a significant determinant of anterior tibial translation (P <.0005) and peak ACL strain (P = .04). A significant correlation (r = 0.52, P <.0005) was observed between anterior tibial translation and ACL strain. Cadaveric simulations of landing produced a mean axial impact load of 4070 ± 732 N. Simulated landing significantly increased the mean peak anterior tibial translation to 10.4 ± 3.5 mm and the mean peak ACL strain to 6.8% ± 2.8% (P <.0005) compared with the prelanding condition. Significant correlations were observed between peak ACL strain during simulated landing and anterior tibial translation quantified by knee arthrometry. Conclusion Our first hypothesis is supported by a significant correlation between arthrometry displacement collected during laxity tests and concurrent ACL strain calculated from DVRT measurements. Experimental findings also support our second hypothesis that instrumented measures of anterior knee laxity predict peak ACL strain during landing, while specimens with greater knee laxity demonstrated higher levels of peak ACL strain during landing. Clinical Relevance The current findings highlight the importance of instrumented anterior knee laxity assessments as a potential indicator of the risk of ACL injuries in addition to its clinical utility in the evaluation of ACL integrity. PMID:24275863

Cellular and Morphological Alterations in the Vastus Lateralis Muscle as the Result of ACL Injury and Reconstruction.

PubMed

Noehren, Brian; Andersen, Anders; Hardy, Peter; Johnson, Darren L; Ireland, Mary Lloyd; Thompson, Katherine L; Damon, Bruce

2016-09-21

Individuals who have had an anterior cruciate ligament (ACL) tear and reconstruction continue to experience substantial knee extensor strength loss despite months of physical therapy. Identification of the alterations in muscle morphology and cellular composition are needed to understand potential mechanisms of muscle strength loss, initially as the result of the injury and subsequently from surgery and rehabilitation. We performed diffusion tensor imaging-magnetic resonance imaging and analyzed muscle biopsies from the vastus lateralis of both the affected and unaffected limbs before surgery and again from the reconstructed limb following the completion of rehabilitation. Immunohistochemistry was done to determine fiber type and size, Pax-7-positive (satellite) cells, and extracellular matrix (via wheat germ agglutinin straining). Using the diffusion tensor imaging data, the fiber tract length, pennation angle, and muscle volume were determined, yielding the physiological cross-sectional area (PCSA). Paired t tests were used to compare the effects of the injury between injured and uninjured limbs and the effects of surgery and rehabilitation within the injured limb. We found significant reductions before surgery in type-IIA muscle cross-sectional area (CSA; p = 0.03), extracellular matrix (p < 0.01), satellite cells per fiber (p < 0.01), pennation angle (p = 0.03), muscle volume (p = 0.02), and PCSA (p = 0.03) in the injured limb compared with the uninjured limb. Following surgery, these alterations in the injured limb persisted and the frequency of the IIA fiber type decreased significantly (p < 0.01) and that of the IIA/X hybrid fiber type increased significantly (p < 0.01). Significant and prolonged differences in muscle quality and morphology occurred after ACL injury and persisted despite reconstruction and extensive physical therapy. These results suggest the need to develop more effective early interventions following an ACL tear to prevent deleterious alterations within the quadriceps. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

The Anterolateral Ligament: An Anatomic Study on Sex-Based Differences

PubMed Central

Daggett, Matt; Helito, Camilo; Cullen, Matthew; Ockuly, Andrew; Busch, Kyle; Granite, Joseph; Wright, Barth; Sonnery-Cottet, Bertrand

2017-01-01

Background: The anterolateral ligament (ALL) has been shown to have an important role in rotatory stability of the knee. While there is abundant research on sex-based differences related to anterior cruciate ligament (ACL) rupture, there is a paucity of literature related to such differences in the ALL. Purpose: To define any sex-based differences in the ALL with regard to length, width, and thickness. Study Design: Descriptive laboratory study. Methods: The ALL was initially evaluated in 165 unpaired knees (92 males and 65 females after exclusion criteria applied). The length, width, and thickness of the ALL were measured using a digital caliper. Width and thickness were measured at the joint line just superior to the lateral meniscus. The Mann-Whitney test and Student t tests were used to compare measurements between males and females. The Pearson product-moment correlation was subsequently used to determine the correlation between height and weight and the statistically different morphometric variables. Results: The mean (±SD) thickness of the ALL in males was 2.09 ± 0.56 mm, almost twice as thick as females (1.05 ± 0.49 mm; P = 8.8 × 10−20). There was also a statistically significant difference in ALL length (P = 3.8 × 10−7), but no significant difference was found for width. A moderate association was found between donor height and ALL thickness and length. Conclusion: The anatomic measurements of the ALL demonstrate a difference between sexes, and the ALL is significantly thicker in males than females. Clinical Relevance: As the role of the ALL in rotatory stability of the knee becomes better understood, the difference in the thickness of the ALL we have found between the sexes may be another factor why female athletes have an increased incidence of ACL rupture compared with males. This may also help explain why females have issues with knee laxity and rotatory instability. PMID:28321423

DNA compaction by poly (amido amine) dendrimers of ammonia cored and ethylene diamine cored

NASA Astrophysics Data System (ADS)

Qamhieh, K.; Al-Shawwa, J.

2017-06-01

The complexes build-up of DNA and soft particles poly amidoamine (PAMAM) dendrimers of ammonia cored of generations (G1-G6) and ethylenediamine cored of generations (G1-G10) have been studied, using a new theoretical model developed by Qamhieh and coworkers. The model describes the interaction between linear polyelectrolyte (LPE) chain and ion-penetrable spheres. Many factors affecting LPE/dendrimer complex have been investigated such as dendrimer generation, the Bjerrum length, salt concentration, and rigidity of the LPE chain represented by the persistence length. It is found that the wrapping chain length around dendrimer increases by increasing dendrimer`s generation, Bjerrum length, and salt concentration, while decreases by increasing the persistence length of the LPE chain. Also we can conclude that the wrapping length of LPE chain around ethylenediamine cored dendrimers is larger than its length around ammonia cored dendrimers.

50 CFR 648.140 - Black sea bass Annual Catch Limit (ACL).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Black sea bass Annual Catch Limit (ACL... Management Measures for the Black Sea Bass Fishery § 648.140 Black sea bass Annual Catch Limit (ACL). (a) The Black Sea Bass Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial and...

50 CFR 648.140 - Black sea bass Annual Catch Limit (ACL).

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Black sea bass Annual Catch Limit (ACL... Management Measures for the Black Sea Bass Fishery § 648.140 Black sea bass Annual Catch Limit (ACL). (a) The Black Sea Bass Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial and...

50 CFR 648.140 - Black sea bass Annual Catch Limit (ACL).

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Black sea bass Annual Catch Limit (ACL... Management Measures for the Black Sea Bass Fishery § 648.140 Black sea bass Annual Catch Limit (ACL). (a) The Black Sea Bass Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial and...

Reducing the Risk of ACL Injury in Female Athletes

ERIC Educational Resources Information Center

McDaniel, Larry W.; Rasche, Adrienna; Gaudet, Laura; Jackson, Allen

2010-01-01

The Anterior Cruciate Ligament (ACL) is located behind the kneecap (patella) and connects the thigh bone (femur) to the shin bone (tibia). Stabilizing the knee joint is the primary responsibility of the ACL. Injuries that affect the ACL are three to five times more common in females than males. This is a result of anatomical, biomechanical,…

Preventing ACL Injuries in Females: What Physical Educators Need to Know

ERIC Educational Resources Information Center

Toscano, Lisa; Carroll, Brianne

2015-01-01

Anterior cruciate ligament (ACL) injuries happen at a frequent rate, especially in girls and women. While there are many factors that contribute to ACL tears, teaching proper landing techniques and strengthening certain muscles can decrease the incidence of ACL tears, especially in women. This article reviews some of the high-risk factors that…

78 FR 26782 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; State...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-08

...: Administration for Community Living, HHS. ACTION: Notice. SUMMARY: The Administration for Community Living (ACL....eop.gov , Attn: OMB Desk Officer for ACL. FOR FURTHER INFORMATION CONTACT: Elena Fazio at 202-357-3583 or email: [email protected]acl.hhs.gov . SUPPLEMENTARY INFORMATION: In compliance with 44 U.S.C. 3507, ACL...

50 CFR 648.230 - Spiny dogfish Annual Catch Limits (ACLs).

Code of Federal Regulations, 2014 CFR

2014-10-01

... Spiny Dogfish Monitoring Committee shall recommend to the Joint Spiny Dogfish Committee, an ACL for the...) recommended by the SSC as specified in § 648.20. (1) Periodicity. The spiny dogfish ACL may be established on... shall conduct a detailed review of fishery performance relative to the ACL at least every 5 years. (1...

50 CFR 648.230 - Spiny dogfish Annual Catch Limits (ACLs).

Code of Federal Regulations, 2013 CFR

2013-10-01

... Spiny Dogfish Monitoring Committee shall recommend to the Joint Spiny Dogfish Committee, an ACL for the...) recommended by the SSC as specified in § 648.20. (1) Periodicity. The spiny dogfish ACL may be established on... shall conduct a detailed review of fishery performance relative to the ACL at least every 5 years. (1...

77 FR 66746 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-07

...-ACL (Annual Catch Limit) Harvested for Management Area 1A AGENCY: National Marine Fisheries Service... catch, annual catch limit (ACL), optimum yield, domestic harvest and processing, U.S. at-sea processing, border transfer, and the sub-ACL for each management area. The 2012 Domestic Annual Harvest was set as 91...

50 CFR 648.64 - Yellowtail flounder sub-ACLs and AMs for the scallop fishery.

Code of Federal Regulations, 2012 CFR

2012-10-01

... framework adjustment process specified in § 648.90, the scallop fishery shall be allocated a sub-ACL for the... flounder sub-ACL for the scallop fishery is exceeded, the area defined by the following coordinates shall... the corresponding percent overage of the Georges Bank yellowtail flounder sub-ACL, as follows: (i) For...

78 FR 32995 - Snapper-Grouper Fishery of the South Atlantic; 2013 Recreational Accountability Measure and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-03

... catch limit (ACL) for golden tilefish. Furthermore, information from 2013 recreational landings indicate that landings are projected to reach the recreational ACL on June 3, 2013. To account for the 2012 ACL overage and to prevent an ACL overage in 2013, NMFS closes the recreational sector for golden tilefish on...

50 CFR 648.230 - Catch quotas and other restrictions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the Joint Spiny Dogfish Committee, an ACL for the commercial spiny dogfish fishery, which shall equal....20. (1) Periodicity. The spiny dogfish ACL may be established on an annual basis for up to 5 years at... fishery performance relative to the ACL at least every 5 years. (1) If an ACL is exceeded with a frequency...

77 FR 41704 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; Adjustment of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-16

... catch of GB yellowtail flounder by the scallop fishery and is consistent with a request for the ACL... multispecies, scallop, and other fisheries. The allocation to the scallop fishery, known as the sub-ACL, is..., to maximize scallop catch. The groundfish sub-ACL is determined after deducting the sub-ACL allocated...

50 CFR 648.230 - Spiny dogfish Annual Catch Limits (ACLs).

Code of Federal Regulations, 2012 CFR

2012-10-01

... Spiny Dogfish Monitoring Committee shall recommend to the Joint Spiny Dogfish Committee, an ACL for the...) recommended by the SSC as specified in § 648.20. (1) Periodicity. The spiny dogfish ACL may be established on... shall conduct a detailed review of fishery performance relative to the ACL at least every 5 years. (1...

76 FR 61061 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-03

...-ACL (Annual Catch Limit) Harvested for Management Area 3 AGENCY: National Marine Fisheries Service...-ACL (annual catch limit) for Area 3 becomes available, except when transiting as described in this notice. This action is based on the determination that 95 percent of the herring sub-ACL allocated to...

50 CFR 622.58 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

Code of Federal Regulations, 2014 CFR

2014-10-01

... commercial ACL, then during the following fishing year, if commercial landings reach or are projected to reach the commercial ACL, the AA will file a notification with the Office of the Federal Register to close the commercial sector for the remainder of that fishing year. The commercial ACL for royal red...

50 CFR 622.58 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

Code of Federal Regulations, 2013 CFR

2013-10-01

... commercial ACL, then during the following fishing year, if commercial landings reach or are projected to reach the commercial ACL, the AA will file a notification with the Office of the Federal Register to close the commercial sector for the remainder of that fishing year. The commercial ACL for royal red...

77 FR 61299 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-09

...-ACL (Annual Catch Limit) Harvested for Management Area 3 AGENCY: National Marine Fisheries Service..., annual catch limit (ACL), optimum yield, domestic harvest and processing, U.S. at-sea processing, border transfer, and the sub-ACL for each management area. The 2012 Domestic Annual Harvest was set as 91,200...

76 FR 34903 - Revisions to Framework Adjustment 45 to the Northeast Multispecies Fishery Management Plan and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-15

... Management Plan and Sector Annual Catch Entitlements; Updated Annual Catch Limits for Sectors and the Common... (ACLs) for common pool vessels (common pool sub-ACLs), ACLs for sector vessels (sector sub-ACLs), and... number of participants electing to fish in either sectors or the common pool fishery in FY 2011. DATES...

Tunable evolutions of shock absorption and energy partitioning in magnetic granular chains

NASA Astrophysics Data System (ADS)

Leng, Dingxin; Liu, Guijie; Sun, Lingyu

2018-01-01

In this paper, we investigate the tunable characteristics of shock waves propagating in one-dimensional magnetic granular chains at various chain lengths and magnetic flux densities. According to the Hertz contact theory and Maxwell principle, a discrete element model with coupling elastic and field-induced interaction potentials of adjacent magnetic grains is proposed. We also present hard-sphere approximation analysis to describe the energy partitioning features of magnetic granular chains. The results demonstrate that, for a fixed magnetic field strength, when the chain length is greater than two times of the wave width of the solitary wave, the chain length has little effect on the output energy of the system; for a fixed chain length, the shock absorption and energy partitioning features of magnetic granular chains are remarkably influenced by varying magnetic flux densities. This study implies that the magnetic granular chain is potential to construct adaptive shock absorption components for impulse mitigation.

Prevention of anterior cruciate ligament injury in the female athlete

PubMed Central

Silvers, Holly Jacinda; Mandelbaum, Bert R

2007-01-01

The relationships of gender, age and training to the incidence of anterior cruciate ligament (ACL) injury are pivotal to developing a comprehensive neuromuscular and proprioceptive training programme to decrease ACL injuries in female athletes. A prophylactic neuromuscular and proprioceptive training programme may have direct benefit in decreasing the number of ACL injuries in female athletes. This research foundation endorses further epidemiological and biomechanical studies to determine the exact mechanism of ACL injury and the most effective intervention for decreasing ACL injuries in this high‐risk population. PMID:17609222

Mechanisms, Prediction, and Prevention of ACL Injuries: Cut Risk With Three Sharpened and Validated Tools

PubMed Central

Hewett, Timothy E.; Myer, Gregory D.; Ford, Kevin R.; Paterno, Mark V.; Quatman, Carmen E.

2017-01-01

Economic and societal pressures influence modern medical practice to develop and implement prevention strategies. Anterior cruciate ligament (ACL) injury devastates the knee joint leading to short term disability and long term sequelae. Due to the high risk of long term osteoarthritis in all treatment populations following ACL injury, prevention is the only effective intervention for this life-altering disruption in knee health. The “Sequence of Prevention” Model provides a framework to monitor progress towards the ultimate goal of preventing ACL injuries. Utilizing this model, our multidisciplinary collaborative research team has spent the last decade working to delineate injury mechanisms, identify injury risk factors, predict which athletes are at-risk for injury, and develop ACL injury prevention programs. Within this model of injury prevention, modifiable factors (biomechanical and neuromuscular) related to injury mechanisms likely provide the best opportunity for intervention strategies aimed to decrease the risk of ACL injury, particularly in female athletes. Knowledge advancements have led to the development of potential solutions that allow athletes to compete with lowered risk of ACL injury. Design and integration of personalized clinical assessment tools and targeted prevention strategies for athletes at high risk for ACL injury may transform current prevention practices and ultimately significantly reduce ACL injury incidence. This 2016 OREF Clinical Research Award focuses on the authors' work and contributions to the field. The author's acknowledge the many research groups who have contributed to the current state of knowledge in the fields of ACL injury mechanisms, injury risk screening and injury prevention strategies. PMID:27612195

Anterior cruciate ligament- and hamstring tendon-derived cells: in vitro differential properties of cells involved in ACL reconstruction.

PubMed

Ghebes, Corina Adriana; Kelder, Cindy; Schot, Thomas; Renard, Auke J; Pakvis, Dean F M; Fernandes, Hugo; Saris, Daniel B

2017-04-01

Anterior cruciate ligament (ACL) reconstruction involves the replacement of the torn ligament with a new graft, often a hamstring tendon (HT). Described as similar, the ACL and HT have intrinsic differences related to their distinct anatomical locations. From a cellular perspective, identifying these differences represents a step forward in the search for new cues that enhance recovery after the reconstruction. The purpose of this study was to characterize the phenotype and multilineage potential of ACL- and HT-derived cells. ACL- and HT-derived cells were isolated from tissue harvest from patients undergoing total knee arthroplasty (TKA) or ACL reconstruction. In total, three ACL and three HT donors were investigated. Cell morphology, self-renewal potential (CFU-F), surface marker profiling, expression of tendon/ligament-related markers (PCR) and multilineage potential were analysed for both cell types; both had fibroblast-like morphology and low self-renewal potential. No differences in the expression of tendon/ligament-related genes or a selected set of surface markers were observed between the two cell types. However, differences in their multilineage potential were observed: while ACL-derived cells showed a high potential to differentiate into chondrocytes and adipocytes, but not osteoblasts, HT-derived cells showed poor potential to form adipocytes, chondrocytes and osteoblasts. Our results demonstrated that HT-derived cells have low multilineage potential compared to ACL-derived cells, further highlighting the need for extrinsic signals to fully restore the function of the ACL upon reconstruction. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Lateral Intercondylar Ridge: Is it a reliable landmark for femoral ACL insertion?: An anatomical study.

PubMed

Bhattacharyya, Rahul; Ker, Andrew; Fogg, Quentin; Spencer, Simon J; Joseph, Jibu

2018-02-01

Incorrect femoral tunnel placement is the most common cause of graft failure during Anterior Cruciate Ligament (ACL) Reconstruction. A reliable landmark can minimize errors. To identify whether the Lateral Intercondylar Ridge (LIR) is a consistent anatomical structure and define its relationship with the femoral ACL insertion. Phase 1: we studied 23 femoral dry bone specimens macroscopically. Using a digital microscribe, the medial surface of the lateral femoral condyle was reconstructed (3D) to evaluate whether there was an identifiable bony ridge. Phase 2: 7 cadaveric specimens with intact soft tissues were dissected to identify the femoral ACL insertion. A 3D reconstruction of the femoral ACL insertion and the surface allowed us to define the relationship between the LIR and the ACL insertion. All specimens had a defined LIR on the medial surface of the lateral femoral condyle. The ridge was consistently located just anterior to the femoral ACL insertion. The ACL footprint was present in the depression between the ridge and the Inferior Articular Cartilage Margin (IACM). The mean distance from the midpoint of the IACM to the LIR was 10.1 mm. This is the first study to use the microscribe to digitally reconstruct the medial surface of the lateral femoral condyle. It shows that the LIR is a consistent anatomical structure that defines the anterior margin of the femoral ACL insertion, which guides femoral tunnel placement. Our findings support the ruler technique, which is a commonly used method for anatomic single bundle ACL reconstruction. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Gender dimorphic ACL strain in response to combined dynamic 3D knee joint loading: implications for ACL injury risk.

PubMed

Mizuno, Kiyonori; Andrish, Jack T; van den Bogert, Antonie J; McLean, Scott G

2009-12-01

While gender-based differences in knee joint anatomies/laxities are well documented, the potential for them to precipitate gender-dimorphic ACL loading and resultant injury risk has not been considered. To this end, we generated gender-specific models of ACL strain as a function of any six degrees of freedom (6DOF) knee joint load state via a combined cadaveric and analytical approach. Continuously varying joint forces and torques were applied to five male and five female cadaveric specimens and recorded along with synchronous knee flexion and ACL strain data. All data (approximately 10,000 samples) were submitted to specimen-specific regression analyses, affording ACL strain predictions as a function of the combined 6 DOF knee loads. Following individual model verifications, generalized gender-specific models were generated and subjected to 6 DOF external load scenarios consistent with both a clinical examination and a dynamic sports maneuver. The ensuing model-based strain predictions were subsequently examined for gender-based discrepancies. Male and female specimen-specific models predicted ACL strain within 0.51%+/-0.10% and 0.52%+/-0.07% of the measured data respectively, and explained more than 75% of the associated variance in each case. Predicted female ACL strains were also significantly larger than respective male values for both simulated 6 DOF load scenarios. Outcomes suggest that the female ACL will rupture in response to comparatively smaller external load applications. Future work must address the underlying anatomical/laxity contributions to knee joint mechanical and resultant ACL loading, ultimately affording prevention strategies that may cater to individual joint vulnerabilities.

Cotton ACAULIS5 is involved in stem elongation and the plant defense response to Verticillium dahliae through thermospermine alteration.

PubMed

Mo, Huijuan; Wang, Xingfen; Zhang, Yan; Yang, Jun; Ma, Zhiying

2015-11-01

Overexpression of GhACL5 , an ACAULIS5 from cotton, in Arabidopsis increased plant height and T-Spm level. Silencing of GhACL5 in cotton exhibited a dwarf phenotype and reduced resistance to Verticillium dahliae. The Arabidopsis thaliana gene ACAULIS5 (ACL5), for which inactivation causes a defect in stem elongation, encodes thermospermine (T-Spm) synthase. However, limited information is available about improvement in plant height by the overexpression of ACL5 gene, and the biological functions of ACL5 genes in response to biotic stress. Here, this study reports that constitutive expression of the cotton ACL5 gene (GhACL5) in Arabidopsis thaliana significantly increased plant height and elevated the level of T-Spm. Silencing of that gene in cotton reduced the amount of T-Spm and led to a severe dwarf phenotype. Expression of GhACL5 was induced upon treatment with the fungal pathogen Verticillium dahliae and plant hormones salicylic acid, jasmonic acid, and ethylene in resistant cotton plants, but gene silencing in cotton enhanced their susceptibility to V. dahliae infection. Furthermore, T-Spm exposure effectively inhibited V. dahliae growth in vitro. In summary, GhACL5 expression is related to in planta levels of T-Spm and is involved in stem elongation and defense responses against V. dahliae.

3D-Printed Patient-Specific ACL Femoral Tunnel Guide from MRI.

PubMed

Rankin, Iain; Rehman, Haroon; Frame, Mark

2018-01-01

Traditional ACL reconstruction with non-anatomic techniques can demonstrate unsatisfactory long-term outcomes with regards instability and the degenerative knee changes observed with these results. Anatomic ACL reconstruction attempts to closely reproduce the patient's individual anatomic characteristics with the aim of restoring knee kinematics, in order to improve patient short and long-term outcomes. We designed an arthroscopic, patient-specific, ACL femoral tunnel guide to aid anatomical placement of the ACL graft within the femoral tunnel. The guide design was based on MRI scan of the subject's uninjured contralateral knee, identifying the femoral footprint and its anatomical position relative to the borders of the femoral articular cartilage. Image processing software was used to create a 3D computer aided design which was subsequently exported to a 3D-printing service. Transparent acrylic based photopolymer, PA220 plastic and 316L stainless steel patient-specific ACL femoral tunnel guides were created; the models produced were accurate with no statistical difference in size and positioning of the center of the ACL femoral footprint guide to MRI ( p =0.344, p =0.189, p =0.233 respectively). The guides aim to provide accurate marking of the starting point of the femoral tunnel in arthroscopic ACL reconstruction. This study serves as a proof of concept for the accurate creation of 3D-printed patient-specific guides for the anatomical placement of the femoral tunnel during ACL reconstruction.

50 CFR 648.64 - Yellowtail flounder sub-ACLs and AMs for the scallop fishery.

Code of Federal Regulations, 2013 CFR

2013-10-01

... framework adjustment process specified in § 648.90, the scallop fishery shall be allocated a sub-ACL for the... multispecies regulations, if the Georges Bank yellowtail flounder sub-ACL for the scallop fishery is exceeded... overage of the Georges Bank yellowtail flounder sub-ACL, as follows: (i) For years when the Closed Area II...

50 CFR 648.22 - Atlantic mackerel, squid, and butterfish specifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... squid, which, subject to annual review, may be specified for a period of up to 3 years; (2) ACL; ACT... years; (3) ACL; commercial ACT, including RSA, DAH, Tier 3 allocation (up to 7 percent of the DAH), DAP... scientific uncertainty; the stock-wide ABC must be less than or equal to the OFL. (ii) ACL. The ACL or...

50 CFR 622.193 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

Code of Federal Regulations, 2013 CFR

2013-10-01

..., as estimated by the SRD, reach or are projected to reach the commercial ACL (commercial quota... commercial ACL (commercial quota) specified in § 622.190(a)(2)(iii), the AA will file a notification with the... of the fishing year. After the commercial ACL for the longline component is reached or projected to...

50 CFR 648.64 - Yellowtail flounder sub-ACLs and AMs for the scallop fishery.

Code of Federal Regulations, 2014 CFR

2014-10-01

... framework adjustment process specified in § 648.90, the scallop fishery shall be allocated a sub-ACL for the... multispecies regulations, if the Georges Bank yellowtail flounder sub-ACL for the scallop fishery is exceeded... flounder sub-ACL, as follows: (i) For years when the Closed Area II Sea Scallop Access Area is open, the...

77 FR 74119 - Snapper-Grouper Fishery of the South Atlantic; 2012 Commercial Accountability Measure and Closure...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-13

... estimated by the Science Research Director, are projected to reach the commercial annual catch limit (ACL... of the ACL if they occur. The final rule for Amendment 17B to the FMP established ACLs for eight... commercial ACL (commercial quota) for snowy grouper is 82,900 lb (37,603 kg), gutted weight, for the current...

76 FR 61285 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; South Atlantic Snapper-Grouper...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-04

... reduces the 2011-2012 recreational annual catch limit (ACL) for black sea bass based on the 2010-2011 recreational ACL overage. This action is necessary to reduce overfishing of the South Atlantic black sea bass... controls to prevent ACLs from being exceeded, and correct or mitigate the ACL if an overage occurs. On...

76 FR 61059 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-03

...-ACL (Annual Catch Limit) Harvested for Management Area 1B AGENCY: National Marine Fisheries Service...-ACL for Area 1B becomes available, except when transiting as described in this notice. This action is based on the determination that 95 percent of the Atlantic herring sub-ACL allocated to Area 1B for 2011...

76 FR 61284 - Accountability Measures and Reduced Season for the South Atlantic Recreational Sector of Golden...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-04

... catch limit (ACL) overage, and as a result closes the recreational sector. This action is necessary to... overages of the ACL if they occur. On December 30, 2010, NMFS issued a final rule (75 FR 82280) to... if these ACLs are reached or exceeded. The recreational ACL for golden tilefish, implemented through...

50 CFR 622.193 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

Code of Federal Regulations, 2014 CFR

2014-10-01

..., as estimated by the SRD, reach or are projected to reach the commercial ACL (commercial quota... commercial ACL (commercial quota) specified in § 622.190(a)(2)(iii), the AA will file a notification with the... of the fishing year. After the commercial ACL for the longline component is reached or projected to...

50 CFR 622.388 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

Code of Federal Regulations, 2014 CFR

2014-10-01

....384(b)(1) (commercial ACL), the AA will file a notification with the Office of the Federal Register to... reach the recreational ACL of 8.092 million lb (3.670 million kg), the AA will file a notification with... tracking the ACL, recreational landings will be monitored based on the commercial fishing year, July 1...

50 CFR 622.388 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

Code of Federal Regulations, 2013 CFR

2013-10-01

....384(b)(1) (commercial ACL), the AA will file a notification with the Office of the Federal Register to... reach the recreational ACL of 8.092 million lb (3.670 million kg), the AA will file a notification with... tracking the ACL, recreational landings will be monitored based on the commercial fishing year, July 1...

50 CFR 648.64 - Yellowtail flounder sub-ACLs and AMs for the scallop fishery.

Code of Federal Regulations, 2011 CFR

2011-10-01

... framework adjustment process specified in § 648.90, the scallop fishery shall be allocated a sub-ACL for the Georges Bank and Southern New England/Mid-Atlantic stocks of yellowtail flounder. The sub-ACL for the 2011... measure. (1) If the Georges Bank yellowtail flounder sub-ACL for the scallop fishery is exceeded, the area...

50 CFR 648.22 - Atlantic mackerel, squid, and butterfish specifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... squid, which, subject to annual review, may be specified for a period of up to 3 years; (2) ACL; ACT... years; (3) ACL; commercial ACT, including RSA, DAH, Tier 3 allocation (up to 7 percent of the DAH), DAP... scientific uncertainty; the stock-wide ABC must be less than or equal to the OFL. (ii) ACL. The ACL or...

50 CFR 622.280 - Annual catch limits (ACLs) and accountability measures (AMs).

Code of Federal Regulations, 2014 CFR

2014-10-01

... commercial ACL of 1,157,001 lb (524,807 kg), round weight, the AA will file a notification with the Office of... ACL for that following year by the amount of the commercial overage in the prior fishing year. (2... recreational ACL of 14,187,845 lb (6,435,498 kg), round weight, then during the following fishing year...

78 FR 13284 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; 2013 Accountability Measures for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-27

... (ACL) to 410,157 lb (186,044 kg), based on the 2012 commercial ACL overage. These actions are necessary... the ACL if they occur. Section 303(a)(15) of the Magnuson-Stevens Act mandates the establishment of... established the Gulf greater amberjack stock ACL equal to the greater amberjack stock allowable biological...

50 CFR 648.22 - Atlantic mackerel, squid, and butterfish specifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... squid, which, subject to annual review, may be specified for a period of up to 3 years; (2) ACL; ACT... years; (3) ACL; commercial ACT, including RSA, DAH, Tier 3 allocation (up to 7 percent of the DAH), DAP... ABC must be less than or equal to the OFL. (ii) ACL. The ACL or Domestic ABC is calculated using the...

[Effects of posterior tibial slope on non-contact anterior cruciate ligament rupture and stability of anterior cruciate ligament rupture knee].

PubMed

Yue, De-bo; E, Sen; Wang, Bai-liang; Wang, Wei-guo; Guo, Wan-shou; Zhang, Qi-dong

2013-05-07

To retrospectively explore the correlation between anterior cruciate ligament (ACL)-ruptured knees, stability of ACL-rupture knee and posterior tibial slope (PTS). From January 2008 to October 2012, 150 knees with ACL rupture underwent arthroscopic surgery for ACL reconstruction. A control group was established for subjects undergoing arthroscopic surgery without ACL rupture during the same period. PTS was measured on a digitalized lateral radiograph. Lachman and mechanized pivot shift tests were performed for assessing the stability of knee. There was significant difference (P = 0.007) in PTS angle between the patients with ACL rupture (9.5 ± 2.2 degrees) and the control group (6.6 ± 1.8 degrees). Only among females, increased slope of tibial plateau had effect on the Lachman test. There was a higher positive rate of pivot shift test in patients of increased posterior slope in the ACL rupture group. Increased posterior tibial slope (>6.6) appears to contribute to non-contact ACL injuries in females. And the changes of tibial slope have no effect upon the Lachman test. However, large changes in tibial slope affect pivot shift.

The Effect of Skeletal Maturity on the Regenerative Function of Intrinsic ACL Cells

PubMed Central

Mastrangelo, Ashley N.; Magarian, Elise M.; Palmer, Matthew P.; Vavken, Patrick; Murray, Martha M.

2010-01-01

Anterior cruciate ligament (ACL) injuries are an important clinical problem, particularly for adolescent patients. The effect of skeletal maturity on the potential for ACL healing is as yet unknown. In this study, we hypothesized that fibroblastic cells from the ACLs of skeletally immature animals would proliferate and migrate more quickly than cells from adolescent and adult animals. ACL tissue from skeletally immature, adolescent, and adult pigs and sheep were obtained and cells obtained using explant culture. Cell proliferation within a collagen–platelet scaffold was measured at days 2, 7, and 14 of culture using AMMTT assay. Cellular migration was measured at 4 and 24 h using a modified Boyden chamber assay, and cell outgrowth from the explants also measured at 1 week. ACL cells from skeletally immature animals had higher proliferation between 7 and 14 days (p < 0.01 for all comparisons) and higher migration potential at all time points in both species (p < 0.01 for all comparisons).ACL cells from skeletally immature animals have greater cellular proliferation and migration potential than cells from adolescent or adult animals. These experiments suggest that skeletal maturity may influence the biologic repair capacity of intrinsic ACL cells. PMID:19890988

Effect of simulation on knowledge of advanced cardiac life support, knowledge retention, and confidence of nursing students in Jordan.

