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PubMed1992

Reconstruction of ligaments with expanded polytetrafluoroethylene. An experimental study in rabbits.

The medial collateral ligaments in the knee joints of 15 rabbits were replaced with expanded polytetrafluoroethylene (E-PTFE). The joints were not immobilised postoperatively, and their structure and function were evaluated after 12 months. Range of motion was equal in all groups. Stability of the knee joints and breaking strength of the ligaments were similar in the group in which the ligament had been reconstructed and in the sham operated control group (n = 8). The group in which the ligament had been severed and left to heal by formation of scar tissue (n = 7) had significantly reduced joint stability and the breaking strength of the medial collateral ligament was significantly less. The E-PTFE ligaments were well incorporated into the surrounding tissues. There were no adverse tissue reactions and the articular cartilage looked normal both macroscopically and microscopically. These results indicate that E-PTFE might be a useful substitute for damaged ligaments, at least in smaller joints like metacarpophalangeal and interphalangeal joints.

Animals↗
PubMed1987

Immobilization and retraining of cruciate ligaments in the rat.

Fifty male rats, aged 40 days, were assigned to one of five groups to examine the influence of immobilization and retraining on the strength and elastic stiffness of the anterior and posterior cruciate ligaments. Following the experimental treatments, the anterior ligament from the right leg and the posterior ligament from the left leg were tested in tension at a separation speed of 50 mm/min. After 4 weeks of cast immobilization, the separation force of the anterior ligament declined by one fourth and elastic stiffness of both ligaments declined by one fourth and one third, respectively. No changes occurred in the separation force of the posterior ligament. Following a 6-week retraining swimming program, the separation force and elastic stiffness values had returned to control levels. Additionally, there was a transition from avulsion type failures in the immobilized groups of animals to insertion site and intraligament failures in animals subjected to rehabilitative swimming exercise. This was indicative of a return in the strength of the osseous component of the bone-ligament-bone complex following immobilization.

Adaptation, Physiological↗
PubMed2000

The apical ligament: anatomy and functional significance.

OBJECT: The authors conducted a study to describe the detailed anatomy of the apical ligament and to acknowledge or refute its historical description as a functionally significant contributor to craniocervical stability. METHODS: In 20 adult human cadavers measurements of the apical ligament were obtained, and its detailed anatomy was observed. Ranges of motion were also assessed to discern the function of the apical ligament. CONCLUSIONS: Results of the study support the concept that the apical ligament is best described as a vestigial structure that offers no significant added stability to the craniocervical junction. In fact, this ligament was absent in 20% of the specimens examined. These data will aid physicians who frequently view images or manage clinical problems of the craniocervical junction because they may focus on other ligaments of this area and not the apical ligament.

Adult↗
PubMed1999

[Arthroscopic reconstruction of the posterior cruciate ligament. Magnetic resonance study for bone tunnel positioning and comparison with clinical results].

INTRODUCTION: The success of arthroscopic cruciate ligament reconstruction depends on several factors, such as patient selection, correct surgical execution, and postoperative rehabilitation. Technical considerations include graft choice, positioning, fixation, intercondylar notch enlargement, and new ligament tensioning. Graft acceptance is effected by all these factors. Tunnel position is of great importance both for biomechanical reasons and optimal function of the new ligament, and to avoid stress, friction, abnormal strain, and/or damage to the reconstructed ligament. Many orthopedic and radiographic literature studies discuss the exact site of anterior cruciate ligament insertion for the best possible anatomical reconstruction. In contrast, the debate over insertional area and anatomical landmarks is open for the posterior cruciate ligament (PCL), because of the difficult execution of this type of reconstruction and the smaller number of candidates. MATERIAL AND METHODS: Fifty patients with a healthy PCL underwent MRI of the knee for other diagnostic reasons and we measured the position of PCL insertion at the tibial and femoral condyles. We also examined with MRI 20 surgical patients with a reconstructed PCL. Graft position was assessed with the same method and the results compared with physical findings of joint stability and the IKDC form score. RESULTS: Three main landmarks were found on standard axial, coronal and sagittal MR images: T1 on the tibia, and F1 and F2 on the femur. These points refer to the fibrous ligament center and designate the medial, middle and lateral portion of the tibial plateau, as well as the anterior/posterior and high/low positions on the roof of the intercondylar notch and anteromedial side of the medial condyle, respectively. According to these data, the midline position, whether slightly medial or lateral, of tibial insertion, was clinically less important. On the contrary, correct femoral tunnel positioning was found to effect subsequent joint stability and prompt rehabilitation. CONCLUSIONS: This method for MR measurement is easy and repeatable, and can be used for surgical planning and patient follow-up. We found it extremely useful for the correct positioning of bone tunnels, particularly the femoral condyle, in all cases.

