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PubMed2005

Posterior cruciate ligament recess and normal posterior capsular insertional anatomy: MR imaging of cadaveric knees.

PURPOSE: To analyze the normal pattern of fluid accumulation adjacent to the posterior cruciate ligament and anatomic variations of joint capsule insertion sites in the posterosuperior corner of the human knee by using magnetic resonance (MR) imaging in cadaveric specimens. MATERIALS AND METHODS: Fourteen fresh cadaveric knees (obtained and used according to institutional guidelines, with informed consent from relatives of the deceased) from 11 men and three women (six left knees, eight right knees; age range, 70-82 years at time of death; mean age, 76 years +/- 4.4 [standard deviation]) were studied with high-spatial-resolution MR imaging performed before and after intraarticular injection of 35-45 mL gadopentetate dimeglumine. MR images were evaluated by two readers in consensus, with emphasis on location of fluid posterior to the posterior cruciate ligament, communication of that fluid with the medial or lateral compartment of the knee, and the relation of fluid to surrounding structures. Readers also were asked to measure, in the sagittal plane, the distance between the posterior capsular insertion sites and the femoral physeal scar. For anatomic analysis, cadaveric specimens were sectioned in 3-mm-thick slices in the sagittal plane that approximated the sections acquired at MR imaging. RESULTS: In all 14 cadaveric specimens, MR arthrographic images showed a fluid collection behind the posterior cruciate ligament (in the posterior cruciate ligament recess), a finding not evident on images obtained prior to contrast material injection. The recess was distended during flexion, and it communicated only with the medial femorotibial compartment in all cases. Posterior to the posterior cruciate ligament recess, a fat pad was observed in all specimens. Incomplete joint capsule was seen behind the fat pad in seven specimens. Joint capsule insertion was at the level of the femoral physeal scar or between it and a point 15 mm above it. CONCLUSION: The posterior cruciate ligament recess has specific characteristics that allow its identification: communication with the medial compartment of the knee and absence of the adjacent joint capsule.

Aged↗
PubMed1983

Inferior pulmonary ligament: computed tomographic appearance.

A total of 129 normal computed tomograms of the chest was retrospectively reviewed to determine the appearance and frequency of visualization of the inferior pulmonary ligament. The ligament was seen on the left in 67.4% of patients, on the right in 37.2% of patients, on both sides in 27.1% of patients, and on neither side in 22.4% of patients. Of those ligaments seen, 92% on the left and 92% on the right demonstrated a posterior orientation. Examples are shown emphasizing the importance of the inferior pulmonary ligament in relation to lower lobe collapse, pleural effusion, extension of a mediastinal abnormality into the ligament, and the possible intraparenchymal appearance of an abnormality located within the ligament.

Humans↗
PubMed1989

Injuries of the lateral ankle ligaments: classification with tenography and arthrography.

To assess the value of tenography of the peroneal tendon sheaths and of arthrography of the tibiotalar joint for the diagnosis and classification of recent ruptures of the lateral ankle ligaments, the authors performed a prospective study on 108 patients with inversion trauma of the ankle. All patients underwent tenography. Arthrography was performed if results of tenography were negative. All patients with positive tenographic or arthrographic results underwent surgery. Tenography proved to be reliable in the diagnosis of injuries of the calcaneofibular ligament (sensitivity, 88%; specificity, 87%-94%). The positive predictive value of tenography in combination with arthrography was 100% for the diagnosis of lateral ligament ruptures. The authors conclude that a combination of arthrography and tenography is a reliable method for diagnosing recent ruptures of the lateral ankle ligaments and for differentiating between isolated ruptures of the talofibular ligament and combined lesions of both the talofibular and the calcaneofibular ligaments.

Adolescent↗
PubMed1997

Collateral ligaments of the elbow: conventional MR imaging and MR arthrography with coronal oblique plane and elbow flexion.

PURPOSE: To determine the best plane and position of the elbow for optimal visualization of normal and abnormal collateral ligaments with conventional magnetic resonance (MR) imaging and MR arthrography, to determine the normal appearance of the collateral ligaments at MR arthrography and to assess use of MR arthrography in evaluation of collateral ligamentous lesions. MATERIALS AND METHODS: Nine cadaveric elbow specimens were imaged with and without intraarticular administration of gadolinium-containing solution in several planes that were identified as potentially useful in a pilot study in two specimens. MR imaging findings were compared with anatomic findings. RESULTS: Normal and abnormal ligaments were best depicted in a 20 degrees posterior oblique coronal plane in relation to the humeral shaft with the elbows extended and a coronal plane aligned with the humeral shaft with the elbows slightly flexed (20 degrees-30 degrees of flexion). Gadolinium enhancement improved the delineation of normal and abnormal ligaments on T1-weighted images in each case. CONCLUSION: The posterior oblique coronal plane with the elbows extended or the coronal plane aligned with the humeral shaft with the elbows slightly flexed allows accurate assessment of the collateral ligaments. Gadolinium-enhanced MR arthrography of the elbow seems to be a promising technique.

