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At least 19 recordsLinked to original sources
PubMed1992

Development of a computer model to predict strains in the individual fibers of a ligament across the ligamentous occipito-atlanto-axial (C0-C1-C2) complex.

A fresh ligamentous occipito-atlanto-axial (C0-C1-C2) complex was appropriately prepared and serially sectioned into thin slices along the transverse planes. The bony outlines from these slices were digitized and assembled in the proper manner to obtain a three-dimensional model of the complex using the AutoCAD system. Various ligaments were identified on the model and strains in individual fibers of a ligament were predicted based on the principles of rigid body mechanics. The ligament behaviors in axial rotation, flexion, and extension modes were analyzed. The capsular ligament fibers were predicted to undergo strains in all modes. Furthermore, these ligaments experienced the largest strain among the ligaments analyzed. Fibers within a ligament were found to respond differently; some were more active than the others and some did not experience any strain at all. A differential behavior in the right and left side alar ligament fibers was also found in axial rotation. The transverse ligament was predicted to wrap around the dens during axial rotation. The strain within a fiber was found to be a function of the initial length (ligament laxity) and its distance from the center of rotation.

Atlanto-Axial Joint↗
PubMed1992

[Combined injury of the anterior cruciate ligament and the medial collateral ligament of the knee joint--results of two to six years follow-up of surgical treatment].

A retrospective study of 148 combined acute knee injuries with anterior cruciate and medial collateral ligament injuries was performed. Follow-up included 115 patients, 95 of whom were personally examined two to six years postoperatively. Proximal anterior cruciate ligament ruptures were treated with reinsertion in 96 patients, in case of intraligamentous lesions (44 times), augmentation with the semitendinosus tendon was performed. Medial collateral ligament lesions were explored during the operation. Reconstruction of intraligamentous ruptures was performed with sutures (120 times). Distal lesions were refixed with Burri plate or staple. A modified Ellison procedure was routinely performed. Postoperative treatment was cast-free and included immediate physiotherapy using a functional brace. Between the two groups with anterior cruciate ligament reinsertion and augmentation, no significant differences were observed in subjective evaluation (Lysholm score 85 vs. 88), activity level (Tegner score 5.5 vs. 5.4) or anterior stability (KT 1000 at 89 N 6.6 vs. 6.1 mm displacement). A clear pivot shift sign was noted in two knees with reinsertion and in none of the augmented group. Medial stability was reestablished almost completely, independent of the site of lesion or the reconstruction technique (average valgus movement at 30 degrees flexion 0.7+ vs. 0.5+ on injured/contralateral side). We conclude that reinsertion of femoral anterior cruciate ligament ruptures will reestablish anterior stability in most cases, although semitendinosus augmentation appears to give slightly more reliable results. Medial stability is gained by the site-depending reconstruction techniques. Whether intraligamentous medial collateral ligament lesions can be left alone with only the anterior cruciate ligament being reconstructed, cannot be answered by this study.

Adolescent↗
PubMed1978

[A new drill guide for plastic repair of the anterior cruciate ligament by a free ligamenteous graft (author's transl)].

A report of the most widely used grafts for the replacement of the anterior cruciate ligament shows the difficulties of plastic repair. The author recommends the patella ligament used by Brückner but, because of the relative shortness of this ligament, not as a distally based ligamenteous graft but as a free one. The exact topography of the anterior cruciate ligament is given. A new drill guide for repair of this ligament is described and the technique of implantation by making use of that drill guide is explained.

Humans↗
PubMed1976

Tension studies of human knee ligaments. Yield point, ultimate failure, and disruption of the cruciate and tibial collateral ligaments.

Ultimate failure strengths of human tibial collateral and anterior and posterior cruciate ligaments were determined at two different loading rates (12.5 and fifty centimeters per minute) using an Instron Tension Analyzer. The posterior cruciate ligament was significantly stronger than the tibial collateral and anterior cruciate ligaments, which were of equal strength. At ultimate failure the ligaments were intact macroscopically but electron microscopy revealed widespread disruption of the collagen fibrils. Only after further application of stress did actual macroscopic disruption occur, suggesting that microscopic failure of the collagen fibrils in grossly intact ligaments may be a significant cause of clinical instability.

Collagen↗
PubMed1992

Anterior cruciate ligament allograft transplantation for intraarticular ligamentous reconstruction.

A multiplicity of surgical operations have been developed in an attempt to achieve satisfactory function after anterior cruciate ligament (ACL) repair. None of these procedures have been able to reproduce the fiber organization anatomy of attachment site, vascularity, or function of the ACL. Twenty-nine foxhounds received a deep-frozen bone-ACL-bone allograft and a ligament augmentation device (LAD). Biomechanical, microvascular, and histological changes were evaluated 3, 6, and 12 months following implantation. The maximum loads of the allograft/LADs were 34.3% (387.2 N) after 3 months, 49.3% (556.6 N) after 6 months, and 61.1% (698.8 N) after a year. The maximum load was 69.1% (780 N). In general, after 6 months the allografts showed normal collagen orientation. The allografts demonstrated no evidence of infection or immune reaction. No bone ingrowth into the LAD was observed. Polarized light microscopy and periodic acid-schiff staining showed that the new bone-ligament substance interface had intact fiber orientation at the area of the ligament insertion. Microvascular examination using the Spalteholtz technique revealed revascularization and the importance of an infrapatellar fat pad for the nourishment of ACL allografts.