Arthroscopy↗
PubMed2000

Differences in men's and women's mean ankle ligamentous laxity.

The incidence of ligamentous ankle injuries is known to be one of the most common athletic injuries that exists. Recently, there has been a great deal of interest regarding the increased risk of female ligamentous injury, such as the anterior cruciate ligament, lateral ankle sprains and others. The purpose of this study is to evaluate whether or not normal lateral ankle ligamentous laxity is similar in male and female athletes. This study selects 22 male and 27 female college athletes who have had no significant ligamentous ankle injuries requiring medical treatment. They were placed on a Telos ligamentous stress device and stressed to a level of 15 daN. Radiographs were then obtained to determine talar tilt at this level of ankle stress. Results were compared between men and women showing that there was a statistically significant difference. Women had a much greater ligamentous laxity of the lateral ankle than men.

Ankle Injuries↗
PubMed2001

[Immediate microcirculation reaction of periodontal ligaments to experimental intrusion of dog teeth].

OBJECTIVE: The purpose of this study is to investigate the immediate microcirculation reaction of periodontal ligaments to experimental intrusion of dog teeth. METHODS: The forth premolar was chosen as the anchor tooth to intrude the second premolar using an intrusion circle loop. All tissue sections were observed and analyzed using the ink perfusion technique and an image analysis apparatus. RESULTS: The microvascular pattern of periodontal ligaments was changed after the maxillary second premolar had been intruded for 2 hours with 100 g of force. The vascular diameter and volume density diminished, but the vascular number and some parts of the microvasculature, especially capillaries were compressed due to the blood escaping from the periodontal ligament. It showed that the initial effect of 100 g of intrusive force caused adaptable changes in the microcirculation of periodontal ligaments, but no significant impediment of blood flow occurred. CONCLUSION: During the tooth intrusion with 100 g of force, a suitable microenvironment was established for the benefit of the survival of periodontal ligaments, which could avoid overloads imposed on the periodontal ligament and decreased the injury of periodontal tissue. It elucidates that the microcirculation of periodontal ligaments plays an important role in the protection of the periodontal tissue, in terms of biological function.

Animals↗
PubMed1992

Ligamentous reconstruction for posterolateral rotatory instability of the elbow.

Eleven consecutively seen patients who had posterolateral rotatory instability of the elbow joint were managed operatively. The radial collateral-ligament complex was advanced and imbricated in three of them. In seven patients, the ulnar band of the radial collateral ligament (the lateral ulnar collateral ligament) was reconstructed with the palmaris longus tendon and in two of the seven, the reconstruction was augmented with a prosthetic ligament. The ligament was reconstructed with the lateral one-third of the triceps fascia in the remaining patient. Stability was obtained in ten patients, and seven patients had an excellent functional result. There was one failure in one of the patients in whom the ulnar band of the radial collateral ligament had been reconstructed with the palmaris longus tendon and augmented with a prosthetic ligament.

Adolescent↗
PubMed2003

Transverse ligament of the knee in humans.

The purpose of this study was to trace the histological structure of the transverse ligament of the knee and its relation to the inferior lateral genicular artery. Investigations were carried out on 20 lower limbs (10 males, and 10 females) from the Department of Anatomy. It was found that close to the attachment of the transverse ligament to the menisci, bundles of fibres pass in vertical, oblique and horizontal directions, occupying a wide area on the anterior margin of the menisci. These fibres intermingle with bundles of the fibrocartilage of the menisci. In the area of the lateral attachment the inferior lateral genicular artery passes anteriorly to the transverse ligament, giving off numerous branches to the ligament. The medial part of the transverse ligament presents a thick rounded structure, surrounded by loose connective tissue. The fibres are arranged irregularly in bundles running horizontally on a tortuous course and with single spindle-like cells with darkly stained nuclei. The cells are not found at the ends of the ligament. Numerous blood vessels are observed between the bundles of fibres and on the periphery of the ligament.

Cadaver↗
PubMed2006

[Relationship between anatomy of knee collateral ligament and geometry of posterior femoral condylar articular surface].

