Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Collateral Ligaments”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources

Electron microscopic quantification of collagen fibril diameters in the rabbit medial collateral ligament: a baseline for comparison.

To establish a normal baseline for comparison, thirty-one thousand collagen fibril diameters were measured in calibrated transmission electron (TEM) photomicrographs of normal rabbit medial collateral ligaments (MCL's). A new automated method of quantitation was used to compare statistically fibril minimum diameter distributions in one midsubstance location in both MCL's from six animals at 3 months of age (immature) and three animals at 10 months of age (mature). Pooled results demonstrate that rabbit MCL's have statistically different (p less than 0.001) mean minimum diameters at these two ages. Interanimal differences in mean fibril minimum diameters were also significant (p less than 0.001) and varied by 20% to 25% in both mature and immature animals. Finally, there were significant differences (p less than 0.001) in mean diameters and distributions from side-to-side in all animals. These mean left-to-right differences were less than 10% in all mature animals but as much as 62% in some immature animals. Statistical analysis of these data demonstrate that animal-to-animal comparisons using these protocols require a large number of animals with appropriate numbers of fibrils being measured to detect small intergroup differences. With experiments which compare left to right ligaments, far fewer animals are required to detect similarly small differences. These results demonstrate the necessity for rigorous control of sampling, an extensive normal baseline and statistically confirmed experimental designs in any TEM comparisons of collagen fibril diameters.

Animals↗

[Long-term outcome following surgical repair of ruptures of the fibular collateral ligament of the ankle. A report of 50 cases].

The authors report their findings in a series of 49 patients with 50 acute ankle sprains, who underwent surgical repair of their ruptured fibular collateral ligaments. All patients were selected for surgical treatment based upon the findings on stress-films taken under anesthesia, showing a laxity at least superior by 10 degrees to the value found on the contralateral ankle. All patients were reviewed 2 to 12 years after operation. Clinical evaluation was based upon Duquennoy's criteria, and dynamic x-rays were performed in all patients to evaluate residual laxity. The clinical results were good or excellent in 78% of patients, fair in 14% and poor in 8%. Seven patients (14%) complained of subjective instability. Stress films showed residual laxity from 5 to 10 degrees in 10 patients (20%). The authors conclude that their findings do not support the alleged superiority of surgical repair over conservative management of severe ankle sprains.

Adolescent↗

The early effects of joint immobilization on medial collateral ligament healing in an ACL-deficient knee: a gross anatomic and biomechanical investigation in the adult rabbit model.

In this study, the short-term effects of immobilization on joint damage and medial collateral ligament (MCL) healing were investigated in unstable, anterior cruciate ligament (ACL)-deficient knees in rabbits. Forty-six 12-month-old female New Zealand white rabbits were separated into three groups. Animals from each group had surgery on their right knees: group I, sham controls (n = 9); group II, complete transection of the ACL and removal of a 4 mm segment (gap injury) of MCL midsubstance with no immobilization of the limb (n = 19); and group III, same injuries to the ACL and MCL (as group II) but with immobilization of the limb (n = 18). No surgical repair of disrupted ligaments was performed. Left knees served as unoperated contralateral controls. All animals were allowed unrestricted cage activity until sacrifice in subgroups at 3, 6, and 14 weeks of healing when biomechanical properties of all MCLs were measured. All knee joints were systematically examined for gross evidence of damage to articular cartilage, menisci, and periarticular soft tissues. To monitor relative in vivo loads on injured limbs during healing, hindlimb weight bearing was assessed at biweekly intervals. Results indicated that animals in both groups II and III bore relatively lower loads (compared to preinjury values) on their injured hindlimbs. Mechanical testing of MCLs showed only minor changes in sham controls, while group II and III healing MCLs demonstrated significantly lower force and stress at MCL complex failure compared to contralateral controls. In specific comparisons of group III to group II animals, we noted that immobilization prevented joint damage over the early intervals studied. In addition, immobilization resulted in MCL laxity similar to contralateral control values but inhibited development of structural strength and stiffness in healing MCLs. These results suggest that in the rabbit, short-term immobilization of an ACL-deficient knee offers some advantages to the joint and to certain low load behaviors of the healing MCL, but it also results in a smaller quantity of scar tissue that is less able to resist higher loads. Longer-term studies involving remobilization are necessary before the effects of brief immobilization on joint damage and MCL healing in this ACL-deficient model can be fully defined.

Animals↗

Enthesiopathy of the short radial collateral ligaments in racing greyhounds.

In a radiographic survey of the carpi of 100 racing greyhounds there was a 14 per cent incidence of enthesiopathy of the origin of the straight part of the short radial collateral ligament. Enthesiopathy was not identified as a clinical problem in any case, nor was there historical evidence of any adverse effect on performance.

Animals↗

Mechanical properties of the lateral collateral ligament: effect of cruciate instability in the rabbit.