PubMed

Tawalbeh, Loai I; Tubaishat, Ahmad

2014-01-01

This study examined the effect of simulation on nursing students' knowledge of advanced cardiac life support (ACLS), knowledge retention, and confidence in applying ACLS skills. An experimental, randomized controlled (pretest-posttest) design was used. The experimental group (n = 40) attended an ACLS simulation scenario, a 4-hour PowerPoint presentation, and demonstration on a static manikin, whereas the control group (n = 42) attended the PowerPoint presentation and a demonstration only. A paired t test indicated that posttest mean knowledge of ACLS and confidence was higher in both groups. The experimental group showed higher knowledge of ACLS and higher confidence in applying ACLS, compared with the control group. Traditional training involving PowerPoint presentation and demonstration on a static manikin is an effective teaching strategy; however, simulation is significantly more effective than traditional training in helping to improve nursing students' knowledge acquisition, knowledge retention, and confidence about ACLS. Copyright 2014, SLACK Incorporated.

Panoramic Measurement and Analysis of Strain Distribution in the Human ACL Using a Photoelastic Coating Method

NASA Astrophysics Data System (ADS)

Hirokawa, Shunji; Yamamoto, Kouji; Kawada, Takashi

Large and highly variable deformations of the ACL cannot be adequately quantified by one-dimensional and/or localized measurements. Since the complex anatomy of the ACL makes uniform loading of all fiber bundles almost impossible, strains on specific portions being tested are considerably altered during knee movement. To observe the ACL's entire surface, we propose a photoelastic coating method. A simulator jig was used to allow a natural motion of the knee whose medial and lateral femoral bone parts were removed in order to expose the ACL for observation. The simulator jig with the knee was mounted on a universal stand which allows tilt and swivel rotations, so that the exposed ACL might be viewed from any direction. Measurements were performed on the strain distributions over the ACL at various knee angles. The panoramic images of the photoelastic fringe patterns yielded significant results. Special attention was paid for insight into the relation between strain distribution and the directions of fiber run.

The concept of individualized anatomic anterior cruciate ligament (ACL) reconstruction.

PubMed

Hofbauer, M; Muller, B; Murawski, C D; van Eck, C F; Fu, F H

2014-05-01

To describe the concept of individualized anatomic anterior cruciate ligament (ACL) reconstruction. The PubMed/Medline database was searched using keywords pertaining to ACL reconstruction. Relevant articles were reviewed in order to summarize important concepts of individualized surgery in ACL reconstruction. Surgical experiences with case examples are also highlighted. Individualized ACL surgery allows for the customization of surgery to each individual patient. Accounting for graft selection and other characteristics such as anatomy, lifestyle and activity preferences may provide the patient with the best potential for a successful outcome. The surgeon should be comfortable with a variety of graft harvests and surgical techniques when practicing individualized surgery. Individualized anatomic ACL reconstruction is founded on the objective evaluation of functional anatomy and individual characteristics, thereby restoring the ACL as closely as possible to the native anatomy and function. The adoption and subsequent use of individualized surgery may facilitate improved clinical as well as objective outcomes, particularly in the long term. V.

Three-Dimensional Anatomic Evaluation of the Anterior Cruciate Ligament for Planning Reconstruction

PubMed Central

Hoshino, Yuichi; Kim, Donghwi; Fu, Freddie H.

2012-01-01

Anatomic study related to the anterior cruciate ligament (ACL) reconstruction surgery has been developed in accordance with the progress of imaging technology. Advances in imaging techniques, especially the move from two-dimensional (2D) to three-dimensional (3D) image analysis, substantially contribute to anatomic understanding and its application to advanced ACL reconstruction surgery. This paper introduces previous research about image analysis of the ACL anatomy and its application to ACL reconstruction surgery. Crucial bony landmarks for the accurate placement of the ACL graft can be identified by 3D imaging technique. Additionally, 3D-CT analysis of the ACL insertion site anatomy provides better and more consistent evaluation than conventional “clock-face” reference and roentgenologic quadrant method. Since the human anatomy has a complex three-dimensional structure, further anatomic research using three-dimensional imaging analysis and its clinical application by navigation system or other technologies is warranted for the improvement of the ACL reconstruction. PMID:22567310

Topological analysis of polymeric melts: chain-length effects and fast-converging estimators for entanglement length.

PubMed

Hoy, Robert S; Foteinopoulou, Katerina; Kröger, Martin

2009-09-01

Primitive path analyses of entanglements are performed over a wide range of chain lengths for both bead spring and atomistic polyethylene polymer melts. Estimators for the entanglement length N_{e} which operate on results for a single chain length N are shown to produce systematic O(1/N) errors. The mathematical roots of these errors are identified as (a) treating chain ends as entanglements and (b) neglecting non-Gaussian corrections to chain and primitive path dimensions. The prefactors for the O(1/N) errors may be large; in general their magnitude depends both on the polymer model and the method used to obtain primitive paths. We propose, derive, and test new estimators which eliminate these systematic errors using information obtainable from the variation in entanglement characteristics with chain length. The new estimators produce accurate results for N_{e} from marginally entangled systems. Formulas based on direct enumeration of entanglements appear to converge faster and are simpler to apply.

Successful anterior cruciate ligament reconstruction and meniscal repair in osteogenesis imperfecta.

PubMed

Park, Jae-Young; Cho, Tae-Joon; Lee, Myung Chul; Han, Hyuk-Soo

2018-03-20

A case of anterior cruciate ligament (ACL) reconstruction with meniscal repair in an osteogenesis imperfecta patient is reported. A 24-year-old female with osteogenesis imperfecta type 1a suffered from a valgus extension injury resulting in tear of ACL and medial meniscus. She underwent an arthroscopic-assisted ACL reconstruction and medial meniscus repair. Meniscal tear at the menisco-capsular junction of the posterior horn of medial meniscus was repaired with three absorbable sutures via inside-out technique. ACL reconstruction was then performed with a bone-patellar tendon-bone allograft. The patient was followed up for 1 year with intact ACL grafts and healed medial meniscus. This case report showed that successful ACL reconstruction and meniscal repair is possible in an osteogenesis imperfecta patient.Level of evidence V.

Delayed Anterior Cruciate Ligament Reconstruction in Young Patients With Previous Anterior Tibial Spine Fractures.

PubMed

Mitchell, Justin J; Mayo, Meredith H; Axibal, Derek P; Kasch, Anthony R; Fader, Ryan R; Chadayammuri, Vivek; Terhune, E Bailey; Georgopoulos, Gaia; Rhodes, Jason T; Vidal, Armando F

2016-08-01

Avulsion fractures of the anterior tibial spine in young athletes are injuries similar to anterior cruciate ligament (ACL) injuries in adults. Sparse data exist on the association between anterior tibial spine fractures (ATSFs) and later ligamentous laxity or injuries leading to ACL reconstruction. To better delineate the incidence of delayed instability or ACL ruptures requiring delayed ACL reconstruction in young patients with prior fractures of the tibial eminence. Case series; Level of evidence, 4. We identified 101 patients between January 1993 and January 2012 who sustained an ATSF and who met inclusion criteria for this study. All patients had been followed for at least 2 years after the initial injury and were included for analysis after completion of a questionnaire via direct contact, mail, and/or telephone. If patients underwent further surgical intervention and/or underwent later ACL reconstruction, clinical records and operative reports pertaining to these secondary interventions were obtained and reviewed. Differences between categorical variables were assessed using the Fisher exact test. The association between time to revision ACL surgery and fracture type was assessed by Kaplan-Meier plots. The association between need for revision ACL surgery and age, sex, and mechanism of surgery was assessed using logistic regression. Nineteen percent of all patients evaluated underwent delayed ACL reconstruction after a previous tibial spine fracture on the ipsilateral side. While there were a higher proportion of ACL reconstructions in type II fractures, there was not a statistically significant difference in the number of patients within each fracture group who went on to undergo later surgery (P = .29). Further, there was not a significant association between fracture type, sex, or mechanism of injury as it related to the progression to later ACL reconstruction. However, there was a significant association between age at the time of injury and progression to later ACL reconstruction (P = .02). For every year increase in age at the time of injury, the odds of going on to undergo delayed ACL reconstruction were greater by a factor of 1.3 (95% CI, 1.1-1.6). Although an ATSF is a relatively rare injury, our cohort of patients suggests that a subset of young patients with all types of tibial spine fractures will require later ACL reconstruction. There is a need to counsel patients that a delayed ACL rupture is a potential risk after an ATSF, especially as children approach skeletal maturity. Further patient follow-up and prospective studies are required. © 2016 The Author(s).

An equal force theory for network models of soft materials with arbitrary molecular weight distribution

NASA Astrophysics Data System (ADS)

Verron, E.; Gros, A.

2017-09-01

Most network models for soft materials, e.g. elastomers and gels, are dedicated to idealized materials: all chains admit the same number of Kuhn segments. Nevertheless, such standard models are not appropriate for materials involving multiple networks, and some specific constitutive equations devoted to these materials have been derived in the last few years. In nearly all cases, idealized networks of different chain lengths are assembled following an equal strain assumption; only few papers adopt an equal stress assumption, although some authors argue that such hypothesis would reflect the equilibrium of the different networks in contact. In this work, a full-network model with an arbitrary chain length distribution is derived by considering that chains of different lengths satisfy the equal force assumption in each direction of the unit sphere. The derivation is restricted to non-Gaussian freely jointed chains and to affine deformation of the sphere. Firstly, after a proper definition of the undeformed configuration of the network, we demonstrate that the equal force assumption leads to the equality of a normalized stretch in chains of different lengths. Secondly, we establish that the network with chain length distribution behaves as an idealized full-network of which both chain length and density of are provided by the chain length distribution. This approach is finally illustrated with two examples: the derivation of a new expression for the Young modulus of bimodal interpenetrated polymer networks, and the prediction of the change in fluorescence during deformation of mechanochemically responsive elastomers.

Validation of Noncontact Anterior Cruciate Ligament Tears Produced by a Mechanical Impact Simulator Against the Clinical Presentation of Injury.

PubMed

Bates, Nathaniel A; Schilaty, Nathan D; Nagelli, Christopher V; Krych, Aaron J; Hewett, Timothy E

2018-06-01

Anterior cruciate ligament (ACL) injuries are catastrophic events that affect athletic careers and lead to long-term degenerative knee changes. As injuries are believed to occur within the first 50 milliseconds after initial contact during a rapid deceleration task, impact simulators that rapidly deliver impulse loads to cadaveric specimens have been developed. However, no impactor has reproducibly and reliably created ACL injures in a distribution that mimics clinical observation. To better understand ACL injury patterns through a cadaveric investigation that applied in vivo-measured external loads to the knee during simulated landings. Controlled laboratory study. A novel mechanical impact simulator reproduced kinetics from in vivo-recorded drop landing tasks on 45 cadaveric knees. Specimens were exposed to a randomized order of variable knee abduction moment, anterior tibial shear, and internal tibial rotation loads before the introduction of an impulse load at the foot. This process was repeated until a hard or soft tissue injury was induced on the joint. Injuries were assessed by an orthopaedic surgeon, and ligament strain was recorded by implanted strain gauges. The mechanical impact simulator induced ACL injuries in 87% of specimens, with medial collateral ligament (MCL) injuries in 31%. ACL tear locations were 71% femoral side, 21% midsubstance, and 9% tibial side. Peak strain before failure for ACL-injured specimens was 15.3% ± 8.7% for the ACL and 5.1% ± 5.6% for the MCL ( P < .001). The ACL injuries induced by the mechanical impact simulator in the present study have provided clinically relevant in vitro representations of in vivo ACL injury patterns as cited in the literature. Additionally, current ligament strains corroborate the literature to support disproportionate loading of the ACL relative to the MCL during athletic tasks. These findings indicate that the mechanical impact simulator is an appropriate model for examining independent mechanical variables, treatment techniques, and preventive interventions during athletic tasks leading up to and including an ACL injury. Accordingly, this system can be utilized to further parse out contributing factors to an ACL injury as well as assess the shortcomings of ACL reconstruction techniques in a dynamic, simulated environment that is better representative of in vivo injury scenarios.

Quality of Life in Symptomatic Individuals After Anterior Cruciate Ligament Reconstruction, With and Without Radiographic Knee Osteoarthritis.

PubMed

Filbay, Stephanie R; Ackerman, Ilana N; Dhupelia, Sanjay; Arden, Nigel K; Crossley, Kay M

2018-05-01

Study Design Clinical measurement, cross-sectional. Background Individuals who have undergone anterior cruciate ligament (ACL) reconstruction commonly experience long-term impairments in quality of life (QoL), which may be related to persistent knee symptoms or radiographic osteoarthritis (ROA). Understanding the impact of knee symptoms and ROA on QoL after ACL reconstruction may assist in the development of appropriate management strategies. Objectives To (1) compare QoL between groups of individuals after ACL reconstruction (including those who are symptomatic with ROA, symptomatic without ROA, and asymptomatic [unknown ROA status]), and (2) identify specific aspects of QoL impairment in symptomatic individuals with and without ROA post ACL reconstruction. Methods One hundred thirteen participants completed QoL measures (Knee injury and Osteoarthritis Outcome Score QoL subscale [KOOS-QoL], Anterior Cruciate Ligament Quality of Life [ACL-QoL], Assessment of Quality of Life-8 Dimensions [AQoL-8D]) 5 to 20 years after ACL reconstruction. Eighty-one symptomatic individuals underwent radiographs, and 32 asymptomatic individuals formed a comparison group. Radiographic osteoarthritis was defined as a Kellgren-Lawrence grade of 2 or greater for the tibiofemoral and/or patellofemoral joints. Mann-Whitney U tests compared outcomes between groups. Individual ACL-QoL items were used to explore specific aspects of QoL. Results In symptomatic individuals after ACL reconstruction, ROA was related to worse knee-related outcomes on the KOOS-QoL (median, 50; interquartile range [IQR], 38-69 versus median, 69; IQR, 56-81; P<.001) and the ACL-QoL (median, 51; IQR, 38-71 versus median, 66; IQR, 50-82; P = .04). The AQoL-8D scores showed that health-related QoL was impaired in both symptomatic groups compared to the asymptomatic group. The ACL-QoL item scores revealed greater limitations and concern surrounding sport and exercise and social/emotional difficulties in the symptomatic group with ROA. Conclusion Osteoarthritis is associated with worse knee-related QoL in symptomatic individuals after ACL reconstruction. Diagnosing ROA in symptomatic individuals after ACL reconstruction may be valuable, because these individuals may require unique management. Targeted strategies to facilitate participation in satisfying activities have potential to improve QoL in symptomatic people with ROA after ACL reconstruction. J Orthop Sports Phys Ther 2018;48(5):398-408. doi:10.2519/jospt.2018.7830.

High knee abduction moments are common risk factors for patellofemoral pain (PFP) and anterior cruciate ligament (ACL) injury in girls: Is PFP itself a predictor for subsequent ACL injury?

PubMed Central

Myer, Gregory D; Ford, Kevin R; Di Stasi, Stephanie L; Foss, Kim D Barber; Micheli, Lyle J; Hewett, Timothy E

2014-01-01

Background Identifying risk factors for knee pain and anterior cruciate ligament (ACL) injury can be an important step in the injury prevention cycle. Objective We evaluated two unique prospective cohorts with similar populations and methodologies to compare the incidence rates and risk factors associated with patellofemoral pain (PFP) and ACL injury. Methods The ‘PFP cohort’ consisted of 240 middle and high school female athletes. They were evaluated by a physician and underwent anthropometric assessment, strength testing and three-dimensional landing biomechanical analyses prior to their basketball season. 145 of these athletes met inclusion for surveillance of incident (new) PFP by certified athletic trainers during their competitive season. The ‘ACL cohort’ included 205 high school female volleyball, soccer and basketball athletes who underwent the same anthropometric, strength and biomechanical assessment prior to their competitive season and were subsequently followed up for incidence of ACL injury. A one-way analysis of variance was used to evaluate potential group (incident PFP vs ACL injured) differences in anthropometrics, strength and landing biomechanics. Knee abduction moment (KAM) cut-scores that provided the maximal sensitivity and specificity for prediction of PFP or ACL injury risk were also compared between the cohorts. Results KAM during landing above 15.4 Nm was associated with a 6.8% risk to develop PFP compared to a 2.9% risk if below the PFP risk threshold in our sample. Likewise, a KAM above 25.3 Nm was associated with a 6.8% risk for subsequent ACL injury compared to a 0.4% risk if below the established ACL risk threshold. The ACL-injured athletes initiated landing with a greater knee abduction angle and a reduced hamstrings-to-quadriceps strength ratio relative to the incident PFP group. Also, when comparing across cohorts, the athletes who suffered ACL injury also had lower hamstring/quadriceps ratio than the players in the PFP sample (p<0.05). Conclusions In adolescent girls aged 13.3 years, >15 Nm of knee abduction load during landing is associated with greater likelihood of developing PFP. Also, in girls aged 16.1 years who land with >25 Nm of knee abduction load during landing are at increased risk for both PFP and ACL injury. PMID:24687011

Similar Outcomes After Osteochondral Allograft Transplantation in Anterior Cruciate Ligament-Intact and -Reconstructed Knees: A Comparative Matched-Group Analysis With Minimum 2-Year Follow-Up.

PubMed

Wang, Dean; Eliasberg, Claire D; Wang, Tim; Fader, Ryan R; Coxe, Francesca R; Pais, Mollyann D; Williams, Riley J

2017-12-01

To compare failure rates and clinical outcomes of osteochondral allograft transplantation (OCA) in anterior cruciate ligament (ACL)-intact versus ACL-reconstructed knees at midterm follow-up. After a priori power analysis, a prospective registry of patients treated with OCA for focal chondral lesions ≥2 cm 2 in size with minimum 2-year follow-up was used to match ACL-reconstructed knees with ACL-intact knees by age, sex, and primary chondral defect location. Exclusion criteria included meniscus transplantation, realignment osteotomy, or other ligamentous injury. Complications, reoperations, and patient responses to validated outcome measures were reviewed. Failure was defined by any procedure involving allograft removal/revision or conversion to arthroplasty. Kaplan-Meier analysis and multivariate Cox regression were performed to evaluate the association of ACL reconstruction (ACLR) with failure. A total of 50 ACL-intact and 25 ACL-reconstructed (18 prior, 7 concomitant) OCA patients were analyzed. The mean age was 36.2 years (range, 14-62 years). Mean follow-up was 3.9 years (range, 2-14 years). Patient demographics and chondral lesion characteristics were similar between groups. ACL-reconstructed patients averaged 2.2 ± 1.9 prior surgeries on the ipsilateral knee compared with 1.4 ± 1.4 surgeries for ACL-intact patients (P = .014). Grafts used for the last ACLR included bone-patellar tendon-bone autograft, hamstring autograft, Achilles tendon allograft, and tibialis allograft (data available for only 11 of 25 patients). At final follow-up, 22% of ACL-intact and 32% of ACL-reconstructed patients had undergone reoperation. OCA survivorship was 90% and 96% at 2 years and 79% and 85% at 5 years in ACL-intact and ACL-reconstructed patients, respectively (P = .774). ACLR was not independently associated with failure. Both groups demonstrated clinically significant improvements in the Short Form-36 pain and physical functioning, International Knee Documentation Committee subjective, and Knee Outcome Survey-Activities of Daily Living scores at final follow-up (P < .001), with no significant differences in preoperative, postoperative, and change scores between groups. OCA in the setting of prior or concomitant ACLR does not portend higher failure rates or compromise clinical outcomes. Level III, retrospective comparative study. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

A Radiographic Assessment of Failed Anterior Cruciate Ligament Reconstruction: Can Magnetic Resonance Imaging Predict Graft Integrity?

PubMed

Waltz, Robert A; Solomon, Daniel J; Provencher, Matthew T

2014-07-01

Magnetic resonance imaging (MRI) showing an "intact" anterior cruciate ligament (ACL) graft may not correlate well with examination findings. Reasons for an ACL graft dysfunction may be from malpositioned tunnels, deficiency of secondary stabilizers, repeat injuries, or a combination of factors. To evaluate the concordance/discordance of an ACL graft assessment between an arthroscopic evaluation, physical examination, and MRI and secondarily to evaluate the contributing variables to discordance. Case series; Level of evidence, 4. A total of 50 ACL revisions in 48 patients were retrospectively reviewed. The ACL graft status was recorded separately based on Lachman and pivot-shift test data, arthroscopic findings from operative reports, and MRI evaluation and was categorized into 3 groups: intact, partial tear, or complete tear. Two independent evaluators reviewed all of the preoperative radiographs and MRI scans, and interrater and intrarater reliability were evaluated. Concordance and discordance between a physical examination, arthroscopic evaluation, and MRI evaluation of the ACL graft were calculated. Graft position and type, mechanical axis, collateral ligament injuries, chondral and meniscal injuries, and mechanism of injury were evaluated as possible contributing factors using univariate and multivariate analyses. Sensitivity and specificity of MRI to detect a torn ACL graft and meniscal and chondral injuries on arthroscopic evaluation were calculated. The interobserver and intraobserver reliability for the MRI evaluation of the ACL graft were moderate, with combined κ values of .41 and .49, respectively. The femoral tunnel position was vertical in 88% and anterior in 46%. On MRI, the ACL graft was read as intact in 24%; however, no graft was intact on arthroscopic evaluation or physical examination. The greatest discordance was between the physical examination and MRI, with a rate of 52%. An insidious-onset mechanism of injury was significantly associated with discordance between MRI and arthroscopic evaluation of the ACL (P = .0003) and specifically with an intact ACL graft on MRI (P = .0014). The sensitivity and specificity of MRI to detect an ACL graft tear were 60% and 87%, respectively. Caution should be used when evaluating a failed ACL graft with MRI, especially in the absence of an acute mechanism of injury, as it may be unreliable and inconsistent. © 2014 The Author(s).

Addition of Autologous Mesenchymal Stem Cells to Whole Blood for Bio-Enhanced ACL Repair has No Benefit in the Porcine Model

PubMed Central

Proffen, Benedikt L.; Vavken, Patrick; Haslauer, Carla M.; Fleming, Braden C.; Harris, Chad E.; Machan, Jason T.; Murray, Martha M.

2015-01-01

Background Co-culture of mesenchymal stem cells (MSCs) from the retropatellar fat pad and peripheral blood has been shown to stimulate anterior cruciate ligament (ACL) fibroblast proliferation and collagen production in vitro. Current techniques of bio-enhanced ACL repair in animal studies involve adding a biologic scaffold, in this case an extracellular matrix based scaffold saturated with autologous whole blood, to a simple suture repair of the ligament. Whether the enrichment of whole blood with MSCs would further improve the in vivo results of bio-enhanced ACL repair was investigated. Hypothesis/Purpose The hypothesis was that the addition of MSCs derived from adipose tissue or peripheral blood to the blood-extracellular matrix composite, which is used in bio-enhanced ACL repair to stimulate healing, would improve the biomechanical properties of a bio-enhanced ACL repair after 15 weeks of healing. Study Design Controlled laboratory study. Methods Twenty-four adolescent Yucatan mini-pigs underwent ACL transection followed by: 1) bio-enhanced ACL repair, 2) bio-enhanced ACL repair with the addition of autologous adipose-derived MSCs and 3) bio-enhanced ACL repair with the addition of autologous peripheral blood derived MSCs. After fifteen weeks of healing, structural properties of the ACL (yield & failure load, linear stiffness) were measured. Cell and vascular density were measured in the repaired ACL via histology, and its tissue structure was qualitatively evaluated using the Advanced Ligament Maturity Index. Results After fifteen weeks of healing, there were no significant improvements in the biomechanical or histological properties with the addition of adipose-derived MSCs. The only significant change with the addition of peripheral blood MSCs was an increase in knee anteroposterior (AP) laxity when measured at 30 degrees of flexion. Conclusions These findings suggest that the addition of adipose or peripheral blood MSCs to whole blood prior to saturation of an extracellular matrix carrier with the blood did not improve the functional results of bio-enhanced ACL repair after 15 weeks of healing in the pig model. Clinical Relevance Whole blood represents a practical biologic additive to ligament repair, and any other additive (including stem cells) should be demonstrated to be superior to this baseline before clinical use is considered. PMID:25549633

50 CFR 648.65 - Windowpane flounder sub-ACL and AM for the scallop fishery.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Windowpane flounder sub-ACL and AM for...-ACL and AM for the scallop fishery. (a) As specified in § 648.55(d), and pursuant to the biennial framework adjustment process specified in § 648.90, the scallop fishery shall be allocated a sub-ACL for SNE...

50 CFR 622.251 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

Code of Federal Regulations, 2013 CFR

2013-10-01

... to reach the ACL of 2 million lb (907,185 kg), round weight, the AA will file a notification with the... golden crab in or from the South Atlantic EEZ is prohibited. (2) If commercial landings exceed the ACL... the following fishing year to reduce the ACL for that following year by the amount of the overage in...

50 CFR 622.251 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

Code of Federal Regulations, 2014 CFR

2014-10-01

... to reach the ACL of 2 million lb (907,185 kg), round weight, the AA will file a notification with the... golden crab in or from the South Atlantic EEZ is prohibited. (2) If commercial landings exceed the ACL... the following fishing year to reduce the ACL for that following year by the amount of the overage in...

78 FR 61826 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Closure of the 2013 South...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-04

... annual catch limit (ACL) for red snapper on October 8, 2013. Therefore, NMFS closes the commercial sector... commercial ACL for red snapper in the South Atlantic is 21,447 lb (9,728 kg), gutted weight. This ACL was... snapper when the commercial ACL is reached, or is projected to be reached, by filing a notification to...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, D.W.; Boparai, A.S.; Bowers, D.L.

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for fiscal year (FY) 1995 (October 1994 through September 1995). This annual report is the twelfth for the ACL and describes work on 54 continuing and new projects and contributions of the ACL staff to various programs at ANL. The ACL has four technical groups -- Chemical Analysis, Instrumental Analysis, Organic Analysis, and Environmental Analysis.

Angiostrongylus cantonensis (Nematode: Metastrongiloidea): in vitro cultivation of infective third-stage larvae to fourth-stage larvae.

PubMed

Lin, Rong-Jyh; He, Jie-Wen; Chung, Li-Yu; Lee, June-Der; Wang, Jiun-Jye; Yen, Chuan-Min

2013-01-01

The present study to attempt to cultivate Angiostrongylus cantonensis from third-stage larvae (AcL3) to fourth-stage larvae (AcL4) in vitro in defined complete culture medium that contained with Minimum Essential Medium Eagle (MEM), supplemented amino acid (AA), amine (AM), fatty acid (FA), carbohydrate (CA) and 20% fetal calf serum (FCS) was successful. When AcL3 were cultured in the defined complete culture medium at 37°C in a 5% CO2 atmosphere, the larvae began to develop to AcL4 after 30 days of cultivation, and were enclosed within the sheaths of the third molts of the life cycle. Under these conditions, the larvae developed uniformly and reached to the fourth-stage 36 days. The morphology of AcL3 develop to AcL4 were recording and analyzing. Then comparison of A. cantonensis larval morphology and development between in vitro cultivation in defined complete culture medium and in vivo cultivation in infective BALB/c mice. The larvae that had been cultivated in vitro were smaller than AcL4 of infective BALB/c mice. However the AcL3 that were cultured using defined incomplete culture medium (MEM plus 20% FCS with AA+AM, FA, CA, AA+AM+FA, FA+CA, CA+AA+AM or not) did not adequately survive and develop. Accordingly, the inference is made that only the defined complete medium enable AcL3 develop to AcL4 in vitro. Some nematodes have been successfully cultured into mature worms but only a few researches have been made to cultivate A. cantonensis in vitro. The present study is the first to have succeeded in developing AcL3 to AcL4 by in vitro cultivation. Finally, the results of in vitro cultivation studies herein contribute to improving media for the effective development and growth of A. cantonensis. The gap in the A. cantonensis life cycle when the larvae are cultivated in vitro from third-stage larvae to fourth-stage larvae can thus be solved.

Societal and economic impact of anterior cruciate ligament tears.

PubMed

Mather, Richard C; Koenig, Lane; Kocher, Mininder S; Dall, Timothy M; Gallo, Paul; Scott, Daniel J; Bach, Bernard R; Spindler, Kurt P

2013-10-02

An anterior cruciate ligament (ACL) tear is a common knee injury, particularly among young and active individuals. Little is known, however, about the societal impacts of ACL tears, which could be large given the typical patient age and increased lifetime risk of knee osteoarthritis. This study evaluates the cost-effectiveness of ACL reconstruction compared with structured rehabilitation only. A cost-utility analysis of ACL reconstruction compared with structured rehabilitation only was conducted with use of a Markov decision model over two time horizons: the short to intermediate term (six years), on the basis of Level-I evidence derived from the KANON Study and the Multicenter Orthopaedic Outcomes Network (MOON) database; and the lifetime, on the basis of a comprehensive literature review. Utilities were assessed with use of the SF-6D. Costs (in 2012 U.S. dollars) were estimated from the societal perspective and included the effects of the ACL tear on work status, earnings, and disability. Effectiveness was expressed as quality-adjusted life years (QALYs) gained. In the short to intermediate term, ACL reconstruction was both less costly (a cost reduction of $4503) and more effective (a QALY gain of 0.18) compared with rehabilitation. In the long term, the mean lifetime cost to society for a typical patient undergoing ACL reconstruction was $38,121 compared with $88,538 for rehabilitation. ACL reconstruction resulted in a mean incremental cost savings of $50,417 while providing an incremental QALY gain of 0.72 compared with rehabilitation. Effectiveness gains were driven by the higher probability of an unstable knee and associated lower utility in the rehabilitation group. Results were most sensitive to the rate of knee instability after initial rehabilitation. ACL reconstruction is the preferred cost-effective treatment strategy for ACL tears and yields reduced societal costs relative to rehabilitation once indirect cost factors, such as work status and earnings, are considered. The cost of an ACL tear over the lifetime of a patient is substantial, and resources should be directed to developing innovations for injury prevention and for altering the natural history of an ACL injury.

Three-dimensional in vivo patellofemoral kinematics and contact area of anterior cruciate ligament-deficient and -reconstructed subjects using magnetic resonance imaging.

PubMed

Shin, Choongsoo S; Carpenter, R Dana; Majumdar, Sharmila; Ma, C Benjamin

2009-11-01

The purpose of this study was to test whether (1) the 3-dimensional in vivo patellofemoral kinematics and patellofemoral contact area of anterior cruciate ligament (ACL)-deficient knees are different from those of normal, contralateral knees and (2) ACL reconstruction restores in vivo patellofemoral kinematics and contact area. Ten ACL-deficient knees and twelve ACL-reconstructed knees, as well as the contralateral uninjured knees, were tested. Magnetic resonance imaging was performed at full extension and 40 degrees of flexion under simulated partial weight-bearing conditions. Six-degrees of freedom patellofemoral kinematics, patellofemoral contact area, and contact location were analyzed by use of magnetic resonance image-based 3-dimensional patellofemoral knee models. The patella in the ACL-deficient knees underwent significantly more lateral tilt during flexion (P < .05) and tended to translate more laterally (P = .083) than the patella in contralateral knees. After ACL reconstruction, no kinematic parameters were significantly different from those in contralateral knees. The patellofemoral contact areas of ACL-deficient knees at both the extended and flexed positions (37 +/- 22 mm(2) and 357 +/- 53 mm(2), respectively) were significantly smaller than those of contralateral knees (78 +/- 45 mm(2) and 437 +/- 119 mm(2), respectively) (P < .05). After reconstruction, the patellofemoral contact area of ACL-reconstructed knees in the extended position (86 +/- 41 mm(2)) was significantly larger (P < .05) than that of contralateral knees (50 +/- 34 mm(2)), but no difference was detected in the flexed position. Reproducibility of all patellofemoral kinematic parameters, contact centroid translation, and contact area showed coefficients of variation of less than 6.8%. ACL injuries alter patellofemoral kinematics including patellar tilt and patellar lateral translation, but ACL reconstruction with hamstring or allograft restores altered patellar tilt. ACL injuries reduce the patellofemoral contact area at both the extended and flexed positions, but ACL reconstruction enlarges the patellofemoral contact area at extension and restores the normal contact area at low angles of flexion. Level III, case-control study.

Knotting probability of a shaken ball-chain.

PubMed

Hickford, J; Jones, R; du Pont, S Courrech; Eggers, J

2006-11-01

We study the formation of knots on a macroscopic ball chain, which is shaken on a horizontal plate at 12 times the acceleration of gravity. We find that above a certain critical length, the knotting probability is independent of chain length, while the time to shake out a knot increases rapidly with chain length. The probability of finding a knot after a certain time is the result of the balance of these two processes. In particular, the knotting probability tends to a constant for long chains.

No association between static and dynamic postural control and ACL injury risk among female elite handball and football players: a prospective study of 838 players.