OBJECTIVE: To analyze the relationship between the collateral ligament attachment and the epicondylar axis with rotational alignment of the femoral component in the total knee arthroplasty(TKA). METHODS: Twenty normal cadaver knee joints were anatomized and 2 holes were drilled on the distal femur from the deep and superficial insertions of the medial collateral ligaments to the lateral condylar part, respectively. Then, all the knees were scanned by MRI on the sagittal plane, making the drilled hole located relatively to the posterior condylar joint surface on the axial plane, and the posterior condylar angle (PCA) and the condylar twist angle (CTA) were measured. RESULTS: The collateral ligament had the deep and superficial parts, and the deep part was strained during the knee flexing. PCA and CTA were 4.50 +/- 1.26 degrees and 7.10 +/- 0.30 degrees respectively, and there was a significant difference between them (P < 0.05), which were significantly greater than those reported abroad. On the sagittal plane, there was no significant difference between the radius of the posterior medial and lateral condylar circles (P > 0.05). The distance from the center of the posterior condylar circle to the deep insertion of the medial collateral ligament (MCL) (dl) was 4.22 +/- 0.20 mm, and the distance to the superficial insertion of MCL (d2) was 7.36 +/- 0.13 mm. The difference between dl and d2 was significant (P < 0.05). CONCLUSION: The center of the posterior condylar circle passes from the deep insertion of the collateral ligament, which can be regarded as a fixed flexion-extension axis of the knee. By releasing the different parts of the collateral ligaments, the balance of the flexion and extension gap can be obtained, and then varus, valgus or flexed contracture deformity of the knee can be realigned. Besides, the rotational orientation of the femoral prosthesis can be made by a reference to the epicondylar insertion of the collateral ligament.

Adult↗
PubMed1991

Anatomical study on the menisco-femoral ligaments of the knee.

The menisco-femoral ligaments are important accessory ligaments of the knee. They extend from the posterior horn of the lateral meniscus to the lateral aspect of the medial femoral condyle close to the femoral attachment of the posterior cruciate ligament. Most of the authors reported that in some cases these ligaments are absent. But in the 100 knees that we carefully examined, obvious menisco-femoral ligaments were identified in all of the specimens. When the anatomical relationship between the menisco-femoral ligaments and the lateral meniscus is considered, it can be easily speculated that the menisco-femoral ligaments draw the posterior horn of the lateral meniscus in anterior, medial and superior direction during flexion of the knee joint. Thus, the congruency between the lateral meniscus and femoral condyle and the stability of the knee joint increase.

Adult↗
PubMed1991

[Ultrasonography in the study of lesions of the menisci and the collateral ligaments of the knee. Findings in 48 surgically treated patients].

The authors report the results of the study of 48/112 patients who underwent US examination of the knee for gonalgia. Meniscopathy or capsular-ligamentous lesions were clinically suspected. US results were compared with arthroscopic or athrotomic findings; the latter two methods were considered as the reference gold standard. US exhibited 81.2% overall diagnostic accuracy, thus confirming its limitations, more evident than those of arthroscopy and arthrography, CT and MR imaging. Major limitations of US were its failed recognition of meniscal tears smaller than 5-6 mm, and its failed distinction of degenerative meniscopathies from common meniscal fractures (with the exception of 2 cases). Moreover, US did not allow cruciate ligament lesions to be demonstrated; however, in all these cases, US did demonstrate increased capsular thickness (greater than 3 mm at the lower margin of femoral condyle). This indirect sign, together with roudness of parameniscus and capsular-ligamentous limitans (at the hemirhyme), and the direct sign of inhomogeneous hyperechogenicity of the meniscal triangle (normally hypoechoic) contributed to raising overall diagnostic accuracy of US to 89.9%. In the 5 patients with a suspected lesion of the medial collateral ligament examined within 48 hours from trauma, US gave 2 false-positive results in 2 cases where forced abduction test was also positive. Massive edema and swelling of adjacent structures prevented the correct evaluation of ligament limitans. In these 2 cases, a lesion in the anterior cruciate ligament was found at surgery; one of them was associated with a meniscal lesion already diagnosed at US. Both parameniscal and popliteal cysts were correctly diagnosed with US. Due to the well-known limitations of clinics in the diagnosis of knee pain, US could be suggested as the examination of choice to evaluate suspected meniscopathy or ligamentous lesions, thanks to its low cost and short execution time. The use of US could also spare the patients more invasive examinations--e.g., arthroscopy and arthrography--and more expensive ones--e.g., CT and MR imaging.

Adolescent↗
PubMed1991

[The ligaments of the scaphoid bone].

