Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “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 1,045 records · Page 58Linked to original sources
PubMed1996

Extrinsic radiocarpal ligaments: magnetic resonance imaging of normal wrists and scapholunate dissociation.

OBJECTIVE: To determine whether magnetic resonance imaging [MRI] in planes of imaging parallel to the known course of the extrinsic radiocarpal ligaments of the wrist aids in the visualization of these structures. SUBJECTS AND METHODS: MRI was performed on 32 wrists: a single normal cadaveric wrist, 23 normal wrists in volunteers and 8 wrists in patients with known scapholunate dissociation and rotatory scaphoid subluxation. Proton-density and T2-weighted images were obtained in the sagittal plane and gradient recalled echo images in an oblique sagittal plane, selected to parallel the extrinsic radiocarpal ligaments. The images were interpreted by two musculoskeletal radiologists. Each of the six main extrinsic ligaments was assessed for visualization or nonvisualization, and the morphologic features of those visualized were documented. RESULTS: With the exception of the dorsal radioscaphoid ligament, the volar and dorsal extrinsic radiocarpal ligaments were all consistently visualized in the normal wrists. For the eight cases of scapholunate dissociation, MRI demonstrated underlying rupture or thickening of the volar radioscaphocapitate ligament in all wrists and of the dorsal radiolunate ligament in five. CONCLUSION: MRI in the true and oblique sagittal planes can consistently demonstrate the extrinsic radiocarpal ligaments of the wrist. With this technique, extrinsic ligamentous abnormality can be demonstrated in patients with scapholunate dissociation and rotatory scaphoid subluxation.

Adult↗
PubMed1998

Quantitative analysis of collagen fibrils of human cruciate and meniscofemoral ligaments.

The ultrastructural anatomy of collagen fibril diameters in the cruciate and meniscofemoral ligaments, from four young human cadaver knees (mean age, 20 years, range, 17-22 years) was studied using transmission electron microscopy. Samples were harvested from the proximal, middle, and distal regions of the anterior and posterior cruciate ligaments, and the meniscofemoral ligament. Photomicrographs were taken and assessed quantitatively using image analysis software to determine the collagen fibril diameters and eccentricities, and the percentage of total cross sectional area occupied by collagen. The collagen fibril diameter for the anterior cruciate ligament was found to be largest in the distal region but it decreased as it moved proximally. The posterior cruciate ligament had an opposite trend because it decreased from the proximal to the distal region. For the meniscofemoral ligament, the fibrils of the middle region were larger than those of the proximal and distal regions. The percentage of total cross sectional area occupied by collagen, however, did not vary significantly between regions. Fibril eccentricity also varied little between ligament or location. The variability observed in fibril diameters may account for the different mechanical properties of the ligaments.

Adolescent↗
PubMedDate not supplied

Reconstruction of the anterior and posterior cruciate ligaments after knee dislocation. Use of early protected postoperative motion to decrease arthrofibrosis.

We report a critical rating of results for 11 patients with bicruciate ligament reconstructions and immediate protected knee motion after knee dislocations (seven acute and four chronic). Six patients had concurrent repair or reconstruction of medial ligamentous structures, and six had reconstruction of the lateral and posterolateral ligaments. All patients returned for followup at a mean of 4.8 years postoperatively. Follow-up arthrometric testing at 20 degrees of flexion showed 10 knees had less than 3 mm of increased total anterior-posterior displacement and 1 knee had 7 mm of increase. At 70 degrees of flexion, 9 knees had less than 3 mm of increased displacement and 2 knees had more than 6 mm of increase. The failure rates were as follows: 18% of posterior cruciate ligament reconstructions (2 of 11), 9% of anterior cruciate ligament reconstructions (1 of 11), 17% of lateral and posterolateral procedures, and 0% of medial collateral ligament procedures. At followup, five of the seven patients with acute injuries had no limitations with daily or sports activities. Three of the four patients with chronic ruptures were asymptomatic with daily activities, but only one was asymptomatic with light sports. Five patients (all acute injuries) required treatment for knee motion limitations. Nine patients had full range of motion at followup. We concluded that simultaneous bicruciate ligament reconstructions, performed with associated medial or lateral procedures, are warranted to restore function to all ligament structures. Even though immediate motion was used, several patients required early manipulation or arthroscopic debridement, which restored full motion and prevented permanent arthrofibrosis.