PubMed

Steffen, Kathrin; Nilstad, Agnethe; Krosshaug, Tron; Pasanen, Kati; Killingmo, Aleksander; Bahr, Roald

2017-02-01

Research on balance measures as potential risk factors for ACL injury is limited. To assess whether postural control was associated with an increased risk for ACL injuries in female elite handball and football players. Premier league players were tested in the preseason and followed prospectively for ACL injury risk from 2007 through 2015. At baseline, we recorded player demographics, playing experience, ACL and ankle injury history. We measured centre of pressure velocity in single-leg stabilisation tests and reach distances in the Star Excursion Balance Test. To examine the stability of postural control measures over time, we examined their short-term and long-term reproducibility. We generated logistic regression models, 1 for each of the proposed risk factors. A total of 55 (6.6%) out of 838 players (age 21±4 years; height 170±6 cm; body mass 66±8 kg) sustained a non-contact ACL injury after baseline testing (1.8±1.8 years). When comparing normalised balance measures between injured and uninjured players in univariate analyses, none of the variables were statistically associated with ACL injury risk. Short-term and long-term reproducibility of the selected variables was poor. Players with a previous ACL injury had a 3-fold higher risk of sustaining a new ACL injury compared with previously uninjured players (OR 2.9, CI 1.4 to 5.7). None of postural control measures examined were associated with increased ACL injury risk among female elite handball and football players. Hence, as measured in the current investigation, the variables included cannot be used to predict ACL injury risk. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

The transverse ligament as a landmark for tibial sagittal insertions of the anterior cruciate ligament: a cadaveric study.

PubMed

Kongcharoensombat, Wirat; Ochi, Mitsuo; Abouheif, Mohamed; Adachi, Nobuo; Ohkawa, Shingo; Kamei, Goki; Okuhara, Atushi; Shibuya, Hoyatoshi; Niimoto, Takuya; Nakasa, Tomoyuki; Nakamae, Atsuo; Deie, Masataka

2011-10-01

The purpose of this study was to determine the relation between the position of the transverse ligament, the anterior edge of the anterior cruciate ligament (ACL) tibial footprint, and the center of the ACL tibial insertion. We used arthroscopy for localization of the anatomic landmarks, followed by insertions of guide pins under direct visualization, and then the position of these guide pins was checked on plain lateral radiographs. The transverse ligament and the anterior aspect of the ACL tibial footprint were identified by arthroscopy in 20 unpaired cadaveric knees (10 left and 10 right). Guide pins were inserted with tibial ACL adapter drill guides under direct observation at the transverse ligament, the anterior aspect of the tibial footprint, and the center of tibial insertion of the ACL. Then, plain lateral radiographs of specimens were taken. The Amis and Jakob line was used to define the attachment of the ACL tibial insertion and the transverse ligament. A sagittal percentage of the location of the insertion point was determined and calculated from the anterior margin of the tibia in the anteroposterior direction. The transverse ligament averaged 21.20% ± 4.1%, the anterior edge of the ACL tibial insertion averaged 21.60% ± 4.0%, and the center of the ACL tibial insertion averaged 40.30% ± 4.8%. There were similar percent variations between the transverse ligament and the anterior edge of the ACL tibial insertion, with no significant difference between them (P = .38). Intraobserver and interobserver reliability was high, with small standard errors of measurement. This study shows that the transverse ligament coincides with the anterior edge of the ACL tibial footprint in the sagittal plane. The transverse ligament can be considered as a new landmark for tibial tunnel positioning during anatomic ACL reconstruction. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stone, J.P.; Holtsman, S.; Shellabarger, C.J.

Pellets containing 5 mg (/sup 3/H) diethylstilbestrol (DES) and 15 mg cholesterol were implanted S.C. in 84-day-old female Sprague-Dawley (S-D) and ACl rats. DES was released from the implanted pellets exponentially, and the release was not significantly different in S-D rats than in ACl rats. No mammary tumors developed in any treated or untreated S-D rats. In contrast, 90% of the DES-treated ACl rats developed mammary adenocarcinomas. A significant increase in the weight of the pituitary was noted in DES-treated ACl rats. The pituitarities of the treated ACl rats were 2 to 7 times as heavy as were controls, andmore » plasma prolactin levels were 10 to 40 times higher than in controls. In contrast, the pituitaries of treated S-D rats did not significantly increase in weight, and plasma prolactin levels were only 3 to 5 times higher than controls. The uteri of treated S-D rats were significantly heavier than those of control rats and contained large amounts of fluid. This effect was not seen in ACl rats. Although the release of DES from the implanted pellet was essentially the same in ACl and S-D rats, three distinctive strain differences in response to DES were noted: mammary adenocarcinomas were found only in treated ACl rats; pituitary prolactin-cell adenomas and associated elevated plasma prolactins levels were seen only in treated ACl rats; and pyometritis was induced only in treated S-D rats. Mammary adenocarcinomas and prolactin-cell adenoma responses in the treated ACl rats appear to be correlated with the increasing levels of plasma prolactin. This study demonstrates that the prolonged estrogen treatment of ACl and S-D female rats produces distinctly different mammary and pituitary neoplastic responses. This disparity in neoplastic responses appears to be reflected in the difference of degree to which the hypophysical prolactin cells are stimulated to grow and secrete hormone.« less

Osteoarthritis prevalence following anterior cruciate ligament reconstruction: a systematic review and numbers-needed-to-treat analysis.

PubMed

Luc, Brittney; Gribble, Phillip A; Pietrosimone, Brian G

2014-01-01

To determine the prophylactic capability of anterior cruciate ligament (ACL) reconstruction in decreasing the risk of knee osteoarthritis (OA) when compared with ACL-deficient patients, as well as the effect of a concomitant meniscectomy. We also sought to examine the influence of study design, publication date, and graft type as well as the magnitude of change in physical activity from preinjury Tegner scores in both cohorts. We searched Web of Science and PubMed databases from 1960 through 2012 with the search terms osteoarthritis, meniscectomy, anterior cruciate ligament, anterior cruciate ligament reconstruction, and anterior cruciate ligament deficient. Articles that reported the prevalence of tibiofemoral or patellofemoral OA based on radiographic assessment were included. We calculated numbers needed to treat and relative risk reduction with associated 95% confidence intervals for 3 groups (1) patients with meniscal and ACL injury, (2) patients with isolated ACL injury, and (3) total patients (groups 1 and 2). A total of 38 studies met the criteria. Of these, 27 assessed the presence of tibiofemoral osteoarthritis in patients treated with anterior cruciate ligament reconstruction. Overall, ACL reconstruction (ACL-R) yielded a numbers needed to treat to harm of 16 with a relative risk increase of 16%. Anterior cruciate ligament reconstruction along with meniscectomy yielded a numbers needed to treat to benefit of 15 and relative risk reduction of 11%. Isolated ACL-R showed a numbers needed to treat to harm of 8 and relative risk increase of 43%. Activity levels were decreased in both ACL-R (d = -0.90; 95% confidence interval = 0.77, 1.13) and ACL-deficient (d = -1.13; 95% confidence interval = 0.96, 1.29) patients after injury. The current literature does not provide substantial evidence to suggest that ACL-R is an adequate intervention to prevent knee osteoarthritis. With regard to osteoarthritis prevalence, the only patients benefiting from ACL-R were those undergoing concomitant meniscectomy with reconstruction.

Mechanisms of ACL injury in professional rugby union: a systematic video analysis of 36 cases.

PubMed

Montgomery, Connor; Blackburn, Jeff; Withers, Daniel; Tierney, Gregory; Moran, Cathal; Simms, Ciaran

2016-12-30

The mechanisms of ACL injury in rugby are not well defined. To describe the mechanisms of ACL injury in male professional rugby players using systematic video analysis. 36 cases from games played in top professional leagues and international matches were analysed. 5 analysts independently assessed all videos to record the estimated frame/time of initial ground contact, frame/time of ACL tear and a range of play specific variables. This included contact versus non-contact ACL injuries, injury timing, joint flexion angles and foot contact with the ground. 37 side-stepping manoeuvres from a control game were analysed to allow comparison of non-injury versus injury situations. 57% of ACL injuries occurred in a contact manner. 2 main scenarios were identified: (1) offensive running and (2) being tackled, indicating that the ball carrier might be at higher risk of ACL injury. The majority of non-contact ACL injuries resulted from a side-stepping manoeuvre. In most non-contact cases, initial ground contact was through heel strike. Statistical assessment of heel strike at initial ground contact versus non-heel strike cases showed a significant difference in injury versus non-injury outcomes, with heel strike associated with higher injury risk. Non-contact ACL injuries had lower median knee flexion angles and a more dorsiflexed ankle when compared with a control group (10° vs 20°, p≤0.001 and 10° vs 0°, p=0.033 respectively). Over half of ACL injuries in rugby in our analysis resulted from a contact mechanism. For non-contact injuries, lower knee flexion angles and heel-first ground contact in a side-stepping manoeuvre were associated with ACL injury. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Variations of Leaf Cuticular Waxes Among C3 and C4 Gramineae Herbs.

PubMed

He, Yuji; Gao, Jianhua; Guo, Na; Guo, Yanjun

2016-11-01

Modern C4 plants are commonly distributed in hot and dry environments whereas C3 plants predominate in cool and shade areas. At the outmost of plant surface, the deposition and chemical composition of cuticular waxes vary under different environmental conditions. However, whether such variation of cuticular wax is related to the distribution of C3 and C4 under different environmental conditions is still not clear. In this study, leaves of six C3 Gramineae herbs distributed in spring, Roegneria kamoji, Polypogon fugax, Poa annua, Avena fatua, Alopecurus aequalis, and Oplismenus undulatifolius, and four C4 and one C3 Gramineae herbs distributed in summer, Digitaria sanguinalis, Eleusine indica, Setaria viridis, S. plicata, and O. undulatifolius, were sampled and analyzed for cuticular wax. Plates were the main epicuticular wax morphology in both C3 and C4 plants except S. plicata. The plates melted in C4 plants but not in C3 plants. The total cuticular wax amounts in C4 plants were significantly lower than those in C3 plants, except for O. undulatifolius. Primary alcohols were the most abundant compounds in C3 plants, whereas n-alkanes were relatively the most abundant compounds in C4 plants. C 29 was the most abundant n-alkane in C3 plants except for O. undulatifolius, whereas the most abundant n-alkane was C 31 or C 33 in C4 plants. The average chain length (ACL) of n-alkanes was higher in C4 than in C3 plants, whereas the ACL of n-alkanoic acids was higher in C3 than C4 plants. The cluster analysis based on the distribution of n-alkanes clearly distinguished C3 and C4 plants into two groups, except for O. undulatifolius which was grouped with C4 plants. These results suggest that the variations of cuticular waxes among C3 and C4 Gramineae herbs are related to the distribution of C3 and C4 plants under different environmental conditions. © 2016 Wiley-VHCA AG, Zurich, Switzerland.

Combined injuries of the medial collateral ligament and the anterior cruciate ligament. Early ACL reconstruction versus late ACL reconstruction.

PubMed

Petersen, W; Laprell, H

1999-01-01

Aim of this retrospective study is to evaluate the effect of acute and late anterior cruciate ligament (ACL) reconstruction in patients with a combined injury of the ACL and the medial collateral ligament (MCL). All MCL injuries were treated non-operatively. In 27 patients (group I) we performed early ACL reconstruction (within the first 3 weeks after injury). The postoperative rehabilitation protocol included brace treatment for all patients over a period of 6 weeks. In 37 patients we performed late ACL reconstruction (after a minimum of 10 weeks). In this group initial non-operative MCL treatment (6 weeks brace treatment) was followed by a period of accelerated rehabilitation. Patients with late ACL reconstruction had a lower rate of loss of motion after finishing the postoperative rehabilitation programme and a lower rate of re-arthroscopies for a loss of extension (group I: 4 patients, group II: 1 patient). The difference in the mean quadriceps muscle strength (group I: 83.3%, group II: 86.3%) was not statistically significant. After a mean interval of 22 months, we saw no difference in the frequency of anterior or medial instabilities or in the loss of motion. The Lysholm score was significantly better in the group with late ACL reconstruction (group I: 85.3, group II: 89.9). The position on the Tegner activity scale decreased in both groups, to 5.5 in group I (preoperatively: 6.0) and to 5.6 in group II (preoperatively: 5.9). With regard to the lower rate of motion complications in the early postoperative period, the lower rate of re-arthroscopies, and the significantly better results in the Lysholm score, we prefer late ACL reconstruction in the treatment of combined injuries of the ACL and the MCL.

Rate and Risk of Anterior Cruciate Ligament Injury Among Sportswomen in Slovenia

PubMed Central

Vauhnik, Renata; Morrissey, Matthew C.; Rutherford, Olga M.; Turk, Zmago; Pilih, Iztok A.; Perme, Maja Pohar

2011-01-01

Abstract Context: Anterior cruciate ligament (ACL)-injury rate is greater among female athletes than among male athletes. Objective: To investigate the rate and risk of ACL injury among Slovenian sportswomen playing professional basketball, team handball, or volleyball. Design: Prospective cohort study. Setting: The Slovenian National Organizations of basketball, team handball, and volleyball. Patients or Other Participants: During the 2003–2004 season, we prospectively followed 585 Slovenian sportswomen registered in the Slovenian National Organizations of basketball, team handball, and volleyball. Main Outcome Measure(s): We asked sportswomen and coaches to document the occurrence of every significant traumatic knee injury requiring medical attention. Injury rate and injury risk were calculated for sportswomen in each sport group. To calculate injury rate, we estimated the average exposure of each sportswoman during the research period. Results: During the 2003–2004 season, 585 Slovenian sportswomen sustained 12 ACL injuries. The ACL-injury risk was different in athletes participating in the various sports, with basketball players having the greatest ACL-injury risk and volleyball players having the lowest ACL-injury risk (P  =  .04). The risk of ACL injury among Slovenian sportswomen was 2.1 per 100 athletes (95% confidence interval  =  0.9, 3.2), whereas the rate of ACL injury was 0.037 per 1000 exposure hours (95% confidence interval  =  0.016, 0.06). Conclusions: Overall differences in injury risk were found among sports, but no differences were noted among divisions within sports. No differences for injury rate were observed between or within sports. The rate and risk of ACL injury among Slovenian sportswomen are high, with basketball players having the greatest ACL-injury risk. PMID:21214356

Jumping performance differences among elite professional handball players with or without previous ACL reconstruction.

PubMed

Setuain, I; Millor, N; Alfaro, J; Gorostiaga, E; Izquierdo, M

2015-10-01

Handball is one of the most challenging sports for the knee joint. Persistent strength and jumping capacity alterations may be observed among athletes who have suffered anterior cruciate ligament (ACL) injury. The aim of this study was to examine unilateral and bilateral jumping ability differences between previously ACL-reconstructed rehabilitated elite handball athletes and sex, age and uninjured sport activity level-pairs of control players. It was a Cross-sectional study with one factor: previous ACL injury. We recruited 22 male (6 ACL-reconstructed and 16 uninjured control players) and 21 female (6 ACL-reconstructed and 15 uninjured control players) elite handball players who were evaluated 6.2±3.4 years after surgical ACL reconstruction. A battery of jump tests, including both bilateral and unilateral maneuvers, was performed. Two-tailed unpaired (intergroup comparison) and paired (intragroup comparison) t-tests were performed for mean comparisons. The P-value cut-off for significance was set at <0.05. The previously ACL-reconstructed female athletes showed a lower bilateral drop jump contact time (0.429±179.9 vs. 0.349±151 s, P<0.05) and less distance reached (3.820±0.54 vs. 4.428±0.44 m, P<0.05) in the unilateral triple hop for distance (UTHD) on their reconstructed leg compared with the dominant legs of the uninjured control athletes. No significant differences were observed for any other recorded variable. Among the male athletes, no significant differences between groups were found for the studied jumping variables. Previously ACL-reconstructed elite female handball athletes demonstrated both lower vertical bilateral drop jump (VBDJ) contact times and lower UTHD scores for the injured leg several years after injury. These deficits could contribute to an increase in ACL re-injury risk.

Genome-wide association analysis in dogs implicates 99 loci as risk variants for anterior cruciate ligament rupture

PubMed Central

Baker, Lauren A.; Kirkpatrick, Brian; Rosa, Guilherme J. M.; Gianola, Daniel; Valente, Bruno; Sumner, Julia P.; Baltzer, Wendy; Hao, Zhengling; Binversie, Emily E.; Volstad, Nicola; Piazza, Alexander; Sample, Susannah J.

2017-01-01

Anterior cruciate ligament (ACL) rupture is a common condition that can be devastating and life changing, particularly in young adults. A non-contact mechanism is typical. Second ACL ruptures through rupture of the contralateral ACL or rupture of a graft repair is also common. Risk of rupture is increased in females. ACL rupture is also common in dogs. Disease prevalence exceeds 5% in several dog breeds, ~100 fold higher than human beings. We provide insight into the genetic etiology of ACL rupture by genome-wide association study (GWAS) in a high-risk breed using 98 case and 139 control Labrador Retrievers. We identified 129 single nucleotide polymorphisms (SNPs) within 99 risk loci. Associated loci (P<5E-04) explained approximately half of phenotypic variance in the ACL rupture trait. Two of these loci were located in uncharacterized or non-coding regions of the genome. A chromosome 24 locus containing nine genes with diverse functions met genome-wide significance (P = 3.63E-0.6). GWAS pathways were enriched for c-type lectins, a gene set that includes aggrecan, a gene set encoding antimicrobial proteins, and a gene set encoding membrane transport proteins with a variety of physiological functions. Genotypic risk estimated for each dog based on the risk contributed by each GWAS locus showed clear separation of ACL rupture cases and controls. Power analysis of the GWAS data set estimated that ~172 loci explain the genetic contribution to ACL rupture in the Labrador Retriever. Heritability was estimated at 0.48. We conclude ACL rupture is a moderately heritable highly polygenic complex trait. Our results implicate c-type lectin pathways in ACL homeostasis. PMID:28379989

[Arthroscopic refixation of acute proximal anterior cruciate ligament rupture using suture anchors].

PubMed

Achtnich, A; Rosslenbroich, S; Beitzel, K; Imhoff, A B; Petersen, W

2017-04-01

Arthroscopic assisted suture anchor refixation combined with microfracturing of the femoral ACL insertion zone in cases of acute proximal anterior cruciate ligament (ACL) rupture to restore anatomical and biomechanical properties of the native ACL. Acute proximal ACL rupture/avulsion, multiligament injury of the knee CONTRAINDICATIONS: Chronic (>6 weeks) proximal ACL rupture, intraligamentary rupture, as well as previous ACL surgery. Arthroscopic examination of the knee joint, debridement of the femoral insertion zone, examination of the ligament quality by a probe, insertion of a curved lasso through the ACL to place the sutures and use of a drill guide to place the anchor in the middle of the femoral ACL insertion. Microfracturing holes around the femoral footprint were made by an awl to enhance healing properties of the ACL. Partial weight bearing was permitted and crutches were used for 6 weeks, knee brace limited for the first 2 weeks 0‑0-0°, then 0‑0-90° for the following 4 weeks. A total of 20 patients who underwent acute proximal ACL suture anchor refixation were evaluated after a mean follow-up of 28 months. Regarding stability, mean values of the KT-1000 arthrometer indicated stable results (<3 mm), 3 patients had a 1+ Lachman and 4 patients had a 1+ pivot shift. IKDC (International Knee Documentation Committee) score indicated that 17 cases were very good to good (12A, 4B) and in 3 cases the results were satisfactory (3C). Magnetic resonance imaging showed that the ALC was found to be intact in 17 cases. The total rate of revision was 15 % (3/20) because of recurrent instability.

ATP citrate lyase activity is post-translationally regulated by sink strength and impacts the wax, cutin and rubber biosynthetic pathways.

PubMed

Xing, Shufan; van Deenen, Nicole; Magliano, Pasqualina; Frahm, Lea; Forestier, Edith; Nawrath, Christiane; Schaller, Hubert; Gronover, Christian S; Prüfer, Dirk; Poirier, Yves

2014-07-01

Cytosolic acetyl-CoA is involved in the synthesis of a variety of compounds, including waxes, sterols and rubber, and is generated by the ATP citrate lyase (ACL). Plants over-expressing ACL were generated in an effort to understand the contribution of ACL activity to the carbon flux of acetyl-CoA to metabolic pathways occurring in the cytosol. Transgenic Arabidopsis plants synthesizing the polyester polyhydroxybutyrate (PHB) from cytosolic acetyl-CoA have reduced growth and wax content, consistent with a reduction in the availability of cytosolic acetyl-CoA to endogenous pathways. Increasing the ACL activity via the over-expression of the ACLA and ACLB subunits reversed the phenotypes associated with PHB synthesis while maintaining polymer synthesis. PHB production by itself was associated with an increase in ACL activity that occurred in the absence of changes in steady-state mRNA or protein level, indicating a post-translational regulation of ACL activity in response to sink strength. Over-expression of ACL in Arabidopsis was associated with a 30% increase in wax on stems, while over-expression of a chimeric homomeric ACL in the laticifer of roots of dandelion led to a four- and two-fold increase in rubber and triterpene content, respectively. Synthesis of PHB and over-expression of ACL also changed the amount of the cutin monomer octadecadien-1,18-dioic acid, revealing an unsuspected link between cytosolic acetyl-CoA and cutin biosynthesis. Together, these results reveal the complexity of ACL regulation and its central role in influencing the carbon flux to metabolic pathways using cytosolic acetyl-CoA, including wax and polyisoprenoids. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Gender Dimorphic ACL Strain In Response to Combined Dynamic 3D Knee Joint Loading: Implications for ACL Injury Risk

PubMed Central

Mizuno, Kiyonori; Andrish, Jack T.; van den Bogert, Antonie J.; McLean, Scott G.

2009-01-01

While gender-based differences in knee joint anatomies/laxities are well documented, the potential for them to precipitate gender-dimorphic ACL loading and resultant injury risk has not been considered. To this end, we generated gender-specific models of ACL strain as a function of any six degrees of freedom (6DOF) knee joint load state via a combined cadaveric and analytical approach. Continuously varying joint forces and torques were applied to five male and five female cadaveric specimens and recorded along with synchronous knee flexion and ACL strain data. All data (~10,000 samples) were submitted to specimen-specific regression analyses, affording ACL strain predictions as a function of the combined 6 DOF knee loads. Following individual model verifications, generalized gender-specific models were generated and subjected to 6 DOF external load scenarios consistent with both a clinical examination and a dynamic sports maneuver. The ensuing model-based strain predictions were subsequently examined for gender-based discrepancies. Male and female specimen specific models predicted ACL strain within 0.51% ± 0.10% and 0.52% ± 0.07% of the measured data respectively, and explained more than 75% of the associated variance in each case. Predicted female ACL strains were also significantly larger than respective male values for both of simulated 6 DOF load scenarios. Outcomes suggest that the female ACL will rupture in response to comparatively smaller external load applications. Future work must address the underlying anatomical/laxity contributions to knee joint mechanical and resultant ACL loading, ultimately affording prevention strategies that may cater to individual joint vulnerabilities. PMID:19464897

A numerical simulation approach to studying anterior cruciate ligament strains and internal forces among young recreational women performing valgus inducing stop-jump activities.

PubMed

Kar, Julia; Quesada, Peter M

2012-08-01

Anterior cruciate ligament (ACL) injuries are commonly incurred by recreational and professional women athletes during non-contact jumping maneuvers in sports like basketball and volleyball, where incidences of ACL injury is more frequent to females compared to males. What remains a numerical challenge is in vivo calculation of ACL strain and internal force. This study investigated effects of increasing stop-jump height on neuromuscular and bio-mechanical properties of knee and ACL, when performed by young female recreational athletes. The underlying hypothesis is increasing stop-jump (platform) height increases knee valgus angles and external moments which also increases ACL strain and internal force. Using numerical analysis tools comprised of Inverse Kinematics, Computed Muscle Control and Forward Dynamics, a novel approach is presented for computing ACL strain and internal force based on (1) knee joint kinematics and (2) optimization of muscle activation, with ACL insertion into musculoskeletal model. Results showed increases in knee valgus external moments and angles with increasing stop-jump height. Increase in stop-jump height from 30 to 50 cm lead to increase in average peak valgus external moment from 40.5 ± 3.2 to 43.2 ± 3.7 Nm which was co-incidental with increase in average peak ACL strain, from 9.3 ± 3.1 to 13.7 ± 1.1%, and average peak ACL internal force, from 1056.1 ± 71.4 to 1165.4 ± 123.8 N for the right side with comparable increases in the left. In effect this study demonstrates a technique for estimating dynamic changes to knee and ACL variables by conducting musculoskeletal simulation on motion analysis data, collected from actual stop-jump tasks performed by young recreational women athletes.

Functionalized Lipid-Polymer Hybrid Nanoparticles Mediated Codelivery of Methotrexate and Aceclofenac: A Synergistic Effect in Breast Cancer with Improved Pharmacokinetics Attributes.

PubMed

Garg, Neeraj K; Tyagi, Rajeev K; Sharma, Gajanand; Jain, Ashay; Singh, Bhupinder; Jain, Sanyog; Katare, O P

2017-06-05

The present study was aimed to coencapsulate methotrexate (MTX) and aceclofenac (ACL) in fucose anchored lipid-polymer hybrid nanoparticles (Fu-LPHNPs) to achieve target specific and controlled delivery for developing therapeutic interventions against breast cancer. The effective combination therapy requires coadministration of drugs to achieve synergistic effect on tumor with minimum adverse effects. Present study investigates the potential of codelivery of MTX and ACL through LPHNPs in MCF-7 and triple negative breast cancer cells (MDA-MB-231). We obtained LPHNPs in the nanosize range (<150 nm) with better particle size distribution (<0.3). The entrapment and loading efficiency of MTX and ACL was calculated as 85-90% and 10-12%, respectively. The coumarin-6 LPHNP formulations showed rapid internalization within 2 h incubation with MCF-7 and MDA-MB-231 cells. With 8-10 times, greater bioavailability of drug-loaded LPHNPs than free MTX and ACL was obtained. Also, antitumor efficacy of MTX- and ACL-loaded LPHNPs was determined on DMBA-induced experimental breast cancer mouse model. This model showed better control over tumor growth with MTX- and ACL-loaded LPHNPs than the combination of MTX and ACL or MTX alone. ACL-loaded LPHNPs showed prophylactic and anticancer activity in DMBA-induced mouse model at higher dose (10 mg/kg). ACL-LPHNPs confer synergistic anticancer effect when administered in combination with MTX. In conclusion, ACL enhances the therapeutic and anticancer efficacy of MTX, when coencapsulated into fucose-anchored LPHNPs, as confirmed by cell viability and serum angiogenesis (IL-6, TNF-α, IL-1β, COX2, and MMP1) at both transcript and proteome level.

Certain Chemical Substances Containing Varying Carbon Chain Lengths (Alkyl Ranges Using the Cx-y Notation) on the TSCA Inventory

EPA Pesticide Factsheets

This paper explains the conventions that are applied to certain listings of chemical substances containing ranges of alkyl chain lengths (i.e., carbon chains of varying lengths) for chemical substances on the Toxic Substances Control Act (TSCA)

50 CFR 648.120 - Catch quotas and other restrictions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Limit (ACL). (a) The Scup Monitoring Committee shall recommend to the MAFMC separate ACLs for the... frequently exceeded. (2) The MAFMC may specify more frequent or more specific ACL performance review criteria...

Change-of-Direction Biomechanics: Is What's Best for Anterior Cruciate Ligament Injury Prevention Also Best for Performance?

PubMed

Fox, Aaron S

2018-05-02

Change-of-direction maneuvers (e.g., side-step cutting) are an important aspect of performance in multi-directional sports, but these maneuvers are also associated with anterior cruciate ligament (ACL) injury. Despite this, the impact of biomechanics on ACL injury risk and performance is often examined in isolation. The purpose of this review was to examine the alignment between biomechanical recommendations for ACL injury prevention and performance with regard to change-of-direction maneuvers. Several studies linking change-of-direction biomechanics to both ACL injury risk and performance were examined. A degree of overlap was identified between biomechanical strategies that could both reduce ACL injury risk and enhance performance during change-of-direction maneuvers. A fore-foot footfall pattern along with trunk rotation and lateral flexion in the intended cutting direction were identified as biomechanical strategies that could both reduce potentially hazardous knee joint moments and enhance change-of-direction speed. Minimizing knee valgus during change-of-direction maneuvers may also reduce ACL injury risk, with this biomechanical strategy found to have no impact on performance. Certain biomechanical strategies proposed to reduce ACL injury risk were linked to reduced change-of-direction performance. A narrow foot placement and "soft" landings with greater knee flexion were identified as ACL injury prevention strategies that could have a negative impact on performance. The findings of this review emphasize the need to consider both ACL injury risk and performance when examining the biomechanics of change-of-direction maneuvers.

Influenza vaccination can induce new onset anticardiolipins but not β2-glycoprotein-I antibodies among patients with systemic lupus erythematosus

PubMed Central

Vista, Evan S.; Crowe, Sherry R.; Thompson, Linda F.; Air, Gillian M.; Robertson, Julie M.; Guthridge, Joel M.; James, Judith A.

2012-01-01

Summary Background Antiphospholipid syndrome is characterized by autoantibodies against cardiolipins (aCL), lupus anticoagulant, and independent β2-glycoprotein (β2GPI). Controversy exists as to whether vaccination triggers the development of anti-phospholipid antibodies (aPL) in systemic lupus erythematosus (SLE) patients. Methods SLE patients (101) and matched controls (101) were enrolled from 2005 to 2009 and received seasonal influenza vaccinations. Sera were tested by ELISA for aCL at baseline, 2, 6, and 12 weeks after vaccination. Vaccine responses were ranked according to an overall anti-influenza antibody response index. Individuals with positive aCL were further tested for β2GPI antibodies. Results SLE patients and healthy controls developed new onset aCL post-vaccination (12/101 cases and 7/101 controls, OR 1.81, p=0.34). New onset moderate aCL are slightly enriched in African American SLE patients (5/36 cases; p=0.094). The optical density (OD) measurements for aCL reactivity in patients were significantly higher than baseline at 2 weeks (p<0.05), 6 weeks (p<0.05), and 12 weeks (p<0.05) post vaccination. No new β2GPI antibodies were detected among patients with new aCL reactivity. Vaccine response was not different between patients with and without new onset aCL reactivity (p=0.43). Conclusions This study shows transient increases in aCL, but not anti-β2GPI responses, after influenza vaccination. PMID:22235049

Asymmetric ground reaction forces and knee kinematics during squat after anterior cruciate ligament (ACL) reconstruction.

PubMed

Sanford, Brooke A; Williams, John L; Zucker-Levin, Audrey; Mihalko, William M

2016-10-01

This bilateral squat study tests whether people with anterior cruciate ligament (ACL) reconstruction have symmetric three-dimensional ground reaction forces (GRFs) and symmetric anterior-posterior (AP) translation rates of the femur with respect to the tibia when compared with healthy control subjects. We hypothesized that there would be no long-term asymmetry in knee kinematics and kinetics in ACL reconstructed subjects following surgery and rehabilitation. Position and GRF data were collected on eight ACL reconstructed and eight control subjects during bilateral squat. The rate of relative AP translation was determined for each subject. Principal component models were developed for each of the three GRF waveforms. Principal component scores were used to assess symmetry within the ACL reconstructed group and within the control group. ACL reconstructed knees analyzed in early flexion during squat descent displayed a four-fold greater rate of change in anterior translation in the reconstructed knee relative to the contralateral side than did a similar comparison of normal knees. Differences were found between the ACL reconstructed subjects' injured and uninjured limbs for all GRFs. Subjects following ACL reconstruction had asymmetric GRFs and relative rates of AP translation at an average of seven years after ACL reconstructive surgery when compared with control subjects. These alterations in loading may lead to altered load distributions across the knee joint and may put some subjects at risk for future complications such as osteoarthritis. Copyright © 2015 Elsevier B.V. All rights reserved.

Altered lower extremity joint mechanics occur during the star excursion balance test and single leg hop after ACL-reconstruction in a collegiate athlete.

PubMed

Samaan, Michael A; Ringleb, Stacie I; Bawab, Sebastian Y; Greska, Eric K; Weinhandl, Joshua T

2018-03-01

The effects of ACL-reconstruction on lower extremity joint mechanics during performance of the Star Excursion Balance Test (SEBT) and Single Leg Hop (SLH) are limited. The purpose of this study was to determine if altered lower extremity mechanics occur during the SEBT and SLH after ACL-reconstruction. One female Division I collegiate athlete performed the SEBT and SLH tasks, bilaterally, both before ACL injury and 27 months after ACL-reconstruction. Maximal reach, hop distances, lower extremity joint kinematics and moments were compared between both time points. Musculoskeletal simulations were used to assess muscle force production during the SEBT and SLH at both time points. Compared to the pre-injury time point, SEBT reach distances were similar in both limbs after ACL-reconstruction except for the max anterior reach distance in the ipsilateral limb. The athlete demonstrated similar hop distances, bilaterally, after ACL-reconstruction compared to the pre-injury time point. Despite normal functional performance during the SEBT and SLH, the athlete exhibited altered lower extremity joint mechanics during both of these tasks. These results suggest that measuring the maximal reach and hop distances for these tasks, in combination with an analysis of the lower extremity joint mechanics that occur after ACL-reconstruction, may help clinicians and researchers to better understand the effects of ACL-reconstruction on the neuromuscular system during the SEBT and SLH.

"I never made it to the pros…" Return to sport and becoming an elite athlete after pediatric and adolescent anterior cruciate ligament injury-Current evidence and future directions.

