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PubMed1989

Collagenases from periarticular ligaments and tendon: enzyme levels during the development of joint contracture.

Our laboratories have previously demonstrated that normal rabbit periarticular ligaments, anterior cruciate ligaments (ACL), medial collateral ligaments (MCL) and patellar tendon (PT) secrete collagenase. In this current study we examined these connective tissues following an immobilization period of 4 weeks. In the ligaments producing collagenase, activity was expressed only in the control, not in the immobilized joint. Control and experimental patellar tendon samples produce collagenolytic activity, suggesting that the expression of enzyme is less affected in tendons as compared to ligaments. Characterization of these collagenases was carried out using an antiserum directed against rabbit synovial collagenase. We demonstrated that ligament (ACL) and tendon (PT) collagenases cross react with this antibody in a double immunodiffusion assay. Protein blots of PT, ACL and MCL collagenases identified one major species (Mr = 45,000) and a minor species (Mr = 50,000) of immunoreactive proteins in all three connective tissues. Differences between control and experimental enzyme levels appear to be due to less collagenase protein being produced by immobilized ligaments.

Animals↗
PubMedDate not supplied

Relationship of the inguinal ligament to pelvic radiographic landmarks: anatomic correlation and its role in femoral arteriography.

PURPOSE: Because of the known risks of suprainguinal catheterization, an anatomic study of the inguinal ligament was performed in 10 cadavers. MATERIALS AND METHODS: The position of the inguinal ligament as estimated by means of palpation and use of anatomic landmarks was compared with the actual ligament position as determined by means of groin dissection. Infrainguinal contrast material injections were also performed to assess competence of the inguinal ligament against spread of hematomas. RESULTS: The radiographically determined position was an average of 15.2 mm superior to the actual ligament position (range, 3 mm below to 24 mm above). The palpated position of the ligament was an average of 7.8 mm superior to its actual position (range, 7 mm below to 23 mm above). Contrast material injections demonstrated the inability of the inguinal ligament to contain blood or fluid, with formation of retroperitoneal hematomas. CONCLUSION: Puncture of the femoral vessels should be positioned in the midportion of the femoral head, as determined with fluoroscopy for maximum safety during catheterizations.

Angiography↗
PubMedDate not supplied

Kinematics of partial and total ruptures of the medial collateral ligament of the elbow.

In this study the kinematics of partial and total ruptures of the medial collateral ligament of the elbow are investigated. After selective transection of the medial collateral ligament of 8 osteoligamentous intact elbow preparations was performed, 3-dimensional measurements of angular displacement, increase in medial joint opening, and translation of the radial head were examined during application of relevant stress. Increase in joint opening was significant only after complete transection of the anterior part of the medial collateral ligament was performed. The joint opening was detected during valgus and internal rotatory stress only. After partial transection of the anterior bundle of the medial collateral ligament was performed, there was an elbow laxity to valgus and internal rotatory force, which became significant after transection of 100% of the anterior bundle of the medial collateral ligament and was maximum between 70 degrees to 90 degrees of flexion. No radial head movement was seen after partial or total transection of the anterior bundle of the medial collateral ligament was performed. In conclusion, this study indicates that valgus or internal rotatory elbow instability should be evaluated at 70 degrees to 90 degrees of flexion. Detection of partial ruptures in the anterior bundle of the medial collateral ligament based on medial joint opening and increased valgus movement is impossible.

Aged↗
PubMedDate not supplied

Anatomic and histologic studies of lateral collateral ligament complex of the elbow joint.

We studied the gross and histologic anatomic characteristics of the lateral collateral ligament complex of the elbow joint from 15 cadavers to demonstrate its cross-sectional anatomy. The lateral ulnar collateral ligament adheres closely to the supinator, the extensor muscles, its intermuscular fascia, and the anconeus muscle and lies posterior to the radial collateral ligament. The lateral ulnar collateral ligament itself was identified with microscopy as a slender, poor structure consisting of the thick area of the posterolateral capsuloligamentous layer and a poorer structure than the anterior bundle of the medial collateral ligament as the primary stabilizer of the elbow joint. We believe that the lateral ulnar collateral ligament contributes to rather than is a major constraint to the posterolateral rotatory instability as part of the lateral collateral ligament complex with the surrounding tissues.

Aged↗
PubMedDate not supplied

Pelvic nerve plexus trauma at radical and simple hysterectomy: a quantitative study of nerve types in the uterine supporting ligaments.