Activities of Daily Living↗
PubMed2000

Pelvic nerve plexus trauma at radical hysterectomy and simple hysterectomy: the nerve content of the uterine supporting ligaments.

BACKGROUND: A major cause of the pelvic morbidity after a radical hysterectomy (RH) is thought to be damage to the pelvic nerve plexus, but direct evidence is lacking. We set out to determine the nerve content of the uterosacral ligaments (USLs) and cardinal ligaments (CLs) at the level at which they are divided during a radical hysterectomy and a simple hysterectomy. METHODS: Intraoperative cross-sectional biopsies were collected from the lateral third of the uterosacral ligaments (USLs) and cardinal ligaments (CLs) in 20 women undergoing radical hysterectomy (RH) and from the uterine insertion of these ligaments in 11 women undergoing a simple hysterectomy. Quantitative immunocytochemistry was utilized to demonstrate and quantify the nerve content of the uterine supporting ligaments at the level at which they are divided in a RH and in a simple hysterectomy. Indirect immunofluorescence staining of frozen cryostat sections was performed using primary antibodies to PGP 9.5 (a pan-neuronal marker). A computer-assisted image analyzer measured the percentage area of immunoreactivity (PAI) that was used to quantify the nerve density. Confocal microscopy was used to determine the composition and spatial arrangement of nerve fibers in the ligaments. RESULTS: The PAI was significantly greater in the RH biopsies than in the simple hysterectomy biopsies, for both the CLs (P < 0.001) and the USLs (P < 0.001). In the RH biopsies, more nerve tissue was present in the USL than CL (P = 0.01), and compared with the CL more of the nerve fibers in the USL were concentrated in large trunks. Excluding these trunks and autonomic ganglia, the free nerve content of the USL was lower than that of the CL (P < 0.001). The presence of nerve trunks, autonomic ganglia, and free nerve fibers within the lateral third of the USL and CL is consistent with extension of the inferior hypogastric plexus along these ligaments to the pelvic organs. CONCLUSIONS: The uterine supporting ligaments contain autonomic nerves and ganglia, as extensions of the inferior hypogastric plexus. The USLs have a greater nerve density than the CLs. Because RH disrupts more nerve tissue than a simple hysterectomy, these data provide further evidence for the neurogenic etiology of pelvic morbidity after RH.

Cross-Sectional Studies↗
PubMed1998

Elongation patterns of the collateral ligaments of the human knee.

OBJECTIVE: To determine the responses of the medial and lateral collateral ligaments (MCL, LCL) of the human knee to externally applied stresses. DESIGN: Differential variable reluctance transducers were used to measure length changes along the long posterior parallel fibers of the MCL and the middle third of the LCL through a flexion range of 15-120 degrees and a variety of external stresses. BACKGROUND: There is a lack of consensus regarding the collateral ligament response to internal and external tibial rotation. In addition, there are very few studies that have investigated the effects of quadriceps and hamstrings muscle group loads on the strain in the collateral ligaments. METHODS: Three series of tests were performed. First, the passive behavior of the ligaments was obtained as well as the ligament response to 3 degrees of varus and valgus rotation. The next series tested the ligaments' response to 0-10 degrees of internal and external tibial axial rotation. Finally, isolated and co-contracted quadriceps and hamstrings muscle group loads were applied. RESULTS: The instrumented portions of both ligaments were more strained in extension than flexion. Varus rotations stretched the LCL, whereas valgus rotations elongated the MCL. The strain in the MCL was shown to increase during external rotation and decrease during internal rotation. The LCL did not exhibit a uniform response across specimens to internal or external tibial axial rotation, but was consistent between left and right knees from a single cadaver. Highly consistent trends of interactions between muscle loads and the strain in both the MCL and LCL were noted. CONCLUSIONS: The responses of the MCL and LCL to applied stresses are dependent upon the flexion angle of the knee, the influence of muscle loading and, to a lesser extent, anatomic variation in the ligaments themselves. Guidelines for rehabilitation of the collateral ligaments following injury are suggested.