Angiography↗
PubMedDate not supplied

Healing of the patellar tendon autograft after posterior cruciate ligament reconstruction--a process of ligamentization? An experimental study in a sheep model.

Forty-eight skeletally mature sheep underwent posterior cruciate ligament reconstruction with free patellar tendon autografts in one knee; the contralateral knee served as a control. Immediate rehabilitation without immobilization followed. Autograft healing was evaluated by histologic, roentgenographic, and biomechanical techniques up to 2 years postoperatively. After implantation, the autograft tissue underwent necrosis and degeneration, followed by a gradual healing process comprising revascularization, cellular migration, and formation of an extracellular matrix. The autograft bone pegs were osseously incorporated by 6 weeks. After an initial loss of strength, the material properties of the operated knee recovered to only about one-third that of the control. Better alignment of the collagen fiber bundles resulted in increased material properties, up to approximately 50% of the control at 52 weeks. After 2 years, the autograft tissue was found to differ structurally and mechanically from a ligament, suggesting that the autograft may never approach normal ligament characteristics. Degenerative alterations, the wide-spread presence of type III collagen, and abnormal accumulations of glycosaminoglycans in the autograft correlated with a maximum stress of 60% and an elastic modulus of 70% of the control. Although ligamentization was not seen, the staging of autograft healing into different phases based on distinct morphologic manifestations (necrosis, revitalization, collagen formation, and remodeling) and correlating with changing mechanical properties may provide a rationale for rehabilitation protocols with a realistic evaluation of the loading capacity of the replacement tissue.

Animals↗
PubMed1976

Classification of knee ligament instabilities. Part I. The medial compartment and cruciate ligaments.

Based on the clinical and operative findings in sixty-eight knees with acute tears of the medial compartment and cruciate ligaments, a standardized terminology and classification of knee ligament instability is presented. With an intact posterior cruciate ligament, anteromedial, anterolateral, or posterolateral rotatory instability may occur, but not true posteromedial rotatory instability. With the posterior cruciate ligament ruptured, straight anterior, posterior, medial, or lateral instability may be found.

Humans↗
PubMed1992

Semitendinosus Kennedy ligament augmentation device anterior cruciate ligament reconstruction.

This is a prospective study of 78 chronic unilateral isolated anterior cruciate ligament (ACL) patients who were treated with an arthroscopically-assisted reconstruction technique using the semitendinosus tendon, occasionally associated with the gracilis, augmented with the Kennedy-ligament augmentation device (LAD). There was a minimum two-year follow-up period (mean, 34.3 months; range, 24-50 months). Ligamentous surgery was always restricted to the ACL intraarticular reconstruction. Preoperative, intraoperative, and postoperative examinations at three, six, 12, 18, and 24 months, and every year thereafter, including subjective and objective evaluation with KT 1000 arthrometer laxity measurements, were completed. Two-year examination data were available on 77 (98.7%) of the 78 patients compared with preoperative data. The pivot shift (side-to-side difference) improved from 49.3% with Grade 0-1 to 92.2% with Grade 0-1. KT 1000 20-pound anterior drawer (greater than 5 mm side-to-side difference) improved from 49.3% (mean, 6 mm) to 91.1% (mean, 0.55 mm). KT 1000 maximum manual anterior drawer (greater than 5 mm side-to-side difference) improved from 21.9% (mean, 7.8 mm) to 97.4% (mean, 0.55 mm). After ACL reconstruction, 89.6% of patients had a full range of motion and only 10.3% had flexion contractures of less than 5 degrees; 5.2% of patients had mild effusion. Functional Lysholm knee scoring of 100 points improved from 7.7% scoring over 85 points preoperatively (mean, 66.5) to 92.1% postoperatively (mean, 95.6). Instability was controlled in 89.4% of the patients, and 71.4% have been involved in sports after injury. Anterior cruciate ligament reconstruction reduces pathologic laxity, improves lower-leg function, and minimizes flexion contracture and effusion.

Adolescent↗
PubMed1976

[Xeroradiographic studies on the capsule and ligaments of the knee joint. 1. Anatomy of the cruciate and lateral ligaments in the xerotomogram].

The suitability of xeroradiography for contrast arthrography was investigated by in vitro studies. Special attention was devoted to the cruciate and lateral ligaments on xero-ty lateral tomography. The anterior and posterior ligments can be evaluated and defined satisfactorily in the antero-posterior view. The lateral ligaments can be seen on xero-tomography without difficulty. The use of xero-tomography promises to improve the radiological diagnosis of injuries of the capsule and ligaments of the knee joint.