PubMed

Hamrin Senorski, Eric; Seil, Romain; Svantesson, Eleonor; Feller, Julian A; Webster, Kate E; Engebretsen, Lars; Spindler, Kurt; Siebold, Rainer; Karlsson, Jón; Samuelsson, Kristian

2018-04-01

The management of anterior cruciate ligament (ACL) injuries in the skeletally immature and adolescent patient remains an area of controversy in sports medicine. This study, therefore, summarizes and discusses the current evidence related to treating pediatric and adolescent patients who sustain an ACL injury. The current literature identifies a trend towards ACL reconstruction as the preferred treatment option for ACL injuries in the young, largely justified by the risk of further structural damage to the knee joint. Worryingly, a second ACL injury is all too common in the younger population, where almost one in every three to four young patients who sustain an ACL injury and return to high-risk pivoting sport will go on to sustain another ACL injury. The clinical experience of these patients emphasizes the rarity of an athlete who makes it to elite level after a pediatric or adolescent ACL injury, with or without reconstruction. If these patients are unable to make it to an elite level of sport, treatment should possibly be modified to take account of the risks associated with returning to pivoting and strenuous sport. The surveillance of young athletes may be beneficial when it comes to reducing injuries. Further research is crucial to better understand specific risk factors in the young and to establish independent structures to allow for unbiased decision-making for a safe return to sport after ACL injury. Level of evidence V.

Trends in Pediatric and Adolescent Anterior Cruciate Ligament Injuries in Victoria, Australia 2005–2015

PubMed Central

Shaw, Louise; Finch, Caroline F.

2017-01-01

Anterior cruciate ligament (ACL) injuries in children and adolescents have been the focus of recent media attention and parental concern, given their potential for adverse long-term health outcomes and healthcare costs. However, there is limited formal evidence on trends in the incidence of ACL injuries in children. This study utilizes the Victorian Admitted Episodes Dataset (VAED) to characterize epidemiologic trends of hospital-admitted ACL injuries in those aged 5 to 14 years over a period of 10 years from 2005 to 2015. There was a total of 320 cases and the overall annual rate of ACL injuries increased by 147.8% from 2.74 per 100,000 population in 2005/2006 to 6.79 per 100,000 in 2014/2015. The majority (96.9%) of these injuries were in 10- to 14-year-olds. The main in-hospital procedure provided to over 80% of the hospitalized cases involved ACL reconstruction. Sporting activities accounted for 56.6% of ACL injuries. For females, over half (52.4%) of ACL injuries occurred whilst playing ball sports, compared to 35.4% of males. The large increase in ACL injuries in 5- to 14-year-olds in the state of Victoria, Australia over a 10-year period indicates they are a significant and emerging health burden. Population-wide ACL prevention policies are required to halt these trends. Cost effective prevention programs that involve neuromuscular training must be implemented in schools and junior sports teams. PMID:28587262

76 FR 61995 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; Emergency Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-06

...) and Annual Catch Limit (ACL) for GB yellowtail flounder for an additional 186 days, i.e., through the... revised GB yellowtail flounder catch limits for FY 2011, as follows: A U.S. ABC of 1,458 mt; a total ACL of 1,416 mt; a groundfish sub-ACL of 1,142 mt; a scallop fishery sub-ACL of 200.8 mt; and an Other...

Effects of the menstrual cycle on lower-limb biomechanics, neuromuscular control, and anterior cruciate ligament injury risk: a systematic review.

PubMed

Balachandar, Vivek; Marciniak, Jan-Luigi; Wall, Owen; Balachandar, Chandrika

2017-01-01

Anterior cruciate ligament (ACL) injury has a devastating impact on physical and psychological disability. Rates of ACL rupture are significantly greater in females than males during the same sports. Hormonal mechanisms have been proposed but are complex and poorly understood. This systematic review evaluates the effects of menstrual cycle on: 1) lower-limb biomechanics, 2) neuromuscular control, and 3) ACL injury risk. The MEDLINE, CINAHL, SPORTSDiscus, Web of Science, and Google Scholar databases were searched from inception to August 2016 for studies investigating the effects of the menstrual cycle on lower-limb biomechanics, neuromuscular control, and ACL injury risk in females. Three independent reviewers assessed each paper for inclusion and two assessed for quality. Seventeen studies were identified. There is strong evidence that: 1) greatest risk of ACL injury is within the pre-ovulatory phase of the menstrual cycle, and 2) females with greater ACL laxity in the pre-ovulatory phase experience greater knee valgus and greater tibial external rotation during functional activity. Females are at greatest risk of ACL injury during the pre-ovulatory phase of the menstrual cycle through a combination of greater ACL laxity, greater knee valgus, and greater tibial external rotation during functional activity. Ib.

Effects of knee injury primary prevention programs on anterior cruciate ligament injury rates in female athletes in different sports: a systematic review.

PubMed

Michaelidis, Michael; Koumantakis, George A

2014-08-01

Anterior Cruciate Ligament (ACL) injury is frequently encountered in sports. To analyze the effects of ACL injury prevention programs on injury rates in female athletes between different sports. A comprehensive literature search was performed in September 2012 using Pubmed Central, Science Direct, CINAHL, PEDro, Cochrane Library, SCOPUS, SPORTDiscus. The key words used were: 'anterior cruciate ligament', 'ACL', 'knee joint', 'knee injuries', 'female', 'athletes', 'neuromuscular', 'training', 'prevention'. The inclusion criteria applied were: (1) ACL injury prevention training programs for female athletes; (2) Athlete-exposure data reporting; (3) Effect of training on ACL incidence rates for female athletes. 13 studies met the inclusion criteria. Three training programs in soccer and one in handball led to reduced ACL injury incidence. In basketball no effective training intervention was found. In season training was more effective than preseason in ACL injury prevention. A combination of strength training, plyometrics, balance training, technique monitoring with feedback, produced the most favorable results. Comparing the main components of ACL injury prevention programs for female athletes, some sports-dependent training specificity issues may need addressing in future studies, related primarily to the individual biomechanics of each sport but also their most effective method of delivery. Copyright © 2013 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, D.W.; Boparai, A.S.; Bowers, D.L.

This report summarizes the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 2000 (October 1999 through September 2000). This annual progress report, which is the seventeenth in this series for the ACL, describes effort on continuing projects, work on new projects, and contributions of the ACL staff to various programs at ANL. The ACL operates within the ANL system as a full-cost-recovery service center, but it has a mission that includes a complementary research and development component: The Analytical Chemistry Laboratory will provide high-quality, cost-effective chemical analysis and related technical support tomore » solve research problems of our clients--Argonne National Laboratory, the Department of Energy, and others--and will conduct world-class research and development in analytical chemistry and its applications. The ACL handles a wide range of analytical problems that reflects the diversity of research and development (R&D) work at ANL. Some routine or standard analyses are done, but the ACL operates more typically in a problem-solving mode in which development of methods is required or adaptation of techniques is needed to obtain useful analytical data. The ACL works with clients and commercial laboratories if a large number of routine analyses are required. Much of the support work done by the ACL is very similar to applied analytical chemistry research work.« less

Anteroposterior Stability of the Knee during the Stance Phase of Gait after Anterior Cruciate Ligament Deficiency

PubMed Central

Chen, CH; Li, JS; Hosseini, A; Gadikota, HR; Gill, TJ; Li, G

2011-01-01

Quadriceps avoidance and higher flexion strategy 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, ten 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 image 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. PMID:22169387

DOE Office of Scientific and Technical Information (OSTI.GOV)

Do-Dai, D.D.; Youngberg, R.A.; Lanchbury, F.D.

Magnetic resonance findings with clinical and arthroscopic correlation of intraligamentous cysts of the anterior cruciate ligament (ACL) are presented. Three cases of intraligamentous cysts of the ACL were identified out of 681 knee MRI examinations over a 2-year period. Arthroscopy and postoperative MRI were performed in all three patients, each of whom experienced knee pain with extreme flexion and extension. In all three cases the intraligamentous cyst was homogeneously hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging relative to the ACL. Two of the three ACL cysts required a 70{degrees} scope for adequate visualization and establishment of posteromedial andmore » posterolateral portals for arthroscopic treatment. One cyst could not be visualized arthroscopically and probing of the ACL from the anterior portal resulted in drainage of the cyst. No patient had presence of ACL cyst on follow-up MRI or recurrence of symptoms at a mean of 24 months. Intraligamentous cyst of ACL is a rare cause of knee pain. It should be suspected in patients having chronic pain with extremes of motion. Magnetic resonance findings are diagnostic and help to guide arthroscopy. 14 refs., 3 figs.« less

Analysis of the significance of the measurement of acceleration with respect to lateral laxity of the anterior cruciate ligament insufficient knee.

PubMed

Yoshimura, I; Naito, M; Hara, M; Zhang, J

2000-01-01

The purpose of this study was to assess dynamically the lateral thrust of anterior cruciate ligament (ACL) insufficient knees, and from the findings determine any relationship between ACL insufficiency and the later development of osteoarthritis (OA). We investigated 80 knees in 40 patients awaiting ACL reconstruction and 25 knees of 25 patients, which had undergone ACL reconstruction. An acceleration sensor was fixed to the anterior tibial tubercle and this 'acted' in two directions--medial lateral and perpendicular. The peak value of the lateral acceleration immediately after heel strike was significantly greater in the ACL insufficient knees when compared to their opposite normal knees. When the periods from injury were compared, the lateral thrust of the injured side after 3 years or more was significantly greater than in the first 3 years. There was no significant difference between the normal knees and the ACL reconstructed knees. The results indicated that the lateral acceleration peak value was significantly greater in the ACL insufficient knees than in their opposite normal knees.

Rouse mode analysis of chain relaxation in homopolymer melts

DOE PAGES

Kalathi, Jagannathan T.; Kumar, Sanat K.; Rubinstein, Michael; ...

2014-09-15

We use molecular dynamics simulations of the Kremer–Grest (KG) bead–spring model of polymer chains of length between 10 and 500, and a closely related analogue that allows for chain crossing, to clearly delineate the effects of entanglements on the length-scale-dependent chain relaxation in polymer melts. We analyze the resulting trajectories using the Rouse modes of the chains and find that entanglements strongly affect these modes. The relaxation rates of the chains show two limiting effective monomeric frictions, with the local modes experiencing much lower effective friction than the longer modes. The monomeric relaxation rates of longer modes vary approximately inverselymore » with chain length due to kinetic confinement effects. The time-dependent relaxation of Rouse modes has a stretched exponential character with a minimum of stretching exponent in the vicinity of the entanglement chain length. None of these trends are found in models that allow for chain crossing. As a result, these facts, in combination, argue for the confined motion of chains for time scales between the entanglement time and their ultimate free diffusion.« less

Effective approach to strengthening TiO2 nanotube arrays by using double or triple reinforcements

NASA Astrophysics Data System (ADS)

Sun, Mengwei; Yu, Dongliang; Lu, Linfeng; Ma, Weihua; Song, Ye; Zhu, Xufei

2015-08-01

Porous anodic TiO2 nanotube arrays (TNTAs) are fragile and also susceptible to be damaged during physical manipulation. Few studies have involved the improvement of the poor interfacial adhesion of TNTAs to the Ti substrate. Here, the poor adhesion of TNTAs was dramatically improved by appending an additional compact layer (ACL) formed at the interface between TNTAs and the Ti substrate. The adhesion of TNTAs with single-ACL increased with the increase of the ACL thickness. Furthermore, the reinforced TNTAs with double-ACL and triple-ACL have been successfully developed for the first time. The experimental results indicated that the critical load of the TNTAs with triple-ACL is roughly 5.8 times higher than that of the untreated TNTAs. The present results may be helpful to assemble less brittle and large area TNTAs for extensive applications.

Regeneration of the anterior cruciate ligament: Current strategies in tissue engineering

PubMed Central

Nau, Thomas; Teuschl, Andreas

2015-01-01

Recent advancements in the field of musculoskeletal tissue engineering have raised an increasing interest in the regeneration of the anterior cruciate ligament (ACL). It is the aim of this article to review the current research efforts and highlight promising tissue engineering strategies. The four main components of tissue engineering also apply in several ACL regeneration research efforts. Scaffolds from biological materials, biodegradable polymers and composite materials are used. The main cell sources are mesenchymal stem cells and ACL fibroblasts. In addition, growth factors and mechanical stimuli are applied. So far, the regenerated ACL constructs have been tested in a few animal studies and the results are encouraging. The different strategies, from in vitro ACL regeneration in bioreactor systems to bio-enhanced repair and regeneration, are under constant development. We expect considerable progress in the near future that will result in a realistic option for ACL surgery soon. PMID:25621217

MRI Anatomy of the Tibial ACL Attachment and Proximal Epiphysis in a Large Population of Skeletally Immature Knees: Reference Parameters for Planning Anatomic Physeal-Sparing ACL Reconstruction.

PubMed

Swami, Vimarsha Gopal; Mabee, Myles; Hui, Catherine; Jaremko, Jacob Lester

2014-07-01

To aid in performing anatomic physeal-sparing anterior cruciate ligament (ACL) reconstruction, it is important for surgeons to have reference data for the native ACL attachment positions and epiphyseal anatomy in skeletally immature knees. To characterize anatomic parameters of the ACL tibial insertion and proximal tibial epiphysis at magnetic resonance imaging (MRI) in a large population of skeletally immature knees. Cross-sectional study; Level of evidence, 3. The ACL tibial attachment site and proximal epiphysis were examined in 570 skeletally immature knees with an intact ACL (age, 6-15 years) using 1.5-T proton density-weighted sagittal MRI; also measured were the tibial anteroposterior diameter; anterior, central, and posterior ACL attachment positions; vertical height of the epiphysis; and maximum oblique epiphyseal depth extending from the ACL tibial attachment center to the tibial tuberosity. In adolescents (11-15 years of age), the center of the ACL's tibial attachment was 51.5% ± 5.7% of the anteroposterior diameter of the tibia, with no significant differences between sexes or age groups (P > .05 in all cases). Mean vertical epiphyseal height was 15.9 ± 1.7 mm in the adolescent group, with significant differences between 11-year-olds (15.2 ± 1.5 mm) and 15-year-olds (16.6 ± 1.6 mm), P < .001, and between males (16.6 ± 1.5 mm) and females (14.8 ± 1.4), P < .001. Mean maximum oblique depth was 30.0 ± 5.3 mm, with a significant difference between 11-year-olds (26.7 ± 4.9 mm) and 15-year-olds (32.7 ± 5.1 mm), P < .001, and between males (29.7 ± 6.4 mm) and females (27.8 ± 5.2 mm), P < .001. The maximum oblique depth occurred at a mean angle of ~50°, and this angle did not change with age or sex. There was a significant moderate correlation (r = 0.39, P < .001) between epiphyseal vertical height and maximum oblique depth. The center of the ACL tibial attachment was consistently near 51% of the anteroposterior diameter, regardless of age or sex. The vertical depth of the tibial epiphysis was ~16 mm in adolescents. Maximum oblique depth from ACL attachment was ~30 mm, occurring at a mean angle ~50° regardless of age or sex. The normative values for tibial ACL attachment and epiphyseal anatomy presented here may be helpful in selecting candidates for surgery and in planning surgical approaches for pediatric ACL reconstruction. © 2014 The Author(s).

The potential European genetic predisposition for non-contact anterior cruciate ligament injury.

PubMed

Astur, Diego Costa; Andrade, Edilson; Arliani, Gustavo Gonçalves; Debieux, Pedro; Loyola, Leonor Casilla; Dos Santos, Sidney Emanuel Batista; Burbano, Rommel Mario Rodriguez; Leal, Mariana Ferreira; Cohen, Moises

2018-05-04

Previous research has provided evidence of a hereditary predisposition for anterior cruciate ligament (ACL) injury. The purpose of this study was to evaluate the association between ancestral population genetics and risk of non-contact ACL injuries. Blood samples were collected from 177 individuals with a history of non-contact ACL injury and 556 non-injured control individuals for analysis of the genetic material through the use of a panel of 48 INDELs ancestry genetic markers from three ancestral origins. Among patients with non-contact ACL injury, 82% were male and 18% were female. In the control group, 78% were male, and 22% were female. The mean age of the non-contact ACL injury group was 31.7 years (± 10.2), and the control group was 33.8 years (± 13.2). The individual genetic contribution from INDELs of each ancestral origin varied considerably: ranging between 1.5-94.8% contribution for INDELs of African origin (mean of 21.4% of INDELs); between 2 and 96.1% contribution for INDELs of European origin (mean of 66.7% of INDELs); and between 1.3-96.4% contribution for INDELs of Amerindian origin (mean of 11.7% of INDELs). When comparing paired subjects from the non-contact ACL and control groups, the genetic analysis showed that the European ancestry score was higher in the non-contact ACL group than control group (0.70 ± 0.21 vs 0.63 ± 0.22 respectively, p < 0.001), whereas African ancestry scores (ACL group 0.18 ± 0.18 vs control group 0.24 ± 0.21, p < 0.001) and Amerindian ancestry scores (ACL group 0.11 ± 0.09 vs control group 0.12 ± 0.10, n.s.) were lower among the non-contact ACL group than in controls. European INDELs markers were found to represent a potential genetic predisposition for non-contact ACL injuries when compared to African and Amerindian INDELs. This study has the potential to correlate a measurable and distinct genetic marker with risk of a non-contact ACL injury. Thus, it increases knowledge base and volume of molecular and genetical factors associated with this pathology. Furthermore, this study provides guidance and evidence for the development of genetic risk-screening panels for non-contact ACL injury. Level III Diagnostic Study.

Mechanical stretch increases CCN2/CTGF expression in anterior cruciate ligament-derived cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyake, Yoshiaki; Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama; Furumatsu, Takayuki, E-mail: matino@md.okayama-u.ac.jp

Highlights: {yields} CCN2/CTGF localizes to the ligament-to-bone interface, but is not to the midsubstance region of human anterior cruciate ligament (ACL). {yields} Mechanical stretch induces higher increase of CCN2/CTGF gene expression and protein secretion in ACL interface cells compared with ACL midsubstance cells. {yields} CCN2/CTGF treatment stimulates the proliferation of ACL interface cells. -- Abstract: Anterior cruciate ligament (ACL)-to-bone interface serves to minimize the stress concentrations that would arise between two different tissues. Mechanical stretch plays an important role in maintaining cell-specific features by inducing CCN family 2/connective tissue growth factor (CCN2/CTGF). We previously reported that cyclic tensile strain (CTS)more » stimulates {alpha}1(I) collagen (COL1A1) expression in human ACL-derived cells. However, the biological function and stress-related response of CCN2/CTGF were still unclear in ACL fibroblasts. In the present study, CCN2/CTGF was observed in ACL-to-bone interface, but was not in the midsubstance region by immunohistochemical analyses. CTS treatments induced higher increase of CCN2/CTGF expression and secretion in interface cells compared with midsubstance cells. COL1A1 expression was not influenced by CCN2/CTGF treatment in interface cells despite CCN2/CTGF stimulated COL1A1 expression in midsubstance cells. However, CCN2/CTGF stimulated the proliferation of interface cells. Our results suggest that distinct biological function of stretch-induced CCN2/CTGF might regulate region-specific phenotypes of ACL-derived cells.« less

Proteomic Differences between Male and Female Anterior Cruciate Ligament and Patellar Tendon

PubMed Central

Little, Dianne; Thompson, J. Will; Dubois, Laura G.; Ruch, David S.; Moseley, M. Arthur; Guilak, Farshid

2014-01-01

The risk of anterior cruciate ligament (ACL) injury and re-injury is greater for women than men. Among other factors, compositional differences may play a role in this differential risk. Patellar tendon (PT) autografts are commonly used during reconstruction. The aim of the study was to compare protein expression in male and female ACL and PT. We hypothesized that there would be differences in key structural components between PT and ACL, and that components of the proteome critical for response to mechanical loading and response to injury would demonstrate significant differences between male and female. Two-dimensional liquid chromatography-tandem mass spectrometry and a label-free quantitative approach was used to identify proteomic differences between male and female PT and ACL. ACL contained less type I and more type III collagen than PT. There were tissue-specific differences in expression of proteoglycans, and ACL was enriched in elastin, tenascin C and X, cartilage oligomeric matrix protein, thrombospondin 4 and periostin. Between male and female donors, alcohol dehydrogenase 1B and complement component 9 were enriched in female compared to male. Myocilin was the major protein enriched in males compared to females. Important compositional differences between PT and ACL were identified, and we identified differences in pathways related to extracellular matrix regulation, complement, apoptosis, metabolism of advanced glycation end-products and response to mechanical loading between males and females. Identification of proteomic differences between male and female PT and ACL has identified novel pathways which may lead to improved understanding of differential ACL injury and re-injury risk between males and females. PMID:24818782

Incidence of anterior cruciate ligament injuries among elite ballet and modern dancers: a 5-year prospective study.

PubMed

Liederbach, Marijeanne; Dilgen, Faye E; Rose, Donald J

2008-09-01

Ballet and modern dance are jump-intensive activities, but little is known about the incidence of anterior cruciate ligament (ACL) injuries among dancers. Rigorous jump and balance training has been shown in some prospective studies to significantly reduce ACL injury rates among athletes. Dancers advance to the professional level only after having achieved virtuosic jump and balance technique. Therefore, dancers on the elite level may be at relatively low risk for ACL injury. Descriptive epidemiology study. Dance exposure, injuries, and injury conditions were systematically recorded at 4 dance organizations over 5 years. Select neuromuscular and psychometric variables were compared between and within ACL-injured and noninjured dancers. Of 298 dancers, 12 experienced an ACL injury over the 5-year period. The incidence of ACL injury was 0.009 per 1000 exposures. Landing from a jump onto 1 leg was the mechanism of injury in 92% of cases. Incidence was not statistically different between gender or dance groups, although women modern dancers had a 3 to 5 times greater relative risk than women ballet dancers and men dancers. No difference between ACL-injured and noninjured dancers emerged with regard to race, oral contraceptive use, or select musculoskeletal measures. Dancers suffer considerably fewer ACL injuries than athletes participating in team ball sports. The training dancers undertake to perfect lower extremity alignment, jump, and balance skills may serve to protect them against ACL injury. Anterior cruciate ligament injuries happened most often late in the day and season, suggesting an effect of fatigue.

Post-natal molecular adaptations in anteromedial and posterolateral bundles of the ovine anterior cruciate ligament: one structure with two parts or two distinct ligaments?

PubMed

Huebner, Kyla D; O'Brien, Etienne J O; Heard, Bryan J; Chung, May; Achari, Yamini; Shrive, Nigel G; Frank, Cyril B

2012-01-01

The human anterior cruciate ligament (ACL) is a composite structure of two anatomically distinct bundles: an anteromedial (AM) and posterolateral (PL) bundles. Tendons are often used as autografts for surgical reconstruction of ACL following severe injury. However, despite successful surgical reconstruction, some people experience re-rupture and later development of osteoarthritis. Understanding the structure and molecular makeup of normal ACL is essential for its optimal replacement. Reportedly the two bundles display different tensions throughout joint motion and may be fundamentally different. This study assessed the similarities and differences in ultrastructure and molecular composition of the AM and PL bundles to test the hypothesis that the two bundles of the ACL develop unique characteristics with maturation. ACLs from nine mature and six immature sheep were compared. The bundles were examined for mRNA and protein levels of collagen types I, III, V, and VI, and two proteoglycans. The fibril diameter composition of the two bundles was examined with transmission electron microscopy. Maturation does alter the molecular and structural composition of the two bundles of ACL. Although the PL band appears to mature slower than the AM band, no significant differences were detected between the bundles in the mature animals. We thus reject our hypothesis that the two ACL bundles are distinct. The two anatomically distinct bundles of the sheep ACL can be considered as two parts of one structure at maturity and material that would result in a structure of similar functionality can be used to replace each ACL bundle in the sheep.

Effect of reconstruction of the anterior cruciate ligament on proprioception of the knee and the heel strike transient.

PubMed

Co, F H; Skinner, H B; Cannon, W D

1993-09-01

Abnormal proprioception of the knee joint has been documented after rupture of the anterior cruciate ligament (ACL) and may result in the loss of muscular reflexes. Excessive loading from the lack of muscular control may predispose the joint to osteoarthrosis. To investigate this problem, 10 patients were studied at an average of 31.6 months after ACL reconstruction. Three tests of joint proprioception and measurements of the vertical component of heel strike force during normal gait were used. A normal control group also was studied. For two of the proprioception tests (reproduction of passive motion and relative reproduction), there were no statistical differences among the uninjured (control) limbs, the normal contralateral limb of patients with a reconstructed ACL, and the extremity with a reconstructed ACL. In the third test (threshold of detection of motion), which previously has been shown to be adversely affected by ACL injury, the measurements for both extremities of patients with a reconstructed ACL were more accurate than those for the control group. The reconstructed extremity performed less accurately than the contralateral extremity (p < 0.05). The heel strike transient (vertical component of ground reaction force at heel strike) for uninjured and ACL-reconstructed limbs was not significantly different. In fact, the extremity with the reconstructed ACL had a lower transient than the uninjured extremity. Heel strike transients in patients with a reconstructed ACL were higher than those in the controls, but the differences were significant only when corrected for velocity of gait.(ABSTRACT TRUNCATED AT 250 WORDS)

In vivo structural and cellular remodeling of engineered bone-ligament-bone constructs used for anterior cruciate ligament reconstruction in sheep.

PubMed

Florida, Shelby E; VanDusen, Keith W; Mahalingam, Vasudevan D; Schlientz, Aleesa J; Wojtys, Edward M; Wellik, Deneen M; Larkin, Lisa M

2016-11-01

Anterior cruciate ligament (ACL) ruptures rank among the most prevalent and costly sports-related injuries. Current tendon grafts used for ACL reconstruction are limited by suboptimal biomechanical properties. We have addressed these issues by engineering multiphasic bone-ligament-bone (BLB) constructs that develop structural and mechanical properties similar to native ACL. The purpose of this study was to examine the acute remodeling process that occurs as the BLB grafts advance toward the adult ligament phenotype in vivo. Thus, we implanted BLB constructs fabricated from male cells into female host sheep and allowed 3, 7, 14, or 28 days (n = 4 at each time point) for recovery. To address whether or not graft-derived cells were even necessary, a subset of BLB constructs (n = 3) were acellularized, implanted, and allowed 28 days for recovery. At each recovery time point, the following histological analyses were performed: picrosirius red staining to assess collagen alignment and immunohistochemistry to assess both graft development and host immune response. Polymerase chain reaction (PCR) analysis, performed on every explanted BLB, was used to detect the presence of graft-derived male cells remaining in the constructs and/or migration into surrounding host tissue. The analysis of the PCR and histology samples revealed a rapid migration of host-derived macrophages and neutrophils into the graft at 3 days, followed by increased collagen density and alignment, vascularization, innervation, and near complete repopulation of the graft with host cells within 28 days. This study provides a greater understanding of the processes of ligament regeneration in our BLB constructs as they remodel toward the adult ligament phenotype.

[Standards in rehabilitation following anterior cruciate ligament reconstruction in the German-speaking world].

PubMed

Valle, Christina; Hirschmüller, Anja; Schmitt-Sody, Marcus; Haller, Bernhard; Keller, Matthias; Schoch, Wolfgang; Hoffman, Helmut; Minzlaff, Philipp

2018-06-01

 Rehabilitation protocols following anterior cruciate ligament (ACL) reconstruction often differ among orthopaedic surgeons. The primary aim of this study was to investigate which follow-up treatment is recommended by "AGA instructors" certified by the German-speaking Association for Arthroscopic and Open Joint Surgery (AGA). The secondary aim was to compare these findings with the current literature.  A structured anonymous online survey was performed with "AGA instructors" specialised in knee or ACL surgery. All participants were asked about their recommendations for rehabilitation following isolated ACL reconstruction using a questionnaire containing 23 items.  117 out of 218 mail questionnaires were fully completed and analysed. 96.5 % of all surgeons allowed full weight-bearing after 4 weeks or earlier, 52.6 % put a limit on knee flexion, 9.7 % on knee extension after the operation. A brace was prescribed by 82.8 % of all participants. During the first six weeks, isometric training and closed-chain exercises were recommended by the majority of surgeons. Riding a bicycle or driving a car after 6 weeks or earlier was permitted by 78.5 % and 86.2 %, respectively. Jogging (65.5 %) or jumping activities (67.0 %) were allowed after 3 months or earlier. Skiing (53.0 %) or contact/team sport (55.2 % / 46.2 %) was often permitted after 12 months. 82.6 % of all surgeons would like to use return-to-sport test protocols.  Rehabilitation protocols differ significantly even among experienced knee surgeons working as instructors. Their recommendations are often not evidence-based considering the current literature. © Georg Thieme Verlag KG Stuttgart · New York.

Evaluation and comparison of clinical results of femoral fixation devices in arthroscopic anterior cruciate ligament reconstruction.

PubMed

Aydin, Deniz; Ozcan, Mert

2016-03-01

Several femoral fixation devices are available for hamstring tendon autograft in anterior cruciate ligament (ACL) reconstruction, but the best technique is debatable. We hypothesised that different suspensory femoral fixation techniques have no superiority over each other. The aim of this study was to evaluate and compare the clinical results of different suspensory femoral fixation devices in arthroscopic ACL reconstruction. This was a Level III, retrospective, comparative study. A total of 100 consecutive patients who underwent arthroscopic ACL reconstruction in a single institution with a mean follow-up time of 40 months (12-67 months) were divided into three groups according to femoral fixation devices as 'Endobutton' (n=34), 'Transfix' (n=35) and 'Aperfix' (n=31). The length of painful period after surgery, time to return to work and sporting activities, final range of motion, anterior drawer and Lachman tests, knee instability symptoms, International Knee Documentation Committee (IKDC) subjective knee evaluation score, Short Form 36 (SF-36) score, Lysholm knee score and Tegner point of the patients were evaluated and compared between groups. There were no significant differences between the groups. All techniques led to significant recovery in knee instability tests and symptoms. In this study, the clinical results of different suspensory femoral fixation techniques were found to be similar. We believe that different femoral fixation techniques have no effect on clinical results provided that the technique is correctly applied. The surgeon must choose a technique appropriate to his or her experience. Copyright © 2015 Elsevier B.V. All rights reserved.

Return to Sport After Pediatric Anterior Cruciate Ligament Reconstruction and Its Effect on Subsequent Anterior Cruciate Ligament Injury.

PubMed

Dekker, Travis J; Godin, Jonathan A; Dale, Kevin M; Garrett, William E; Taylor, Dean C; Riboh, Jonathan C

2017-06-07

Anterior cruciate ligament (ACL) graft failure and contralateral ACL tears are more frequent in children and adolescents than adults. The reasons for higher subsequent injury rates in this population are incompletely understood. We analyzed a continuous cohort of patients who were <18 years of age. Subjects underwent isolated, primary ACL reconstruction with autograft between 2006 and January 1, 2014, and had a minimum 2-year follow-up. Return-to-sport characteristics were described, and multivariable Cox regression modeling was used to identify predictors of a second ACL injury. Candidate variables included patient factors (age, sex, physeal status, tibial slope, notch width index), surgical characteristics (graft type, surgical technique), measures of recovery (time to return to sport, duration of physical therapy), and patients' preoperative and postoperative sports involvement (primary and secondary sports, number of sports). A total of 112 subjects met inclusion criteria; of these patients, 85 (76%) had complete follow-up data and were analyzed. The mean age (and standard deviation) was 13.9 ± 2.1 years (range, 6 to 17 years); 77% had open physes. The mean follow-up was 48.3 ± 15.3 months. Seventy-seven patients (91%) returned to sports, and 84% returned to the same sport. The mean Marx activity score at the time of the latest follow-up was 13.7 ± 3.5 points. Patients were involved in fewer sports after ACL reconstruction, 1.48 ± 0.92 compared with 1.83 ± 1.01 sports before reconstruction (p = 0.002). Sixteen patients (19%) sustained an ACL graft rupture, 11 patients (13%) sustained a contralateral ACL tear, and 1 of these patients (1%) sustained both. The overall prevalence of a second ACL injury was 32%. Time to return to sport was the only significant predictor of a second ACL injury, with a slower return being protective (hazard ratio per month, 0.87 [95% confidence interval, 0.73 to 0.99]; p = 0.04). Pediatric athletes return to sports at a high rate (91%) after ACL reconstruction. Unfortunately, the prevalence of a second ACL injury is high at 32%. Within this population, an earlier return to sport is predictive of a second ACL injury. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Segond Fractures Are Not a Risk Factor for Anterior Cruciate Ligament Reconstruction Failure.