Aged↗
PubMedDate not supplied

Imaging appearances of lateral ankle ligament reconstruction.

Six patients were retrospectively identified as having undergone lateral ligament reconstruction surgery. The surgical procedures were categorized into four groups: direct lateral ligament repair, peroneus brevis tendon rerouting, peroneus brevis tendon loop, and peroneus brevis tendon split and rerouting. At radiography and magnetic resonance (MR) imaging, the presence of one or more suture anchors in the region of the anterior talofibular ligament indicates direct ligament repair, whereas a fibular tunnel indicates peroneus brevis tendon rerouting or loop. Both ultrasonography (US) and MR imaging demonstrate rerouted tendons as part of lateral ankle reconstruction; however, MR imaging can also depict the rerouted tendon within an osseous tunnel if present, especially if T1-weighted sequences are used. Artifact from suture material may obscure the tendon at MR imaging but not at US. With both modalities, the integrity of the rerouted peroneus brevis tendon is best evaluated by following the tendon proximally from its distal attachment site, which typically remains unchanged. The rerouted tendon or portion of the tendon can then be traced proximally to its reattachment site. Familiarity with the surgical procedures most commonly used for lateral ankle ligament reconstruction, and with the imaging features of these procedures, is essential for avoiding diagnostic pitfalls and ensuring accurate assessment of the ligament reconstruction.

Adult↗
PubMed2005

Knee ligament mechanical properties are not influenced by estrogen or its receptors.

Women are at greater risk of tearing their knee anterior cruciate ligament (ACL) than men participating in similar athletic activities. There is currently no conclusive explanation for this disparity; however, as ACL injuries in women have been linked with estrogen fluctuations during the menstrual cycle, one hypothesis is that estrogen has a direct detrimental effect on knee ligament mechanical properties. This study investigated the influence of estrogen and its receptors (ER alpha and ER beta) on knee ligament mechanical properties. This was achieved by testing the viscoelastic and tensile mechanical properties of knee medial collateral ligaments (MCL) and ACLs from: 1) male Sprague-Dawley rats treated with either estrogen (17alpha-ethynylestradiol; 0.03 mg/kg) or an ER alpha-specific agonist (propyl pyrazole triol; 2 mg/kg), and 2) female mice with a null mutation of the gene encoding for ER beta. Estrogen treatment had no significant effects on the viscoelastic or tensile mechanical properties of the rat MCL or ACL. Similarly, pharmacological stimulation of ER alpha using a selective agonist in rats and genetic modulation of ER beta by null mutation of its gene in mice did not influence MCL or ACL properties. These data indicate that estrogen does not have a major direct effect on ligament mechanical properties. Energies for the prevention of the disproportionately high rate of knee ligament injuries in women may be better spent focusing on more established and modifiable risk factors, such as abnormalities in neuromuscular control about the knee.

Animals↗
PubMed1998

The advanced glycation endproduct, pentosidine, in the carpal ligament in patients with carpal tunnel syndrome undergoing hemodialysis: comparison with idiopathic carpal tunnel syndrome.

BACKGROUND/AIMS: Carpal tunnel syndrome (CTS) is a major complication that occurs in the musculoskeletal system in patients on long-term hemodialysis (HD). Pentosidine is an advanced glycation endproduct (AGE) and there is evidence that shows AGEs contribute to the pathogenesis of the complications in patients undergoing HD. The aim of this study is to investigate whether pentosidine accumulates in the carpal ligament in patients undergoing HD with CTS in comparison with idiopathic CTS. METHODS: Carpal ligaments and skin were obtained during surgery from 28 patients with CTS undergoing HD and 13 patients with idiopathic CTS (ID CTS). Pentosidine was measured by HPLC after hydrolysis of the samples, and amyloid deposits in the samples of HD CTS were examined histologically. RESULTS: Pentosidine levels in ligament and skin were significantly higher in HD CTS than ID CTS. On the other hand, there was no difference in pyridinoline which is a physical cross-link between HD and ID CTS. Amyloid deposits were observed in 14 ligament samples, whereas there was none in 14 other samples. There was no significant difference in pentosidine and pyridinoline in ligament, pentosidine in skin, duration of HD and serum beta2-microglobulin between the amyloid+ group and the amyloid- group. CONCLUSION: A greater concentration of pentosidine in the carpal ligament in HD patients compared with idiopathic patients suggests that an accumulation of AGEs contributes to one of the pathologies of occurrence of CTS in patients undergoing HD.

