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PubMed2005

Carpal collateral ligament desmopathy in three horses.

The radiographic and ultrasonographic findings in three horses with severe damage to the collateral ligaments of the carpus, associated with degenerative joint disease, are described. The horses remained lame despite prolonged rest and medical management, primarily because of the progression of the joint disease. Ultrasonography was found to be an accurate method for diagnosing the injury to the ligaments and is recommended as part of a routine examination in suspected carpal injuries.

Animals↗
PubMed1988

Relationship between peak torque and total work in an isokinetic contraction of the medial collateral ligament insufficient knee.

The aim of this study was to assess the relationship between the isometric and isokinetic peak torques (speed of movement 0, 60, and 180 degrees/s) and the total work output of multiple contractions (180 degrees/s) of the quadriceps and hamstrings in 25 subjects having a chronic, complete insufficiency of the medial collateral ligament of the knee. At every test speed the Pearson product moment (r) and the Spearman rank (rs) correlation coefficients between the peak torque and total work were highly significant for both muscle groups in the uninjured (r = 0.75-0.96, rs = 0.72-0.95) as well as in the medially unstable (r = 0.79-0.93, rs = 0.76-0.92) knees. In both knees and in both muscle groups, the correlation coefficients increased toward the highest speed of the isokinetic movement, obviously since the total work was registered at that speed. The author concludes that in the medial collateral ligament insufficient knees the total work analysis offers little additional information to that attained by more simple measurement, the peak torque analysis.

Adult↗
PubMed2001

Microstructural morphology in the transition region between scar and intact residual segments of a healing rat medial collateral ligament.

This study used a rat model to investigate the microstructural organization of collagen through the transition from scar to intact residual segments of a healing medial collateral ligament (MCL). Twenty-two male retired breeder Sprague-Dawley rats were randomly separated into two groups. Eleven underwent surgical transections of both MCLs and were allowed unrestricted cage activity until euthanized two weeks post surgery. The remaining eleven rats were used as normal controls. All 44 MCLs were harvested including intact femoral and tibial insertions and prepared for scanning electron microscopy (SEM) imaging. At harvest the scar region in the healing ligaments was more translucent than the normal tissue. Ligaments were viewed from femoral to tibial insertions at magnifications of 100X through 20,000X. Tissue away from the scar region in the transected MCLs was indistinguishable from normal tissue in uninjured ligaments. Collagen fibers and fibrils in these tissues were more aligned along the longitudinal axis of the ligament than in the scar tissue. Continuity of collagen fibers and fibrils were consistently observed from the residual portions of the transected ligament through the scar region. Bifurcations/fusions, but no anastomoses, in fibers and fibrils were observed in both normal and scar tissues of ligaments. Qualitatively, bifurcations were encountered more frequently in scar tissue. In the transition region, larger diameter fibers from the residual tissue bifurcated into smaller diameter fibrils in the scar. This connection between larger diameter and smaller diameter fibers and fibrils indicates that bifurcations/fusions are likely to be the dominant way in which force is transmitted from a region with larger fibrils (residual ligament) into and through a region with smaller fibrils (scar).

Animals↗
PubMedDate not supplied

Healing of the medial collateral ligament in unstable rat knees.

Immobilization has been shown to be detrimental to healing ligaments while early motion and exercise increase healing ligament tensile strength. In order to take advantage of early motion and exercise without causing undesirable joint laxity in unstable rat knees we devised an internal joint restabilization procedure. The results in this well-established rat model were encouraging. Exercise in unstable rat knees caused increased medial collateral ligament laxity compared with a group allowed motion ad libitum. Joint laxity was significantly decreased in the restabilized groups and no adverse effects of exercise were noted. Tensile strength was increased in healing medial collateral ligaments of both exercise groups regardless of the stability of the joint. This study supports the use of early aggressive rehabilitation of injured joints considered stable and encourages the development of methods to provide secure dynamic internal or external stabilization of severely injured human joints.

Animals↗
PubMed1996

Influence of dosage and timing of application of platelet-derived growth factor on early healing of the rat medial collateral ligament.

In previous studies, platelet-derived growth factor has demonstrated beneficial in vivo effects on wound healing. We report the results of two studies of platelet-derived growth factor in the rat medial collateral ligament injury model. Experimental injury sites were implanted with platelet-derived growth factor, whereas contralateral controls received only collagen. Twelve days postoperatively, the femur-medial collateral ligament-tibia complex was tested mechanically. Our first study found a marked drop in the effectiveness of platelet-derived growth factor when it was administered more than 24 hours after injury. Dose-response testing showed maximum increases in strength (90%) with 5.0 micrograms of platelet-derived growth factor, but the 1.0 microgram group showed similar strength increases, indicating a probable plateau effect in the response. These results indicate that platelet-derived growth factor has promise for healing ligaments but that it must be administered in appropriate doses soon after injury.