PubMed

Gaunder, Christopher L; Bastrom, Tracey; Pennock, Andrew T

2017-12-01

Segond fractures may be identified when an anterior cruciate ligament (ACL) tear is diagnosed and likely represent an avulsion of the anterolateral ligament. It is currently unclear whether these fractures can be ignored at the time of ACL reconstruction or if they should be addressed surgically. To compare the incidence of Segond fractures in patients undergoing primary ACL reconstruction compared with those undergoing revision ACL reconstruction in an attempt to determine if the presence of a Segond fracture predisposes to ACL reconstruction failure. Cross-sectional study; Level of evidence, 3. A retrospective review of all patients undergoing primary or revision ACL reconstruction between 2007 and 2014 was performed. Demographic data (age, sex, body mass index), injury variables (acuity, mechanism of injury), and radiographic features (concomitant ligamentous injuries, growth plate status) were documented. Each Segond fracture was analyzed for its specific location, size, displacement, and healing using both radiographs and magnetic resonance imaging. Statistical analysis was performed using a P value of <.05. A total of 552 patients underwent primary ACL reconstruction, and 47 patients underwent revision ACL reconstruction who met inclusion criteria. The incidence of Segond fractures was 6% in the primary reconstruction group. The fracture fragment averaged 6.6 mm in height and 2.3 mm in width and was displaced a mean of 5.0 mm. The fracture fragment bed was localized at the tibial attachment site of the anterolateral ligament a mean 20.6 mm posterior to the Gerdy tubercle in nearly all patients. After ACL reconstruction, the Segond fracture healed in 90% of patients. The incidence of Segond fractures was 3 times as common in male patients ( P = .02); otherwise, its presence was not associated with any other demographic data, injury variables, or radiographic features ( P > .05). No patients undergoing revision surgery had a Segond fracture, and no patient with a Segond fracture had graft failure. Patients with a Segond fracture are at no higher risk to require revision ACL reconstruction compared with patients without a Segond fracture. This may be attributable to its high union rate. At the time of primary ACL reconstruction, if a Segond fracture is identified, it can be ignored (not repaired or reconstructed), and this approach does not appear to predispose to early ACL graft failure.

Cell Differentiation during Sexual Development of the Fungus Sordaria macrospora Requires ATP Citrate Lyase Activity

PubMed Central

Nowrousian, Minou; Masloff, Sandra; Pöggeler, Stefanie; Kück, Ulrich

1999-01-01

During sexual development, mycelial cells from most filamentous fungi differentiate into typical fruiting bodies. Here, we describe the isolation and characterization of the Sordaria macrospora developmental mutant per5, which exhibits a sterile phenotype with defects in fruiting body maturation. Cytological investigations revealed that the mutant strain forms only ascus precursors without any mature spores. Using an indexed cosmid library, we were able to complement the mutant to fertility by DNA-mediated transformation. A single cosmid clone, carrying a 3.5-kb region able to complement the mutant phenotype, has been identified. Sequencing of the 3.5-kb region revealed an open reading frame of 2.1 kb interrupted by a 66-bp intron. The predicted polypeptide (674 amino acids) shows significant homology to eukaryotic ATP citrate lyases (ACLs), with 62 to 65% amino acid identity, and the gene was named acl1. The molecular mass of the S. macrospora ACL1 polypeptide is 73 kDa, as was verified by Western blot analysis with a hemagglutinin (HA) epitope-tagged ACL1 polypeptide. Immunological in situ detection of the HA-tagged polypeptide demonstrated that ACL is located within the cytosol. Sequencing of the mutant acl1 gene revealed a 1-nucleotide transition within the coding region, resulting in an amino acid substitution within the predicted polypeptide. Further evidence that ACL1 is essential for fruiting body maturation comes from experiments in which truncated and mutated versions of the acl1 gene were used for transformation. None of these copies was able to reconstitute the fertile phenotype in transformed per5 recipient strains. ACLs are usually involved in the formation of cytosolic acetyl coenzyme A (acetyl-CoA), which is used for the biosynthesis of fatty acids and sterols. Protein extracts from the mutant strain showed a drastic reduction in enzymatic activity compared to values obtained from the wild-type strain. Investigation of the time course of ACL expression suggests that ACL is specifically induced at the beginning of the sexual cycle and produces acetyl-CoA, which most probably is a prerequisite for fruiting body formation during later stages of sexual development. We discuss the contribution of ACL activity to the life cycle of S. macrospora. PMID:9858569

Cell differentiation during sexual development of the fungus Sordaria macrospora requires ATP citrate lyase activity.

PubMed

Nowrousian, M; Masloff, S; Pöggeler, S; Kück, U

1999-01-01

During sexual development, mycelial cells from most filamentous fungi differentiate into typical fruiting bodies. Here, we describe the isolation and characterization of the Sordaria macrospora developmental mutant per5, which exhibits a sterile phenotype with defects in fruiting body maturation. Cytological investigations revealed that the mutant strain forms only ascus precursors without any mature spores. Using an indexed cosmid library, we were able to complement the mutant to fertility by DNA-mediated transformation. A single cosmid clone, carrying a 3.5-kb region able to complement the mutant phenotype, has been identified. Sequencing of the 3.5-kb region revealed an open reading frame of 2.1 kb interrupted by a 66-bp intron. The predicted polypeptide (674 amino acids) shows significant homology to eukaryotic ATP citrate lyases (ACLs), with 62 to 65% amino acid identity, and the gene was named acl1. The molecular mass of the S. macrospora ACL1 polypeptide is 73 kDa, as was verified by Western blot analysis with a hemagglutinin (HA) epitope-tagged ACL1 polypeptide. Immunological in situ detection of the HA-tagged polypeptide demonstrated that ACL is located within the cytosol. Sequencing of the mutant acl1 gene revealed a 1-nucleotide transition within the coding region, resulting in an amino acid substitution within the predicted polypeptide. Further evidence that ACL1 is essential for fruiting body maturation comes from experiments in which truncated and mutated versions of the acl1 gene were used for transformation. None of these copies was able to reconstitute the fertile phenotype in transformed per5 recipient strains. ACLs are usually involved in the formation of cytosolic acetyl coenzyme A (acetyl-CoA), which is used for the biosynthesis of fatty acids and sterols. Protein extracts from the mutant strain showed a drastic reduction in enzymatic activity compared to values obtained from the wild-type strain. Investigation of the time course of ACL expression suggests that ACL is specifically induced at the beginning of the sexual cycle and produces acetyl-CoA, which most probably is a prerequisite for fruiting body formation during later stages of sexual development. We discuss the contribution of ACL activity to the life cycle of S. macrospora.

Development and Validation of a Short Version of the Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) Scale

PubMed Central

Webster, Kate E.; Feller, Julian A.

2018-01-01

Background: The Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) scale was developed to measure an athlete’s psychological readiness to return to sport after anterior cruciate ligament (ACL) injury and reconstruction surgery. The scale is being used with increasing frequency in both research and clinical settings. Purpose: To generate and validate a short version of the ACL-RSI scale. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The ACL-RSI scale was administered to 535 patients who had undergone ACL reconstruction surgery. Reliability (Cronbach alpha) was determined and factor analysis of the full scale was undertaken along with a process of item selection and elimination. A second group of 250 patients participated in a predictive validation analysis. This group completed the ACL-RSI scale at 6 months and reported return-to-sport outcomes 12 months following ACL reconstruction surgery. The predictive validity of both scales (full and short versions) was assessed by use of receiver operating characteristic (ROC) curve statistics. Results: The scale was found to have high internal consistency (Cronbach alpha, 0.96), which suggested that item redundancy was present. After an item selection process, the scale was reduced to a 6-item format. Cronbach alpha for the short version was 0.92, and factor analysis confirmed the presence of 1 factor accounting for 71% of the total variance. Scores for the short version were significantly different between patients who had and those who had not returned to sport. Six-month ACL-RSI scores for both the full and short versions had fair to good predictive ability for 12-month return-to-sport outcomes (full version: area under ROC curve, 0.77 [95% CI, 0.7-0.8]; short version: area under ROC curve, 0.75 [95% CI, 0.7-0.8]). Conclusion: A 6-item short version of the ACL-RSI scale was developed from a large cohort of patients undergoing ACL reconstruction. The short version appears to be as robust as the full version for discriminating between and predicting return-to-sport outcomes. The short version of the ACL-RSI may be of use in busy clinical settings to help identify athletes who may find return to sport challenging. PMID:29662909

Effect of ACL graft material on joint forces during a simulated in vivo motion in the porcine knee: examining force during the initial cycles.

PubMed

Boguszewski, Daniel V; Wagner, Christopher T; Butler, David L; Shearn, Jason T

2014-11-01

This study compared three-dimensional forces in knees containing anterior cruciate ligament (ACL) graft materials versus the native porcine ACL. A six-degree-of-freedom (DOF) robot simulated gait while recording the joint forces and moments. Knees were subjected to 10 cycles of simulated gait in intact, ACL-deficient, and ACL-reconstructed knee states to examine time zero biomechanical performance. Reconstruction was performed using bone-patellar tendon-bone allograft (BPTB), reconstructive porcine tissue matrix (RTM), and an RTM-polymer hybrid (Hybrid). Forces and moments were examined about anatomic DOFs throughout the gait cycle and at three key points during gait: heel strike (HS), mid stance (MS), toe off (TO). Compared to native ACL, each graft restored antero-posterior (A-P) forces throughout gait. However, all failed to mimic normal joint forces in other DOFs. For example, each reconstructed knee showed greater compressive forces at HS and TO compared to the native ACL knee. Overall, the Hybrid graft restored more of the native ACL forces following reconstruction than did BPTB, while RTM grafts were the least successful. If early onset osteoarthritis is in part caused by altered knee kinematics, then understanding how reconstruction materials restore critical force generation during gait is an essential step in improving a patient's long-term prognosis. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Effects of a Prophylactic Knee Sleeve on Anterior Cruciate Ligament Loading During Sport Specific Movements.

PubMed

Sinclair, Jonathan; Taylor, Paul John

2017-07-17

Prophylactic knee bracing is extensively utilized in athletic populations, to reduce the high risk from knee injuries, but their role in the attenuation of anterior cruciate ligament (ACL) pathologies is not well understood. The aim of the current investigation was to investigate the effects of a prophylactic knee sleeve on ACL loading parameters linked to the aetiology of injury in recreational athletes. Laboratory. Repeated measures. Thirteen healthy male recreational athletes. Intervention Participants performed run, cut and single leg hop movements under two conditions; prophylactic knee sleeve and no-sleeve. Biomechanical data was captured using an eight-camera 3D motion capture system and a force platform. Peak ACL force, average ACL load rate and instantaneous ACL load rate were quantified using a musculoskeletal modelling approach. The results showed that both average and instantaneous ACL load rates were significantly reduced when wearing the knee sleeve in the hop (sleeve = 612.45/ 1286.39N/kg/s & no-sleeve = 743.91/ 1471.42 N/kg/s) and cut (sleeve = 222.55/ 1058.02 N/kg/s & no-sleeve = 377.38/ 1183.01 N/kg/s) movements. Given the biomechanical association between ACL loading and the aetiology of ACL injuries, it is proposed that athletes may be able to attenuate their risk from injury during cut and hop movements through utilization of a prophylactic knee sleeve.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 1993 (October 1992 through September 1993). This annual report is the tenth for the ACL and describes continuing effort on projects, work on new projects, and contributions of the ACL staff to various programs at ANL. The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. The ACL also has research programs in analyticalmore » chemistry, conducts instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems. Some routine or standard analyses are done, but it is common for the Argonne programs to generate unique problems that require development or modification of methods and adaption of techniques to obtain useful analytical data. The ACL is administratively within the Chemical Technology Division (CMT), its principal ANL client, but provides technical support for many of the technical divisions and programs at ANL. The ACL has four technical groups--Chemical Analysis, Instrumental Analysis, Organic Analysis, and Environmental Analysis--which together include about 45 technical staff members. Talents and interests of staff members cross the group lines, as do many projects within the ACL.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skyhar, M.J.; Danzig, L.A.; Hargens, A.R.

Twelve freshly killed mature male rabbits were used to study the effects of continuous passive motion (CPM) on regional and overall nonvascular nutritional pathways of the anterior cruciate ligament (ACL). One hundred fifty microcuries of /sup 35/S-sulfate was injected intraarticularly into each knee joint. The right knee underwent CPM for 1 hour, while the left knee remained immobilized. Both knee joints were then isolated and immediately frozen. The ACLs were removed while still mostly frozen, and sectioned into anterior, middle, and posterior thirds for the six rabbits in Group 1, and proximal, middle, and distal thirds for the six rabbitsmore » in Group 2. In addition, quadriceps tendon samples were harvested from each limb of three rabbits. After appropriate processing, all samples were counted in a scintillation counter, and counts per minute per milligram of tissue were calculated. There was significantly higher uptake in rest extremity ACLs compared to CPM extremity ACLs (P = 0.0001). No significant difference was demonstrated in regional uptake comparing respective thirds of the ACL in either Group 1 or Group 2. Quadriceps tendon uptake trended higher in the limbs exposed to CPM compared to those maintained at rest (P = 0.14). The ACL uses diffusion as a primary nutrient pathway. CPM does not increase nutrient uptake by the ACL in this avascular model, but CPM may facilitate transport of metabolites out of the joint. No regional differences in uptake within the ACL occurred in either group.« less

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

PubMed

Chen, Chih-Hui; Li, Jing-Sheng; Hosseini, Ali; Gadikota, Hemanth R; Gill, Thomas J; Li, Guoan

2012-03-01

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. Copyright © 2011 Elsevier B.V. All rights reserved.

Interactions between collagen gene variants and risk of anterior cruciate ligament rupture.

PubMed

O'Connell, Kevin; Knight, Hayley; Ficek, Krzysztof; Leonska-Duniec, Agata; Maciejewska-Karlowska, Agnieszka; Sawczuk, Marek; Stepien-Slodkowska, Marta; O'Cuinneagain, Dion; van der Merwe, Willem; Posthumus, Michael; Cieszczyk, Pawel; Collins, Malcolm

2015-01-01

The COL5A1 and COL12A1 variants are independently associated with modulating the risk of anterior cruciate ligament (ACL) rupture in females. The objective of this study was to further investigate if COL3A1 and COL6A1 variants independently, as well as, collagen gene-gene interactions, modulate ACL rupture risk. Three hundred and thirty-three South African (SA, n = 242) and Polish (PL, n = 91) participants with diagnosed ACL ruptures and 378 controls (235 SA and 143 PL) were recruited. Participants were genotyped for COL3A1 rs1800255 G/A, COL5A1 rs12722 (T/C), COL6A1 rs35796750 (T/C) and COL12A1 rs970547 (A/G). No significant associations were identified between COL6A1 rs35796750 and COL3A1 rs1800255 genotypes and risk of ACL rupture in the SA cohort. The COL3A1 AA genotype was, however, significantly (p = 0.036) over-represented in the PL ACL group (9.9%, n = 9) when compared to the PL control (CON) group (2.8%, n = 4). Although there were genotype distribution differences between the SA and PL cohorts, the T+A-inferred pseudo-haplotype constructed from COL5A1 and COL12A1 was significantly over-represented in the female ACL group when compared to the female CON group within the SA (T+A ACL 50.5%, T+A CON 38.1%, p = 0.022), PL (T+A ACL 56.3%, T+A CON 36.3%, p = 0.029) and combined (T+A ACL 51.8%, T+A CON 37.5%, p = 0.004) cohorts. In conclusion, the novel main finding of this study was a significant interaction between the COL5A1 rs12722 T/C and COL12A1 rs970547 A/G variants and risk of ACL injury. These results highlight the importance of investigating gene-gene interactions in the aetiology of ACL ruptures in multiple independent cohorts.

Failure Rate and Clinical Outcomes of Anterior Cruciate Ligament Reconstruction Using Autograft Hamstring Versus a Hybrid Graft.

PubMed

Leo, Brian M; Krill, Michael; Barksdale, Leticia; Alvarez-Pinzon, Andres M

2016-11-01

To compare the revision rate and subjective outcome measures of autograft hamstring versus a soft tissue hybrid graft combining both autograft hamstring and tibialis allograft for isolated anterior cruciate ligament (ACL) reconstruction. A single-center retrospective, nonrandomized, comparative study of isolated ACL reconstruction revision rates for subjects who underwent arthroscopic reconstruction of the ACL using autograft hamstring or a soft tissue hybrid graft using both autograft hamstring and tibialis allograft was performed. Patients with isolated ACL tears were included and underwent anatomic single-bundle reconstruction using an independent tunnel drilling technique and a minimum of 24 months' follow-up. The primary outcome assessed was the presence or absence of ACL rerupture. Secondary clinical outcomes consisted of the International Knee Documentation Committee, University of California at Los Angeles (UCLA) ACL quality of life assessment, and the visual analog pain scale. Between February 2010 and April 2013, 95 patients with isolated ACL tears between ages 18 and 40 met the inclusion criteria and were enrolled. Seventy-one autograft hamstring and 24 soft tissue hybrid graft ACL reconstructions were performed during the course of this study. The follow-up period was 24 to 32 months (mean 26.9 months). There were no statistically significant differences in patient demographics or Outerbridge classification. No statistically significant differences in ACL retears (5.6% auto, 4.2% hybrid; P = .57) were found between groups. Clinical International Knee Documentation Committee and UCLA ACL quality of life assessment improvement scores revealed no statistically significant differences in autograft and hybrid graft reconstructions (41 ± 11, 43 ± 13; P = .65) (38 ± 11, 40 ± 10; P = .23). The mean pain level decreased from 8.1 to 2.8 in the autograft group and 7.9 to 2.5 in the hybrid group (P = .18). The use of a hybrid soft tissue graft has a comparable rerupture rate and clinical outcome to ACL reconstruction using autograft hamstring. Level III, retrospective comparative study. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Knee joint kinematics after dynamic intraligamentary stabilization: cadaveric study on a novel anterior cruciate ligament repair technique.

PubMed

Schliemann, Benedikt; Lenschow, Simon; Domnick, Christoph; Herbort, Mirco; Häberli, Janosch; Schulze, Martin; Wähnert, Dirk; Raschke, Michael J; Kösters, Clemens

2017-04-01

Dynamic intraligamentary stabilization (DIS) has been introduced for the repair of acute anterior cruciate ligament (ACL) tears as an alternative to delayed reconstruction. The aim of the present study was to compare knee joint kinematics after DIS to those of the ACL-intact and ACL-deficient knee under simulated Lachman/KT-1000 and pivot-shift tests. We hypothesized that DIS provides knee joint kinematics equivalent to an intact ACL. With the use of a robotic knee simulator, knee kinematics were determined in simulated Lachman/KT-1000 and pivot-shift tests at 0°, 15°, 30°, 60°, and 90° of flexion in eight cadaveric knees under the following conditions: (1) intact ACL, (2) ACL deficiency, (3) DIS with a preload of 60 N, and (4) DIS with a preload of 80 N. Statistical analyses were performed using two-factor repeated-measures analysis of variance. The significance level was set at a p value of <0.05. After DIS with a preload of either 60 N or 80 N, the anterior translation was significantly reduced in the simulated Lachman/KT-1000 and pivot-shift tests when compared to the ACL-deficient knee (p < 0.05). No significant differences were observed between the DIS reconstruction with a preload of 80 N and the intact ACL with regard to anterior laxity in either test. However, DIS with a preload of only 60 N was not able to restore knee joint kinematics to that of an intact knee in all degrees of flexion. DIS with a preload of 80 N restores knee joint kinematics comparable to that of an ACL-intact knee and is therefore capable of providing knee joint stability during ACL healing. DIS therefore provides a new technique for primary ACL repair with superior biomechanical properties in comparison with other techniques that have been described previously, although further clinical studies are required to determine its usefulness in clinical settings.

Muscle Activation During ACL Injury Risk Movements in Young Female Athletes: A Narrative Review.

PubMed

Bencke, Jesper; Aagaard, Per; Zebis, Mette K

2018-01-01

Young, adolescent female athletes are at particular high risk of sustaining a non-contact anterior cruciate ligament (ACL) injury during sport. Through the last decades much attention has been directed toward various anatomical and biomechanical risk factors for non-contact ACL injury, and important information have been retrieved about the influence of external loading factors on ACL injury risk during given sports-specific movements. However, much less attention has been given to the aspect of neuromuscular control during such movements and only sparse knowledge exists on the specific muscle activation patterns involved during specific risk conditions. Therefore, the aim of this narrative review was (1) to describe anatomical aspects, strength aspects and biomechanical aspects relevant for the understanding of ACL non-contact injury mechanisms in young female athletes, and (2) to review the existing literature on lower limb muscle activation in relation to risk of non-contact ACL-injury and prevention of ACL injury in young female athletes. Studies investigating muscle activity patterns associated with sports-specific risk situations were identified, comprising cohort studies, intervention studies and prospective studies. Based on the retrieved studies, clear gender-specific differences in muscle activation and coordination were identified demonstrating elevated quadriceps activity and reduced hamstring activity in young female athletes compared to their male counterparts, and suggesting young female athletes to be at elevated risk of non-contact ACL injury. Only few studies ( n = 6) examined the effect of preventive exercise-based intervention protocols on lower limb muscle activation during sports-specific movements. A general trend toward enhanced hamstring activation was observed during selected injury risk situations (e.g., sidecutting and drop landings). Only a single study examined the association between muscle activation deficits and ACL injury risk, reporting that low medial hamstring activation and high vastus lateralis activation prior to landing was associated with an elevated incidence of ACL-injury. A majority of studies were performed in adult female athletes. The striking paucity of studies in adolescent female athletes emphasizes the need for increased research activities to examine of lower limb muscle activity in relation to non-contact ACL injury in this high-risk athlete population.

Risk of Anterior Cruciate Ligament Fatigue Failure Is Increased by Limited Internal Femoral Rotation During In Vitro Repeated Pivot Landings

PubMed Central

Beaulieu, Mélanie L.; Wojtys, Edward M.; Ashton-Miller, James A.

2015-01-01

Background A reduced range of hip internal rotation is associated with increased peak anterior cruciate ligament (ACL) strain and risk for injury. It is unknown, however, whether limiting the available range of internal femoral rotation increases the susceptibility of the ACL to fatigue failure. Hypothesis Risk of ACL failure is significantly greater in female knee specimens with a limited range of internal femoral rotation, smaller femoral-ACL attachment angle, and smaller tibial eminence volume during repeated in vitro simulated single-leg pivot landings. Study Design Controlled laboratory study. Methods A custom-built testing apparatus was used to simulate repeated single-leg pivot landings with a 4×-body weight impulsive load that induces knee compression, knee flexion, and internal tibial torque in 32 paired human knee specimens from 8 male and 8 female donors. These test loads were applied to each pair of specimens, in one knee with limited internal femoral rotation and in the contralateral knee with femoral rotation resisted by 2 springs to simulate the active hip rotator muscles’ resistance to stretch. The landings were repeated until ACL failure occurred or until a minimum of 100 trials were executed. The angle at which the ACL originates from the femur and the tibial eminence volume were measured on magnetic resonance images. Results The final Cox regression model (P = .024) revealed that range of internal femoral rotation and sex of donor were significant factors in determining risk of ACL fatigue failure. The specimens with limited range of internal femoral rotation had a failure risk 17.1 times higher than did the specimens with free rotation (P = .016). The female knee specimens had a risk of ACL failure 26.9 times higher than the male specimens (P = .055). Conclusion Limiting the range of internal femoral rotation during repetitive pivot landings increases the risk of an ACL fatigue failure in comparison with free rotation in a cadaveric model. Clinical Relevance Screening for restricted internal rotation at the hip in ACL injury prevention programs as well as in individuals with ACL injuries and/or reconstructions is warranted. PMID:26122384

Osteoarthritis Prevalence Following Anterior Cruciate Ligament Reconstruction: A Systematic Review and Numbers-Needed-to-Treat Analysis

PubMed Central

Luc, Brittney; Gribble, Phillip A.; Pietrosimone, Brian G.

2014-01-01

Objective: To determine the prophylactic capability of anterior cruciate ligament (ACL) reconstruction in decreasing the risk of knee osteoarthritis (OA) when compared with ACL-deficient patients, as well as the effect of a concomitant meniscectomy. We also sought to examine the influence of study design, publication date, and graft type as well as the magnitude of change in physical activity from preinjury Tegner scores in both cohorts. Data Sources: We searched Web of Science and PubMed databases from 1960 through 2012 with the search terms osteoarthritis, meniscectomy, anterior cruciate ligament, anterior cruciate ligament reconstruction, and anterior cruciate ligament deficient. Study Selection: Articles that reported the prevalence of tibiofemoral or patellofemoral OA based on radiographic assessment were included. We calculated numbers needed to treat and relative risk reduction with associated 95% confidence intervals for 3 groups (1) patients with meniscal and ACL injury, (2) patients with isolated ACL injury, and (3) total patients (groups 1 and 2). Data Extraction: A total of 38 studies met the criteria. Of these, 27 assessed the presence of tibiofemoral osteoarthritis in patients treated with anterior cruciate ligament reconstruction. Data Synthesis: Overall, ACL reconstruction (ACL-R) yielded a numbers needed to treat to harm of 16 with a relative risk increase of 16%. Anterior cruciate ligament reconstruction along with meniscectomy yielded a numbers needed to treat to benefit of 15 and relative risk reduction of 11%. Isolated ACL-R showed a numbers needed to treat to harm of 8 and relative risk increase of 43%. Activity levels were decreased in both ACL-R (d = −0.90; 95% confidence interval = 0.77, 1.13) and ACL-deficient (d = −1.13; 95% confidence interval = 0.96, 1.29) patients after injury. Conclusions: The current literature does not provide substantial evidence to suggest that ACL-R is an adequate intervention to prevent knee osteoarthritis. With regard to osteoarthritis prevalence, the only patients benefiting from ACL-R were those undergoing concomitant meniscectomy with reconstruction. PMID:25232663

Risk of anterior cruciate ligament fatigue failure is increased by limited internal femoral rotation during in vitro repeated pivot landings.

PubMed

Beaulieu, Mélanie L; Wojtys, Edward M; Ashton-Miller, James A

2015-09-01

A reduced range of hip internal rotation is associated with increased peak anterior cruciate ligament (ACL) strain and risk for injury. It is unknown, however, whether limiting the available range of internal femoral rotation increases the susceptibility of the ACL to fatigue failure. Risk of ACL failure is significantly greater in female knee specimens with a limited range of internal femoral rotation, smaller femoral-ACL attachment angle, and smaller tibial eminence volume during repeated in vitro simulated single-leg pivot landings. Controlled laboratory study. A custom-built testing apparatus was used to simulate repeated single-leg pivot landings with a 4×-body weight impulsive load that induces knee compression, knee flexion, and internal tibial torque in 32 paired human knee specimens from 8 male and 8 female donors. These test loads were applied to each pair of specimens, in one knee with limited internal femoral rotation and in the contralateral knee with femoral rotation resisted by 2 springs to simulate the active hip rotator muscles' resistance to stretch. The landings were repeated until ACL failure occurred or until a minimum of 100 trials were executed. The angle at which the ACL originates from the femur and the tibial eminence volume were measured on magnetic resonance images. The final Cox regression model (P = .024) revealed that range of internal femoral rotation and sex of donor were significant factors in determining risk of ACL fatigue failure. The specimens with limited range of internal femoral rotation had a failure risk 17.1 times higher than did the specimens with free rotation (P = .016). The female knee specimens had a risk of ACL failure 26.9 times higher than the male specimens (P = .055). Limiting the range of internal femoral rotation during repetitive pivot landings increases the risk of an ACL fatigue failure in comparison with free rotation in a cadaveric model. Screening for restricted internal rotation at the hip in ACL injury prevention programs as well as in individuals with ACL injuries and/or reconstructions is warranted. © 2015 The Author(s).

Direct versus indirect ACL femoral attachment fibres and their implications on ACL graft placement.

PubMed

Moulton, Samuel G; Steineman, Brett D; Haut Donahue, Tammy L; Fontboté, Cristián A; Cram, Tyler R; LaPrade, Robert F

2017-01-01

To further elucidate the direct and indirect fibre insertion morphology within the human ACL femoral attachment using scanning electron microscopy and determine where in the footprint each fibre type predominates. The hypothesis was that direct fibre attachment would be found centrally in the insertion site, while indirect fibre attachment would be found posteriorly adjacent to the posterior articular cartilage. Ten cadaveric knees were dissected to preserve and isolate the entirety of the femoral insertion of the ACL. Specimens were then prepared and evaluated with scanning electron microscopy to determine insertional fibre morphology and location. The entirety of the fan-like projection of the ACL attachment site lay posterior to the lateral intercondylar ridge. In all specimens, a four-phase architecture, consistent with previous descriptions of direct fibres, was found in the centre of the femoral attachment site. The posterior margin of the ACL attachment attached directly adjacent to the posterior articular cartilage with some fibres coursing into it. The posterior portion of the ACL insertion had a two-phase insertion, consistent with previous descriptions of indirect fibres. The transition from the ligament fibres to bone had less interdigitations, and the interdigitations were significantly smaller (p < 0.001) compared to the transition in the direct fibre area. The interdigitations of the direct fibres were 387 ± 81 μm (range 282-515 μm) wide, while the interdigitations of indirect fibres measured 228 ± 75 μm (range 89-331 μm). The centre of the ACL femoral attachment consisted of a direct fibre structure, while the posterior portion had an indirect fibre structure. These results support previous animal studies reporting that the centre of the ACL femoral insertion was comprised of the strongest reported fibre type. Clinically, the femoral ACL reconstruction tunnel should be oriented to cover the entirety of the central direct ACL fibres and may need to be customized based on graft type and the fixation device used during surgery.

Dependence of the product chain-length on detergents for long-chain E-polyprenyl diphosphate synthases

PubMed Central

Pan, Jian-Jung; Ramamoorthy, Gurusankar; Poulter, C. Dale

2013-01-01

Long-chain E-polyprenyl diphosphate synthases (E-PDS) catalyze repetitive addition of isopentenyl diphosphate (IPP) to the growing prenyl chain of an allylic diphosphate. The polyprenyl diphosphate products are required for the biosynthesis of ubiquinones and menaquinones required for electron transport during oxidative phosphorylation to generate ATP. In vitro, the long-chain PDSs require addition of phospholipids or detergents to the assay buffer to enhance product release and maintain efficient turnover. During preliminary assays of product chain-length with anionic, zwitterionic, and non-ionic detergents, we discovered considerable variability. Examination of a series of non-ionic PEG detergents with several long-chain E-PDSs from different organisms revealed that in vitro incubations with nonaethylene glycol monododecyl ether or Triton X-100 typically gave chain lengths that corresponded to those of the isoprenoid moieties in respiratory quinones synthesized in vivo. In contrast incubations in buffer with n-butanol, CHAPS, DMSO, n-octyl-β-glucopyranoside, or β-cyclodextrin or in buffer without detergent typically proceeded more slowly and gave a broad range of chain lengths. PMID:23802587

50 CFR 660.410 - Conservation objectives, ACLs, and de minimis control rules.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., except where the ACL escapement level for a stock is higher than the conservation objective, in which case annual management measures will be designed to ensure that the ACL for that stock is met, or where...

50 CFR 660.410 - Conservation objectives, ACLs, and de minimis control rules.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., except where the ACL escapement level for a stock is higher than the conservation objective, in which case annual management measures will be designed to ensure that the ACL for that stock is met, or where...

50 CFR 660.410 - Conservation objectives, ACLs, and de minimis control rules.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., except where the ACL escapement level for a stock is higher than the conservation objective, in which case annual management measures will be designed to ensure that the ACL for that stock is met, or where...

Tunnel current across linear homocatenated germanium chains

NASA Astrophysics Data System (ADS)

Matsuura, Yukihito

2014-01-01

The electronic transport properties of germanium oligomers catenating into linear chains (linear Ge chains) have been theoretically studied using first principle methods. The conduction mechanism of a Ge chain sandwiched between gold electrodes was analyzed based on the density of states and the eigenstates of the molecule in a two-probe environment. Like that of silicon chains (Si chains), the highest occupied molecular orbital of Ge chains contains the extended σ-conjugation of Ge 4p orbitals at energy levels close to the Fermi level; this is in contrast to the electronic properties of linear carbon chains. Furthermore, the conductance of a Ge chain is expected to decrease exponentially with molecular length L. The decay constant β, which is defined as e-βL, of a Ge chain is similar to that of a Si chain, whereas the conductance of the Ge chains is higher than that of Si chains even though the Ge-Ge bond length is longer than the Si-Si bond length.

Characterization of Hydrophobic Interactions of Polymers with Water and Phospholipid Membranes Using Molecular Dynamics Simulations

NASA Astrophysics Data System (ADS)

Drenscko, Mihaela

Polymers and lipid membranes are both essential soft materials. The structure and hydrophobicity/hydrophilicity of polymers, as well as the solvent they are embedded in, ultimately determines their size and shape. Understating the variation of shape of the polymer as well as its interactions with model biological membranes can assist in understanding the biocompatibility of the polymer itself. Computer simulations, in particular molecular dynamics, can aid in characterization of the interaction of polymers with solvent, as well as polymers with model membranes. In this thesis, molecular dynamics serve to describe polymer interactions with a solvent (water) and with a lipid membrane. To begin with, we characterize the hydrophobic collapse of single polystyrene chains in water using molecular dynamics simulations. Specifically, we calculate the potential of mean force for the collapse of a single polystyrene chain in water using metadynamics, comparing the results between all atomistic with coarse-grained molecular simulation. We next explore the scaling behavior of the collapsed globular shape at the minimum energy configuration, characterized by the radius of gyration, as a function of chain length. The exponent is close to one third, consistent with that predicted for a polymer chain in bad solvent. We also explore the scaling behavior of the Solvent Accessible Surface Area (SASA) as a function of chain length, finding a similar exponent for both all-atomistic and coarse-grained simulations. Furthermore, calculation of the local water density as a function of chain length near the minimum energy configuration suggests that intermediate chain lengths are more likely to form dewetted states, as compared to shorter or longer chain lengths. Next, in order to investigate the molecular interactions between single hydrophobic polymer chains and lipids in biological membranes and at lipid membrane/solvent interface, we perform a series of molecular dynamics simulations of small membranes using all atomistic and coarse-grained methods. The molecular interaction between common polymer chains used in biomedical applications and the cell membrane is unknown. This interaction may affect the biocompatibility of the polymer chains. Molecular dynamics simulations offer an emerging tool to characterize the interaction between common degradable polymer chains used in biomedical applications, such as polycaprolactone, and model cell membranes. We systematically characterize with long-time all-atomistic molecular dynamics simulations the interaction between single polycaprolactone chains of varying chain lengths with a model phospholipid membrane. We find that the length of polymer chain greatly affects the nature of interaction with the membrane, as well as the membrane properties. Furthermore, we next utilize advanced sampling techniques in molecular dynamics to characterize the two-dimensional free energy surface for the interaction of varying polymer chain lengths (short, intermediate, and long) with model cell membranes. We find that the free energy minimum shifts from the membrane-water interface to the hydrophobic core of the phospholipid membrane as a function of chain length. These results can be used to design polymer chain lengths and chemistries to optimize their interaction with cell membranes at the molecular level.