OBJECTIVE: Using neuropeptide and enzyme markers to autonomic nerves, we sought to demonstrate and quantify the nerve types contained within the uterosacral ligaments (USLs) and cardinal ligaments (CLs) that are divided during radical hysterectomy (RH). METHODS: Cross-sectional biopsies were collected from the lateral third of the USL and the CL in 24 women who had an RH for cervical cancer, and from the uterine insertion of these ligaments in 11 women who had a simple hysterectomy for benign disease. We applied indirect immunofluorescence with FITC-conjugated secondary antibodies, using polyclonal primary antibodies to neuropeptide markers that predominate within somatic and autonomic nerves, to show different populations of the following nerve types within the biopsies: neuropeptide Y (NPY) and tyrosine hydroxylase (TH) for sympathetic nerves; vasoactive intestinal polypeptide (VIP) for parasympathetic nerves; substance P (SP) for nociceptive and sensory-motor nerves; and calcitonin gene-related peptide (CGRP) for sensory and sensory-motor nerves. The percentage area of immunoreactivity (PAI), determined by a computer-assisted image analyzer attached to a fluorescent microscope, was used as an objective quantitative measure of nerve density. Confocal microscopy was used to determine the composition and spatial arrangement of nerve fibers in the ligaments. RESULTS: The PAI was greater for all markers tested in both the USL and CL (P <.001) in RH compared with simple hysterectomy biopsies. For RH specimens, the PAI was greater for the sympathetic, sensory, and sensory-motor nerve markers in the USL compared with the CL (P <.01), but the PAI for VIP was similar (P >.05). Conversely, excluding the large trunks and associated ganglia, the free nerve fiber PAI in the CL was greater than that of the USL for all nerve markers (P <.001). The staining of peripheral autonomic ganglia and associated fibers, for NPY and TH, indicates that some sympathetic nerves are preganglionic with their cell bodies within the pelvic plexus. CONCLUSIONS: Significantly more autonomic nerves are transected in the more lateral division of the uterine supporting ligaments during a radical hysterectomy than during a simple hysterectomy. Sympathetic, parasympathetic, sensory, and sensory-motor nerve types are present within the CL and USL. The proportions of each nerve type differ between the two ligaments, and sympathetic nerves in the USL are the single largest nerve type. The uterine supporting ligaments are a major pathway for autonomic nerves to the pelvic organs.

Biopsy↗
PubMed1997

The shear behaviour of the rabbit medial collateral ligament.

This study was conducted to determine whether load is transmitted via shear through the matrix between ligament fibres rather than solely as tension in the fibres. Thirty-six rabbit medial collateral ligaments were subjected to uniaxial tension tests. Twenty-four of these ligament complexes were incised laterally to create longitudinal shear planes, while the remaining 12 complexes served as controls. Data were used in conjunction with finite element models to determine how shear transfer, if any, occurred in the ligament. Non-linear, anisotropic, plane stress finite element models were able to simulate the non-linear structural behaviour shown by uncut control ligaments under normal tensile testing. The finite element models were also able to reproduce the ligament load deformation behaviour observed in the shear tests. Results indicated that some load was transferred between the collagen fibres and other constituents in the ground substance of these ligaments and possibly also through fibres missed during the cutting procedure. The exact manner in which the load was transmitted remains unclear and requires further investigation and quantification.

Animals↗
PubMed2006

[Knee ligament injuries].

Like no other joint of the human body the knee depends on intact ligaments. Knee instability due to ligament injuries will cause abnormal joint kinematics, and thereby is made responsible for secondary damage to other important knee joint structures. Diagnosis of knee ligament injuries is based on the detailed history with often typical injury patterns, as well as on the physical examination with specific knee ligament tests. In addition radiological evaluation is used. The range of knee ligament injuries is wide. Beginning with an isolated medial collateral ligament rupture which will heal with conservative treatment, they range to knee dislocation, a serious injury which needs emediate care and is associated with a high incidence of complications. Surgical procedures aim to reconstruct knee ligaments as anatomical as possible to provide for a long term stable knee joint.

Algorithms↗
PubMed2000

Altered expression level of calbindin D28k in the periodontal ligament of rat molar in response to changes in occlusal force.

