Double Bundles Research Articles

Paper 150: Tibiofemoral Kinematics Following Anatomic Reconstruction of the Double Bundles of the Anterior Cruciate Ligament

Paper 150: Tibiofemoral Kinematics Following Anatomic Reconstruction of the Double Bundles of the Anterior Cruciate Ligament

Arthroscopic reconstruction of posterior cruciate ligament with ligament advanced reinforcement system Y-shape double bundles artificial ligament

Objective To study the operative techniques and clinical effect of arthroscopic reconstruction for posterior cruciate ligament (PCL) with ligament advanced reinforcement system (LARS)Y-shape double bundles artificial ligament. Methods From June 2006 to August 2010,14 patients (10 males and 4 females,at age range of 19-58 years,mean 38 years) with PCL ruptures were treated with LARS under arthroscopic observation.The injury causes included sports contusion in nine patients,traffic accidents in three and falling from height in two.Five patients were with left knee injury and three with right knee injury.The course of injury was 10-30 days (average 15.7 days).MRI indicated complete PCL ruptures in 14 patients and complete anterior cruciate ligament (ACL) ruptures in two.The combined injuries included medial meniscus injury in five patients,lateral meniscus injury in three and posterior acetabular wall fracture in one.The preoperative Lysholn score was (40 ± 7.9 ) points ( range,20-55 points).According to the international knee documentation committee (IKDC) grading,three patients were rated as grade C and 11 as grade D preoperatively.The operation was performed under arthroscopic observation.The ending point and tunnel of PCL of the femur and tibia were drilled with the help of a locator. Results All the patients obtained primary healing,with no complications such as infection,spontaneous rupture or laxity of graft postoperatively.The regular follow-up for all cases ranged from6-60 months ( average 20.5 months).The postoperative Lysholn score was ( 88 ± 3.6 ) points ( 84-93 points),with statistical difference in comparison with the preoperative score (P ＜ 0.05 ) The IKDCgrading was A in 10 patients and B in four 12 months postoperatively. Conclusions Arthroscopic reconstruction with LARS artificial ligaments can effectively recover the stability of the knees,avoid the complications brought by autologous tendon and prevent the allograft rejection complications induced by allogenic tendon graft.The treatment is characterized by simple procedures,minor wound and fast recovery. Key words: Knee joint; Posterior cruciate ligament; Arthroscopes; Artificial ligament

Editor’s note

Editor’s note

Tension Changes Within the Bundles of Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction at Different Knee Flexion Angles: A Study Using a 3-Dimensional Finite Element Model

The aim of this study was to determine the change in length and tension of the reconstructed anterior cruciate ligament (ACL) double bundles at different knee flexion angles by use of a 3-dimensional finite element model. The right knees of 12 living subjects were scanned with a high-resolution computed tomography scanner at 0°, 45°, 90°, and 135° of knee flexion. Several modeling programs were used to simulate double-bundle ACL reconstruction. A finite element model of each bundle with a tension of 20 N was put into each tunnel followed by fixation of the bundles. The tension and length changes of each bundle at different knee flexion angles were assessed. For the anteromedial bundle, the length decreased gradually between 45° and 90° of knee flexion and then reached a plateau, whereas the length of the posterolateral bundle significantly decreased at 45° and 90° of flexion but then increased at full flexion. The reaction force of the anteromedial graft slightly decreased at 45° and then remained constant between 90° and 135° of knee flexion. The reaction force of the posterolateral bundle at full extension slightly decreased at 45° and 90° of flexion, followed by a rebound increase at 135°. We found that both bundles functioned throughout the arc of flexion with consistency in tension, although their lengths decreased. The 2 ACL grafts did not function in a reciprocal manner, unlike previous descriptions. The data obtained for length and tension versus flexion angle have the potential to suggest the appropriate knee position for graft fixation and tensioning to be near extension in clinical situations.