Humans↗
PubMed1978

[The pulmonary ligament (pulmo-diaphragmatic ligament) (author's transl)].

The paper considers the appearances of the contour of the diaphragm and of the normal irregularities of the diaphragm. The hitherto existing opinion of ill defined or tented diaphragmatic outlines always being the result of pleurodiaphragmatic implications in inflammatory or fibrotic processes in the basis of the lung needs to be corrected: In a great number of p.a. chest roentgenograms of healthy persons a more or less obvious ill definition or tenting of the medial part of the diaphragma can be found, caused by a variation of the pulmonary ligament characterized by its connection with the diaphragmatic pleura. Ill definition and tenting of the diaphragmatic outline caused by this variation of the pulmonary ligament are called physiological alterations, contrary to similar pathological (e.g. adhesive) ones. Only if this anatomical variation exists a pulmonary ligament can be roentgenologically visualized directly.

Diaphragm↗
PubMed1992

Comparison of reconstruction of the anterior cruciate ligament with and without a Kennedy ligament-augmentation device. A randomized, prospective study.

In a randomized, prospective study, sixty-four patients who were operated on for a torn anterior cruciate ligament were divided into two groups: thirty patients (the control group) had repair with the Marshall-MacIntosh technique alone, and thirty-four patients had repair with the same technique but with the addition of a Kennedy ligament-augmentation device. The preoperative characteristics were essentially identical in the two groups. The postoperative management, resumption of athletic activities, and occurrence of complications were also similar. All patients were followed for more than two years. No significant functional or clinical difference between the two groups was found with respect to residual laxity determined either from dynamic radiographs or with the KT-1000 arthrometer. There was no evidence that the addition of the Kennedy ligament-augmentation device gave results that were superior to those obtained with the Marshall-MacIntosh technique alone.

Adult↗
PubMed1992

Effusions after anterior cruciate ligament reconstruction using the ligament augmentation device.

Persistent effusions occurred in 4.3% (seven patients) of 164 patients who underwent anterior cruciate ligament (ACL) reconstruction using an autograft augmented with the ligament augmentation device (LAD) between 1986 and 1989. No bacteria were cultured from the joint fluid. The radiograph in each case showed a tibial drill hole located anteriorly or anterolaterally. Arthroscopy confirmed an abraded LAD in six cases and breakage of the LAD in one case and impingement of the graft on the femoral condyle during extension. Under polarized light microscopy, the histology of the synovia showed foreign body giant cells in one case and particles among the proliferative cells in four cases. The effusions subsided in two cases after notchplasty and in five cases after removal of the LAD. Impingement of the graft on the femoral condyle due to incorrect positioning of the tibial drill hole presumably produced particles that induced synovitis and effusions.

Adolescent↗
PubMed1977

[Xero-radiographic examination of the capsule and ligaments of the knee joint. II. Demonstration of injuries to the cruciate and lateral ligaments and menisci (author's transl)].

The value of xero-radiography for demonstrating injuries to the capsule and ligaments of the knee has been investigated. A tomographic method was used in conjunction with arthrography of the knee. The results have shown that, in vitro, injuries of the cruciate and lateral ligaments and of the capsule are well shown by xero-tomography and that it is possible to evaluate their extent. Simultaneous demonstration of injuries to the menisci is less certain. In order to show these accurately, special methods would have to be employed. Despite the higher radiation dose which must be expected, and the greater complexity of this technique, we consider that a clinical investigation of the method is indicated.

Cartilage, Articular↗
PubMed1978

The repair of cruciate ligaments with flexible carbon fibre. A longer term study of the induction of new ligaments and of the fate of the implanted carbon.

Carbon fibre appears to induce the formation of tendon in both animals and humans. Experiments have been conducted in sheep in which new anterior cruciate ligaments have been induced in response to the implantation of filamentous carbon fibre. Long-term studies indicate that the carbon fibre slowly breaks up at the site of implantation and later begins to appear in the regional lymph nodes.

Achilles Tendon↗
PubMed1992

[Ligament repair with PDS (polydioxanone) in chronic insufficiency of the fibular ligament of the upper ankle joint: experimental and clinical experiences].

From September 1988 till February 1989, 14 patients with chronic ligamentous rupture of the ankle had been operated on using PDS-plasty. Of 12 patients checked in follow-up examination (mean postoperative period 45 weeks), only two showed good or very good results. Most patients had the same signs of chronic instability as preoperatively. Two patients had been reoperated on. Intraoperatively we did not find a biological substitute along the PDS guide line. In an experiment on the rat we examined histological changes and tensile strength at appointed times. Histological data showed no biological substitute of PDS. We also found residues of PDS even after 300 days. After a short time loss of tensile strength occurred. In view of an aseptical necrosis that occurred in our experiments, we must point out the risk of foreign body granulomas.

Adolescent↗