Journal Article↗
PubMed1998

A new method for measuring wrist-joint ligament length changes during sagittal and frontal motion.

OBJECTIVE: The present study addresses elongation patterns of selected capsular wrist ligaments during two types of planar wrist motion. DESIGN. IN VITRO: continuous measurement of capsular ligament elongation using miniature displacement transducers. BACKGROUND: The function of the capsular wrist ligaments in carpal kinematics is still to be determined unambiguously. Most previous studies on carpal ligament behaviour were realised using X-ray stereophotogrammetric methods. METHODS: Elongation of the palmar radiolunate, radiocapitate and ulnocapitate ligaments, as well as of the dorsal radiotriquetral ligament during frontal and sagittal wrist motion were analysed in 10 anatomical specimens using miniature differential variable reluctance transducers. Wrist motion was tracked using a six-degree-of-freedom electrogoniometer. RESULTS AND CONCLUSIONS: In most instances, the elongation of these ligaments was similar for two motion modalities tested (guided by a rail or free) with, however, a trend to larger individual variations and smaller elongation during free motion for several ligaments. The capsular ligaments considered in this study displayed length changes inferior to 15% of the initial length. The individual elongation patterns and ranges were highly variable, contrasting with excellent intra-individual reproducibility.

Journal Article↗
PubMed2002

Arthroscopic release of the rotator interval and coracohumeral ligament: An anatomic study in cadavers.

PURPOSE: The purpose of this cadaveric study was to examine the anatomy of the normal glenohumeral joint relevant to an arthroscopic rotator interval release and define both the endpoints of a complete release of the coracohumeral ligament and the relationship to surrounding tendons and nerves. TYPE OF STUDY: An anatomic cadaveric study. METHODS: Fifteen fresh-frozen cadaveric specimens were studied with 5 specimens in group I and 10 specimens in group II. Group I specimens were used to examine the relevant anatomy, including the structures at risk, the dimensions of the rotator interval, and potential endpoints for release of the coracohumeral ligament. Measurements included (1) the supraspinatus to the subscapularis distance, (2) the distance from the rotator interval to the deep surface of the coracoid process, and (3) the distance from the rotator interval to the coracoacromial ligament at the level of the glenoid. Group II specimens underwent arthroscopic release of the rotator interval using the appearance of the coracoacromial ligament as the superficial endpoint. Dissection was then performed to examine for complete release of the coracohumeral ligament and to assess the structures at risk of injury. RESULTS: The distance from the anterior edge of supraspinatus to the superior edge of subscapularis at the glenoid rim was 21.6 mm, which increased to 27.8 mm with joint distention. The minimum distance from the rotator interval to the deep surface of the coracoid process was 11.4 mm. Before distention, the coracoacromial ligament was an average of 6.2 mm from the rotator interval capsule. Arthroscopic release from the supraspinatus to the subscapularis resulted in complete resection of the coracohumeral ligament in all 15 specimens. There were no specimens with evidence of injury to the biceps tendon, supraspinatus, subscapularis, or the conjoint tendon. CONCLUSIONS: This study confirms that intra-articularly directed arthroscopic release of the rotator interval can safely lead to complete release of the coracohumeral ligament if dissection is taken superficially to the level of the coracoacromial ligament.

Arthroscopy↗
PubMed2004

Spiral ligament and stria vascularis changes in cochlear otosclerosis: effect on hearing level.