The scaphoid has three separately directed ligamentous connections, directed 1. proximally, toward the distal radius, 2. distally, toward the distal carpal row, and 3. ulnarly, toward the adjacent lunate. The palmar radiocarpal ligament consists of three distinct fiber complexes. Two of them, the radiocapitate and deep radioscapholunate, insert on the scaphoid, whereas the collateral ligament courses to the distal pole of the scaphoid. Dorsally, the dorsal radiocarpal ligament passes the proximal pole of the scaphoid without direct attachment. The dorsal arcuate ligament spans the midcarpal joint, from the scaphoid tubercle to the triquetrum. The well developed interosseous scapholunate ligament connects the proximal pole of the scaphoid with the lunate in a distally concave semicircular fashion. Short ligaments extend between the distal pole of the scaphoid and the trapezium palmarly, dorsally and radially, and between the distal pole of the scaphoid and the trapezoid palmarly and radially.

Carpal Bones↗
PubMed1991

Radiographic evaluation of the corporotransverse ligament at the L5 intervertebral foramen: a cadaveric study.

An extraforaminal ligament bisecting the L5/S1 intervertebral foramen and known as the corporotransverse ligament was studied in 15 adult embalmed cadavers. Its relationship to the L5 ventral ramus, sympathetic chain and gray ramus communicans was observed and recorded. The corporotransverse ligament has been implicated as a site for potential entrapment of the L5 nerve. The purpose of this study was to determine if the ligament could be detected radiographically. A single sample spine containing the ligament was hemisected and the neural, vascular and adipose tissue removed. Plain film, linear tomography and axial computed tomography (CT) slices were evaluated and the results compared. The corporotransverse ligament was not visualized by either plain film or linear tomography. Due to its superior resolution in the imaging of soft tissues, the ligament was well demonstrated by CT. Further studies with the neural tissue intact, imaging with magnetic resonance and in vivo comparison studies are recommended.

Dissection↗
PubMed1990

Fibrocartilage in the attachment zones of the quadriceps tendon and patellar ligament of man.

Differences are reported in the quantities and distribution of uncalcified fibrocartilage at the attachment sites of the quadriceps tendon and the patellar ligament. The largest quantity of fibrocartilage was characteristic of the quadriceps tendon. A prominent wedge of fibrocartilage was seen in the proximal part of the tibial attachment of the patellar ligament, though there was no fibrocartilage in the most superficial fibres. Little fibrocartilage was seen at the patellar attachment of the patellar ligament. According to other workers, there is a similar change in angle (about 35 degrees) between the quadriceps insertion (in relation to the patella) and the tibial attachment of the patellar ligament (in relation to the tibia). However, there is virtually no change in angle at the origin of the patellar ligament (relative to the patella). Thus, fibrocartilage is least conspicuous where there is little motility near an attachment site. It is suggested that the larger amount of fibrocartilage in the quadriceps tendon compared with the tibial attachment of the patellar ligament may be related to the greater absolute size (and particularly anterior-posterior thickness) of the tendon compared with the ligament.

Aged↗
PubMed1990

Direct measurement of resultant forces in the anterior cruciate ligament. An in vitro study performed with a new experimental technique.

A new technique was used to measure the resultant forces in the anterior cruciate ligament during a series of loading experiments on seventeen fresh-frozen cadaver specimens. The base of the ligament's tibial attachment was mechanically isolated with a coring cutter, and a specially designed load-transducer was fixed to the bone-plug that contained the ligament's tibial insertion so that the resultant forces were directly measured by the load-cell. Although the magnitudes of values for forces varied considerably between specimens for a given test condition, the patterns of loading with respect to direction of loading and the angle of flexion of the knee were remarkably consistent. Passive extension of the knee generated forces in the ligament only during the last 10 degrees of extension; at 5 degrees of hyperextension, the forces ranged from fifty to 240 newtons (mean, 118 newtons). When a 200-newton pull of the quadriceps tendon was applied to extend a knee slowly against tibial resistance, however, the force in the ligament increased at all angles of flexion of the knee. Internal tibial torque always generated greater forces in the ligament than did external tibial torque; higher forces were recorded as the knee was extended. The greatest forces (133 to 370 newtons) were generated when ten newton-meters of internal tibial torque was applied to a hyperextended knee. Fifteen newton-meters of applied varus moment generated forces of ninety-four to 177 newtons at full extension; fifteen newton-meters of applied valgus moment generated a mean force of fifty-six newtons, which remained unchanged with flexion of the knee. The force during straight anterior translation of the tibia was approximately equal to the anterior force applied to the tibia. The application of 925 newtons of tibiofemoral contact force reduced the mean force in the ligament that was generated by 200 newtons of anterior pull on the tibia by 36 per cent at full extension and 46 per cent at 20 degrees of flexion.