Both the medial and lateral meniscal allograft transplantation following the anterior cruciate ligament reconstruction by arthroscopic surgical technique

To discuss the minimal invasive arthroscopic surgery technique and clinical results of both the medial and lateral meniscal transplantation following the anterior cruciate ligament reconstruction with double bundles and bone tunnels. In August 2008 a minimal invasive surgery of both the medial and lateral meniscal allograft transplantation following anterior cruciate ligament reconstruction was preformed for 1 case with both the medial and lateral meniscectomy by arthroscopic surgery. The method of two bone plugs attached on tibial plateau was employed for medial meniscal allograft transplantation and the technique the bridge in slot for lateral meniscal allograft transplantation. The VAS, Lysholm score and IKDC rating were recorded before and after operation. The stability of knee was assessed by Lachman test, drawer sign and pivot shift test. The patient was followed up 26 month after the operations. The degrees of knee flexion, extension and function of walk were normal. The Lachman test, drawer sign and pivot shift test were nearly normal. The VAS after operation was 2 points lower than that before operation. The Lysholm score post-operation was 20 points higher than pre-operation. The IKDC became B degree in late following-up from C degree before the operation. MRI revealed anterior cruciate ligament graft was continuous and the meniscal allograft was normal shape on year 1 after the operation. The posterior horn of medial meniscal allograft and anterior corner of lateral meniscal allograft showed slightly shrunk. The second-look arthroscopy showed that the healing occurring between meniscal allograft and the capsule and meniscal allograft was normal shape on month 18 after the operation. The anterior horn of medial and lateral meniscus was slightly worn. Both the medial and lateral meniscal transplantation following the anterior cruciate ligament reconstruction in appropriately selected patients with the medial and lateral meniscus-deficient knee may recover the knee mechanic balance and stability, which is a option of treatment for that young and activity patients. It is proposed that the medial and lateral meniscal grafts harvested from a single donator. Attention should be paid to the direction of the bone tunnels fixing the horns of the meniscus in order to avoid communication with the tunnels of anterior cruciate ligament reconstruction.

Ehresmann doubles and Drinfel'd doubles for Lie algebroids and Lie bialgebroids

The word ‘double’ was used by Ehresmann to mean ‘an object X in the category of all X’. Double categories, double groupoids and double vector bundles are instances, but the notion of Lie algebroid cannot readily be doubled in the Ehresmann sense, since a Lie algebroid bracket cannot be defined diagrammatically. In this paper we use the duality of double vector bundles to define a notion of double Lie algebroid, and we show that this abstracts the infinitesimal structure (at second order) of a double Lie groupoid.

Transcription of pH-sensitive supramolecular assemblies into silica: from straight, coiled, and helical tubes to single and double fan-like bundles

The transcription of self-assembled organic structures by the sol–gel process is a powerful method in the synthesis of inorganic materials with controlled sizes, shapes, and porosities. Lithocholic acid (LCA) shows pH-sensitive supramolecular assemblies in aqueous solution, which can be used as tunable templates in the synthesis of silica replicas. Micro- and submicro-scale silica structures from straight, coiled, and helical tubes to single and double fan-like bundles are formed by the sol–gel transcription of pH-sensitive LCA assemblies with tetraethoxysilane (TEOS) in the presence of ammonia catalyst.

Posterior cruciate ligament reconstruction by double bundle-double tunnel Y-shape of the anterior tibialis tendon allograft