OBJECTIVE: To investigate the effect of changes within the spiral ligament and stria vascularis on hearing in cochlear otosclerosis, we examined spiral ligament hyalinization, stria vascularis atrophy, and sensory hearing loss in cochlear otosclerosis and described changes in ion transport molecule expression. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS: Thirty-two cochleae from 24 temporal bone donors with histologic evidence of cochlear otosclerosis, including spiral ligament hyalinization. INTERVENTION: Audiography. MAIN OUTCOME MEASURES: Measurements of spiral ligament width, stria vascularis, and bone-conduction thresholds were compared by the amount of hyalinization. Expression of the ion transport molecules Na,K-ATPase, connexin 26, and carbonic anhydrase II were assessed by immunohistochemical techniques. RESULTS: Hyalinization most often involved the posterior basal turn (88%) and the posterior middle turn (27%). Spiral ligament hyalinization correlated significantly with stria vascularis atrophy in the posterior middle turn of the cochlea (rho = -0.63, p < 0.01). There was a trend toward a significant association in the posterior basal turn (rho = -0.31, p < 0.08). Bone-conduction thresholds at 2,000 and 4,000 Hz were significantly associated with the amount of stria vascularis atrophy (rho = -0.44, -0.40, p < 0.05). In addition, we observed decreased immunostaining for both carbonic anhydrase II with Type I fibrocytes and Na,K-ATPase with stria vascularis and Type II and Type IV fibrocytes of the spiral ligament in cochlear otosclerosis sections compared with normal cochlea. Na,K-ATPase staining within the stria vascularis was further decreased in the presence of spiral ligament hyalinization. No significant differences were seen with connexin 26 immunostaining. However, immunostaining results were somewhat inconsistent. CONCLUSION: These data suggest that spiral ligament structure and function are essential for stria vascularis survival. In addition, dampened expression of ion transport molecules within the spiral ligament and stria vascularis may disrupt potassium ion recycling, resulting in loss of endocochlear potential and sensory hearing loss.

Aged↗
PubMed1986

The relationship of actin to ligament contraction.

A surgical model of a contracting ligament was established in a Z-lengthened, rat medial collateral ligament. These lengthened ligaments contracted back to a normal degree of tightness in a three-week period. Immunofluorescent actin staining of cryostat ligament sections was increased in these contracted ligaments, compared with sham-operated ligaments that had not contracted. In vitro culture of ligament fibroblasts confirmed that they (like fibroblasts from other systems) produce large, actin, stress fibers thought to be involved in cell contraction. Transmission electron-microscopic examination of normal ligament demonstrated the cytoplasm of fibroblast cell processes extending out to and surrounding collagen fibrils, indicating a closer involvement with established fibrils than was expected. On the basis of these observations, it is hypothesized that intracellular proteins, such as actin, allow the fibroblast to exert forces and actively contribute to the contraction of ligamentous tissues.

Animals↗
PubMed1995

Adhesiveness of human ligament fibroblasts to laminin.

The adhesiveness of fibroblasts from the human anterior cruciate and medial collateral ligaments to the laminin molecule was studied, with particular emphasis on the intrinsic differences between fibroblasts from the two ligaments. Cellular adhesion strength, adhesion area, laminin concentration, and seeding time were examined. Cell adhesion to laminin anchored with poly-D-lysine to a cleaned cover glass was measured with a micropipette micromanipulation system after seeding. The adhesion strength of fibroblasts from the anterior cruciate ligament to laminin was greater than and significantly different from that of fibroblasts from the medial collateral ligament, depending on the laminin concentration. Fibroblasts from the anterior cruciate ligament also exhibited an increase in adhesion strength, dependent on laminin concentration of as much as 30 micrograms/ml, at which the laminin receptors were thought to be saturated. Fibroblasts from the medial collateral ligament did not show such an increase except at laminin concentrations of 5-10 micrograms/ml. There was no significant difference in adhesion area between fibroblasts from the two ligaments except after 45 minutes at a laminin concentration of 40 micrograms/ml. For both, the adhesion to laminin showed little correlation to seeding time during periods of as long as 60 minutes. Measurements of adhesion area also failed to show a significant correlation to seeding time for fibroblasts from either ligament at laminin concentrations of 20 and 40 micrograms/ml. Adhesion strength normalized by adhesion area had no correlation to seeding time.(ABSTRACT TRUNCATED AT 250 WORDS)

Anterior Cruciate Ligament↗
PubMed1996

Subfailure injury of the rabbit anterior cruciate ligament.