Concomitant soft tissue injury resulting from knee instability following cruciate rupture is a serious clinical problem. To study this injury mechanism, the biomechanical properties of the lateral collateral ligament were measured at 0, 4, 8, 12, and 16 weeks post-operatively in rabbits having the anterior and posterior cruciate ligaments sectioned. No significant changes were found in the ligament's cross-sectional area, tensile mechanical response, or in its hexosamine content. The predominant mode of ligament failure was by bone avulsion at the insertion sites (78 percent) with 86 percent of paired limbs failing in a similar manner.

Animals↗

The effect of postoperative collateral ligament laxity in total knee arthroplasty.

Forty-seven patients who had been treated by 63 total knee arthroplasties were assessed at 12-84 months after the operation. The data were analyzed to determine if collateral ligament laxity had a detrimental effect on the clinical outcome. The Hospital for Special Surgery (HSS) score was used to make the clinical assessment and a modified HSS score, which excluded points awarded for laxity, was also used. Unidirectional (varus or valgus) and total (varus and valgus) laxity were used as a basis of analysis. None of the examined parameters produced results suggesting that lax knees were worse than stable knees. Indeed, knees with increasing laxity through the categories of mild and moderate showed better statistically significant results in HSS score and pain than those with lesser degrees of laxity. Seventy-five percent of the knees with unidirectional laxity were classified as excellent; only 38.5% of the stable knees were graded as excellent (p less than 0.01). Only 9% of the lax knees had complaints of pain; 38% of the stable knees were painful (p less than 0.05). No significant difference in functional score and walking ability was noted between the lax and the stable knees. Seventy-eight percent of the lax knees had a range of motion over 100 degrees; 62.5% of the stable knees achieved this range.

Adult↗

Hamstring/quadriceps strength ratios in knees with medial collateral ligament insufficiency. Isokinetic and isometric results and their relation to patients' long-term recovery.

The purpose of this study was to investigate the peak torque and total work hamstring/quadriceps strength ratios (HQ-ratios) of 25 knees with medial collateral ligament (MCL) insufficiency and to find out the possible relation between different HQ-ratios and the long-term outcome of the patients. The isokinetic (speed 60 and 180 degrees/sec) and isometric muscle strengths were measured by a Cybex II dynamometer. Three standardized knee scoring scales were used to determine the subjective, clinical, and radiological outcome of the knees with MCL insufficiency. All tests showed great interpersonal variation in HQ-ratios even in the healthy knees (range from 23% to 183%). The average HQ-ratios between the uninjured and injured legs did not differ significantly from each other (range from 40% to 82%). The mean peak torques and total work of hamstrings as well as of quadriceps were slightly, but not significantly lower in the injured leg than on the uninjured side. The follow-up scores did not differ significantly between patient groups with low (less than or equal to 50%), optimal (50-80%), or high (greater than or equal to 80%) absolute HQ-ratios of the MCL insufficient knee. However, in every test the scores were significantly better for patients with an HQ-ratio difference of less than or equal to 15% between the injured and the uninjured side than for those with a clear difference (greater than 15%). The findings suggest that the HQ-ratio is a patient-specific parameter and that any general recommendation on its optimal value is difficult to give.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Lateral ulnar collateral ligament of the elbow: optimization of evaluation with two-dimensional MR imaging.

PURPOSE: To compare, in a cadaveric model, magnetic resonance (MR) imaging techniques with differing contrast and spatial resolution properties in the evaluation of disruption of the lateral ulnar collateral ligament (LUCL) at the elbow. MATERIALS AND METHODS: LUCL tears were surgically created in eight of 28 cadaveric elbow specimens. All specimens underwent 1.5-T MR imaging with the following pulse sequences: T1-weighted spin echo (SE), intermediate-weighted fast SE, fat-suppressed T2-weighted fast SE, gradient-recalled echo (GRE) with high spatial resolution, intermediate-weighted fast SE with high spatial resolution, and fat-suppressed T1-weighted SE with intraarticular administration of gadopentetate dimeglumine (MR arthrography). All images were obtained in the oblique coronal plane. Two radiologists independently graded the LUCL with separate and side-by-side assessment. RESULTS: Areas under the receiver operating characteristic curve were as follows for readers A and B, respectively: T1-weighted SE imaging, 0.64 and 0.62; intermediate-weighted fast SE imaging, 0.87 and 0.67; T2-weighted fast SE imaging, 0.68 and 0.69; GRE imaging, 0.56 and 0.68; MR arthrography, 0.84 and 0.85; and intermediate-weighted imaging with high spatial resolution, 0.92 and 0.88. Interobserver reliability was poor with T1-weighted SE imaging (kappa = 0.13) and GRE imaging (kappa = 0.18), fair with T2-weighted fast SE imaging (kappa = 0.36), and moderate with MR arthrography (kappa = 0.46), intermediate-weighted fast SE imaging (kappa = 0.55), and intermediate-weighted imaging with high spatial resolution (kappa = 0.59). CONCLUSION: Intermediate-weighted imaging with high spatial resolution and MR arthrography showed the greatest overall ability to enable the diagnosis of LUCL tears.

Aged↗

Medial collateral ligament injuries in football. Nonoperative management of grade I and grade II sprains.