The present immunohistochemical study was designed to investigate the alteration in the expression level of calbindin D28k in the periodontal ligament of the rat molar in response to changes in occlusal force to clarify the physiological role(s) of this protein in the ligament. In normal periodontal ligament of the lower first molar, immunoreactivity for calbindin D28k was found in the spindle-shaped cells, presumably fibroblasts, at the alveolar portion of the ligament at the distal side of the mesial root and mesial side of the distal root. Following the overload of occlusal force to the upper first molar by bite-raising, the number and immunoreactivity of the positive cells in the periodontal ligament of the lower first molar increased gradually. A more significant increase was detected at 7 d following the bite-raising compared to the normal animals. When occlusal force was removed by the extraction of the upper first molar, the expression level of calbindin D28k in the periodontal ligament of the lower first molar rapidly decreased, however a subsequent gradual increase was recognized. Statistical analysis of the spatial immunoreactivity of calbindin D28k in the periodontal ligament was performed and showed statistically significant differences. The present results suggest that calbindin D28k may play important roles in the homeostasis and cytoprotection of the periodontal fibroblasts against occlusal force.

Analysis of Variance↗
PubMed2001

The effects of a high-carbohydrate diet on the stress-strain behavior of the periodontal ligament of the distal root of the mandibular first molar in hamsters.

We analyzed stress-strain curves in transverse sections at three different root levels of the cervical, middle, and apical regions of the distal root of the mandibular first molar in hamsters fed a high-carbohydrate (experimental group) or standard (control group) diet for 8 weeks. Each section was loaded in vitro at a rate of 5 mm/min in an extrusive direction. The rupture sites and the structures of birefringent collagen fibers in the periodontal ligament were also analyzed. The maximum shear stress, tangent modulus, and failure strain energy density of the periodontal ligament were significantly greater in the cervical region than in the middle and apical regions in both the control and experimental groups. The maximum shear stress, tangent modulus, and failure strain energy density of the periodontal ligament in the experimental group were significantly lower than those in the control group at the cervical and middle regions. The maximum shear strain was significantly greater in the experimental group than in the control group at the middle and apical regions. Histological sections showed that the periodontal ligament ruptured irregularly in both groups. The collagenous fibers of the ligament in the experimental group appeared to be thinner and less birefringent at the cervical and middle regions of the root. These results suggest that a high-carbohydrate diet differentially affects the collagen fibers in the periodontal ligament as a function of the root level, and that these effects are evident in changes in the mechanical properties of the ligament.

Analysis of Variance↗
PubMed2003

Viscoelastic behavior and structural properties of the coracoclavicular ligaments.

During contact sports such as football, hockey or rugby, the coracoclavicular ligaments are commonly ruptured. Currently, the limited biomechanical data on the properties and function of these ligaments have led to debate on the "gold standard" treatment for these injuries. Therefore, the objective of this study was to characterize the geometry, viscoelastic behavior and structural properties of the coracoclavicular ligaments (n=11). The trapezoid and conoid were found to have similar length (9.6+/-4.4 vs. 11.2+/-4.1 mm) and cross-sectional area (103+/-43 vs. 69+/-51 mm2), respectively (P>0.05). Static and cyclic stress relaxation tests were then performed, followed by uniaxial tensile testing with the insertions of each ligament aligned to ensure a uniform distribution of load across the fibers. No significant differences were observed for the trapezoid and conoid during the static (36+/-8% vs. 31+/-7%) and cyclic (23+/-12% vs. 16+/-6%) stress relaxation tests, respectively (P>0.05). Similarly, no statistically significant differences were found between the trapezoid and conoid for linear stiffness (83+/-40 vs. 70+/-23 N mm(-1)), ultimate load (312+/-133 vs. 266+/- 108 N), energy absorbed at failure (820+/-576 vs. 752+/- 410 N mm), percent elongation (74+/-47% vs. 62+/-22%) and elongation at failure (5.8+/-2.2 vs. 6.1+/-1.6 mm), respectively (P>0.05). A comparison of our data to previous studies suggests that the complex fiber orientation of these ligaments has a significant role in determining the maximum load that can be transferred between the clavicle and scapula by each bone-ligament-bone complex. Our findings also further confirm the functional role of the coracoclavicular ligaments in supporting the upper extremity, and provide data for reconstruction and rehabilitation protocols as well as computational models.

Acromioclavicular Joint↗
PubMed2005

Proteoglycans and catabolic products of proteoglycans present in ligament.