Objective To investigate the clinical results of posterior cruciate ligament (PCL) reconstruction by double bundle-double tunnel Y-shape of the anterior tibialis tendon allograft. Methods From March 2001 to January 2008, 47 patients underwent PCL reconstruction were included. The allogeneic adult anterior tibialis tendon was prepared into the Y-shape double bundles with the length of 130 mm; A bundle was defined as A-side; B-side was two short bundle (B1, B2 bundle). A bundle was 70 mm in length with a diameter of 10-12 mm. B1 bundle (anterolateral bundle) was 55 mm long with a diameter of 6 mm; B2 bundle(posteromedial bundle) was about 50 mm with a diameter of 6 mm. The allograft ligament was installed through the antero-medial approach. Absorbable interface screws were fixed in the tibial tunnel firstly, and then in the femoral tundles. When being fixed, anterolateral bundle was in flexion of 90°, postero-medial bundle was in 30°. Assisted exercise with knee an angle-locked walking aid had continued for 8-10 weeks. Results The average operating time were 45 min. The average follow-up time was 49.5 months. Preoperative Lachmann was positive in all cases while Lachmann was negative in 39 cases, weakly positive in 5 cases, and positive in 4 cases postoperatively. Post-operative KT-1000 testing, Lysholm score and Tegner activity levels has improved significantly compare with the pre-operative ones. Conclusion The double folded bundles of adult anterior tibialis tendon has sufficient length and diameter for posterior cruciate ligament reconstruction with power tension. The methods of ligament passing through the tunnel has improved to ease the procedure. Key words: Arthroscopy; Posterior cruciate ligament; Knee joint; Muscle, skeletal

Double affine bundles

A theory of double affine and special double affine bundles, i.e. differential manifolds with two compatible (special) affine bundle structures, is developed as an affine counterpart of the theory of double vector bundles. The motivation and basic examples come from Analytical Mechanics, where double affine bundles have been recognized as a proper geometrical tool in a frame independent description of many important systems. Different approaches to the (special) double affine bundles are compared and carefully studied together with the problems of double vector bundle models and hulls, duality, and relations to associated phase spaces, contact structures, and other canonical constructions.

Lie algebroid structures on double vector bundles and representation theory of Lie algebroids

A VB -algebroid is essentially defined as a Lie algebroid object in the category of vector bundles. There is a one-to-one correspondence between VB -algebroids and certain flat Lie algebroid superconnections, up to a natural notion of equivalence. In this setting, we are able to construct characteristic classes, which in special cases reproduce characteristic classes constructed by Crainic and Fernandes. We give a complete classification of regular VB -algebroids, and in the process we obtain another characteristic class of Lie algebroids that does not appear in the ordinary representation theory of Lie algebroids.

Higher vector bundles and multi-graded symplectic manifolds

A natural explicit condition is given ensuring that an action of the multiplicative monoid of non-negative reals on a manifold F comes from homotheties of a vector bundle structure on F , or, equivalently, from an Euler vector field. This is used in showing that double (or higher) vector bundles present in the literature can be equivalently defined as manifolds with a family of commuting Euler vector fields. Higher vector bundles can be therefore defined as manifolds admitting certain N n -grading in the structure sheaf. Consequently, multi-graded (super)manifolds are canonically associated with higher vector bundles that is an equivalence of categories. Of particular interest are symplectic multi-graded manifolds which are proven to be associated with cotangent bundles. Duality for higher vector bundles is then explained by means of the cotangent bundles as they contain the collection of all possible duals. This gives, moreover, higher generalizations of the known “universal Legendre transformation” T ∗ E ≃ T ∗ E ∗ , identifying the cotangent bundles of all higher vector bundles in duality. The symplectic multi-graded manifolds, equipped with certain homological Hamiltonian vector fields, lead to an alternative to Roytenberg’s picture generalization of Lie bialgebroids, Courant brackets, Drinfeld doubles and can be viewed as geometrical base for higher BRST and Batalin–Vilkovisky formalisms. This is also a natural framework for studying n -fold Lie algebroids and related structures.

Cordaitalean Seed Plants from the Early Permian of North China. II. Reconstruction of Cordaixylon tianii