Joint loads resulting in ACL rupture: Effects of age, sex, and body mass on injury load and mode of failure in a mouse model.

PubMed

Blaker, Carina L; Little, Christopher B; Clarke, Elizabeth C

2017-08-01

Anterior cruciate ligament (ACL) tears are a common knee injury with a known but poorly understood association with secondary joint injuries and post-traumatic osteoarthritis (OA). Female sex and age are known risk factors for ACL injury but these variables are rarely explored in mouse models of injury. This study aimed to further characterize a non-surgical ACL injury model to determine its clinical relevance across a wider range of mouse specifications. Cadaveric and anesthetized C57BL/6 mice (9-52 weeks of age) underwent joint loading to investigate the effects of age, sex, and body mass on ACL injury mechanisms. The ACL injury load (whole joint load required to rupture the ACL) was measured from force-displacement data, and mode of failure was assessed using micro-dissection and histology. ACL injury load was found to increase with body mass and age (p < 0.001) but age was not significant when controlling for mass. Sex had no effect. In contrast, the mode of ACL failure varied with both age and sex groups. Avulsion fractures (complete or mixed with mid-substance tears) were common in all age groups but the proportion of mixed and mid-substance failures increased with age. Females were more likely than males to have a major avulsion relative to a mid-substance tear (p < 0.01). This data compliments studies in human cadaveric knees, and provides a basis for determining the severity of joint injury relative to a major ACL tear in mice, and for selecting joint loading conditions in future experiments using this model. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1754-1763, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Digital image correlation-aided mechanical characterization of the anteromedial and posterolateral bundles of the anterior cruciate ligament.

PubMed

Mallett, Kaitlyn F; Arruda, Ellen M

2017-07-01

The anterior cruciate ligament (ACL) is one of the most commonly injured soft tissue structures in the articular knee joint, often requiring invasive surgery for patients to restore pre-injury knee kinematics. There is a pressing need to understand the role of the ACL in knee function, in order to select proper replacements. Digital image correlation (DIC), a non-contact full field displacement measurement technique, is an established tool for evaluating non-biological materials. The application of DIC to soft tissues has been in the nascent stages, largely due to patterning challenges of such materials. The ACL is notoriously difficult to mechanically characterize, due to the complex geometry of its two bundles and their insertions. This paper examines the use of DIC to determine the tensile mechanical properties of the AM and PL bundles of ovine ACLs in a well-known loading state. Homogenous loading in the mid-substance of the bundles provides for accurate development of stress/strain curves using DIC. Animal to animal variability is reduced, and the bundles are stiffer than previously thought when tissue-level strains are accurately measured. The anterior cruciate ligament (ACL), a major stabilizing ligament of the articular knee joint, is one of the most commonly injured soft tissue structures in the knee. Often, invasive surgery is required to restore pre-injury knee kinematics, and there are several long-term consequences of ACL reconstructions, including early-onset osteoarthritis. The role of the ACL in knee stability and motion has received much attention in the biomechanics community. This paper examines the use of a non-contact full-field displacement measurement technique, digital image correlation, to determine the tensile mechanical properties of the ACL. The focus of this work is to investigate the intrinsic mechanical properties of the ACL, as new knowledge in these areas will aid clinicians in selecting ACL replacements. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Is current training in basic and advanced cardiac life support (BLS & ACLS) effective? A study of BLS & ACLS knowledge amongst healthcare professionals of North-Kerala.

PubMed

Nambiar, Madavan; Nedungalaparambil, Nisanth Menon; Aslesh, Ottapura Prabhakaran

2016-01-01

Healthcare professionals are expected to have knowledge of current basic and advanced cardiac life support (BLS/ACLS) guidelines to revive unresponsive patients. A cross-sectional study was conducted to evaluate the current practices and knowledge of BLS/ACLS principles among healthcare professionals of North-Kerala using pretested self-administered structured questionnaire. Answers were validated in accordance with American Heart Association's BLS/ACLS teaching manual and the results were analysed. Among 461 healthcare professionals, 141 (30.6%) were practicing physicians, 268 (58.1%) were nurses and 52 (11.3%) supporting staff. The maximum achievable score was 20 (BLS 15/ACLS 5). The mean score amongst all healthcare professionals was 8.9±4.7. The mean score among physicians, nurses and support staff were 8.6±3.4, 9±3.6 and 9±3.3 respectively. The majority of healthcare professionals scored ≤50% (237, 51.4%); 204 (44.3%) scored 51%-80% and 20 (4.34%) scored >80%. Mean scores decreased with age, male sex and across occupation. Nurses who underwent BLS/ACLS training previously had significantly higher mean scores (10.2±3.4) than untrained (8.2±3.6, P =0.001). Physicians with <5 years experience ( P =0.002) and nurses in the private sector ( P =0.003) had significantly higher scores. One hundred and sixty three (35.3%) healthcare professionals knew the correct airway opening manoeuvres like head tilt, chin lift and jaw thrust. Only 54 (11.7%) respondents were aware that atropine is not used in ACLS for cardiac arrest resuscitation and 79 (17.1%) correctly opted ventricular fibrillation and pulseless ventricular tachycardia as shockable rhythms. The majority of healthcare professionals (356, 77.2%) suggested that BLS/ACLS be included in academic curriculum. Inadequate knowledge of BLS/ACLS principles amongst healthcare professionals, especially physicians, illuminate lacunae in existing training systems and merit urgent redressal.

Review of evolution of tunnel position in anterior cruciate ligament reconstruction.

PubMed

Rayan, Faizal; Nanjayan, Shashi Kumar; Quah, Conal; Ramoutar, Darryl; Konan, Sujith; Haddad, Fares S

2015-03-18

Anterior cruciate ligament (ACL) rupture is one of the commonest knee sport injuries. The annual incidence of the ACL injury is between 100000-200000 in the United States. Worldwide around 400000 ACL reconstructions are performed in a year. The goal of ACL reconstruction is to restore the normal knee anatomy and kinesiology. The tibial and femoral tunnel placements are of primordial importance in achieving this outcome. Other factors that influence successful reconstruction are types of grafts, surgical techniques and rehabilitation programmes. A comprehensive understanding of ACL anatomy has led to the development of newer techniques supplemented by more robust biological and mechanical concepts. In this review we are mainly focussing on the evolution of tunnel placement in ACL reconstruction, focusing on three main categories, i.e., anatomical, biological and clinical outcomes. The importance of tunnel placement in the success of ACL reconstruction is well researched. Definite clinical and functional data is lacking to establish the superiority of the single or double bundle reconstruction technique. While there is a trend towards the use of anteromedial portals for femoral tunnel placement, their clinical superiority over trans-tibial tunnels is yet to be established.

Review of evolution of tunnel position in anterior cruciate ligament reconstruction

PubMed Central

Rayan, Faizal; Nanjayan, Shashi Kumar; Quah, Conal; Ramoutar, Darryl; Konan, Sujith; Haddad, Fares S

2015-01-01

Anterior cruciate ligament (ACL) rupture is one of the commonest knee sport injuries. The annual incidence of the ACL injury is between 100000-200000 in the United States. Worldwide around 400000 ACL reconstructions are performed in a year. The goal of ACL reconstruction is to restore the normal knee anatomy and kinesiology. The tibial and femoral tunnel placements are of primordial importance in achieving this outcome. Other factors that influence successful reconstruction are types of grafts, surgical techniques and rehabilitation programmes. A comprehensive understanding of ACL anatomy has led to the development of newer techniques supplemented by more robust biological and mechanical concepts. In this review we are mainly focussing on the evolution of tunnel placement in ACL reconstruction, focusing on three main categories, i.e., anatomical, biological and clinical outcomes. The importance of tunnel placement in the success of ACL reconstruction is well researched. Definite clinical and functional data is lacking to establish the superiority of the single or double bundle reconstruction technique. While there is a trend towards the use of anteromedial portals for femoral tunnel placement, their clinical superiority over trans-tibial tunnels is yet to be established. PMID:25793165

Quantum communication beyond the localization length in disordered spin chains.

PubMed

Allcock, Jonathan; Linden, Noah

2009-03-20

We study the effects of localization on quantum state transfer in spin chains. We show how to use quantum error correction and multiple parallel spin chains to send a qubit with high fidelity over arbitrary distances, in particular, distances much greater than the localization length of the chain.

50 CFR 648.82 - Effort-control program for NE multispecies limited access vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... ACL for a particular stock to be exceeded. If such catch resulted in the overall ACL for a particular... amount of the overage of the overall ACL for that stock multiplied by the common pool's share of the...

Long-Term Data Reveal Rate and Risk Factors for Subsequent Surgeries Following Initial ACL Reconstruction

MedlinePlus

... and Risk Factors for Subsequent Surgeries Following Initial ACL Reconstruction By Colleen Labbe, M.S. | December 1, 2013 ... surgery to reconstruct a torn anterior cruciate ligament (ACL) eventually need to have additional surgery on the ...

The Rational Behavior Model: A Multi-Paradigm, Tri-Level Software Architecture for the Control of Autonomous Vehicles

DTIC Science & Technology

1993-03-01

possible over a RF link when surfaced and over acoustic telemetry when submerged . Lockheed Missiles and Space Company has been awarded the contract to...ACL), is purely hierarchical and consists of three major components: the Data Manager, the ACL Controller, and the Model- 22 Based Reasoner ( MBR ). The...Data Manager receives, processes, and analyzes sensor and status data for use by the MBR and ACL Controller. The ACL Controller communicates commands

A Prospective Investigation of Biomechanical Risk Factors for Patellofemoral Pain Syndrome. The Joint Undertaking to Monitor and Prevent ACL Injury (JUMP-ACL) Cohort

DTIC Science & Technology

2009-09-24

flexion angle, decreased vertical ground-reaction force , and increased hip internal rotation angle during the jump -landing task. Additionally, decreased...was to determine the biomechanical risk factors for PFPS. The specific factors examined were lower extremity kinematics and kinetics during a jump ...ACL Injury [ JUMP -ACL] study) in which baseline data are collected for participants at all 3 service academies (USNA, United States Air Force Academy

Crossover transition in flowing granular chains

NASA Astrophysics Data System (ADS)

Ulrich, Xialing; Fried, Eliot; Shen, Amy Q.

2009-09-01

We report on the dynamical and statistical behavior of flowing collections of granular chains confined two-dimensionally (2D) within a rotating tumbler. Experiments are conducted with systems of chains of fixed length, but various lengths are considered. The dynamics are punctuated by cascades of chains along a free-surface cascades, which drive the development of mixed porous/laminar packing arrangements in bulk. We investigate the conformation of the system, as characterized by the porosity of the flow region occupied by the chains and the mean-square end-to-end distance of the chains during flow. Both of these measures show crossover transitions from a 2D self-avoiding walk to a 2D random walk when the chain length becomes long enough to allow self-contact.

Structure-guided investigation of lipopolysaccharide O-antigen chain length regulators reveals regions critical for modal length control.

PubMed

Kalynych, Sergei; Ruan, Xiang; Valvano, Miguel A; Cygler, Miroslaw

2011-08-01

The O-antigen component of the lipopolysaccharide (LPS) represents a population of polysaccharide molecules with nonrandom (modal) chain length distribution. The number of the repeat O units in each individual O-antigen polymer depends on the Wzz chain length regulator, an inner membrane protein belonging to the polysaccharide copolymerase (PCP) family. Different Wzz proteins confer vastly different ranges of modal lengths (4 to >100 repeat units), despite having remarkably conserved structural folds. The molecular mechanism responsible for the selective preference for a certain number of O units is unknown. Guided by the three-dimensional structures of PCPs, we constructed a panel of chimeric molecules containing parts of two closely related Wzz proteins from Salmonella enterica and Shigella flexneri which confer different O-antigen chain length distributions. Analysis of the O-antigen length distribution imparted by each chimera revealed the region spanning amino acids 67 to 95 (region 67 to 95), region 200 to 255, and region 269 to 274 as primarily affecting the length distribution. We also showed that there is no synergy between these regions. In particular, region 269 to 274 also influenced chain length distribution mediated by two distantly related PCPs, WzzB and FepE. Furthermore, from the 3 regions uncovered in this study, region 269 to 274 appeared to be critical for the stability of the oligomeric form of Wzz, as determined by cross-linking experiments. Together, our data suggest that chain length determination depends on regions that likely contribute to stabilize a supramolecular complex.

Majorana bound states in the finite-length chain

NASA Astrophysics Data System (ADS)

Zvyagin, A. A.

2015-08-01

Recent experiments investigating edge states in ferromagnetic atomic chains on superconducting substrate are analyzed. In particular, finite size effects are considered. It is shown how the energy of the Majorana bound state depends on the length of the chain, as well as on the parameters of the model. Oscillations of the energy of the bound edge state in the chain as a function of the length of the chain, and as a function of the applied voltage (or the chemical potential) are studied. In particular, it has been shown that oscillations can exist only for some values of the effective potential.

Simulation of Anterior Cruciate Ligament Deficiency in a Musculoskeletal Model with Anatomical Knees

PubMed Central

Guess, Trent M; Stylianou, Antonis

2012-01-01

Abnormal knee kinematics and meniscus injury resulting from anterior cruciate ligament (ACL) deficiency are often implicated in joint degeneration even though changes in tibio-femoral contact location after injury are small, typically only a few millimeters. Ligament reconstruction surgery does not significantly reduce the incidence of early onset osteoarthritis. Increased knowledge of knee contact mechanics would increase our understanding of the effects of ACL injury and help guide ACL reconstruction methods. Presented here is a cadaver specific computational knee model combined with a body-level musculoskeletal model from a subject of similar height and weight as the cadaver donor. The knee model was developed in the multi-body framework and includes representation of the menisci. Experimental body-level measurements provided input to the musculoskeletal model. The location of tibio-menisco-femoral contact as well as contact pressures were compared for models with an intact ACL, partial ACL transection (posterolateral bundle transection), and full ACL transection during a muscle driven forward dynamics simulation of a dual limb squat. During the squat, small changes in femur motion relative to the tibia for both partial and full ACL transection push the lateral meniscus in the posterior direction at extension. The central-anterior region of the lateral meniscus then becomes “wedged” between the tibia and femur during knee flexion. This “wedging” effect does not occur for the intact knee. Peak contact pressure and contact locations are similar for the partial tear and complete ACL transection during the deep flexion portion of the squat, particularly on the lateral side. The tibio-femoral contact location on the tibia plateau shifts slightly to the posterior and lateral direction with ACL transection. PMID:22470411

Lateral Radiographic Landmarks for ACL and LCL Footprint Origins During All-Epiphyseal Femoral Drilling in Skeletally Immature Knees.

PubMed

Shea, Kevin G; Cannamela, Peter C; Fabricant, Peter D; Terhune, E Bailey; Polousky, John D; Milewski, Matthew D; Ganley, Theodore J; Anderson, Allen F

2017-03-15

This study was conducted to evaluate the spatial relationship of the anterior cruciate ligament (ACL) and lateral collateral ligament (LCL) femoral footprint origins in knee specimens from skeletally immature donors as viewed on lateral radiographs. Fourteen cadaver specimens of skeletally immature knees from children between 7 and 11 years old at the time of death were examined through gross dissection. Metallic pins were placed at the center of the ACL and LCL femoral footprints, and computed tomography (CT) scans were performed. Sagittal plane CT images were merged to create a view analogous to an intraoperative C-arm image with overlaid ACL and LCL ligament footprints. Ligament origins were then measured as a percent of the epiphyseal depth (% P-A [posterior-anterior]) and height (% P-D [proximal-distal]). The ACL origin was centered at a point located 14% (14% P-A) of the total lateral femoral condyle (LFC) depth from the most posterior aspect of the LFC and 38% (38% P-D) of the LFC height from the most proximal aspect of the posterior physis. The LCL origin was centered at a point 27% P-A and 37% P-D. When viewed on a sagittal CT reconstruction analogous to a perfect lateral intraoperative fluoroscopic view, the ACL footprint origin is posterior and slightly inferior to the LCL origin. Both origins are distal to the distal femoral physis and are posterior to the origin of the popliteus. This study demonstrates a consistent relationship between the origin of the ACL and LCL, which may be useful in guiding safe tunnel placement during all-epiphyseal ACL reconstruction in skeletally immature knees. This anatomic reference can be used intraoperatively to guide and radiographically evaluate ACL tunnel placement while avoiding the LCL origin in skeletally immature patients.

Femoral intercondylar notch width size: a comparison between siblings with and without anterior cruciate ligament injuries.

PubMed

Keays, S L; Keays, R; Newcombe, P A

2016-03-01

Anterior cruciate ligament (ACL) injuries in siblings are commonly observed in the clinic. One, possibly genetic, factor contributing to the pathogenesis of sibling injuries may be narrow intercondylar notches, which are well recognized as predisposing to ACL injury. This study aimed primarily to: (1) assess the incidence of ACL injuries in siblings within an existing study cohort, (2) compare intercondylar notch width size in injured compared to matched uninjured control siblings and (3) compare the number of injured versus control sibling pairs sharing a narrow notch. Twenty-four ACL-injured siblings from 10 families were matched for age, gender, family composition and sports activity, with 24 uninjured siblings from another 10 families. Intercondylar radiographs were taken to calculate anterior and posterior notch width indices (NWI). Notch size and the number of narrow notches in sibling pairs were compared between groups. Thirteen of 72 ACL-study participants had siblings with torn ACLs. Mean anterior NWI was 0.18 and 0.24 (p < 0.001), and mean posterior NWI was 0.26 and 0.3 (p = 0.006) for injured and uninjured siblings, respectively. Sixty percent of injured sibling pairs shared a narrow notch, while no uninjured sibling pairs did so (p = 0.003). This study showed that siblings (and often sibling pairs) with injuries do have significantly narrower notches than those without. This could partly explain the prevalence of ACL injuries in siblings. To reduce ACL-injury rates, we advise that siblings of ACL-injured athletes with narrow notches, be radiologically screened, and if necessary, cautioned and counselled regarding preventative training. Case-control study, Level III.

Acute non-contact anterior cruciate ligament tears are associated with relatively increased vastus medialis to semimembranosus cross-sectional area ratio: a case-control retrospective MR study.

PubMed

Wieschhoff, Ged G; Mandell, Jacob C; Czuczman, Gregory J; Nikac, Violeta; Shah, Nehal; Smith, Stacy E

2017-11-01

Hamstring muscle deficiency is increasingly recognized as a risk factor for anterior cruciate ligament (ACL) tears. The purpose of this study is to evaluate the vastus medialis to semimembranosus cross-sectional area (VM:SM CSA) ratio on magnetic resonance imaging (MRI) in patients with ACL tears compared to controls. One hundred knee MRIs of acute ACL tear patients and 100 age-, sex-, and side-matched controls were included. Mechanism of injury, contact versus non-contact, was determined for each ACL tear subject. The VM:SM CSA was measured on individual axial slices with a novel method using image-processing software. One reader measured all 200 knees and the second reader measured 50 knees at random to assess inter-reader variability. The intraclass correlation coefficient (ICC) was calculated to evaluate for correlation between readers. T-tests were performed to evaluate for differences in VM:SM CSA ratios between the ACL tear group and control group. The ICC for agreement between the two readers was 0.991 (95% confidence interval 0.984-0.995). Acute ACL tear patients have an increased VM:SM CSA ratio compared to controls (1.44 vs. 1.28; p = 0.005). Non-contact acute ACL tear patients have an increased VM:SM CSA ratio compared to controls (1.48 vs. 1.20; p = 0.003), whereas contact acute ACL tear patients do not (1.23 vs. 1.26; p = 0.762). Acute non-contact ACL tears are associated with increased VM:SM CSA ratios, which may imply a relative deficiency in hamstring strength. This study also demonstrates a novel method of measuring the relative CSA of muscles on MRI.

[Use and evaluation of Action Checklist for health risk management of employees working long hours].

PubMed

Nakao, Tomo; Kawase, Yohei; Shinmi, Ryosuke; Yamashita, Makiko; Mitsuhashi, Akira; Fukuda, Hanako; Kawanam, Shoko; Hiro, Hisanori; Horie, Seichi

2008-12-01

In Japan, the Industrial Safety and Health Law requires an employer to implement medical interviews for employees working long hours. The law stipulates the criteria of the targeted workers as those whose working time exceeds the legal limit of working hours, those with accumulated fatigue, and those who desire to receive an interview from a physician. Therefore, the employers should make an appropriate system to identify the workers who require a medical interview among employees working long hours with increasing health risks. In this study, we used "The Action Checklist for health risk management of employees working long hours (ACL)" and evaluated its efficacy. We conducted two studies: a seminar study, using ACL as an educational material in the seminar targeting occupational health professionals, and an interventional study, distributing materials with ACL in one group of small-scale enterprises and not in another group. In the seminar study, we observed a greater number of practical answers to the problems hypothetically set in the seminar among the occupational health professionals who used ACL. The results of a questionnaire given after the seminar revealed ACL was favorably accepted among 80% of all the participants in the seminar as "I have fully understood the usage of ACL" and "ACL seems to be useful in my workplace". In the interventional study, we could not see positive results from the distribution of ACL, possibly because of the low response rate, short interventional term or distribution without individual explanation. Further investigation and efforts should be considered to widely diffuse ACL with individual explanations, to prevent health disorders caused or aggravated by working long hours.

Attachment area of fibres from the horns of lateral meniscus: anatomic study with special reference to the positional relationship of anterior cruciate ligament.

PubMed

Fujishiro, Hitomi; Tsukada, Sachiyuki; Nakamura, Tomomasa; Nimura, Akimoto; Mochizuki, Tomoyuki; Akita, Keiichi

2017-02-01

Although studies support the clinical importance of the fibres from the horns of lateral meniscus (LM), few studies have investigated the detailed anatomy. This anatomic study was conducted to analyse the structural details of LM with special reference to (1) the attachment area of the fibres from the anterior and posterior horns and (2) the positional relationship between these fibres and the anterior cruciate ligament (ACL). A total of 24 cadaveric knees were used in the macroscopic investigation, and six knees were used in the histological investigation. Micro-computed tomography analysis was also performed to assess the anatomy of the posteriormost fibre from the posterior horn of LM. Based on the macroscopic investigations, the outer fibres from the anterior horn of LM extended to ACL and seemed to intermingle with ACL fibres. However, the histological investigations showed a distinct border between the fibres and ACL. The inner fibres from the anterior horn of LM attached to the lateral intercondylar tubercle serving as a lateral margin of ACL attachment. Fibres from the posterior horn of LM were separated into anterolateral and posteromedial crura which attached to the posterior aspect of the lateral and medial intercondylar tubercles, respectively. These two crura formed the posterior margin of the ACL attachment, except for the central part of ACL. The outer fibres from the anterior horn of LM adjoined ACL. The inner fibres from the anterior horn of LM and two crura from the posterior horn of LM formed the border of the attachment area of ACL. The distinctive fibre anatomy from LM could provide a surgical landmark during arthroscopic surgery.

Comparison of traditional advanced cardiac life support (ACLS) course instruction vs. a scenario-based, performance oriented team instruction (SPOTI) method for Korean paramedic students.

PubMed

Lee, Christopher C; Im, Mark; Kim, Tae Min; Stapleton, Edward R; Kim, Kyuseok; Suh, Gil Joon; Singer, Adam J; Henry, Mark C

2010-01-01

Current Advanced Cardiac Life Support (ACLS) course instruction involves a 2-day course with traditional lectures and limited team interaction. We wish to explore the advantages of a scenario-based performance-oriented team instruction (SPOTI) method to implement core ACLS skills for non-English-speaking international paramedic students. The objective of this study was to determine if scenario-based, performance-oriented team instruction (SPOTI) improves educational outcomes for the ACLS instruction of Korean paramedic students. Thirty Korean paramedic students were randomly selected into two groups. One group of 15 students was taught the traditional ACLS course. The other 15 students were instructed using a SPOTI method. Each group was tested using ACLS megacode examinations endorsed by the American Heart Association. All 30 students passed the ACLS megacode examination. In the traditional ACLS study group an average of 85% of the core skills were met. In the SPOTI study group an average of 93% of the core skills were met. In particular, the SPOTI study group excelled at physical examination skills such as airway opening, assessment of breathing, signs of circulation, and compression rates. In addition, the SPOTI group performed with higher marks on rhythm recognition compared to the traditional group. The traditional group performed with higher marks at providing proper drug dosages compared to the SPOTI students. However, the students enrolled in the SPOTI method resulted in higher megacode core compliance scores compared to students trained in traditional ACLS course instruction. These differences did not achieve statistical significance due to the small sample size. Copyright 2010 Elsevier Inc. All rights reserved.

Risk factors for acute knee injury in female youth football.

PubMed

Hägglund, Martin; Waldén, Markus

2016-03-01

To prospectively evaluate risk factors for acute time-loss knee injury, in particular ACL injury, in female youth football players. Risk factors were studied in 4556 players aged 12-17 years from a randomised controlled trial during the 2009 season. Covariates were both intrinsic (body mass index, age, relative age effect, onset of menarche, previous acute knee injury or ACL injury, current knee complaints, and familial disposition of ACL injury) and extrinsic (no. of training sessions/week, no. of matches/week, match exposure ratio, match play with other teams, and artificial turf exposure). Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated from individual variable and multiple Cox regression analyses. Ninety-six acute knee injuries were recorded, 21 of them ACL injuries. Multiple Cox regression showed a fourfold higher ACL injury rate for players with familial disposition of ACL injury (HR 3.57; 95% CI 1.48-8.62). Significant predictor variables for acute knee injury were age >14 years (HR 1.97; 95% CI 1.30-2.97), knee complaints at the start of the season (HR 1.98; 95% CI 1.30-3.02), and familial disposition of ACL injury (HR 1.96; 95% CI 1.22-3.16). No differences in injury rates were seen when playing on artificial turf compared with natural grass. Female youth football players with a familial disposition of ACL injury had an increased risk of ACL injury and acute knee injury. Older players and those with knee complaints at pre-season were more at risk of acute knee injury. Although the predictive values were low, these factors could be used in athlete screening to target preventive interventions. II.

Return to Play and Future ACL Injury Risk Following ACL Reconstruction In Soccer Athletes From the MOON Group

PubMed Central

Brophy, Robert H.; Schmitz, Leah; Wright, Rick W.; Dunn, Warren R.; Parker, Richard D.; Andrish, Jack T.; McCarty, Eric C.; Spindler, Kurt P.

2013-01-01

Background There is limited information on outcomes and return to play (RTP) after ACL reconstruction (ACLR) in soccer athletes. Hypothesis The purpose of this study was to (i) test the hypotheses that player sex, side of injury and graft choice do not influence RTP, and (ii) define the risk for future ACL injury in soccer players after ACLR. Study design Retrospective cohort study, Level II. Methods Soccer players in a prospective cohort were contacted to determine RTP following ACLR. Information regarding if and when they returned to play, their current playing status, the primary reason they stopped playing soccer (if relevant) and incidence of subsequent ACL surgery was recorded. Results Initially, 72% of 100 soccer athletes (55 male, 45 female) with a mean age of 24.2 years at the time of ACL reconstruction returned to soccer. At average follow up of 7.0 years, 36% were still playing, a significant decrease compared to initial RTP (p<0.0001). Based on multivariate analysis, older athletes (p=0.006) and females (p=0.037) were less likely to return to play. Twelve soccer athletes had undergone further ACL surgery, including 9 on the contralateral knee and 3 on the ipsilateral knee. In a univariate analysis, females were more likely to have future ACL surgery (20% v. 5.5%, p=0.03). Soccer athletes who underwent ACLR on their non-dominant limb had a higher future rate of contra-lateral ACLR (16%) than soccer athletes who underwent ACLR on their dominant limb (3.5%) (p=0.03). Conclusion Younger and male soccer players are more likely to return to play after ACL reconstruction. Return to soccer following ACLR declines over time. PMID:23002201

The Use of Platelets to Affect Functional Healing of an Anterior Cruciate Ligament (ACL) Autograft in a Caprine ACL Reconstruction Model

PubMed Central

Spindler, Kurt P.; Murray, Martha M.; Carey, James L.; Zurakowski, David; Fleming, Braden C.

2009-01-01

Many anterior cruciate ligament (ACL) reconstructions have increased laxity postoperatively. We hypothesized that enhancing an ACL graft with a collagen-platelet composite (CPC) would improve knee laxity and graft structural properties. We also hypothesized the platelet concentration in the CPC would affect these parameters. Twelve goats underwent ACL reconstruction with autologous patellar tendon graft. In six goats, a collagen-platelet composite was placed around the graft (CPC group). In the remaining six goats, the collagen scaffold only was used (COLL group). Three goats were excluded due to complications. After 6 weeks in vivo, anterior–posterior (AP) laxity and tensile properties of the ACL reconstructed knees were measured and normalized against the contralateral intact knee. At a knee flexion angle of 30°, the average increase in AP laxity was 40% less in the CPC group than the COLL group (p = 0.045). At 60°, the AP laxity was 30% less in the CPC group, a difference that was close to statistical significance (p = 0.080). No differences were found between treatment groups with respect to the structural properties (p > 0.30). However, there were significant correlations between serum platelet concentration and AP laxity (R2 = 0.643; p = 0.009), maximum load (R2 = 0.691; p = 0.006), and graft stiffness (R2 = 0.840; p < 0.001). In conclusion, use of a CPC to enhance healing of an allograft ACL reconstruction inversely correlated with early sagittal plane laxity and the systemic platelet count was highly predictive of ACL reconstruction graft strength and stiffness at 6 weeks. These findings emphasize the importance of further research on delineating the effect of platelets in treating of ACL injuries. PMID:19009602

EFFECT OF AXIAL TIBIAL TORQUE DIRECTION ON ACL RELATIVE STRAIN AND STRAIN RATE IN AN IN VITRO SIMULATED PIVOT LANDING

PubMed Central

Oh, Youkeun K.; Kreinbrink, Jennifer L.; Wojtys, Edward M.; Ashton-Miller, James A.

2011-01-01

Anterior cruciate ligament (ACL) injuries most frequently occur under the large loads associated with a unipedal jump landing involving a cutting or pivoting maneuver. We tested the hypotheses that internal tibial torque would increase the anteromedial (AM) bundle ACL relative strain and strain rate more than would the corresponding external tibial torque under the large impulsive loads associated with such landing maneuvers. Twelve cadaveric female knees [mean (SD) age: 65.0 (10.5) years] were tested. Pretensioned quadriceps, hamstring and gastrocnemius muscle-tendon unit forces maintained an initial knee flexion angle of 15°. A compound impulsive test load (compression, flexion moment and internal or external tibial torque) was applied to the distal tibia while recording the 3-D knee loads and tibofemoral kinematics. AM-ACL relative strain was measured using a 3mm DVRT. In this repeated measures experiment, the Wilcoxon Signed-Rank test was used to test the null hypotheses with p<0.05 considered significant. The mean (± SD) peak AM-ACL relative strains were 5.4±3.7 % and 3.1±2.8 % under internal and external tibial torque, respectively. The corresponding mean (± SD) peak AM-ACL strain rates reached 254.4±160.1 %/sec and 179.4±109.9 %/sec, respectively. The hypotheses were supported in that the normalized mean peak AM-ACL relative strain and strain rate were 70% and 42% greater under internal than external tibial torque, respectively (p=0.023, p=0.041). We conclude that internal tibial torque is a potent stressor of the ACL because it induces a considerably (70%) larger peak strain in the AM-ACL than does a corresponding external tibial torque. PMID:22025178

Recovery of Psychological Readiness May Differ Between Genders Following ACL Reconstruction in Adolescent Athletes

PubMed Central

Milewski, Matthew David; Kostyun, Regina; Iannicelli, Julie P.; Kostyun, Kyle J.; Solomito, Matthew; Nissen, Carl W.