Aged↗
PubMed1988

The collateral ligaments of the knee joint in the cat and man. Morphological and functional study of the internal arrangement of fibers.

The present investigation of fiber arrangement in the collateral ligaments of the knee was carried out in cats and man in various positions of flexion and extension, without compression load. In all knee joint positions, the fibers of the collateral ligaments are twisted except for the fibers in the meniscal part of the medial collateral ligament which have a parallel arrangement. Furthermore, most of the fibers in the collateral ligaments are taut in all positions of the knee joint in both cat and man. By means of planar models representing different fiber arrangements, the kinematic behavior of the collateral ligaments was analyzed. It appears that a crossed (twisted) arrangement of the fibers is most effective in rotatory movements, whereas a parallel orientation is most effective in translation. Our data further indicate that, in measuring the changes in lengths of ligaments during joint motion, one cannot neglect the internal arrangement of fibers and the geometry of the articular surfaces and menisci.

Animals↗
PubMed1989

A reevaluation of the distribution of 3H-proline in the transseptal ligament of the mouse in radioautography.

It is generally accepted that there is uniform collagen metabolism within the periodontal and transseptal ligaments. The present study suggested regional variations in the incorporation and removal of 3H-proline within the transseptal ligament in radioautography, suggesting variable rates of collagenous protein remodeling coincident with physiological tooth movements. Highest numbers of silver grains were over the middle third of the ligament during both incorporation and removal phases (p less than 0.001). Rates of grain removal were greater in the middle than in mesial or distal thirds (p less than 0.001). The half-life of labeled proteins was significantly less in the middle than in mesial or distal thirds (p less than 0.005). Because there were no significant regional differences in cell numbers, regional variability in grain incorporation and removal within the transseptal ligament likely indicates regional differences in cellular synthetic or degradative activity coincident with remodeling of the transseptal ligament during physiological drift and suggests that the center of this ligament may experience more stress and, thus, remodels more rapidly.

Animals↗
PubMed1990

Spiral ligament tension fibroblasts and extracellular fibres in the guinea pig.

Fibroblasts with stress fibres and their relationship to extracellular matrix fibres were described in the marginal regions of the spiral ligament in several mammalian species. Location, structure and attachment of these cells suggested that they facilitated the development of radial tension in the basilar membrane-spiral ligament complex. In this study, fibroblast structure and relationship with the extracellular matrix was examined by light and transmission electron microscopy in the guinea pig spiral ligament. Tension fibroblasts were found in marginal and subcentral regions of the spiral ligament. Their ultrastructure was described. They were related to the trabeculated extracellular matrix and were numerous in the marginal region at the spiral ligament-otic capsule interface. Their comparative anatomy and role in the development of spiral ligament-otic capsule tension was discussed.

Animals↗
PubMed1995

A quantitative study on the myelinated fiber innervation of the periodontal ligament of cat canine teeth.

The periodontal ligament is richly innervated with mechanosensitive afferent nerve fibers, and the location of the mechanoreceptive terminals within the ligament is of functional significance. In this study, we have obtained quantitative information on mechanoreceptor distribution in the lower canine teeth of the cat. Using light microscopy, we quantified the number of myelinated axons in the periodontal ligament at 1 mm, 3 mm, and 5 mm from the tooth root apex. Grouped axons and axons which were isolated in the cemental half of the ligament (and therefore putative mechanoreceptors) were identified. The mean total number of axons was 1290 (n = 20) at 1 mm from the apex, 1290 at 3 mm, and 814 at 5 mm. The distribution of axons around the tooth root circumference was found to be non-uniform. Near the root apex, the highest numbers of grouped axons were located distally and mesially, and in the middle region of the root, the highest numbers were found mesially. The highest numbers of isolated axons at the apical levels were located distally, and in the mid-root region, mesially. At all levels, the lingual region was the most sparsely innervated by both groups. There was a positive correlation between the number of grouped axons and the width of the ligament in the same region, but this correlation was much weaker for isolated axons, suggesting that their distribution does not result only from the volume of tissue. Variations in the number of axons and, to a lesser extent, the dimensions of the periodontal ligament were considerable.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed2001

Distribution of biglycan and decorin in collateral and cruciate ligaments and menisci of the rabbit knee joint.