The aim of the present study was to characterize the proteoglycans and catabolic products of proteoglycans present in the tensile region of ligament and explant cultures of this tissue, and to compare these with those observed in the tensile region of tendon. Approx. 90% of the total proteoglycans in fresh ligament was decorin, as estimated by N-terminal amino acid sequence analysis. Other species that were detected were biglycan and the large proteoglycans versican (splice variants V(0) and/or V1 and/or V2) and aggrecan. Approx. 23% of decorin detected in the matrix was degraded. Intact decorin and decorin fragments similar to those observed in the matrix that retained the N-terminus were also observed in the medium of ligament cultures. Intact biglycan core protein was detected in the matrix and medium of ligament cultures, and two fragments originating from the N-terminal region of biglycan were observed in the matrix of cultured ligament. Versican and versican fragments that retained the N-terminus of versican core protein were detected in fresh matrix and medium of tendon cultures. Approx. 42% of versican present in the fresh ligament was degraded. Aggrecan catabolites appearing in the culture medium were derived from aggrecanase cleavage of the core protein. An intact link protein and a degradation product from the N-terminal region of type XII collagen were also detected in the medium of the ligament explant.

Aggrecans↗
PubMed2002

The functional anatomy of the human anterior talofibular ligament in relation to ankle sprains.

The anterior talofibular ligament is the most commonly injured ligament in the ankle. Despite considerable interest in the clinical outcome of treatment protocols, we do not know whether the distinctive pattern of localization of the injuries relates to regional differences in the structure and molecular composition of the ligament. To address this issue, ligaments were examined by histology and immunohistochemistry. Differences in the structure of its two attachments (i.e. entheses) were evaluated with quantitative, morphometric techniques, and regional differences in the distribution of collagens, glycosaminoglycans and proteoglycans were determined qualitatively by immunolabelling. Morphometric analyses showed that bone density was less at the fibular attachment, but that enthesis fibrocartilage was more prominent. Immunohistochemistry revealed the presence of a fibrocartilage (containing type II collagen and aggrecan) at the site where the ligament wraps around the lateral talar articular cartilage in a plantarflexed and inverted foot: the fibrocartilage is regarded as an adaptation to resisting compression. We propose that avulsion fractures are less common at the talar end of the ligament because (1) bone density is greater here than at the fibular enthesis, and (2) stress is dissipated away from the talar enthesis by the 'wrap-around' fibrocartilaginous character of the ligament near the talar articular facet.

Aged↗
PubMed2003

Pollical oblique ligament in humans and non-human primates.

A morphological study of the oblique ligament in the thumb is presented. The ligament was consistently described in human specimens and compared with dissections of non-human primates from different species. The oblique ligament was found in some, but not all, specimens in each of the following species examined: chimpanzee, orangutan, gibbon, anubis baboon, hamadryas baboon, squirrel monkey, lemur and marmoset. A revised identity of the oblique ligament is proposed as a reinforced distal border of a fibro-osseous annular pollical flexor sheath and whose function is not independent of the flexor sheath. The constant presence and tendinous trait of the pollical oblique ligament in humans, when compared with non-human primates, supports the notion that the oblique ligament strengthens the pollical flexor sheath in humans for restraint of the flexor pollicis longus tendon during forceful precision pinching. A derivation of the pollical oblique ligament is considered as representing a vestigial radial limb of a flexor pollicis superficialis tendon in the thumb.

Animals↗
PubMed1999

Dorsal intercarpal ligament capsulodesis for scapholunate dissociation: biomechanical analysis in a cadaver model.

The purpose of this study was to evaluate in cadavers a new method for treating scapholunate dissociations, dorsal intercarpal ligament capsulodesis (DILC), and to compare its performance with that of a previously described soft tissue reconstruction, Blatt capsulodesis (BC). A cadaver model was used to simulate normal and abnormal wrist motions. The positions of the scaphoid and lunate and their changes with wrist motion and ligament condition were recorded using biplanar radiographs taken posteroanteriorly and laterally. The scapholunate gap was measured on the posteroanterior radiographs and the scapholunate angle was measured on the lateral view radiographs. Following scapholunate interosseous ligament sectioning, a diastasis developed between the scaphoid and lunate that was maximum in the clenched fist position 2.1 +/- 0.33 mm (mean +/- SEM) with the ligament intact versus 8.0 +/- 1.74 mm after the ligament was sectioned. Dorsal intercarpal ligament capsulodesis reduced gap formation more than BC, including when the specimens were in the clenched fist position: increased gap versus intact specimens equals 1.0 mm for DILC versus 3.7 mm for BC. The differences in diastasis were statistically significant between BC and DILC when the wrist was in extension, radial deviation, and clenched fist positions. After the scapholunate interosseous ligament was divided, the scaphoid flexed relative to the lunate. Both capsulodeses improved scapholunate alignment and there was a trend for DILC to correct the scapholunate angle more than BC. The results demonstrate that DILC is an attractive alternative to BC ex vivo. Because DILC does not tether the scaphoid to the distal radius, as BC does, improved wrist motion, especially flexion, might be possible in vivo. The use of DILC in the treatment of scapholunate dissociation warrants further investigation and clinical trials.