2016-01-01

Objectives: Injury to the anterior cruciate ligament (ACL) is a traumatic and emotional event for adolescent athletes. Preparation to return to play (RTP) and the potential risk of re-injury are often equally as emotional as the injury, and have been identified as possible limiting factors to a successful rehabilitation and RTP. In order to create a comprehensive rehabilitation model, further understanding of psychological readiness following surgical intervention is needed. The purpose of this study was to determine if clinical outcomes of subjective knee function and psychological readiness differ between genders following ACL reconstruction surgery in adolescent athletes, and if higher knee function and physiological readiness was associated with an earlier to RTP. Methods: Athletes who underwent ACL reconstruction surgery and were successfully returned back to unrestricted sport were included in the analysis. At approximately six months post surgery, knee function was assessed using the validated International Knee Documentation Committee (IKDC) Subjective Form, and psychological readiness was assessed using the validated ACL-Return to Sport after Injury (ACL-RSI) scale. Formal clearance to resume unrestricted sport was obtained from clinic notes. A T-test was used to determine if demographics, IKDC and ACL-RSI scores between genders. A mixed effects random intercept regression model was used to determine the association of time to RTP with IKDC and ACL-RSI scores. Results: A total of 45 adolescent athletes (23 females) were included in this analysis. No significant differences were found between males and females for age (16.2±1.5 years, 16.3±2.2 years) and average time to RTP (7.3±2.0 months, 7.3±1.8 months). No significant differences in IKDC scores were found between males and females (88±10%, 87±10%). A trend was identified that males demonstrated higher ACL-RSI scores at six month post surgery than females (81±14%, 72±17%, p = 0.063). In females, higher IKDC scores (p=0.013, Ɓ =-0.09) and higher ACL-RSI scores (p = 0.002, Ɓ = -0.06) were associated with an earlier time to RTP. This association was not found in male athletes. Conclusion: Although both genders felt their knee would function well during sport at approximately six months following ACL reconstruction, male athletes seem to demonstrate an overall stronger psychological readiness to RTP. However, better scores on the ACL-RSI and IKDC were associated with an earlier RTP only in female athletes. The results of this study suggest a difference in the psychological readiness to RTP between male and female adolescent athletes approximately six months following ACL reconstruction. Further investigations are warranted to investigate the psychological hurdles that face each gender when trying to RTP following an ACL injury. A better understanding of these emotional limitations could help to clinically identify patients that may benefit from counseling.

Biomimetic tissue-engineered anterior cruciate ligament replacement

PubMed Central

Cooper, James A.; Sahota, Janmeet S.; Gorum, W. Jay; Carter, Janell; Doty, Stephen B.; Laurencin, Cato T.

2007-01-01

There are >200,000 anterior cruciate ligament (ACL) ruptures each year in the United States, and, due to the poor healing properties of the ACL, surgical reconstruction with autograft or allograft tissue is the current treatment of these injuries. To regenerate the ACL, the ideal matrix should be biodegradable, porous, and exhibit sufficient mechanical strength to allow formation of neoligament tissue. Researchers have developed ACL scaffolds with collagen fibers, silk, biodegradable polymers, and composites with limited success. Our group has developed a biomimetic ligament replacement by using 3D braiding technology. In this preliminary in vivo rabbit model study for ACL reconstruction, the histological and mechanical evaluation demonstrated excellent healing and regeneration with our cell-seeded, tissue-engineered ligament replacement. PMID:17360607

Fine Aerosol Associated Non-Polar Organics in Jammu, AN Urban Location in the Foothill Region of North Western Himalayas

NASA Astrophysics Data System (ADS)

Yadav, S.; Bamotra, S.

2017-12-01

A comprehensive study was done on the mass, composition and sources of fine aerosol associated non-polar organics in Jammu, an urban location in the foothill region of North - Western Himalayas. Systematic multi-scale sampling was done from October, 2015 to February, 2017 to collect fine aerosol (PM2.5) samples every week using a Fine Particulate Sampler (Envirotech, APM 550 MFC) which operates at a constant flow rate of 16.7 L/minute. The Non- polar organic compounds comprising of n-alkanes, PAHs, isoprenoid hydrocarbons and nicotine were analyzed using Thermal desorption Gas Chromatography Mass Spectrometry (TD-GC-MS) method. The n-alkane associated diagnostic parameters include—mass weighted Averaged Chain Length (ACL); Carbon number with maximum concentration (Cmax); Petroleum derived n-alkanes (PNA%), Carbon Preference Index (CPI) and the percentage contribution of Wax n-alkanes from plants (WNA%). These diagnostic parameters along with PAH based molecular ratios were used to understand the diurnal and seasonal variations in different biogenic and petrogenic source contributions in this part of Himalayas. The presence of source specific tracers like Levoglucosan, Retene, Isoquinoline and nicotine also corroborated our findings. Further Fine aerosols associated Black Carbon, an important marker for burning was determined using Optical Transmissometer. Significant multiscale variations were found in the Fine aerosol load, associated Non-polar organics, source tracers/contributions and Black Carbon.

Return to Play and Player Performance After Anterior Cruciate Ligament Injury in Elite Australian Rules Football Players

PubMed Central

Liptak, Matthew G.; Angel, Kevin R.

2017-01-01

Background: Australian Rules football is a highly aerobic and anaerobic game that at times requires players to perform cutting or pivoting maneuvers, potentially exposing them to anterior cruciate ligament (ACL) injury. At present, there are limited data available addressing the impact of ACL injury on return to play and preinjury form after ACL reconstruction. Purpose: To determine the prevalence of ACL injury and the incidence of further ACL injury, and to consider player return to play and return to preinjury form after ACL reconstruction. It was hypothesized that elite-level Australian Football League (AFL) players do not return to preinjury form until, at minimum, 2 years after returning to play. Study Design: Case series; Level of evidence, 4. Methods: A retrospective analysis was undertaken on a cohort of elite AFL players who injured their ACL between 1990 and 2000. Return to play after ACL reconstruction was determined by the mean number of ball disposals, or release of the ball by the hand or foot, at 1, 2, and 3 years after return to play and compared with preinjury form. Associations between player and injury characteristics, method of reconstruction, and outcomes (return to play, preinjury form, and further ACL injury) were examined. Results: During the included seasons, a total of 2723 AFL players were listed. Of these, 131 (4.8%) sustained an ACL injury, with 115 players eligible for inclusion. Of 115 players, 26% did not return to elite competition, while 28% of those who did return experienced further ACL injury. The adjusted mean number of disposals (± standard error of the mean) was significantly lower at 1 year (12.21 ± 0.63; P = .003), 2 years (12.09 ± 0.65; P = .008), and 3 years (11.78 ± 0.77; P = .01) after return to play compared with preinjury (14.23 ± 0.67). On average, players did not return to preinjury form by 3 years (P < .01). Players aged 30 years or older were less likely to return to play compared with younger players (P = .0002), moderate-weight players were more likely to return to play compared with lighter-weight players (P = .007), and there were significantly increased odds of not returning to play if the dominant side was injured (odds ratio, 0.10; 95% CI, 0.03-0.34; P = .0002). Conclusion: On average, AFL players do not return to their preinjury form after ACL injury and reconstruction, a common injury in this sporting population. This along with the high occurrence of reinjury highlights the career-threatening nature of ACL injury for elite AFL players. PMID:28680894

Antioxidative effect of lipophilized caffeic acid in fish oil enriched mayonnaise and milk.

PubMed

Alemán, Mercedes; Bou, Ricard; Guardiola, Francesc; Durand, Erwann; Villeneuve, Pierre; Jacobsen, Charlotte; Sørensen, Ann-Dorit Moltke

2015-01-15

The antioxidative effect of lipophilized caffeic acid was assessed in two different fish oil enriched food products: mayonnaise and milk. In both emulsion systems, caffeic acid esterified with fatty alcohols of different chain lengths (C1-C20) were better antioxidants than the original phenolic compound. The optimal chain length with respect to protection against oxidation was, however, different for the two food systems. Fish oil enriched mayonnaise with caffeates of medium alkyl chain length (butyl, octyl and dodecyl) added resulted in a better oxidative stability than caffeates with shorter (methyl) or longer (octadecyl) alkyl chains. Whereas in fish oil enriched milk emulsions the most effective caffeates were those with shorter alkyl chains (methyl and butyl) rather than the ones with medium and long chains (octyl, dodecyl, hexadecyl and eicosyl). These results demonstrate that there might be an optimum alkyl chain length for each phenolipid in each type of emulsion systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of carbon chain length of starting materials on the formation of carbon dots and their optical properties

NASA Astrophysics Data System (ADS)

Pan, Xiaohua; Zhang, Yan; Sun, Xiaobo; Pan, Wei; Yu, Guifeng; Si, Shuxin; Wang, Jinping

2018-04-01

Carbon dots (CDs) have attracted increasing attention due to their high performances and potential applications in wide range of areas. However, their emission mechanism is not clear so far. In order to reveal more factors contributing to the emission of CDs, the effect of carbon chain length of starting materials on the formation of CDs and their optical properties was experimentally investigated in this work. In order to focus on the effect of carbon chain length, the starting materials with C, O, N in fully identical forms and only carbon chain lengths being different were selected for synthesizing CDs, including citric acid (CA) and adipic acid (AA) as carbon sources, and diamines with different carbon chain lengths (H2N(CH2)nNH2, n = 2, 4, 6) as nitrogen sources, as well as ethylenediamine (EDA) as nitrogen source and diacids with different carbon chain lengths (HOOC(CH2)nCOOH, n = 0, 2, 4, 6) as carbon sources. Therefore, the effect of carbon chain length of starting materials on the formation and optical properties of CDs can be systematically investigated by characterizing and comparing the structures and optical properties of as-prepared nine types of CDs. Moreover, the density of –NH2 on the surface of the CDs was quantitatively detected by a spectrophotometry so as to elucidate the relationship between the –NH2 related surface state and the optical properties.

Influence of Anterior Cruciate Ligament Tear on Thigh Muscle Strength and Hamstring-to-Quadriceps Ratio: A Meta-Analysis.

PubMed

Kim, Hyun-Jung; Lee, Jin-Hyuck; Ahn, Sung-Eun; Park, Min-Ji; Lee, Dae-Hee

2016-01-01

Theoretical compensation after anterior cruciate ligament (ACL) tear could cause quadriceps weakness and hamstring activation, preventing anterior tibial subluxation and affecting the expected hamstring-to-quadriceps ratio. Although quadriceps weakness often occurs after ACL tears, it remains unclear whether hamstring strength and hamstring-to-quadriceps ratio increase in ACL deficient knees. This meta-analysis compared the isokinetic muscle strength of quadriceps and hamstring muscles, and the hamstring-to-quadriceps ratio, of the injured and injured limbs of patients with ACL tears. This meta-analysis included all studies comparing isokinetic thigh muscle strengths and hamstring-to-quadriceps ratio in the injured and uninjured legs of patients with ACL tear, without or before surgery. Thirteen studies were included in the meta-analysis. Quadriceps and hamstring strengths were 22.3 N∙m (95% CI: 15.2 to 29.3 N∙m; P<0.001) and 7.4 N∙m (95% CI: 4.3 to 10.5 N∙m; P<0.001) lower, respectively, on the injured than on the uninjured side. The mean hamstring-to-quadriceps ratio was 4% greater in ACL deficient than in uninjured limbs (95% CI: 1.7% to 6.3%; P<0.001). Conclusively, Decreases were observed in both the quadriceps and hamstring muscles of patients with ACL tear, with the decrease in quadriceps strength being 3-fold greater. These uneven reductions slightly increase the hamstring-to-quadriceps ratio in ACL deficient knees.

Magnesium ring device to restore function of a transected anterior cruciate ligament in the goat stifle joint.

PubMed

Farraro, Kathryn F; Sasaki, Norihiro; Woo, Savio L-Y; Kim, Kwang E; Tei, Matteo M; Speziali, Andrea; McMahon, Patrick J

2016-11-01

A bioresorbable, mono-crystalline magnesium (Mg) ring device and suture implantation technique were designed to connect the ends of a transected anterior cruciate ligament (ACL) to restabilize the knee and load the ACL to prevent disuse atrophy of its insertion sites and facilitate its healing. To test its application, cadaveric goat stifle joints were evaluated using a robotic/universal force-moment sensor testing system in three states: Intact, ACL-deficient, and after Mg ring repair, at 30°, 60°, and 90° of joint flexion. Under a 67-N anterior tibial load simulating that used in clinical examinations, the corresponding anterior tibial translation (ATT) and in-situ forces in the ACL and medial meniscus for 0 and 100 N of axial compression were obtained and compared with a control group treated with suture repair. In all cases, Mg ring repair reduced the ATT by over 50% compared to the ACL-deficient joint, and in-situ forces in the ACL and medial meniscus were restored to near normal levels, showing significant improvement over suture repair. These findings suggest that Mg ring repair could successfully stabilize the joint and load the ACL immediately after surgery, laying the framework for future in vivo studies to assess its utility for ACL healing. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2001-2008, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Influence of Anterior Cruciate Ligament Tear on Thigh Muscle Strength and Hamstring-to-Quadriceps Ratio: A Meta-Analysis

PubMed Central

Ahn, Sung-Eun; Park, Min-Ji; Lee, Dae-Hee

2016-01-01

Theoretical compensation after anterior cruciate ligament (ACL) tear could cause quadriceps weakness and hamstring activation, preventing anterior tibial subluxation and affecting the expected hamstring-to-quadriceps ratio. Although quadriceps weakness often occurs after ACL tears, it remains unclear whether hamstring strength and hamstring-to-quadriceps ratio increase in ACL deficient knees. This meta-analysis compared the isokinetic muscle strength of quadriceps and hamstring muscles, and the hamstring-to-quadriceps ratio, of the injured and injured limbs of patients with ACL tears. This meta-analysis included all studies comparing isokinetic thigh muscle strengths and hamstring-to-quadriceps ratio in the injured and uninjured legs of patients with ACL tear, without or before surgery. Thirteen studies were included in the meta-analysis. Quadriceps and hamstring strengths were 22.3 N∙m (95% CI: 15.2 to 29.3 N∙m; P<0.001) and 7.4 N∙m (95% CI: 4.3 to 10.5 N∙m; P<0.001) lower, respectively, on the injured than on the uninjured side. The mean hamstring-to-quadriceps ratio was 4% greater in ACL deficient than in uninjured limbs (95% CI: 1.7% to 6.3%; P<0.001). Conclusively, Decreases were observed in both the quadriceps and hamstring muscles of patients with ACL tear, with the decrease in quadriceps strength being 3-fold greater. These uneven reductions slightly increase the hamstring-to-quadriceps ratio in ACL deficient knees. PMID:26745808

Video Analysis of Anterior Cruciate Ligament (ACL) Injuries

PubMed Central

Carlson, Victor R.; Sheehan, Frances T.; Boden, Barry P.

2016-01-01

Background: As the most viable method for investigating in vivo anterior cruciate ligament (ACL) rupture, video analysis is critical for understanding ACL injury mechanisms and advancing preventative training programs. Despite the limited number of published studies involving video analysis, much has been gained through evaluating actual injury scenarios. Methods: Studies meeting criteria for this systematic review were collected by performing a broad search of the ACL literature with use of variations and combinations of video recordings and ACL injuries. Both descriptive and analytical studies were included. Results: Descriptive studies have identified specific conditions that increase the likelihood of an ACL injury. These conditions include close proximity to opposing players or other perturbations, high shoe-surface friction, and landing on the heel or the flat portion of the foot. Analytical studies have identified high-risk joint angles on landing, such as a combination of decreased ankle plantar flexion, decreased knee flexion, and increased hip flexion. Conclusions: The high-risk landing position appears to influence the likelihood of ACL injury to a much greater extent than inherent risk factors. As such, on the basis of the results of video analysis, preventative training should be applied broadly. Kinematic data from video analysis have provided insights into the dominant forces that are responsible for the injury (i.e., axial compression with potential contributions from quadriceps contraction and valgus loading). With the advances in video technology currently underway, video analysis will likely lead to enhanced understanding of non-contact ACL injury. PMID:27922985

Clinical, biomechanical and morphological assessment of anterior cruciate ligament Kevlar®-based artificial prosthesis in rabbit model.

PubMed

de la Garza-Castro, Santiago; González-Rivera, Carlos E; Vílchez-Cavazos, Félix; Morales-Avalos, Rodolfo; Barrera-Flores, Francisco J; Elizondo-Omaña, Rodrigo E; Soto-Dominguez, Adolfo; Acosta-Olivo, Carlos; Mendoza-Lemus, Oscar F

2017-07-27

The aim of this study was to evaluate the clinical, biomechanical and morphological characteristics of a Kevlar®-based prosthetic ligament as a synthetic graft of the anterior cruciate ligament (ACL) in an experimental animal model in rabbits. A total of 27 knees of rabbits randomly divided into 3 groups (control, ACL excision and ACL replacement with a Kevlar® prosthesis) were analyzed using clinical, biomechanical and morphological tests at 6, 12 and 18 weeks postprocedure. The mean displacement in mechanical testing was 0.73 ± 0.06 mm, 1.58 ± 0.19 mm and 0.94 ± 0.20 mm for the control, ACL excision and ACL replacement with synthetic prosthesis groups, respectively. The results showed an improvement in the stability of the knee with the use of the Kevlar® synthetic prosthesis in the biomechanical testing (p<0.05) compared with rabbits that underwent ACL excision, in addition to displacements that were larger but comparable to that in the control group (p>0.05), between the replacement group and the control group. The histological study revealed a good morphological adaptation of the synthetic material to the knee. This study proposes a new animal model for the placement and evaluation of Kevlar®-based synthetic ACL implants. The studied prosthesis showed promising behavior in the clinical and biomechanical tests and in the histological analysis. This study lays the foundation for further basic and clinical studies of artificial ACL prostheses using this material.

Postoperative Time Dependent Tibiofemoral Articular Cartilage Contact Kinematics during Step-up after ACL Reconstruction

PubMed Central

Lin, Lin; Li, Jing-Sheng; Kernkamp, Willem A.; Hosseini, Ali; Kim, ChangWan; Yin, Peng; Wang, Lianxin; Tsai, Tsung-Yuan; Asnis, Peter; Li, Guoan

2016-01-01

This study was to investigate the in vivo tibiofemoral cartilage contact locations before and after anterior cruciate ligament (ACL) reconstruction at 6 and 36 months. Ten patients with unilateral ACL injury were included. A step-up motion was analyzed using a combined magnetic resonance modeling and dual fluoroscopic imaging techniques. The preoperative (i.e. ACL deficient and healthy contralateral) and postoperative cartilage contact locations at 6 and 36 months were analyzed. Similar patterns of the cartilage contact locations during the step-up motion were found for the preoperative and postoperative knee states as compared to the preoperative healthy contralateral side. At the end of step-up motion, the medial contact locations at postoperative 36 months were more anterior when compared to the preoperative healthy contralateral (p=0.02) and 6 months postoperative knee states (p=0.01). The changes of the cartilage contact locations at 36 months after ACL reconstruction compared to the healthy contralateral side were strongly correlated with the changes at 6 months postoperatively. This study showed that the tibiofemoral cartilage contact locations of the knee changes with time after ACL reconstruction, implying an ongoing recovery process within the 36 months after the surgery. There could be an association between the short-term (6 months) and longer-term (36 months) contact kinematics after ACL reconstruction. Future studies need to investigate the intrinsic relationship between knee kinematics at different times after ACL reconstruction. PMID:27720228

Does sterilization with fractionated electron beam irradiation prevent ACL tendon allograft from tissue damage?

PubMed

Schmidt, T; Grabau, D; Grotewohl, J H; Gohs, U; Pruß, A; Smith, M; Scheffler, S; Hoburg, A

2017-02-01

Allografts are frequently used for anterior cruciate ligament (ACL) reconstruction. However, due to the inherent risk of infection, a method that achieves complete sterilization of grafts is warranted without impairing their biomechanical properties. Fractionation of electron beam (FEbeam) irradiation has been shown to maintain similar biomechanical properties compared to fresh-frozen allografts (FFA) in vitro. Therefore, aim of this study was to evaluate the biomechanical properties and early remodelling of grafts that were sterilized with fractionated high-dose electron beam irradiation in an in vivo sheep model. ACL reconstruction was performed in 18 mature merino mix sheep. Sixteen were reconstructed with allografts sterilized with FEbeam irradiation (8 × 3.4 kGy) and two with FFA. Eight FFA from prior studies with identical surgical reconstruction and biomechanical and histological analyzes served as controls. Half of the animals were sacrificed at 6 and 12 weeks, and biomechanical testing was performed. Anterior-posterior laxity (APL) was assessed with an AP drawer test at 60° flexion, and load to failure testing was carried out. Histological evaluation of mid-substance samples was performed for descriptive analysis, cell count, crimp and vessel density. For statistical analysis a Kruskal-Wallis test was used for overall group comparison followed by a Mann-Whitney U test for pairwise comparison of the histological and biomechanical parameters. Biomechanical testing showed significantly decreased stiffness in FEbeam compared to FFA at both time points (p ≤ 0.004). APL was increased in FEbeam compared to FFA, which was significant at 6 weeks (p = 0.004). Median of failure loads was decreased in FEbeam grafts, with 12 reconstructions already failing during cyclic loading. Vessel density was decreased in FEbeam compared to FFA at both time points, with significant differences at 12 weeks (p = 0.015). Crimp length was significantly shorter in FEbeam compared to FFA at both time points (p ≤ 0.004) and decreased significantly in both groups from 6 to 12 weeks (p ≤ 0.025). ACL reconstruction with fractionated Ebeam sterilization significantly alters the biomechanical properties and the early remodelling process of treated grafts in vivo. Therefore, this sterilization method cannot be recommended for clinical application. As substantial changes in the remodelling are inherent in this study, care in the rehabilitation of even low-dose sterilized allografts, used for ACL reconstruction, is recommended.

Unit and internal chain profile of African rice (Oryza glaberrima) amylopectin.

PubMed

Gayin, Joseph; Abdel-Aal, El-Sayed M; Manful, John; Bertoft, Eric

2016-02-10

High-performance anion-exchange chromatography was used to study the unit chain profiles of amylopectins and their φ,β-limit dextrins from two African rice (Oryza glaberrima) accessions-TOG 12440 and IRGC 103759. The samples were compared with two Asian rice (Oryza sativa) samples (cv Koshihikari and cv WITA 4) and one O. sativa × O. glaberrima cross (NERICA 4). The ratio of short:long chains ranged between 12.1 and 13.8, and the ratio of A:B-chains was ∼ 1.0 in all samples. A significant difference was observed in the distribution of internal chains with regards to the proportion of short "fingerprint" B-chains (Bfp-chains), which in the φ,β-limit dextrins have a degree of polymerization (DP) 3-7. The African rice starches and NERICA 4 had higher levels of Bfp-chains, but the major group of short B-chains (DP 8-25) was similar to that of the Asian rice samples. The average chain length (CL), internal chain length (ICL), and total internal chain length (TICL) were similar in all samples. However, the external chain length (ECL) was longer in the African rice samples and NERICA 4. ECL correlated positively and significantly (p<0.05) with gelatinization transition temperatures and enthalpy suggesting differences between the two rice types in cooking properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

50 CFR 648.200 - Specifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Limit (OFL), Acceptable Biological Catch (ABC), Annual Catch Limit (ACL), Optimum yield (OY), domestic... (BT), the sub-ACL for each management area, including seasonal periods as specified at § 648.201(d... (from 0 to 3 percent of the sub-ACL from any management area). Recommended specifications shall be...

50 CFR 648.200 - Specifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Limit (OFL), Acceptable Biological Catch (ABC), Annual Catch Limit (ACL), Optimum yield (OY), domestic... (BT), the sub-ACL for each management area, including seasonal periods as specified at § 648.201(d... (from 0 to 3 percent of the sub-ACL from any management area). Recommended specifications shall be...

50 CFR 648.200 - Specifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Limit (OFL), Acceptable Biological Catch (ABC), Annual Catch Limit (ACL), Optimum yield (OY), domestic... (BT), the sub-ACL for each management area, including seasonal periods as specified at § 648.201(d... (from 0 to 3 percent of the sub-ACL from any management area). Recommended specifications shall be...

50 CFR 648.143 - Minimum sizes.

Code of Federal Regulations, 2011 CFR

2011-10-01

... black sea bass fishery adopted by the ASMFC. (1) Commercial ACL overage evaluation. The commercial sector ACL will be evaluated based on a single-year examination of total catch (landings and dead discards). Both landings and dead discards will be evaluated in determining if the commercial sector ACL...

50 CFR 648.200 - Specifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Limit (OFL), Acceptable Biological Catch (ABC), Annual Catch Limit (ACL), Optimum yield (OY), domestic... (BT), the sub-ACL for each management area, including seasonal periods as specified at § 648.201(d... (from 0 to 3 percent of the sub-ACL from any management area). Recommended specifications shall be...

[Intra-articular reinforcement of a partially torn anterior cruciate ligament (ACL) using newly developed UHMWPE biomaterial in combination with Hexalon ACL/PCL screws: ex-vivo mechanical testing of an animal knee model].

PubMed

Fedorová, P; Srnec, R; Pěnčík, J; Dvořák, M; Krbec, M; Nečas, A

2015-01-01

PURPOSE OF THE STUDY Recent trends in the experimental surgical management of a partial anterior cruciate ligament (ACL) rupture in animals show repair of an ACL lesion using novel biomaterials both for biomechanical reinforcement of a partially unstable knee and as suitable scaffolds for bone marrow stem cell therapy in a partial ACL tear. The study deals with mechanical testing of the newly developed ultra-high-molecular-weight polyethylene (UHMWPE) biomaterial anchored to bone with Hexalon biodegradable ACL/PCL screws, as a new possibility of intra-articular reinforcement of a partial ACL tear. MATERIAL AND METHODS Two groups of ex vivo pig knee models were prepared and tested as follows: the model of an ACL tear stabilised with UHMWPE biomaterial using a Hexalon ACL/PCL screw (group 1; n = 10) and the model of an ACL tear stabilised with the traditional, and in veterinary medicine used, extracapsular technique involving a monofilament nylon fibre, a clamp and a Securos bone anchor (group 2; n = 11). The models were loaded at a standing angle of 100° and the maximum load (N) and shift (mm) values were recorded. RESULTS In group 1 the average maximal peak force was 167.6 ± 21.7 N and the shift was on average 19.0 ± 4.0 mm. In all 10 specimens, the maximum load made the UHMWPE implant break close to its fixation to the femur but the construct/fixation never failed at the site where the material was anchored to the bone. In group 2, the average maximal peak force was 207.3 ± 49.2 N and the shift was on average 24.1 ± 9.5 mm. The Securos stabilisation failed by pullout of the anchor from the femoral bone in nine out of 11 cases; the monofilament fibre ruptured in two cases. CONCLUSIONS It can be concluded that a UHMWPE substitute used in ex-vivo pig knee models has mechanical properties comparable with clinically used extracapsular Securos stabilisation and, because of its potential to carry stem cells and bioactive substances, it can meet the requirements for an implant appropriate to the unique technique of protecting a partial ACL tear. In addition, it has no critical point of ACL substitute failure at the site of its anchoring to the bone (compared to the previously used PET/PCL substitute). Key words: knee stabilisation, stifle surgery, ultra-high-molecular-weight polyethylene, UHMWPE, nylon monofilament thread, biodegradable screw, bone anchor.

Risk of Secondary Injury in Younger Athletes After Anterior Cruciate Ligament Reconstruction

PubMed Central

Wiggins, Amelia J.; Grandhi, Ravi K.; Schneider, Daniel K.; Stanfield, Denver; Webster, Kate E.; Myer, Gregory D.

2017-01-01

Background Injury to the ipsilateral graft used for reconstruction of the anterior cruciate ligament (ACL) or a new injury to the contralateral ACL are disastrous outcomes after successful ACL reconstruction (ACLR), rehabilitation, and return to activity. Studies reporting ACL reinjury rates in younger active populations are emerging in the literature, but these data have not yet been comprehensively synthesized. Purpose To provide a current review of the literature to evaluate age and activity level as the primary risk factors in reinjury after ACLR. Study Design Systematic review and meta-analysis. Methods A systematic review of the literature was conducted via searches in PubMed (1966 to July 2015) and EBSCO host (CINAHL, Medline, SPORTDiscus [1987 to July 2015]). After the search and consultation with experts and rating of study quality, 19 articles met inclusion for review and aggregation. Population demographic data and total reinjury (ipsilateral and contralateral) rate data were recorded from each individual study and combined using random-effects meta-analyses. Separate meta-analyses were conducted for the total population data as well as the following subsets: young age, return to sport, and young age + return to sport. Results Overall, the total second ACL reinjury rate was 15%, with an ipsilateral reinjury rate of 7% and contralateral injury rate of 8%. The secondary ACL injury rate (ipsilateral + contralateral) for patients younger than 25 years was 21%. The secondary ACL injury rate for athletes who return to a sport was also 20%. Combining these risk factors, athletes younger than 25 years who return to sport have a secondary ACL injury rate of 23%. Conclusion This systematic review and meta-analysis demonstrates that younger age and a return to high level of activity are salient factors associated with secondary ACL injury. These combined data indicate that nearly 1 in 4 young athletic patients who sustain an ACL injury and return to high-risk sport will go on to sustain another ACL injury at some point in their career, and they will likely sustain it early in the return-to-play period. The high rate of secondary injury in young athletes who return to sport after ACLR equates to a 30 to 40 times greater risk of an ACL injury compared with uninjured adolescents. These data indicate that activity modification, improved rehabilitation and return-to-play guidelines, and the use of integrative neuromuscular training may help athletes more safely reintegrate into sport and reduce second injury in this at-risk population. PMID:26772611

Double-bundle anterior cruciate ligament reconstruction is superior to single-bundle reconstruction in terms of revision frequency: a study of 22,460 patients from the Swedish National Knee Ligament Register.

PubMed

Svantesson, Eleonor; Sundemo, David; Hamrin Senorski, Eric; Alentorn-Geli, Eduard; Musahl, Volker; Fu, Freddie H; Desai, Neel; Stålman, Anders; Samuelsson, Kristian

2017-12-01

Studies comparing single- and double-bundle anterior cruciate ligament (ACL) reconstructions often include a combined analysis of anatomic and non-anatomic techniques. The purpose of this study was to compare the revision rates between single- and double-bundle ACL reconstructions in the Swedish National Knee Ligament Register with regard to surgical variables as determined by the anatomic ACL reconstruction scoring checklist (AARSC). Patients from the Swedish National Knee Ligament Register who underwent either single- or double-bundle ACL reconstruction with hamstring tendon autograft during the period 2007-2014 were included. The follow-up period started with primary ACL reconstruction, and the outcome measure was set as revision surgery. An online questionnaire based on the items of the AARSC was used to determine the surgical technique implemented in the single-bundle procedures. These were organized into subgroups based on surgical variables, and the revision rates were compared with the double-bundle ACL reconstruction. Hazard ratios (HR) with 95% confidence interval (CI) was calculated and adjusted for confounders by Cox regression. A total of 22,460 patients were included in the study, of which 21,846 were single-bundle and 614 were double-bundle ACL reconstruction. Double-bundle ACL reconstruction had a revision frequency of 2.0% (n = 12) and single-bundle 3.2% (n = 689). Single-bundle reconstruction had an increased risk of revision surgery compared with double-bundle [adjusted HR 1.98 (95% CI 1.12-3.51), p = 0.019]. The subgroup analysis showed a significantly increased risk of revision surgery in patients undergoing single-bundle with anatomic technique using transportal drilling [adjusted HR 2.51 (95% CI 1.39-4.54), p = 0.002] compared with double-bundle ACL reconstruction. Utilizing a more complete anatomic technique according to the AARSC lowered the hazard rate considerably when transportal drilling was performed but still resulted in significantly increased risk of revision surgery compared with double-bundle ACL reconstruction [adjusted HR 1.87 (95% CI 1.04-3.38), p = 0.037]. Double-bundle ACL reconstruction is associated with a lower risk of revision surgery than single-bundle ACL reconstruction. Single-bundle procedures performed using transportal femoral drilling technique had significantly higher risk of revision surgery compared with double-bundle. However, a reference reconstruction with transportal drilling defined as a more complete anatomic reconstruction reduces the risk of revision surgery considerably. III.

Collaborative virtual reality based advanced cardiac life support training simulator using virtual reality principles.

PubMed

Khanal, Prabal; Vankipuram, Akshay; Ashby, Aaron; Vankipuram, Mithra; Gupta, Ashish; Drumm-Gurnee, Denise; Josey, Karen; Tinker, Linda; Smith, Marshall

2014-10-01

Advanced Cardiac Life Support (ACLS) is a series of team-based, sequential and time constrained interventions, requiring effective communication and coordination of activities that are performed by the care provider team on a patient undergoing cardiac arrest or respiratory failure. The state-of-the-art ACLS training is conducted in a face-to-face environment under expert supervision and suffers from several drawbacks including conflicting care provider schedules and high cost of training equipment. The major objective of the study is to describe, including the design, implementation, and evaluation of a novel approach of delivering ACLS training to care providers using the proposed virtual reality simulator that can overcome the challenges and drawbacks imposed by the traditional face-to-face training method. We compare the efficacy and performance outcomes associated with traditional ACLS training with the proposed novel approach of using a virtual reality (VR) based ACLS training simulator. One hundred and forty-eight (148) ACLS certified clinicians, translating into 26 care provider teams, were enrolled for this study. Each team was randomly assigned to one of the three treatment groups: control (traditional ACLS training), persuasive (VR ACLS training with comprehensive feedback components), or minimally persuasive (VR ACLS training with limited feedback components). The teams were tested across two different ACLS procedures that vary in the degree of task complexity: ventricular fibrillation or tachycardia (VFib/VTach) and pulseless electric activity (PEA). The difference in performance between control and persuasive groups was not statistically significant (P=.37 for PEA and P=.1 for VFib/VTach). However, the difference in performance between control and minimally persuasive groups was significant (P=.05 for PEA and P=.02 for VFib/VTach). The pre-post comparison of performances of the groups showed that control (P=.017 for PEA, P=.01 for VFib/VTach) and persuasive (P=.02 for PEA, P=.048 for VFib/VTach) groups improved their performances significantly, whereas minimally persuasive group did not (P=.45 for PEA, P=.46 for VFib/VTach). Results also suggest that the benefit of persuasiveness is constrained by the potentially interruptive nature of these features. Our results indicate that the VR-based ACLS training with proper feedback components can provide a learning experience similar to face-to-face training, and therefore could serve as a more easily accessed supplementary training tool to the traditional ACLS training. Our findings also suggest that the degree of persuasive features in VR environments have to be designed considering the interruptive nature of the feedback elements. Copyright © 2014 Elsevier Inc. All rights reserved.