Ligamentous injuries range in severity from a simple sprain to a complete rupture. Although sprains occur more frequently than complete failures, only a few studies have investigated the phenomena of these subfailure injuries. The purpose of our study was to document the changes in the load-deformation curve until the failure point, after the ligament has been subjected to an 80% subfailure stretch. Thirteen paired fresh rabbit bone-anterior cruciate ligament-bone preparations were used. One of the pairs (control) was stretched until failure; the other (experimental) was first stretched to 80% of the failure deformation of the control and then stretched to failure. Comparisons were made between the load-deformation curves of the experimental and control specimens. The nonlinear load-deformation curves were characterized by eight parameters: failure load (Ffail), failure deformation (Dfail), energy until failure (Efail), deformations measured at 5, 10, 25, and 50% of the failure load (D5, D10, D25, and D50, respectively), and stiffness measured at 50% of the failure force (K50). There were no significant differences in the values for Ffail, Dfail, and Efail between the experimental and control ligaments (p > 0.33). In contrast, the deformation values were all larger for the experimental than the control ligaments (p > 0.01). The deformations D5, D10, D25, and D50 (mean +/- SD) for the control were 0.36 +/- 0.13, 0.49 +/- 0.23, 0.81 +/- 0.35, and 1.23 +/- 0.41 mm. The corresponding deformations for the experimental ligaments were, respectively, 209, 186, 153, and 130% of the control values. K50 was also greater for the experimental ligament (125.0 +/- 41.7 N/mm compared with 108.7 +/- 31.4 N/mm, p < 0.03). These findings indicate that even though the strength of the ligament did not change due to a subfailure injury, the shape of the load-displacement curve, especially at low loads, was significantly altered. Under the dynamic in vivo loading conditions of daily living, this may result in increased joint laxity, additional loads being applied to other joint structures, and, with time, to joint problems.

Animals↗
PubMed1996

Expression of collagen and matrix metalloproteinases in ruptured human anterior cruciate ligament: an in situ hybridization study.

The biological basis for failure of the human anterior cruciate ligament to heal after rupture is unknown. Since this failure could be influenced by abnormalities in matrix protein production or degradation, or both, several diverse matrix protein markers were utilized to survey the state of these extracellular proteins in intrinsic anterior cruciate ligament fibroblasts. Matrix gene expression was visualized by in situ hybridization 9 to 365 days after rupture using probes for type-I collagen, collagenase, 72kDa-gelatinase, and tissue inhibitor of metalloproteinase. Remnants of anterior cruciate ligament were biopsied arthroscopically from 20 patients at reconstruction, fixed in 4% paraformaldehyde, and processed with cDNA probes for the aforementioned mRNAs. mRNA expression of type-I collagen was detected in all specimens, was equally distributed throughout the remnants, and remained evident even at 1 year after injury. Neither of the matrix-degrading enzymes nor their inhibitor (tissue inhibitor of metalloproteinase) was expressed at substantial levels at any time point. Collagen expression within the anterior cruciate ligament confirmed the viability of the ligament remnants for as long as 1 year after rupture. The lack of significant expression of the two matrix-degrading metalloproteinases by the fibroblasts is not consistent with an autodegradation of the remaining ruptured ligament tissue, and whether the lack of matrix remodelling may account, at least in part, for the poor healing response of the anterior cruciate ligament remains to be determined. This initial investigation by in situ hybridization techniques provides a descriptive profile of matrix gene expression in the damaged human anterior cruciate ligament.

Adolescent↗
PubMed1997

Braided polypropylene augmentation device in reconstructive surgery of the anterior cruciate ligament: long-term clinical performance of 594 patients and short-term arthroscopic results, failure analysis by scanning electron microscopy, and synovial histomorphology.