Adult↗
PubMed1999

Histopathology of the palmar beak ligament in trapeziometacarpal osteoarthritis.

Eighteen cadaver hands were studied to investigate the relationship between degeneration of the palmar beak ligament and articular disease of the trapeziometacarpal joint. Eight of 18 joints had chondromalacia alone; 10 contained areas of eburnation in the palmar aspect of the joint. Beak ligament degeneration correlated closely with the presence of articular degeneration; all joints with eburnation demonstrated frank detachment of the ligament from its metacarpal insertion site. Histologically, the collagen fibers of the beak ligament were disorganized at the metacarpal attachment. The normal insertional zone of fibrocartilage was often unrecognizable on the metacarpal side and, in more degenerative specimens, an intervening synovial recess appeared at the palmar beak of the metacarpal. The trapezial insertion of the beak ligament showed no degenerative change. Increasingly severe cartilage disease was associated with progressive and selective degeneration of the collagen framework of the beak ligament at its insertion onto the thumb metacarpal. These localized histopathologic findings further support the existence of an anatomically distinct intra-articular beak ligament essential to the normal function of the trapeziometacarpal joint and suggest an etiologic relationship to osteoarthritic disease.

Aged↗
PubMed1999

Forearm interosseous ligament isometry.

Biomechanical testing was performed to determine isometric interosseous ligament graft placement as a preliminary step for reconstruction after an axial forearm disruption. Twenty-five combinations of potential ligament graft placement were studied on 7 fresh-frozen cadavers. Suture was used to simulate these potential ligament reconstructions, and suture excursion was used as an index of isometry. Ligament orientation was defined by the angle formed between the ulna and the suture (surrogate graft). Ligament position was defined by its insertion on the ulna as a percentage of ulna length. Suture-ulna angles from 9 degrees to 38 degrees produced significantly less suture excursion than angles of > or = 39 degrees. Minimal suture excursion was noted at angles of < or = 20 degrees, which we feel represents the optimal range for reconstruction. The optimal location on the ulna for isometric interosseous ligament reconstruction was at 25% to 30% of total ulna length, as measured proximally from the distal ulna articular surface. The radius isometric location is optimally located by a vector starting from the ulna isometric point and directed toward the proximal radius at an angle of < or = 20 degrees relative to the long axis of the ulna. Interosseous ligament reconstruction may prove beneficial in the long-term outcome of reconstruction after axial forearm disruption.

Aged↗
PubMed1999

Autograft replacements for the scapholunate ligament: a biomechanical comparison of hand-based autografts.

An ideal replacement for the scapholunate ligament (SLL) has not been found. The carpometacarpal bone-ligament-bone complex at the base of the second and third metacarpal is proposed as a replacement for the SLL in this study. A cadaveric study of matched SLL, second metacarpal-trapezoid ligament, third metacarpal-capitate ligament, and dorsal periosteal retinaculum was performed. Stiffness and strength were obtained from fresh-frozen specimens tested to failure with a hydraulic distractor. The second metacarpal-trapezoid ligament and the third metacarpal-capitate ligament most closely approximated the stiffness and strength of the SLL. The dorsal periosteal retinaculum was significantly less stiff and was significantly weaker than the SLL. This study indicates that the second or third carpometacarpal ligaments are grafts that approximate the mechanical properties of the SLL.

Carpal Bones↗
PubMed2002

The mechanical properties of the human hip capsule ligaments.

The human hip capsule is adapted to facilitate upright posture, joint stability, and ambulation, yet it routinely is excised in hip surgery without a full understanding of its mechanical contributions. The objective of this study was to provide information about the mechanical properties of the ligaments that form the hip capsule. Cadaver bone-ligament-bone specimens of the iliofemoral, ischiofemoral, and femoral arcuate ligaments were tested to failure in tension. The hip capsule was found to be an inhomogeneous structure and should be recognized as being composed of discrete constituent ligaments. The anterior ligaments, consisting of the 2 arms of the iliofemoral ligament, were much stronger than the posterior ischiofemoral ligament, withstanding greater force at failure and exhibiting greater stiffness. Knowledge of the anatomy and mechanical properties of the capsule may help the hip surgeon choose an appropriate surgical approach or repair strategy.

Aged↗