Aged↗
PubMed1990

[Double-contrast arthrography of the knee in traumatic capsular-ligamentous lesions. A critical review].

The authors conducted a statistical study and a critical review on a series of 1,300 patients examined with double-contrast fluoroscopically guided knee arthrography using a simple examination technique. Arthrographic diagnoses were subsequently compared with arthrotomic (500 patients), arthroscopic (350 patients), and clinical (450 patients) diagnoses. The critical review pointed out the high diagnostic accuracy (90%) and the good sensitivity (87%) of arthrographic examination in patients affected with pathologic conditions of the cruciate ligaments. In collateral ligament diseases and in capsular ruptures arthrographic sensitivity was not as high but still acceptable (74%). Capsular tears and medial collateral ligament tears can be identified when contrast medium is seen leaking from the knee joint. Cruciate ligament tears may be partial or complete: if a tear is partial the synovial surface of the cruciate ligament cannot be identified the cruciate ligament is wavy, lumpy, or focally thin, while in complete tears the synovial surface of the cruciate ligament cannot be identified either entirely or partially.

Arthrography↗
PubMed1989

Magnetic resonance imaging of posttraumatic spinal ligament injury.

We evaluated the role of magnetic resonance imaging (MRI) in the detection of ligament injury in 37 patients after acute traumatic spinal injury. Thirty-five patients had fractures, one had neurologic deficit with normal x-rays, and one had evidence of cervical instability on flexion/extension plain films. MRI examinations were performed acutely (average 10.8 d after injury) using T1- and T2-weighted multiplanar imaging. Two radiologists blindly evaluated all MRI examinations. Subsequently, 35 plain films, 16 tomograms, and 30 computed tomography (CT) scans were also evaluated. Nineteen patients were considered to have torn posterior ligaments on the basis of their clinical, radiographic and surgical findings. MRI detected ligament damage in 17. All patients considered to have intact posterior ligament complexes clinically and radiographically had no evidence of ligament damage on MRI. T2-weighted sequences were essential for detection of ligament injury. We conclude that MRI is an accurate method for assessment of the integrity of spinal ligaments after acute trauma.

Adolescent↗
PubMed1985

Carbon-PGLA prostheses for ligament reconstruction. Experimental basis and short-term results in man.

The efficiency of a pure carbon prosthesis to reconstruct intra-articular ligamentous loss of substance was evaluated on 14 sheep with an 18-month follow-up study of recent and old ACL experimental injuries. Functional results showed a correlation between a tightened implant, the stability of the knee, and the absence of severe arthritis. The rupture strength of the newly formed ligament amounts to about 300 Newtons (N). That of the normal ACL amounts to 250-550 N. The structure gives a viscoelastic behavior to the prosthesis. This tissue was made of collagen fibers surrounding the carbon fibers and running generally in the direction of the ligament. In the osseous tunnels, the newly formed lamellar bone invaded and surrounded the implant. Carbon fiber fragmentation occurred, and fibers were found in the synovia and in the homolateral, inguinal, and paraaortic lymph nodes. No degeneration, necrosis of tissue, or cellular toxicity was found. On these bases, the carbon prosthesis was modified by adding a resorbable copolymer of polyglycollic (PGA) and polylactic acid (PLA) around the fibers and a resorbable sheath of the same polymer. This carbon-PGA/PLA prosthesis was used in 23 patients with a three- to 12-month follow-up period. Patients were evaluated by clinical tests and by functional control of the ligament. The indications for prosthetic replacement were: recent mop-end tears of the ACL, cruciate ligament reconstruction in chronic knee instability, and wide rotator cuff loss of substance. Five complications occurred because of hematomas and/or sepsis and prosthesis breakage. Eighteen of 23 patients had good clinical results with good function in five. The conclusions are that PGA/PLA produces a clean and flexible ligament, thus eliminating carbon fiber articular deposits and allowing a normal function. Inflammatory postoperative reactions seem to be more frequent than with other procedures and call for operative and clinical care in order to eliminate hematoma and sepsis. The efficiency of a rehabitable carbon-PGA/PLA prosthesis in intra-articular ligamentous defects in man will be confirmed only by controlled long-term clinical observations.

Adult↗