Long-term clinical results and short-term arthroscopic and microscopic findings from two augmented reconstruction procedures for the ruptured anterior cruciate ligament are reported. The braided polypropylene ligament augmentation device (Kennedy model) was used with temporary double-end fixation in 279 patients to augment the attachment of the anterior cruciate ligament after acute proximal rupture and in 315 patients to augment a bone-tendon-bone autograft, mainly after chronic instability. Check arthroscopy was performed and the metal fixation hardware was removed after a mean of 11 months. Of the 569 patients evaluated, 101 partial or total breakages of the ligament augmentation device were found. Together with nine breakages detected late in the follow-up period, 110 (19.3%) failures were found. Most of these failures were accompanied by effusion that was immediately alleviated when the failed device was removed. No generalized synovitis was visible. Scanning electron microscopic analysis of 24 retrieved failed ligament augmentation devices showed fatigue to be the principal failure mode, together with local abrasion at the fracture. Synovial biopsies were taken during arthroscopy in 84 patients with and without ligament augmentation device-failure who had given informed consent, and histological evaluation revealed that in 21 patients, chronic but no acute synovial inflammation was found, and wear particles could be identified in foreign body cells in 17. Statistically, the presence of chronic synovitis was predicted neither by wear particles and foreign body cells nor by abrasion or fatigue failure of the ligament augmentation device. Irrespective of the failures, for which ligament augmentation device removal is recommended, in the final Orthopaedische Arbeitsgemeinschaft Knie evaluation (after a mean of 6.2 years), excellent and good clinical results were found in 83.6% of all 594 patients.

Adolescent↗
PubMed1993

The bone-ligament junction: a comparison between biological and artificial ACL reconstruction.

The physiological bone-ligament junction is composed of four zones: ligament, fibrocartilage, calcified fibrocartilage and bone. It plays a very important part in the distribution of mechanical loads applied to ligaments so as to diminish stress concentration or shearing at the interface. This paper examines types of bone and neoligament insertion after anterior cruciate ligament (ACL) reconstruction with a Dacron prothesis, the Leeds-Keio scaffold ligament (LK), patellar tendon with LAD augmentation (PT+LAD) and bone patellar tendon bone alone (PT). The anterior cruciate reconstructions were implanted in 16 sheep via double-isometric bone tunnels without postoperative knee immobilization. Histological examination of the new insertions (using haematoxylin-eosin, Giemsa, Masson, and Mallory stains) was performed following animal sacrifice after 2, 3, 6 and 9 months. A layer of fibrocartilage between the bone and the ligament was observed with PT, followed by a nearly normal insertion after 6 months. With PT, followed by PT+LAD, the augmentation was surrounded by fibrous tissue (also noted inside the LAD). The PT insertion was virtually physiological after 3-6 months. With the LK scaffold, fibrous tissue was noted in and around the scaffold, even after 6 and 9 months. With the Dacron prosthesis, fibrous tissue around the ligament was unaccompanied by ingrowth into the prosthesis. Nerve endings (pacinian corpuscles) were only present in the PT. These findings show that even after 9 months artificial ligaments are separated from bone by fibrous tissue and devoid of the histological and biomechanical features of a physiological junction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2002

The reference point to measure the anterior intermeniscal ligament's thickness: an MRI study.

The purpose of this study was to identify a reliable reference point for measuring anterior intermeniscal ligament thickness and to investigate the morphological characteristics of the ligament at its attachment site to anterior horns of both menisci by MRI. MRI was performed in 98 knees of randomly chosen patients. The anterior intermeniscal ligament was detected in 61 knees (62.2%). The average ligament length was 29.8 mm. Men had significantly longer anterior intermeniscal ligament than women patients (32.5 vs. 27.8 mm). The thickness of anterior intermeniscal ligaments at their attachment sites to menisci was usually less than 3 mm; a thickness of 3 mm or more at the attachment site to anterior horns of the meniscus was defined as "cordlike." It is suggested that the "cordlike" pattern is a variation of the anterior intermeniscal ligament's attachment characteristics, and that this might have a significant role in meniscal translations during knee motion, and also that the "cordlike" pattern could be clinically important with respect to its relationship to the anterior horn of medial meniscus. The attachment site of the ligament is a reliable reference point for measuring its thickness.