From a single Early Permian locality in the Taiyuan Formation of northern China, a new whole‐plant cordaitalean is reconstructed and named Cordaixylon tianii (B. Tian and S.‐J. Wang) S.‐J. Wang and J. Hilton sp. nov. The reconstruction is based on pairs of plant organs found in organic attachment, supplemented with cases where two or more co‐occurring morphospecies share distinctive anatomical features. Stems have sympodial primary vascular architecture with endarch primary xylem maturation of the cauline bundles, which surround a septate pith. Leaf traces are endarch, most diverging from the pith margin as double bundles (less frequently singly) and bearing leaves in 3/8 and 5/13 phyllotaxis. Leaves are long and straplike, resembling those of the previously reconstructed Cordaixylon dumusum Rothwell and S. Warner, but with a geniculate posture that justifies their segregation as Cordaites tianii S.‐J. Wang and J. Hilton sp. nov. Both male and female cones are compound, borne irregularly as epicormic branches, and when isolated conform to the morphogenus Cordaitanthus. Pollen cones with numerous pollen organs borne on apically concentrated fertile scales are largely consistent with the morphospecies Cordaitanthus concinnus Delevoryas, but subtle distinctions permit their description as C. tianii S.‐J. Wang and J. Hilton sp. nov. Ovulate cones are described as Cordaitanthus shanxiensis S.‐J. Wang and J. Hilton sp. nov.; each cone contains several cardiocarpalean ovules that have a distinctive tuberculate integumentary structure and are assignable to the morphospecies Cardiocarpus tuberculatus S.‐J. Wang, J. Hilton, and B. Tian. The reconstructed plant most closely resembles C. dumusum from the Late Pennsylvanian of North America, but (often subtle) diagnostic characters are well distributed across the organs of the two conceptual whole plants, permitting confident distinction at species level. The plant is reconstructed as a large, suberect or fully erect shrub.

Anatomic double-bundle ACL reconstruction with femoral cortical bone bridge support using hamstrings

While ACL reconstruction using single-tunnel and single-bundle techniques generally yields good clinical results, more and more studies are now reporting results that are not entirely satisfactory, as this type of reconstruction only exerts control over forward tibial shifting, not tibial rotation, when activities that exert high functional demands are undertaken. As a result, recent years have seen the appearance of numerous techniques for anatomic ACL reconstruction that reproduce both the anteromedial and posterolateral bundles of the ligament and therefore offer potentially improved rotational control. This article outlines a technique for anatomic ACL reconstruction. Said technique uses central and anteromedial portals, which afford a better perspective of the intercondylar notch. The main features of this technique are: (1) Double bone tunnels in the femur and tibia. The femoral tunnels are created using the out-in technique. (2) Double bundles with hamstring tendon grafts. (3) Tibial fixation by means of interference screws. (4) Femoral fixation in which the graft is supported by a cortical bone bridge and an interference screw in one of the tunnels. We feel that the main advantage of this technique is precisely that it introduces a new feature (a cortical femoral bone bridge) and is not necessarily dependent on specific double-bundle instrumentation, using only regular drill guides to create out-in femoral tunnels. This enables said tunnels to be located with ease and precision. The femoral fixation model itself, with the support provided by the cortical bone bridge, potentially guarantees a level of resistance that can be further increased with the aid of one or two interference screws, thus avoiding the need for post fixation techniques that require the use of screws or buttons.

Biomechanical evaluation of intra-articular and extra-articular procedures in anterior cruciate ligament reconstruction: A finite element analysis

Intra-articular techniques (single and double bundles) are the most widely used procedures for the anterior cruciate ligament reconstruction. Lemaire introduced in 1967 the extra-articular techniques, and combined intra-articular and extra-articular reconstruction, to better restore the stability of the knee. However, the effectiveness of these procedures (intra-articular, extra-articular combined or not with intra-articular) seems to be controversial. In the present study, we developed numerical models of a knee joint to evaluate the effects of these different procedures on the kinematics and biomechanics of the knee during an internal rotation test. Six cases were simulated: intact anterior cruciate ligament, intra-articular reconstructed anterior cruciate ligament (single and double bundles), extra-articular reconstructed anterior cruciate ligament alone, and combination of extra- and intra-articular reconstructions. The loading condition was an internal tibial torque of 2 N m at 0 degrees, 15 degrees, 30 degrees and 45 degrees of knee flexion. Internal rotation of the tibia and forces within the grafts and the ligaments were calculated. This study showed that both single and double bundles intra-articular reconstructions restore similar internal rotation control and biomechanics of the soft structures as the intact anterior cruciate ligament situation. On the other hand, our results indicate that extra-articular reconstruction reduces appreciably the internal rotation and modifies the charges distribution in the soft structures when compared to the intact anterior cruciate ligament. The extra-articular procedure alters the kinematics of the knee, which might overconstraint the ligaments and the femorotibial joints, leading to the failure of the anterior cruciate ligament reconstruction.