The small leucine-rich proteoglycans (PGs) biglycan and decorin, and their mRNAs, have been localized during neonatal development and aging (3 weeks to 2 years) of collateral and cruciate ligaments and of menisci of the rabbit knee joint. In the collateral ligaments, biglycan and decorin are found between the bundles of collagen fibers at all ages. In cruciate ligaments the PGs are primarily around the cells. In neonatal ligaments all the cells express the mRNAs for biglycan and decorin, but in the collateral ligaments the number expressing the mRNAs is reduced at 8 months. In 3--week menisci the PGs are uniformly distributed in the matrix, but by 8 months biglycan is present primarily in the central fibrocartilaginous regions, whereas decorin is found peripherally. In neonates, all the cells express the mRNAs but the number is reduced in 8-month menisci. The results illustrate the precise localizations of biglycan and decorin in healthy rabbit ligaments and menisci which, after injury, must be reproduced in the repair tissue for normal strength to be regained. (J Histochem Cytochem 49:877-885, 2001)

Animals↗
PubMedDate not supplied

Direct evidence of the anterior cruciate ligament-hamstring reflex arc in humans.

It has been emphasized that the anterior cruciate ligament plays an important role in the proprioceptive feedback system. The anterior cruciate ligament-hamstring reflex has been revealed in animal experiments, but it has not been established in humans. The purpose of this study was to demonstrate direct evidence of the anterior cruciate ligament-hamstring reflex arc. Nine knees in nine healthy subjects were investigated. The anterior cruciate ligament was stimulated by the use of wire electrodes inserted using an arthroscopic technique. Electromyographic signals from the biceps femoris and the semitendinosus muscles were recorded with surface electrodes. The change in electromyographic activity was analyzed after electrical stimulation in the normal knee condition, and again after intraarticular sensation had been interrupted with a local anesthetic. After electrical stimulation, subjects demonstrated increased electromyographic activity of the hamstring muscles in the normal knee condition. This response indicates the existence of an anterior cruciate ligament-hamstring reflex arc. Conversely, there was no change in activity for the hamstring muscle in the anesthetized knee because the afferent impulse from the neural elements of the anterior cruciate ligament had been removed.

Adult↗
PubMedDate not supplied

Dynamic lateral patellar tilt in the anterior cruciate ligament-deficient knee. A magnetic resonance imaging analysis.

An open-configuration magnetic resonance imaging scanner was used to document patellar tracking abnormalities in 11 anterior cruciate ligament-injured knees. The contralateral normal knees were used as controls. Images were obtained with the quadriceps muscles at rest (knee flexion at 40 degrees, 25 degrees, and 10 degrees) and with the quadriceps muscles contracted (knee flexion at 40 degrees and 25 degrees). When the quadriceps muscles were at rest there were no differences in patellar alignment between the anterior cruciate ligament-injured knees and the contralateral normal knees. When the quadriceps muscles were maximally contracted at 40 degrees of flexion, the patellae of the anterior cruciate ligament-injured knees tilted laterally 3.6 degrees relative to the resting state. When the quadriceps muscles were contracted at 25 degrees of flexion, the patellae of the anterior cruciate ligament-injured knees tilted laterally approximately 4 degrees relative to the resting state. Quadriceps-active lateral patellar tilt at 25 degrees of flexion was greater in the anterior cruciate ligament-injured knees than in the contralateral normal knees, and it correlated with instrumented measurements of anterior tibial translation. Dynamic lateral patellar tilt during open kinetic chain exercises and during other activities that produce anterior tibial translation may contribute to extensor mechanism dysfunction in the anterior cruciate ligament-injured knee.

Adult↗
PubMedDate not supplied

Relationship of ulnar collateral ligament strain to amount of medial olecranon osteotomy.

Athletes at risk for valgus extension overload are also at risk for tears of the anterior bundle of the ulnar collateral ligament. Some athletes develop ligament tears after procedures for valgus extension overload such as posteromedial olecranon osteotomy. The amount of posteromedial olecranon that can be resected before ulnar collateral ligament strain, and risk of injury, increases is unknown. We dissected and mounted five fresh-frozen human cadaveric elbows to allow strain gauge monitoring of the ulnar collateral ligament with varying valgus stress, elbow flexion angle, and medial osteotomy. The average strain to failure was 11.96%+/-6.51%, corresponding to a load of 347.71+/-46.42 N. The maximum tensile force recorded at failure was 416.24 N. Three-way repeated-measures analysis of variance revealed no significant change in strain with change in the amount of osteotomy for a given applied load and angle of flexion. On the basis of these data, we conclude that the effect of medial olecranon osteotomy on ulnar collateral ligament strain may be small. Small sample size, elderly specimens, and the variables inherent in the experimental setup and mathematical modeling make it difficult to extrapolate these results to in vivo behavior of the anterior ulnar collateral ligament. Further work is needed before definitive guidelines for olecranon osteotomy can be formulated.