Adolescent↗
PubMed1998

Lateral ligament injuries of the knee.

Between 1982 and 1994 28 patients were treated for acute lateral knee ligament injuries; 25 patients, with a median age of 25.5 (range 16-75) years at injury, appeared for follow-up. Seven patients had isolated injury of the lateral collateral ligament/capsular structures, the remaining 19 patients had concomitant ligament injuries in the knee. Eight patients were treated conservatively, 1 with plaster immobilization and 7 with early mobilization. Eighteen patients underwent surgery, 17 of these within 3 weeks of injury. Repair/reconstruction of the cruciate ligaments was done at the same time as the lateral collateral ligament repair in 10 patients. At follow-up after a median of 7.5 years (range 6 months to 13 years), 11 had no varus instability, 7 had 1+, 5 had 2+, and 2 patients had 3+ varus instability. All patients with a final result of 2+ or 3+ had combined ligament injuries. The surgically treated lateral collateral ligament injuries all had a primary instability of 2+ or more. These patients showed an improvement in varus instability from a mean of 2.83+ preoperatively to a mean of 1.17+ postoperatively. Two-thirds of the surgically treated patients were stable or had a 1+ instability at follow-up. One conservatively treated patient with a 2+ varus instability and 1 with 1+ showed no improvement. Five conservatively treated patients with initial varus instability of 1+ were stable at follow-up. One patient with a 1+ varus instability had anterior cruciate ligament (ACL) rupture. He had a primary ACL reconstruction without lateral repair. He had no varus instability at follow-up. Our study supports the notion that operation performed at an early stage in fresh injuries with a varus instability of 2+ or more gives improved stability as a final result. Conservative treatment may not be expected to give an improved stability, but is sufficient in mild varus instability (1+) without additional cruciate ligament injuries.

Adolescent↗
PubMed2006

Tissue engineering for anterior cruciate ligament reconstruction: a review of current strategies.

The anterior cruciate ligament (ACL) is one the most commonly injured ligaments of the knee. Chronic ACL insufficiency can result in episodic instability, chondral and meniscal injury, and early osteoarthritis. The intra-articular environment of the ligament precludes normal healing and surgical replacement of the injured ligament is often mandated to restore stability. Current surgical strategies include the use of local autograft or allograft tissues for ligament reconstruction. These procedures have yielded superior long-term clinical results yet have the potential for serious associated morbidities. Existing limitations have prompted ongoing research designed to engineer a replacement ligament that will parallel the native ACL in both its biologic properties and mechanical durability. Ligament engineering necessitates the use of appropriate source cells and a growth matrix to support cell proliferation and collagen synthesis. The identification of appropriate growth modulators including both biochemical factors and mechanical stimuli are requisites for successful tissue growth. The characterization of the elements essential for successful graft development represents a significant challenge for investigators. This review examines the current literature regarding the potential and limitations of ligament engineering and describes the development of a novel 3-dimensional scaffold and bioreactor system at our institution.

Animals↗
PubMed2005

Three-dimensional finite element modeling of ligaments: technical aspects.

The objective of this paper is to describe strategies for addressing technical aspects of the computational modeling of ligaments with the finite element (FE) method. Strategies for FE modeling of ligament mechanics are described, differentiating between whole-joint models and models of individual ligaments. Common approaches to obtain three-dimensional ligament geometry are reviewed, with an emphasis on techniques that rely on volumetric medical image data. Considerations for the three-dimensional constitutive modeling of ligaments are reviewed in the context of ligament composition and structure. A novel approach to apply in situ strain to FE models of ligaments is described, and test problems are presented that demonstrate the efficacy of the approach. Approaches for the verification and validation of ligament FE models are outlined. The paper concludes with a discussion of future research directions.

Algorithms↗