Rhexoxylon brunoi Artabe, Brea et Zamuner, sp. nov., a new Triassic corystosperm from the Paramillo de Uspallata, Mendoza, Argentina

A new species of Rhexoxylon from the Upper Triassic of Argentina is described. The material was collected at El Paramillo de Uspallata area and comes from Los Colorados Formation. There is a big buried specimen and scattered material which is preserved by silicification, corresponding to an adult eccentric, oval trunk, whose diameter is 71×58 cm. Three zones can be distinguished: pith, vascular (with perimedullar bundles and centrifugal wedges of secondary xylem) and cork layer. Rhexoxylon brunoi Artabe, Brea et Zamuner, sp. nov. has a heterogeneous pith with parenchyma cells and idioblasts. Perimedullar bundles make up two cycles; the first one is complete constituted by double collateral bundles, facing each other, with secondary growth. The second one is incomplete, showing just the centripetal xylem sector. Peripheral centrifugal secondary xylem wedges show extensive development, reaching up to 38 cm of thickness. The tracheids of secondary xylem have opposite uni- to biseriate bordered radial pitting, and crossfields with one or two simple, slanted lenticular pits. Outside of the xylem a cork layer of about 2 cm persists conforming a longitudinally and transversely fractured rhytidome-like zone. Rhexoxylon brunoi shows a morpho-structural pattern determined by high activity of normal cambium, moderate activity of supernumerary cambium and scarce activity of remanent cambium.

Drinfel’d doubles and Ehresmann doubles for Lie algebroids and Lie bialgebroids

We show that the Manin triple characterization of Lie bialgebras in terms of the Drinfel’d double may be extended to arbitrary Poisson manifolds and indeed Lie bialgebroids by using double cotangent bundles, rather than the direct sum structures (Courant algebroids) utilized for similar purposes by Liu, Weinstein and Xu. This is achieved in terms of an abstract notion of double Lie algebroid (where “double” is now used in the Ehresmann sense) which unifies many iterated constructions in differential geometry.

Floral Morphology and Anatomy of Bonnetiaceae

DICKISON, W. C. (Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 275993280) and A. L. WEITZMAN (Department of Botany, Smithsonian Institution, Washington, DC 20560). Floral morphology and anatomy of Bonnetiaceae. J. Torrey Bot. Soc. 125:268-286. 1998.-A detailed study of floral morphology and anatomy of three genera comprising a narrowly circumscribed dicotyledonous family Bonnetiaceae is presented. Flowers are subtended by bracteoles and possess a perianth that is clearly differentiated into a 5-parted calyx and corolla composed of rather thick members. The androecium contains numerous stamens that are united at the base to form a short tube or collar or the stamens are pentadelphous and grouped at the base into five bundles that are positioned in the petal planes. Stamen fascicle traces are reported for the first time in flowers of Bonnetiaceae and are shown to originate close to, or adnate to, the median petal trace. Occasionally, two fascicle bundles arise side by side from a common gap as double bundles. Anther morphology and attachment is variable. Ploiarium possesses nectariferous discs that alternate with the stamen clusters. The presence of nectariferous tissue in Archytaea is variable. Nectaries can be supplied by double bundles, supporting the view that the nectaries of Plioarium and Archytaea represent transformed stamens. Gynoecia are compound, superior, and 3-carpellate or 5-carpellate. Styles range from divided to the base to undivided, and uniformly have a papillate stigma and a central canal filled with transfusion tissue. Placentation changes from axile to essentially parietal at midlevel of the ovary. Ovules are bitegmic, and contrasted with the putatively closely related Theaceae in which the elongated inner integument forms the micropyle, the outer integument projects well beyond the inner one. In addition to the degree of style fusion and carpel number, other important differences among genera of Bonnetiaceae are found in anther wall structure and floral vascular patterns. Major features of variation in the floral vascular system relate to the number and degree of independence of sepallary and petal traces; degree of independence of the androecial vascularization; the organization of the central ovarian vascular system; and the condition of the stylar vasculature. Comparisons are made among the flowers of Bonnetiaceae, Theaceae and Cluisiaceae.