Collateral Ligaments↗
PubMedDate not supplied

The effect of the menstrual cycle on anterior cruciate ligament injuries in women as determined by hormone levels.

Anterior cruciate ligament injury rates are reported to be two to eight times higher in women than in men within the same sport. Because the menstrual cycle with its monthly hormonal fluctuations is one of the most basic differences between men and women, we investigated the association between the distribution of confirmed anterior cruciate ligament tears and menstrual cycle phase. Sixty-nine female athletes who sustained an acute anterior cruciate ligament injury were studied within 24 hours of injury at four centers. The mechanism of injury, menstrual cycle details, use of oral contraceptives, and history of previous injury were recorded. Urine samples were collected to validate menstrual cycle phase by measurement of estrogen, progesterone, and luteinizing hormone metabolites and creatinine levels at the time of the anterior cruciate ligament tear. Results from the hormone assays indicate that the women had a significantly greater than expected percentage of anterior cruciate ligament injuries during midcycle (ovulatory phase) and a less than expected percentage of those injuries during the luteal phase of the menstrual cycle. Oral contraceptive use diminished the significant association between anterior cruciate ligament tear distribution and the ovulatory phase.

Adolescent↗
PubMedDate not supplied

Anterior drawer test for acute anterior talofibular ligament injuries of the ankle. How much load should be applied during the test?

BACKGROUND: There is a lack of consensus regarding the magnitude of load for performing the anterior drawer test in evaluating acute ankle injuries. PURPOSE: To determine how much load should be applied during the anterior drawer test to detect the integrity of the anterior talofibular ligament. METHODS: First, the anterior-posterior load-displacement response of nine cadaveric ankles was measured. Second, anterior displacement of the ankle was measured at 30 and 60 N of anterior load in 14 patients with acute tears of the anterior talofibular ligament. RESULTS: In the cadaver study, the increased displacement by sectioning of the ligament measured at 10, 20, 30, and 40 N of anterior load were significantly greater than those measured at 60 N. In vivo examination of the subjects without anesthesia demonstrated that the injured-to-normal displacement value at 30 N of anterior load was significantly greater than the value at 60 N. CONCLUSIONS: This study suggests that a large magnitude of anterior load is not necessary to detect the integrity of the ligament during the anterior drawer test. CLINICAL RELEVANCE: When evaluating the integrity of the anterior talofibular ligament in cases of acute ankle ligament injury, a relatively low-magnitude load should be applied.

Acute Disease↗
PubMedDate not supplied

Biomechanical evaluation of a new ulnar collateral ligament reconstruction technique with interference screw fixation.

BACKGROUND: Techniques for ulnar collateral ligament reconstruction have evolved. HYPOTHESIS: Ulnar collateral ligament reconstruction with interference screw fixation restores elbow kinematics and failure strength to that of the native ligament. STUDY DESIGN: Controlled laboratory study. METHODS: Of 10 matched pairs of cadaveric elbows, one underwent kinematic testing under conditions of an intact, released, and reconstructed ligament. Single 5-mm diameter bone tunnels were created at the isometric anatomic insertion sites on the medial epicondyle and sublime tubercle. Graft fixation was achieved with 5 x 15 mm soft tissue interference screws. The reconstructed and contralateral intact elbows were then tested to failure. RESULTS: Average stiffness for intact elbows (42.81 +/- 11.6 N/mm) was significantly greater than for reconstructed elbows (20.28 +/- 12.5 N/mm). Ultimate moment for intact elbows (34.0 +/- 6.9 N.m) was not significantly different from reconstructed elbows (30.6 +/- 19.2 N.m). Release of the ulnar collateral ligament caused a significant increase in valgus instability. Reconstruction restored valgus stability to near that of the intact elbow. CONCLUSIONS: With this reconstruction method, failure strength was comparable with that of the native ligament and physiologic elbow kinematics were reliably restored. CLINICAL RELEVANCE: This technique returns elbow kinematics to near normal, with less soft tissue dissection and risk of ulnar nerve injury and ease of graft insertion, tensioning, and fixation.

Adult↗

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