Are Female Soccer Players at an Increased Risk of Second Anterior Cruciate Ligament Injury Compared With Their Athletic Peers?

PubMed

Allen, Melissa M; Pareek, Ayoosh; Krych, Aaron J; Hewett, Timothy E; Levy, Bruce A; Stuart, Michael J; Dahm, Diane L

2016-10-01

Female soccer players have a well-known risk for anterior cruciate ligament (ACL) injury, but few studies have reported on second ACL injuries in this population. To (1) report the rates of subsequent ACL injury (ipsilateral graft rupture or contralateral tear) in competitive female soccer players, (2) compare these rates with those of other female athletes of similar competitive level, (3) determine risk factors for second ACL injury, and (4) report clinical outcome scores in this population. Cohort study; Level of evidence, 3. The medical records at a single institution were reviewed for female patients who were injured during a competitive athletic event and treated with primary ACL reconstruction (ACLR) between 1998 and 2013. Patients were followed for a mean of 68.8 months postoperatively (range, 24-115.2 months). Clinical outcome was obtained via Lysholm and International Knee Documentation Committee (IKDC) scores. Soccer players were matched 1:1 to non-soccer athletes for age, activity level, and graft type. A total of 180 female ACLR patients with a mean ± SD age of 19.6 ± 6.9 years met the study inclusion and exclusion criteria (90 soccer players and 90 non-soccer players). Soccer players sustained more second ACL injuries, including both graft failures (11% vs 1%; P < .01) and contralateral ACL tears (17% vs 4%; P < .01), compared with non-soccer players. Of the 67 patients who returned to soccer after ACLR (mean age, 17.5 years; range, 13-27 years), significantly more had graft tears compared with those who did not return to soccer (15% vs 0%, respectively; P = .04); however, the difference in contralateral ACL tears (19% for returning players vs 9% for those who did not return; P = .34) was not significant. Relatively older age (odds ratio, 1.5 per year; P = .03) was a significant risk factor for ACL graft tear but not for contralateral ACL injury. Both groups had similar mean Lysholm (96 vs 95) and IKDC scores (95 vs 96) at final follow-up. Twenty-eight percent of all female soccer players and 34% of those players who returned to soccer had a second ACL tear. Soccer players had an increased rate of both graft tear and contralateral ACL injury compared with similar non-soccer athletes. Older age and return to soccer were significant risk factors for graft rupture. © 2016 The Author(s).

All-Inside, All-Epiphyseal Anterior Cruciate Ligament Reconstruction in Skeletally Immature Athletes: Return to Sport, Incidence of Second Surgery, and 2-Year Clinical Outcomes.

PubMed

Cordasco, Frank A; Mayer, Stephanie Watson; Green, Daniel W

2017-03-01

Anterior cruciate ligament (ACL) injuries in skeletally immature athletes are increasing. To evaluate the 2-year clinical outcomes of all-inside, all-epiphyseal ACL reconstruction in skeletally immature athletes with 3 to 6 years of remaining growth, with a focus on return to sport and the incidence of second surgery. Case series; Level of evidence, 4. Twenty-three skeletally immature athletes were prospectively evaluated after all-epiphyseal ACL reconstruction utilizing a hamstring autograft. The athletes' age, sex, sport, mechanism of injury, radiographs, and magnetic resonance imaging (MRI) findings were noted. The evaluation included a physical examination, KT-1000 arthrometer measurements, isokinetic testing, and validated outcome scores. Standing radiographs and spoiled gradient recalled echo MRI scans were obtained at 6, 12, and 24 months postoperatively. A quality of movement assessment and return-to-sport performance analysis were also performed. Of the 23 athletes, 6 were female (mean age, 11.3 years), and 17 were male (mean age, 12.6 years). At a minimum follow-up of 2 years (range, 24-45 months), the mean International Knee Documentation Committee score was 94.6 ± 4.9, the mean Lysholm score was 97.9 ± 4.0, the mean Marx activity rating scale score was 13.4 ± 3.6, and the mean Hospital for Special Surgery Pediatric Functional Activity Brief Scale score was 23.9 ± 7.0. Lachman and pivot-shift test results were negative in all patients. The mean side-to-side difference on the KT-1000 arthrometer was 0.9 ± 0.5 mm and less tight on the operated side. No significant growth disturbances were noted; however, 6 athletes had a leg-length discrepancy of more than 5 mm (range, 6-18 mm). Two patients had overgrowth in the femur of more than 15 mm (16 mm and 18 mm). Two athletes (8.7%) required second surgery. The mean time to return to unrestricted activity was 13.5 months (range, 8-22 months). The all-inside, all-epiphyseal ACL reconstruction technique using a hamstring autograft demonstrates excellent subjective and objective clinical outcomes in skeletally immature athletes without physeal arrest.

[Construction of dengue virus-specific full-length fully human antibody libraries by mammalian display technology].

PubMed

Wen, Yangming; Lan, Kaijian; Wang, Junjie; Yu, Jingyi; Qu, Yarong; Zhao, Wei; Zhang, Fuchun; Tan, Wanlong; Cao, Hong; Zhou, Chen

2013-06-01

To construct dengue virus-specific full-length fully human antibody libraries using mammalian cell surface display technique. Total RNA was extracted from peripheral blood mononuclear cells (PBMCs) from convalescent patients with dengue fever. The reservoirs of the light chain and heavy chain variable regions (LCκ and VH) of the antibody genes were amplified by RT-PCR and inserted into the vector pDGB-HC-TM separately to construct the light chain and heavy chain libraries. The library DNAs were transfected into CHO cells and the expression of full-length fully human antibodies on the surface of CHO cells was analyzed by flow cytometry. Using 1.2 µg of the total RNA isolated from the PBMCs as the template, the LCκ and VH were amplified and the full-length fully human antibody mammalian display libraries were constructed. The kappa light chain gene library had a size of 1.45×10(4) and the heavy chain gene library had a size of 1.8×10(5). Sequence analysis showed that 8 out of the 10 light chain clones and 7 out of the 10 heavy chain clones randomly picked up from the constructed libraries contained correct open reading frames. FACS analysis demonstrated that all the 15 clones with correct open reading frames expressed full-length antibodies, which could be detected on CHO cell surfaces. After co-transfection of the heavy chain and light chain gene libraries into CHO cells, the expression of full-length antibodies on CHO cell surfaces could be detected by FACS analysis with an expressible diversity of the antibody library reaching 1.46×10(9) [(1.45×10(4)×80%)×(1.8×10(5)×70%)]. Using 1.2 µg of total RNA as template, the LCκ and VH full-length fully human antibody libraries against dengue virus have been successfully constructed with an expressible diversity of 10(9).

Understanding the effect of alkyl chains of gemini cations on the physicochemical and cellular properties of polyurethane micelles.

PubMed

Pan, Zhicheng; Fang, Danxuan; Song, Yuanqing; Song, Nijia; Ding, Mingming; Li, Jiehua; Luo, Feng; Li, Jianshu; Tan, Hong; Fu, Qiang

2018-06-06

Cationic gemini quaternary ammonium (GQA) has been used as a cell internalization promoter to improve the permeability of the cell membrane and enhance the cellular uptake. However, the effect of the alkyl chain length on the cellular properties of nanocarriers has not been elucidated yet. In this study, we developed a series of polyurethane micelles containing GQAs with various alkyl chain lengths. The alteration of the gemini alkyl chain length was found to change the distribution of GQA surfactants in the micellar structure and affect the surface charge exposure, stability, and the protein absorption properties of nanocarriers. Moreover, we also clarified the role of the alkyl chain length in tumor cell internalization and macrophage uptake of polyurethane micelles. This work provides a new understanding on the effect of the GQA alkyl chain length on the physicochemical and biological properties of nanomedicines, and offers guidance on the rational design of effective drug delivery systems where the issue of functional group exposure at the micellar surface should be considered.

Implementation and application of ACL in campus network

NASA Astrophysics Data System (ADS)

Zheng, Shiyong; Li, Zhao; Li, Biqing

2017-03-01

In this paper, it firstly introduces the related knowledge of access control list (ACL) technology, hardware requirements and software configuration. Then it discusses the topological structure of campus network from the perspective of campus network planning as well as demonstrates the application of ACL technology in campus network combined with examples.

50 CFR 648.24 - Fishery closures and accountability measures.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) Mackerel commercial landings overage repayment. If the mackerel ACL is exceeded, and commercial fishery... repayment. If the mackerel ACL is exceeded, and the recreational fishery landings are responsible for the... single-year adjustment. (5) Non-landing AMs, by sector. In the event that the ACL is exceeded, and that...

50 CFR 648.102 - Summer flounder specifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... with each ACL and ACT, a sector-specific research set-aside, estimates of sector-related discards... ensure the sector-specific ACL for an upcoming fishing year or years will not be exceeded. The measures... measures that are projected to ensure the sector-specific ACL for an upcoming fishing year or years will...

50 CFR 648.142 - Time restrictions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... specification process, for use in conjunction with the ACL and ACT, sector-specific research set-asides... measures, as needed, that are projected to ensure the sector-specific ACL for an upcoming year or years... additional recreational measures are necessary to assure that the recreational sector ACL is not exceeded, he...

50 CFR 648.292 - Tilefish specifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... available data to determine if the ACL, ACT, or total allowable landings (TAL) requires modification to... that review, the Monitoring Committee will recommend ACL, ACT, and TAL to the Tilefish Committee of the... recommend to the MAFMC the appropriate ACL, ACT, TAL, and other management measures for a single fishing...

50 CFR 660.508 - Annual specifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., quota, Annual Catch Limit (ACL) (defined at § 600.310(f)(2)) or Annual Catch Target (ACT) (defined at... guideline, quota, ACL, or ACT, including any apportionment between the directed fishery and set-aside for..., quota, ACL or ACT will contain the following information if available or applicable: (1) The estimated...

50 CFR 648.292 - Tilefish specifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... available data to determine if the ACL, ACT, or total allowable landings (TAL) requires modification to... that review, the Monitoring Committee will recommend ACL, ACT, and TAL to the Tilefish Committee of the... recommend to the MAFMC the appropriate ACL, ACT, TAL, and other management measures for a single fishing...

50 CFR 648.293 - Tilefish trip limits.

Code of Federal Regulations, 2011 CFR

2011-10-01

... forth as follows: § 648.293 Tilefish accountability measures. (a) If the ACL is exceeded, the amount of the ACL overage that cannot be directly attributed to IFQ allocation holders having exceeded their IFQ allocation will be deducted from the ACL in the following fishing year. All overages directly attributable to...

50 CFR 648.87 - Sector allocation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... sector's allocation of the overall ACL available to all vessels issued a limited access NE multispecies... the GB cod ACL available to all vessels issued a limited access NE multispecies permit, that sector... this example, if the overall GB cod ACL available to all vessels issued a limited access NE...

77 FR 50112 - Agency Information Collection Activities: Submission for OMB Review; Comment Request...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-20

... for Community Living (ACL) is announcing that the proposed collection of information listed below has... to the OMB Desk Officer for ACL, Office of Information and Regulatory Affairs, OMB. FOR FURTHER.... 3507, ACL has submitted the following proposed collection of information to OMB for review and...

50 CFR 648.24 - Fishery closures and accountability measures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... § 648.26 will be prohibited. (2) Mackerel commercial landings overage repayment. If the mackerel ACL is... recreational landings overage repayment. If the mackerel ACL is exceeded, and the recreational fishery landings... ACL is exceeded, and that the overage has not been accommodated through other landing-based AMs, but...

50 CFR 648.24 - Framework adjustments to management measures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the mackerel ACL is exceeded, and commercial fishery landings are responsible for the overage, then... data. (4) Mackerel recreational landings overage repayment. If the mackerel ACL is exceeded, and the.... In the event that the ACL is exceeded, and that the overage has not been accommodated through other...

50 CFR 648.102 - Time restrictions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... MAFMC, through the specifications process, for use in conjunction with each ACL and ACT, a sector... commercial quota, along with other measures, as needed, that are projected to ensure the sector-specific ACL... that are projected to ensure the sector-specific ACL for an upcoming fishing year or years will not be...

50 CFR 648.162 - Bluefish specifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... following measures to ensure that the ACL specified by the process outlined in § 648.160(a) will not be... necessary to ensure that the ACL will not be exceeded. The MAFMC shall review these recommendations and... September 1 measures necessary to ensure that the applicable ACL will not be exceeded. The MAFMC's...

50 CFR 648.162 - Bluefish specifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... following measures to ensure that the ACL specified by the process outlined in § 648.160(a) will not be... necessary to ensure that the ACL will not be exceeded. The MAFMC shall review these recommendations and... September 1 measures necessary to ensure that the applicable ACL will not be exceeded. The MAFMC's...

50 CFR 622.43 - Closures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... following closure restrictions apply (See § 622.49 for closure provisions when an ACL is reached or... quota specified in § 622.42, or the ACL specified in 622.49, being reached and subsequent data indicate that the quota or ACL was not reached, the Assistant Administrator may file a notification to that...

50 CFR 660.55 - Allocations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... fishery allocations. Prior to the setting of fishery allocations, the TAC, ACL, or ACT when specified, is... in the non-groundfish fishery that is deducted from the ACL or ACT when specified. (2) The commercial... from the TAC, OY, ACL, or ACT when specified. For the catcher/processor and mothership sectors of the...

77 FR 23652 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Annual Catch Limit...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-20

... Annual Catch Limit Amendment (Comprehensive ACL Amendment) for the Fishery Management Plan for the... the South Atlantic Fishery Management Council (Council). The Comprehensive ACL Amendment specified, in... FMP. A final rule implementing the Comprehensive ACL Amendment was published in the Federal Register...

50 CFR 648.293 - Tilefish accountability measures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Measures for the Tilefish Fishery § 648.293 Tilefish accountability measures. (a) If the ACL is exceeded, the amount of the ACL overage that cannot be directly attributed to IFQ allocation holders having exceeded their IFQ allocation will be deducted from the ACL in the following fishing year. All overages...

50 CFR 648.293 - Tilefish accountability measures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Measures for the Tilefish Fishery § 648.293 Tilefish accountability measures. (a) If the ACL is exceeded, the amount of the ACL overage that cannot be directly attributed to IFQ allocation holders having exceeded their IFQ allocation will be deducted from the ACL in the following fishing year. All overages...

50 CFR 648.24 - Fishery closures and accountability measures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... in § 648.26. (2) Mackerel commercial landings overage repayment. If the mackerel ACL is exceeded and... the event that the ACL is exceeded, and that the overage has not been accommodated through the landing... ACL is exceeded and the recreational fishery landings are responsible for the overage, then the...

50 CFR 648.73 - Closed areas.

Code of Federal Regulations, 2011 CFR

2011-10-01

... ocean quahog Accountability Measures. (a) Commercial ITQ fishery. (1) If the ACL for surfclam or ocean.... (2) Any amount of an ACL overage that cannot be otherwise attributed to an ITQ allocation holder will be deducted from the appropriate ACL in the following fishing year. (b) Maine mahogany quahog fishery...

50 CFR 648.102 - Summer flounder specifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... with each ACL and ACT, a sector-specific research set-aside, estimates of sector-related discards... ensure the sector-specific ACL for an upcoming fishing year or years will not be exceeded. The measures... measures that are projected to ensure the sector-specific ACL for an upcoming fishing year or years will...

50 CFR 648.293 - Tilefish accountability measures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Measures for the Tilefish Fishery § 648.293 Tilefish accountability measures. (a) If the ACL is exceeded, the amount of the ACL overage that cannot be directly attributed to IFQ allocation holders having exceeded their IFQ allocation will be deducted from the ACL in the following fishing year. All overages...

50 CFR 648.102 - Summer flounder specifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... with each ACL and ACT, a sector-specific research set-aside, estimates of sector-related discards... ensure the sector-specific ACL for an upcoming fishing year or years will not be exceeded. The measures... measures that are projected to ensure the sector-specific ACL for an upcoming fishing year or years will...

50 CFR 660.508 - Annual specifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., quota, Annual Catch Limit (ACL) (defined at § 600.310(f)(2)) or Annual Catch Target (ACT) (defined at... guideline, quota, ACL, or ACT, including any apportionment between the directed fishery and set-aside for..., quota, ACL or ACT will contain the following information if available or applicable: (1) The estimated...

50 CFR 648.162 - Bluefish specifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... following measures to ensure that the ACL specified by the process outlined in § 648.160(a) will not be... necessary to ensure that the ACL will not be exceeded. The MAFMC shall review these recommendations and... September 1 measures necessary to ensure that the applicable ACL will not be exceeded. The MAFMC's...

50 CFR 660.55 - Allocations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... of fishery allocations, the ACL or ACT when specified is reduced by the Pacific Coast treaty Indian... deducted from the ACL or ACT when specified. (2) The commercial harvest guideline for Pacific whiting is...(f) and 600.745, will be deducted from the ACL or ACT when specified. Set-aside amounts will be...

50 CFR 648.292 - Tilefish specifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... available data to determine if the ACL, ACT, or total allowable landings (TAL) requires modification to... that review, the Monitoring Committee will recommend ACL, ACT, and TAL to the Tilefish Committee of the... recommend to the MAFMC the appropriate ACL, ACT, TAL, and other management measures for a single fishing...

50 CFR 648.122 - Season and area restrictions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the ASMFC through the specifications process, for use in conjunction with each ACL and ACT, a sector... commercial quota, along with other measures, as needed, that are projected to ensure the sector-specific ACL... determines that additional recreational measures are necessary to ensure that the sector ACL will not be...

50 CFR 660.55 - Allocations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... fishery allocations. Prior to the setting of fishery allocations, the TAC, ACL, or ACT when specified, is... in the non-groundfish fishery that is deducted from the ACL or ACT when specified. (2) The commercial... from the TAC, OY, ACL, or ACT when specified. For the catcher/processor and mothership sectors of the...

50 CFR 648.123 - Gear restrictions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... available for landing scup for the remainder of the period. (1) Commercial ACL overage evaluation. The commercial sector ACL will be evaluated based on a single-year examination of total catch (landings and dead discards). Both landings and dead discards will be evaluated in determining if the commercial sector ACL...

50 CFR 660.508 - Annual specifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., quota, Annual Catch Limit (ACL) (defined at § 600.310(f)(2)) or Annual Catch Target (ACT) (defined at... guideline, quota, ACL, or ACT, including any apportionment between the directed fishery and set-aside for..., quota, ACL or ACT will contain the following information if available or applicable: (1) The estimated...

50 CFR 648.292 - Tilefish specifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... available data to determine if the ACL, ACT, or total allowable landings (TAL) requires modification to... that review, the Monitoring Committee will recommend ACL, ACT, and TAL to the Tilefish Committee of the... recommend to the MAFMC the appropriate ACL, ACT, TAL, and other management measures for a single fishing...

The AFRL MITLL WMT16 News Translation Task System: We put NMT in your MT Rescoring so you can MT while you MT

DTIC Science & Technology

2016-08-07

of the 52nd Annual Meeting of the Association for Compu- tational Linguistics (Volume 1: Long Papers), Pro- ceedings of the ACL , Long Papers, pages...Pro- ceedings of the 54th Annual Conference of the As- sociation of Computational Linguistics ( ACL 2016), Berlin, Germany, August. Association for...translation. In Proceedings of the 45th Annual Meeting of the ACL on Interactive Poster and Demonstration Sessions, ACL ’07, pages 177–180. Minh-Thang Luong

Gender differences in the restoration of knee joint biomechanics during gait after anterior cruciate ligament reconstruction.

PubMed

Asaeda, Makoto; Deie, Masataka; Fujita, Naoto; Kono, Yoshifumi; Terai, Chiaki; Kuwahara, Wataru; Watanabe, Hodaka; Kimura, Hiroaki; Adachi, Nobuo; Sunagawa, Toru; Ochi, Mitsuo

2017-03-01

The aim of our study was to evaluate the effects of gender on recovery of knee joint biomechanics over the stance phase of gait after reconstruction of the anterior cruciate ligament (ACL). Gait parameters and knee joint kinematics and kinetics were compared in 32 patients (16 male and 16 female) who underwent ACL reconstruction for a unilateral ACL deficiency, with comparison to an age-, height-, and weight-matched Control group. Knee flexion, adduction and tibial rotation angles were measured and knee extension and abduction moment was calculated by inverse dynamics methods. Females exhibited more tibial external rotation, in both the Control and ACL groups (P<0.05), which was not changed after ACL reconstruction. Prior to reconstruction, sagittal plane biomechanics were changed, in both males and females, compared to the Control groups (P<0.05). These abnormal sagittal plane mechanics were recovered at 12months, but not six months post-reconstruction. We identified gender-based differences in tibial rotation that influenced the kinematics and kinetics of the knee over the stance phase of gait, both pre-operatively and post-ACL reconstruction. Evaluation of biomechanical effects of ACL injury, before and after reconstruction, should be separately evaluated for females and males. Copyright © 2017 Elsevier B.V. All rights reserved.

Analytical Chemistry Laboratory. Progress report for FY 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, D.W.; Boparai, A.S.; Bowers, D.L.

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 1996. This annual report is the thirteenth for the ACL. It describes effort on continuing and new projects and contributions of the ACL staff to various programs at ANL. The ACL operates in the ANL system as a full-cost-recovery service center, but has a mission that includes a complementary research and development component: The Analytical Chemistry Laboratory will provide high-quality, cost-effective chemical analysis and related technical support to solve research problems of our clients --more » Argonne National Laboratory, the Department of Energy, and others -- and will conduct world-class research and development in analytical chemistry and its applications. Because of the diversity of research and development work at ANL, the ACL handles a wide range of analytical chemistry problems. Some routine or standard analyses are done, but the ACL usually works with commercial laboratories if our clients require high-volume, production-type analyses. It is common for ANL programs to generate unique problems that require significant development of methods and adaption of techniques to obtain useful analytical data. Thus, much of the support work done by the ACL is very similar to our applied analytical chemistry research.« less

Structure of gel phase saturated lecithin bilayers: temperature and chain length dependence.

PubMed Central

Sun, W J; Tristram-Nagle, S; Suter, R M; Nagle, J F

1996-01-01

Systematic low-angle and wide-angle x-ray scattering studies have been performed on fully hydrated unoriented multilamamellar vesicles of saturated lecithins with even chain lengths N = 16, 18, 20, 22, and 24 as a function of temperature T in the normal gel (L beta') phase. For all N, the area per chain Ac increases linearly with T with an average slope dAc/dT = 0.027 A2/degree C, and the lamellar D-spacings also increase linearly with an average slope dD/dT = 0.040 A/degree C. At the same T, longer chain length lecithins have more densely packed chains, i.e., smaller Ac's, than shorter chain lengths. The chain packing of longer chain lengths is found to be more distorted from hexagonal packing than that of smaller N, and the distortion epsilon of all N approaches the same value at the respective transition temperatures. The thermal volume expansion of these lipids is accounted for by the expansion in the hydrocarbon chain region. Electron density profiles are constructed using four orders of low-angle lamellar peaks. These show that most of the increase in D with increasing T is due to thickening of the bilayers that is consistent with a decrease in tilt angle theta and with little change in water spacing with either T or N. Because of the opposing effects of temperature on area per chain Ac and tilt angle 0, the area expansivity alpha A is quite small. A qualitative theoretical model based on competing head and chain interactions accounts for our results. PMID:8842227

Mechanical tensile properties of the anterolateral ligament.

PubMed

Zens, Martin; Feucht, Matthias J; Ruhhammer, Johannes; Bernstein, Anke; Mayr, Hermann O; Südkamp, Norbert P; Woias, Peter; Niemeyer, Philipp

2015-12-01

In a noticeable percentage of patients anterolateral rotational instabilities (ALRI) remain after an isolated ACL reconstruction. Those instabilities may occur due to an insufficiently directed damage of anterolateral structures that is often associated with ACL ruptures. Recent publications describe an anatomical structure, termed the anterolateral ligament (ALL), and suggest that this ligament plays a significant role in the pathogenesis of ALRI of the knee joint. However, only limited knowledge about the biomechanical characteristics and tensile properties of the anterolateral ligament exists. The anterolateral ligament was dissected in four fresh-frozen human cadaveric specimens and all surrounding tissue removed. The initial length of the anterolateral ligament was measured using a digital caliper. Tensile tests with load to failure were performed using a materials testing machine. The explanted anterolateral ligaments were histologically examined to measure the cross-sectional area. The mean ultimate load to failure of the anterolateral ligament was 49.90 N (± 14.62 N) and the mean ultimate strain was 35.96% (± 4.47%). The mean length of the ligament was 33.08 mm (± 2.24) and the mean cross-sectional area was 1.54 m m (2) (± 0.48 m m (2)). Including the areal measurements the maximum tension was calculated to be 32.78 [Formula: see text] (± 4.04 [Formula: see text]). The anterolateral ligament is an anatomical structure with tensile properties that are considerably weaker compared to other peripheral structures of the knee. Knowledge of the anterolateral ligament's tensile strengths may help to better understand its function and with graft choices for reconstruction procedures.

All-inside, All-epiphyseal ACL Reconstruction in Skeletally Immature Athletes: Incidence of Second Surgery and Two-year Clinical Outcomes

PubMed Central

Cordasco, Frank A.; Mayer, Stephanie W.; Graziano, Jessica; deMille, Polly; Chiaia, Theresa; McCarthy, Moira; Nawabi, Danyal H.; Green, Daniel W.

2015-01-01

Objectives: Anterior cruciate ligament (ACL) injuries in skeletally immature athletes are increasing secondary to multiple factors that include increased participation and level of competition within sports, sports specialization and societal factors. Conservative treatment of these injuries has a poor natural history due to recurrent instability with meniscal and articular cartilage damage. The purpose of this study was to evaluate the 2 year clinical outcomes of an all-inside, all-epiphyseal ACL reconstruction in skeletally immature athletes with 3-6 years of remaining growth, with a focus upon return to play and the incidence of second surgery. Methods: Twenty-three skeletally immature athletes (mean chronologic age 11.8 yrs, [range 10-13]) were prospectively evaluated following an all-inside, all-epiphyseal ACL reconstruction utilizing hamstring autograft. The mean bone age (Greulich and Pyle method) was 12.1 years. There were 6 females and 17 males. Five athletes were involved in recreational sport and 18 participated competitively. Lacrosse (40%) and Soccer (27%) were the two most common sports associated with ACL injury in our cohort. All athletes were evaluated with a physical examination, KT-1000 arthrometry, isokinetic testing, and validated outcome scores including the International Knee Documentation Committee score (IKDC), the Lysholm score and Marx activity rating scale. Standing radiographs and SPGR MRI analysis was performed at 6, 12 and 24 months post-op depending upon skeletal age. A Return to Play performance analysis was also analyzed where symmetry, alignment control and the ability to decelerate were assessed during progressively challenging movement patterns encountered in sport. Results: At a minimum follow-up of 2 years (range 2-4.5), the mean IKDC score was 94.5 ± 5.4, the mean Lysholm score was 98.1 ± 4.1 and the mean Marx activity rating scale score was 12.8 ± 3.1. Lachman and pivot shift testing was negative in all patients. The mean side-to-side difference in the KT-1000 arthrometry was 1.0 ± 0.6 mm, with the maximum difference in the cohort being 2 mm. Isokinetic testing showed a mean deficit of 4.3% in extension torque and 9.1% in flexion torque at a repetition speed of 180 degrees per second. No angular deformities, significant leg length discrepancy or physeal disturbances were observed on postoperative radiographs or MRI. Two athletes (8.6%) required a second surgery: 1 (4.3%) had a traumatic graft disruption at 10 months and underwent revision ACLR and 1 (4.3%) required meniscectomy for an incompletely healed meniscal repair at 13 months. There were no contralateral injuries in this cohort of athletes. The mean time for return to unrestricted competitive activity after successful completion of the Return to Play analysis was 12.5 +/- 1.25 months from the time of surgery. Conclusion: An all-inside, all-epiphyseal ACL reconstruction technique using hamstring autograft demonstrates excellent subjective and objective clinical outcomes in skeletally immature athletes without growth disturbance. Return to Play assessment is an important tool to guide the young athlete and his or her family regarding resumption of competitive sports. In our experience, young athletes were on average released for full return to sport after 1 year from ACL reconstruction.

Biosynthesis of medium chain length alkanes for bio-aviation fuel by metabolic engineered Escherichia coli.

PubMed

Wang, Meng; Nie, Kaili; Cao, Hao; Xu, Haijun; Fang, Yunming; Tan, Tianwei; Baeyens, Jan; Liu, Luo

2017-09-01

The aim of this work was to study the synthesis of medium-chain length alkanes (MCLA), as bio-aviation product. To control the chain length of alkanes and increase the production of MCLA, Escherichia coli cells were engineered by incorporating (i) a chain length specific thioesterase from Umbellularia californica (UC), (ii) a plant origin acyl carrier protein (ACP) gene and (iii) the whole fatty acid synthesis system (FASs) from Jatropha curcas (JC). The genetic combination was designed to control the product spectrum towards optimum MCLA. Decanoic, lauric and myristic acid were produced at concentrations of 0.011, 0.093 and 1.657mg/g, respectively. The concentration of final products nonane, undecane and tridecane were 0.00062mg/g, 0.0052mg/g, and 0.249mg/g respectively. Thioesterase from UC controlled the fatty acid chain length in a range of 10-14 carbons and the ACP gene with whole FASs from JC significantly increased the production of MCLA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of amylose nanoparticles prepared via nanoprecipitation: Influence of chain length distribution.

PubMed

Chang, Yanjiao; Yang, Jingde; Ren, Lili; Zhou, Jiang

2018-08-15

The influence of chain length distribution of amylose on size and structure of the amylose nanoparticles (ANPs) prepared through nanoprecipitation was investigated. Amylose with different chain length distributions was obtained by β-amylase treating amylose paste for different times and measured by size exclusion chromatography (SEC) and fluorophore-assisted carbohydrate electrophoresis (FACE). ANPs prepared via precipitation were characterized by using dynamic light scattering (DLS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results showed that the β-amylase treatments led to decrease in chain length of amylose, and it was the most important factor affecting size of ANPs. When hydrolysis degree of amylose was 52.8%, mean size of ANPs decreased from 206.4 nm to 102.7 nm. All the ANPs displayed a V-type crystalline structure and the effect of amylose chain length on crystallinity of the precipitated ANPs was negligible in the investigated range. Copyright © 2018 Elsevier Ltd. All rights reserved.

Exploring the impact of the side-chain length on peptide/RNA binding events.

PubMed

Sbicca, Lola; González, Alejandro López; Gresika, Alexandra; Di Giorgio, Audrey; Closa, Jordi Teixido; Tejedor, Roger Estrada; Andréola, Marie-Line; Azoulay, Stéphane; Patino, Nadia

2017-07-19

The impact of the amino-acid side-chain length on peptide-RNA binding events has been investigated using HIV-1 Tat derived peptides as ligands and the HIV-1 TAR RNA element as an RNA model. Our studies demonstrate that increasing the length of all peptide side-chains improves unexpectedly the binding affinity (K D ) but reduces the degree of compactness of the peptide-RNA complex. Overall, the side-chain length appears to modulate in an unpredictable way the ability of the peptide to compete with the cognate TAR RNA partner. Beyond the establishment of non-intuitive fundamental relationships, our results open up new perspectives in the design of effective RNA ligand competitors, since a large number of them have already been identified but few studies report on the modulation of the biological activity by modifying in the same way the length of all chains connecting RNA recognition motives to the central scaffold of a ligand.

Flexible chain molecules in the marginal and concentrated regimes: universal static scaling laws and cross-over predictions.

PubMed

Laso, Manuel; Karayiannis, Nikos Ch

2008-05-07

We present predictions for the static scaling exponents and for the cross-over polymer volumetric fractions in the marginal and concentrated solution regimes. Corrections for finite chain length are made. Predictions are based on an analysis of correlated fluctuations in density and chain length, in a semigrand ensemble in which mers and solvent sites exchange identities. Cross-over volumetric fractions are found to be chain length independent to first order, although reciprocal-N corrections are also estimated. Predicted scaling exponents and cross-over regimes are compared with available data from extensive off-lattice Monte Carlo simulations [Karayiannis and Laso, Phys. Rev. Lett. 100, 050602 (2008)] on freely jointed, hard-sphere chains of average lengths from N=12-500 and at packing densities from dilute ones up to the maximally random jammed state.