Quantum differentials and the q-monopole revisited

The q-monopole bundle introduced previously is extended to ageneral construction for quantum group bundles with nonuniversaldifferential calculi. We show that the theory applies to several otherclasses of bundles as well, including bicrossproduct quantum groups, thequantum double and combinatorial bundles associated with covers of compactmanifolds.

Geometric relationships between whitefly feeding behavior and vascular bundle arrangements

AbstractThis study revealed strong evidence that nymphs of the silverleaf whitefly, Bemisia argentifolii Bellows and Perring, are obligate feeders on vascular bundles and that there are large differences between different host plants as to the availability of vascular bundles to silverleaf whitefly nymphs. The relationship between nymphs and leaf vascular bundles was studied using 1) leaf sectioning and 2) techniques of leaf clearing of intact leaves. A geometric model is presented of the feeding relationship of vascular bundle‐using homopterans. The relative abundance of vascular bundles was examined in six species of host plants that varied from highly preferred to tolerably acceptable. Included in order of acceptance were cantaloupe, cotton, hibiscus, broccoli, lantana and lettuce. The length of vascular bundle per 1.0 mm2 of leaf surface ranged from about 10 mm in cantaloupe to 2.8 mm in lettuce. Salivary sheaths were found to connect with vascular bundles in 100% of the intact nymphs examined by the staining and clearing technique. However only 64% of those examined by the sectioning technique appeared to be connected to vascular bundles. This indicates that the sectioning technique leads to a high rate of error, causing an underestimation of the importance of direct contact with vascular bundles. About 50% of epidermal stylet penetrations were through epidermal cells; the remaining 50% went through intercellular junctions. On cotton leaves, the distance between the point of labial contact with the leaf surface and the nearest point of the vascular bundle rarely exceeded 60 μm. Our studies show that while 50% of lettuce leaf‐surface was beyond 60 μm of a vascular bundle, only 10% of cantaloupe leaf surface area was outside of the 60 μm range. In cotton, mean distance from labium to the nearest point of the vascular bundle was 40.9 μm (SEM = 2.66, N = 50, range 0–80 μm). Over 98% of all salivary sheaths went to minor veins (78% to single‐filament vascular bundles, nearly 20% to double filament bundles). Fewer than 2% went to bundles with 3 or more filaments.

Sciatic nerve regeneration navigated by laminin-fibronectin double coated biodegradable collagen grafts in rats

Biodegradable type I collagen tube grafts filled longitudinally with laminin and fibronectin double coated collagen fiber bundles (L-F grafts) were implanted to promote sciatic nerve regeneration in rats. Grafts filled with uncoated collagen fibers were used as control. A 1 cm defect on the right sciatic nerve was filled with a graft in the manner of bridging. Thirty days after implantation, several newly developed nerve fasciculi were found at the middle portion of the L-F grafts in contrast to no developed nerves in the controls. After 60 days, the middle and distal portions of both grafts included well-developed nerve tissues with prominent myelinated and unmyelinated nerve fibers surrounded by perineural cells, but the control distal portion showed fewer nerve fibers. All artificial collagen elements were completely degraded and absorbed at 30 days, and new nerve tissues surrounded by an epineurium successfully connected the proximal stump to the distal stump of the initially separated nerve. Descending and ascending action potentials were evoked in all grafts at 60 days. These results indicated that laminin and fibronectin may promote the growth of axons in biodegradable collagen grafts, which guided nerve regeneration well and allowed the formation of epineurium.