Animals↗
PubMed1998

Material characterization of human medial collateral ligament.

The objectives of this study were to determine the longitudinal and transverse material properties of the human medial collateral ligament (MCL) and to evaluate the ability of three existing constitutive models to describe the material behavior of MCL. Uniaxial test specimens were punched from ten human cadaveric MCLs and tensile tested along and transverse to the collagen fiber direction. Using load and optical strain analysis information, the tangent modulus, tensile strength and ultimate strain were determined. The material coefficients for each constitutive model were determined using nonlinear regression. All specimens failed within the substance of the tissue. Specimens tested along the collagen fiber direction exhibited the typical nonlinear behavior reported for ligaments. This behavior was absent from the stress-strain curves of the transverse specimens. The average tensile strength, ultimate strain, and tangent modulus for the longitudinal specimens was 38.6 +/- 4.8 MPa, 17.1 +/- 1.5 percent, and 332.2 +/- 58.3 MPa, respectively. The average tensile strength, ultimate strain, and tangent modulus for the transverse specimens was 1.7 +/- 0.5 MPa, 11.7 +/- 0.9 percent, and 11.0 +/- 3.6 MPa, respectively. All three constitutive models described the longitudinal behavior of the ligament equally well. However, the ability of the models to describe the transverse behavior of the ligament varied.

Aged↗
PubMed1996

The postnatal development of the insertions of the medial collateral ligament in the rat knee.

Bone soft tissue remodelling at the femoral and tibial insertions of the medial collateral ligament (MCL) of the rat knee was monitored at regular intervals from birth to 120 days of age in 40 Sprague Dawley rats. At birth the femoral insertion originated from the perichondrium of the epiphysis. By day 8 the perichondrium within the insertion had turned into fibrocartilage. Secondary ossification of the femoral epiphysis had progressed in the region near to the insertion site by day 15. The epiphyseal cartilage was entirely replaced by bone by day 40 except for the fibrocartilage within the insertion. After that stage, no qualitative change in zonal insertion characteristics was observed, but only increase in size and decrease in cellularity. At birth, the tibial ligament inserted onto the thin cortical bone of the metaphysis via periosteum. At day 8, osteoclasts started to resorb the thin cortical bone at the ligament insertion, thus forming a metaphyseal depression between days 10 and 20. From days 20 to 120, the insertion remained qualitatively unchanged, showing three zones, the ligament, periosteum, and metaphyseal trabecular bone. The deep periosteal layer showed osteoclastic activity in the proximal part and osteoblastic activity in the distal part. The migration-mechanism of the ligament insertion during growth seems to be caused by this growth-related osteoclastic resorption of the proximal metaphyseal bone and by simultaneous osteogenic activity, which successively cements the distal part of the ligament to bone. The persistence of the periosteal layer and the metaphyseal depression for up to 120 days may be regarded as a sign of continuing growth in this animal model. This is the first investigation showing that the formation of the metaphyseal depression is a purely postnatal event, and suggests that this process might be initiated by the change in mode of growth and joint biomechanics after birth, enabling ligament development and migration in a growing and increasingly loaded weight-bearing joint. The mainly resorptive process, which takes place during development of the tibial MCL insertion, may account for the tensile failure of this ligament that commonly occurs at this site during growth. The pronounced morphological differences between the chondral femoral and the periosteal tibial attachment of the adult MCL are apparently caused by the different postnatal development processes at epiphyses and metaphyses.

Animals↗
PubMed1993

Non-operative treatment of acute medial collateral ligament lesions of the knee joint.

From 1985 to 1990 102 patients with isolated lesions of the medial collateral ligament of the knee were managed non-operatively with early protected motion and physical therapy. Eighty-six returned to a follow-up examination. The mean follow-up time was 44.2 months. The knees were stable in all but two cases and showed good or excellent results. Ninety-seven percent of the patients returned to their earlier activity level.

Adult↗
PubMedDate not supplied

Elbow joint laxity after experimental radial head excision and lateral collateral ligament rupture: efficacy of prosthetic replacement and ligament repair.