During four academic years (1974-1978) at a major university, 51 of 70 knee injuries sustained by football players were Grade I or II sprains of the medial collateral ligament of the knee. All were managed identically with an active rehabilitation program involving partial or no immobilization. Players with Grade I sprains returned to full, unprotected participation after an average of 10.6 days of time loss; those with Grade II sprains returned after 19.5 days. Neither group showed an appreciably increased likelihood of reinjury. The likelihood of sustaining any knee injury was more than three times greater during spring as opposed to fall football.

Athletic Injuries↗

The "epiligament" of the rabbit medial collateral ligament: a quantitative morphological study.

The thin layer of connective tissue covering ligaments--the epiligament--has not been well described. The aim of the present study was to define, describe, and quantify the structure of the epiligament of the rabbit medial collateral ligament (MCL) using polarized light, scanning-electron, transmission-electron microscopy, and computerized histomorphometry. Epiligament was composed of woven bundles of collagen fibers, 3 morphologically-distinct cell types (spinous-shaped cells, cuboidal-shaped cells, and fat cells), and a neurovascular network that periodically arborized into the MCL. The areal fraction of vessels was significantly greater in the epiligament than in the MCL. The epiligament was significantly thicker on the superficial surface of the MCL than the deep surface, and the thickness of epiligament changed significantly during skeletal growth. Based on these structural features we speculate that the epiligament serves several important functions including: (1) protecting the MCL against abrasion, (2) supporting the neurovasculature, (3) controlling water and metabolite flux into the epiligament and possibly the MCL, and (4) being a source of extracellular matrix, cells, and vasculature during ligament growth and during ligament healing.

Animals↗

Breakdancer's thumb--partial rupture of the ulnar collateral ligament with a fracture of the proximal phalanx of the thumb.

Breakdancing is an acrobatic dance that involves spinning on various parts of the body including the head, dorsal spine and hand. Three cases are reported of partial rupture of the ulnar collateral ligament (UCL) of the thumb, associated with a fracture of the base of the proximal phalanx which occurred as a result of torsional forces applied to the abducted and hyperextended thumb. It appears to be a distinct clinical entity. In all cases, open reduction was required and led to excellent functional recovery.

Adolescent↗

Glycosaminoglycan metabolism of the medial meniscus, the medial collateral ligament and the hip joint capsule in experimental osteoarthritis caused by immobilization of the rabbit knee.

A study was made of glycosaminoglycan metabolism in experimental osteoarthritis caused by immobilization of the rabbit knee in extension. Samples from the medial meniscus, the medial collateral ligament of the knee and the hip joint capsule were obtained and analysed after 2, 6, 10, 17, 30 and 87 days of immobilization, samples from the mobile limb serving as controls. The tissue concentrations of glycosaminoglycans were determined from measurements of hexosamine and uronic acid after prior papain proteolysis and subsequent purification. The uptake of 35S-sulphate (DPM/microgram hexosamine) was used as an indicator of the synthesis rate of sulphated glycosaminoglycans. In both early and advanced immobilization osteoarthritis, the synthesis rate and the content of glycosaminoglycans were increased in all tissues.

Animals↗

Effect of forearm abduction on the ulnar collateral ligament.

Seven fresh cadaveric elbows from one woman and three men were studied to determine if the forearm abduction mobilization commonly used to restore the last 20 degrees of elbow extension produced an increase in the length of the anterior band of the ulnar collateral ligament. Initial ligament length and maximum length during mobilization were measured with a dial caliper and recorded on videocassette. Results indicated no significant difference between ligament lengths at rest and during the mobilization. The mechanism by which the forearm abduction mobilization restores elbow extension remains unknown.

Aged↗

[The use of carbon fiber strands for replacement of collateral ligaments at the knee joint (author's transl)].

Two different anchorage systems of carbon fiber strands were tested on 16 human cadaver knees. To pull the C-strands out of the scale and channel anchorage almost the same force was necessary as to break the natural collateral ligaments. The ingrowth of connective tissues and newly formed bone around the C-fibers was studied in 11 sheep. A biomechanical strength test revealed, 3 months after implantation, a 60% strength compared to the natural ligaments. Histologically a C-fiber connective tissue composite with collagen fibers was found. Newly formed bone closely surrounded the carbon. These results indicate that carbon fiber strands are suitable for ligament replacement, which allows early joint motion. Good long-term results could be assumed as a result of the high biocompatibility.

Biomechanical Phenomena↗

Medial collateral ligament instability and ulnar neuritis in the athlete's elbow.

Athletes who participate in overhand sports may sustain a host of injuries to the medial elbow. The chronic repetitive stress caused by the high velocity nature of the overhand throwing mechanism predisposes these athletes to overuse injuries. Medial collateral ligament instability and ulnar neuritis are common disorders seen in this patient population. A thorough understanding of the anatomy of the medial elbow as well as the pathophysiology of these disorders and their nonsurgical and surgical treatments are essential to providing these athletes with optimal care and hastening their return to sports.

Arthroplasty↗