The objectives of this experimental study were to investigate the effect of radial head excision and lateral collateral ligament (LCL) division on elbow joint laxity and to determine the efficacy of radial head prosthetic replacement and LCL repair. Valgus, varus, internal rotation, and external rotation of the ulna were measured during passive flexion-extension and application of a 0.75-Nm torque in 6 intact cadaveric elbows and after (1) either excision of the radial head or division of the LCL, (2) removal of both constraints, (3) isolated radial head prosthetic replacement, (4) isolated LCL repair, and (5) radial head replacement combined with LCL repair. Isolated radial head excision increased varus (mean, 4.8 degrees) and external rotatory laxity (mean, 7.1 degrees), as did isolated LCL division (mean, 14.1 degrees for varus; mean, 14.7 degrees for external rotation). After removal of both constraints, varus and external rotatory laxities were increased by 19.0 degrees and 20.1 degrees, respectively, compared with the intact specimens. Isolated radial head replacement reduced mean varus laxity to 14.6 degrees and mean external rotatory laxity to 14.8 degrees. Isolated LCL repair normalized varus laxity but resulted in a 2.9 degrees increase in external rotatory laxity. The combined procedures restored laxity completely. The radial head is a constraint to varus and external rotation in the elbow joint, functioning by maintaining tension in the LCL. Still, removal of both constraints induces severe laxity, and in this case, prosthetic replacement may substitute for the constraining capacity of the native radial head. The combination of LCL repair and radial head replacement restores laxity completely, but an isolated LCL repair performs almost as well, probably by compensating for the ligamentous tension lost from radial head excision.

Adult↗
PubMed2003

Primary repair of the collateral ligament of the proximal interphalangeal joint using a suture anchor.

Ten out of 12 complete ruptures of the collateral ligament of the proximal interphalangeal joint were repaired primarily using a suture anchor. Active finger exercise was started gently by taping the injured finger to adjacent one one week postoperatively. All patients returned to their original occupation or sports activities within seven weeks of operation. No patients complained of pain on the involved finger at rest or during movement. There was no instability of the proximal interphalangeal joint on manual lateral stress test postoperatively.

Adolescent↗
PubMed1997

Collagen fibril diameters in the rabbit medial collateral ligament scar: a longer term assessment.

Previous transmission electron microscopic investigations of collagen fibril diameters in rabbit medial collateral ligament (MCL) scars have indicated a homogeneous population of small fibrils for the first 40 weeks of healing. In this study, four 8 mm MCL gap scars were studied at 78 weeks of healing and another three at 104 weeks. Results showed increased heterogeneity in the distribution of fibril diameters in all scars, with the appearance of progressively slightly larger fibrils in 78 and 104 week specimens. All longer term scars still contained roughly 90% small fibrils plus some "patches" of larger fibrils, but there was considerable variation between animals in these proportions. No scar contained the fibril populations typical of uninjured adult rabbit MCLs. These results suggest slow but on-going collagen fibril turnover and remodeling in this gap healing rabbit MCL model via currently unidentified mechanisms.

Animals↗
PubMed1993

Knee immobilization inhibits biomechanical maturation of the rabbit medial collateral ligament.

In this investigation, the effect of immobilization on the structural biomechanical properties of the immature rabbit medial collateral ligament (MCL) was quantified. The right hindlimbs of ten, three-month-old female New Zealand White rabbits were immobilized. The hindlimbs of the first group (n = 5) were immobilized for one month, until the rabbits were four months of age. The hindlimbs of the second group (n = 5) were immobilized for three months, until the rabbits were six months of age. Left hindlimbs were not surgically treated and served as contralateral controls. Fifteen normal animals were kept in similar cages until they were killed in subgroups at three, four, or six months of age. Biomechanical investigations after the animals were killed included the testing of a number of MCL structural properties, including prefailure and strength tests. Results showed that the maturation of MCL structural properties were inhibited during immobilization with signs of structural degradation becoming more obvious at the longer period of immobilization. Results also demonstrated that the structural mechanical properties of the contralateral MCLs were significantly altered. These results suggest that knee mobility is essential to the normal maturation of MCL mechanical properties and that contralateral MCLs cannot be used as normal controls in this immature rabbit model of immobility.

Age Factors↗
PubMed1996

Catabolism and loss of proteoglycans from cultures of bovine collateral ligament.

This paper investigates the kinetics and mechanism of loss of the two major proteoglycan species from cultures of bovine collateral ligament. Following incubation of ligament with [35S]sulfate after 6 days in culture, the rate of loss of the predominant proteoglycan species, decorin, from the matrix was shown to be much slower (t1/2 approximately 18 days) than that of the large chondroitin sulfate proteoglycan (t1/2 approximately 1.4 days). Analysis of 35S-labeled proteoglycans released into the medium between Days 11 and 15 of the culture period on a column of Sepharose CL-4B revealed that these macromolecules constituted mainly decorin of similar hydrodynamic size to that present in the matrix. Furthermore, analysis of core proteins using gel electrophoresis followed by fluorography or immunodetection with LF-94, an antibody directed against the amino-terminal region of decorin, indicated that the core proteins of decorin released into the medium and those remaining in the matrix of ligament cultures had a similar molecular mass (approximately 49 kDa). Analysis of both the 35S-labeled and endogenous macromolecules using 5/6/3-B-3, an antibody directed against terminal unsaturated chondroitin-6-sulfate disaccharides, revealed that three core proteins with molecular masses greater than approximately 200 kDa were present in the matrix. Four additional core proteins (range approximately 80-200 kDa) derived from the large proteoglycan were detected in the medium of ligament cultures. These findings indicate that, unlike decorin, the loss of the large chondroitin sulfate proteoglycan from the matrix of ligament cultures involved proteolytic cleavage of its core protein. No difference in the hydrodynamic size of the 35S-labeled glycosaminoglycan chains derived from either proteoglycan species remaining in the matrix or released into the medium of ligament cultures was observed.

Animals↗
PubMed2000

Estrogen-dependent tensile properties of the rabbit knee medial collateral ligament.

The influence of oophorectomy or continuous administration of estradiol on the tensile properties of the rabbit knee medial collateral ligament was investigated. Young postpubertal female New Zealand white rabbits were either oophorectomized or underwent a sham operation. The sham-operated animals received in addition a daily dosage of 4 mg 17beta-estradiol. After 5 months the animals were killed, and the material properties of the bone-ligament-bone complex in one knee were determined using a material testing machine and video system, and compared to non-treated control animals. There was no difference in elastic modulus between the groups. However, the ligaments from low-dose estrogen-treated animals had a smaller cross-sectional area and a higher ultimate tensile strength than those from controls or oophorectomized rabbits (P<0.04-0.0003).

Animals↗
PubMed2004

Reconstruction of the medial femoral condyle and medial collateral ligament in total knee arthroplasty using tendoachilles allograft with a calcaneal bone block.

Absence or compromise of the medial collateral ligament (MCL) in conjunction with osseous defects of the medial femoral condyle in total knee arthroplasty (TKA) is a challenging reconstructive problem. Treatment usually requires a highly constrained TKA with or without ligamentous reconstruction. To restore the medial femoral condylar bone and to provide ligamentous stability on the medial side of the knee, the authors present a technique for reconstruction of the medial femoral condyle and MCL using a tendoachilles allograft with a calcaneal bone block. The construct also can be augmented with a semitendinosus tendon autograft. Two illustrative cases and a review of the literature are presented.

Achilles Tendon↗
PubMed2004

A biomechanical modeling of injury, repair, and rehabilitation of ulnar collateral ligament injuries of the thumb.

PURPOSE: The use of early active motion protocols after repair of the thumb ulnar collateral ligament (UCL) theoretically could avoid the complications of postoperative immobilization and improve ligament healing. The goals of this study were as follows: (1) to develop an accurate model of acute UCL rupture, (2) to determine the strain pattern in the UCL during constrained active thumb motion in intact and repaired thumbs, and (3) to determine the load to failure and strain of the UCL during rupture in forced abduction. METHODS: Sixteen fresh-frozen adult cadaver thumbs were mounted in a testing apparatus designed for testing the strain in the UCL during constrained active motion and abduction load to failure. Strain data for the UCL during motion were measured. Specimens were tested to failure using an MTS machine. Dynamic strain data were acquired throughout the loading cycle. Repair of the torn ligament was performed with a suture anchor technique. Strain and load-to-failure measurements then were repeated in the repaired specimens. Differences in the strain values and failure forces between the intact and repaired specimens then were compared. RESULTS: A reliable model of a UCL rupture was created. Strains in the UCL were similar during active motion in both intact and repaired specimens. A significant decrease in maximum load to failure was noted in repaired specimens but failure reliably occurred at strains 3 times greater than expected with active motion. CONCLUSIONS: A controlled active motion therapy protocol after suture anchor repair of a ruptured UCL of the thumb is safe from a biomechanical point of view.

Adult↗