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PubMed1976

[Some aspects concerning the problem of lesions of the ulnar collateral ligament of the thumb (author's transl)].

The authors report on their experience on 20 old lesions of the ulnar collateral ligament of the MP joint of the thumb. They used a modified technique according to Strandell.--Follow up investigations were made in an average range of 17.5 months after the operation. All the colateral ligaments were stable. The procedure is not to be used for heavy manual working persons. If there is an osteoarthritis in the MP joint, arthrodesis is the alternative method.

Adolescent↗
PubMedDate not supplied

Stress deprivation effect on metabolic turnover of the medial collateral ligament collagen. A comparison between nine- and 12-week immobilization.

The effects of intermediate-term immobilization on the medial collateral ligament (MCL) of the rabbit knee are profound. Immobilization causes atrophy with reduction of collagen mass and increased collagen degradation in th immobilized MCL. The matrix composition, as reflected by collagen turnover, changed dramatically as the period of immobilization was increased from nine to 12 weeks. Collagen degradation during these three additional weeks increases, as demonstrated by the fact that at 12 weeks, collagen degradation is 28% higher than that in controls, compared with 14% at nine weeks. Degradation, balanced by new collagen synthesis, produced very minor net decrease in total collagen mass (-2%) after nine weeks, but a large decrease in total collagen mass (-27%) is observed at the end of 12 weeks. Exponential degradation has occurred as immobilization has continued, and ligament regenerative capacity apparently has failed.

Animals↗
PubMed2006

Spatial distribution and orientation of dermatan sulfate in human medial collateral ligament.

The proteoglycan decorin and its associated glycosaminoglycan (GAG), dermatan sulfate (DS), regulate collagen fibril formation, control fibril diameter, and have been suggested to contribute to the mechanical stability and material properties of connective tissues. The spatial distribution and orientation of DS within the tissue are relevant to these mechanical roles, but measurements of length and orientation from 2D transmission electron microscopy (TEM) are prone to errors from projection. The objectives of this study were to construct a 3D geometric model of DS GAGs and collagen fibrils, and to use the model to interpret TEM measurements of the spatial orientation and length of DS GAGs in the medial collateral ligament of the human knee. DS was distinguished from other sulfated GAGs by treating tissue with chondroitinase B, an enzyme that selectively degrades DS. An image processing pipeline was developed to analyze the TEM micrographs. The 3D model of collagen and GAGs quantified the projection error in the 2D TEM measurements. Model predictions of 3D GAG orientation were highly sensitive to the assumed GAG length distribution, with the baseline input distribution of 69+/-23 nm providing the best predictions of the angle measurements from TEM micrographs. The corresponding orientation distribution for DS GAGs was maximal at orientations orthogonal to the collagen fibrils, tapering to near zero with axial alignment. Sulfated GAGs that remained after chondroitinase B treatment were preferentially aligned along the collagen fibril. DS therefore appears more likely to bridge the interfibrillar gap than non-DS GAGs. In addition to providing quantitative data for DS GAG length and orientation in the human MCL, this study demonstrates how a 3D geometric model can be used to provide a priori information for interpretation of geometric measurements from 2D micrographs.

Chondroitinases and Chondroitin Lyases↗
PubMedDate not supplied

Internal fluid flow increases cellular interconnects between Medial Collateral Ligament fibroblasts and cellular extensions within three-dimensional collagen matrixes.

The interconnectivity of fibroblasts within the ligamentous extracellular matrix has been largely overlooked. Studies on the cell-to-cell contacts with their neighbors via gap junctions in ligament fibroblasts, and works on the ability of fibroblasts to generate interconnected networks in vivo, suggest interfibroblastic interactions play an important role in fundamental biological processes, including homeostasis and wound healing. The current study examines how fluidic shear stresses imposed by internal flow can be used to mediate the formation of three-dimensional, interconnected fibroblast networks within collagen solutions. Several fibroblast-collagen solutions were exposed to shear stresses via Poiselle Flow. The consequent changes in cell networking, interconnections, and cell morphology within collagen matrixes exhibited by cells derived from Bovine Medial Collateral Ligaments were analyzed. Results illustrate that higher imposed stresses generate cells with more dendritic and/or branched morphologies, which form more visible three-dimensional networks within collagen matrixes than fibroblast-collagen solutions that were unexposed to shear stress.

Animals↗
PubMed1987

Collagen alteration in medial collateral ligament healing in a rabbit model.

The purpose of this study was to evaluate changes over time in surgically ruptured medial collateral ligament (MCL) with respect to collagen synthesis, collagen degradation and collagen type. Our method involved prelabeling collagen in growing rabbits using 3H-proline followed by surgical injury to the MCL. Animals were sacrificed at intervals up to 40 weeks post-injury. At each time point total hydroxyproline, changes in collagen mass, and collagen synthesis and degradation were determined and related to the unruptured control MCL. A separate semiquantitative determination of collagen type was also performed on the midsubstance of each healing and control ligament. Results showed an increase in total collagen mass and a decrease in collagen concentration in all healing ligaments. Concommitantly, an increase in the collagen turnover rate was observed. Relative turnover was greatest at 3 to 6 weeks after injury and returned toward the normal rate by 40 weeks. Type I collagen was partially replaced by type III, probably as a result of increased synthesis during scar formation. The mechanism for collagen remodeling (replacement of mass and concentration in an organized fashion) in untreated rabbit MCL scar appears functional by virtue of its chronicity but, due to a shift in collagen type, it may also be qualitatively inadequate.

Animals↗
PubMed1992

Surgical management of chronic ulnar collateral ligament insufficiency of the thumb metacarpophalangeal joint.

We studied 33 patients with "gamekeeper's thumb" who underwent surgical treatment comprising ulnar collateral ligament (UCL) advancement in 14, arthrodesis in 11, reconstruction in 6, and primary repair in 2. Results were satisfactory in 76% of the cases and unsatisfactory in 24%. From our study and review of the literature, we concluded that the best results are obtained after surgical treatment in the acute stage, because results are inconsistent and poorer after treatment of chronic lesions; reconstructive procedures based on the surgical pathology are recommended over UCL advancement and late primary repairs; and arthrodesis is a reliable salvage procedure.

Adolescent↗
PubMed1990

Transplantation of the rabbit medial collateral ligament. II. Biomechanical evaluation of frozen/thawed allografts.

This study was designed to test the mechanical behavior of a frozen/thawed bone-medial collateral ligament (MCL)-bone allograft in a rabbit model and to compare allograft behavior with contralateral unoperated ligaments as well as a group of normal bone-ligament-bone preparations prior to freezing. Twenty-five mature rabbits received similarly frozen bone-MCL-bone allografts and were subsequently allowed to heal without immobilization in groups of five for 3, 6, 12, 24, or 48 weeks after transplantation. A series of biomechanical tests was performed on each allograft, contralateral, and external normal control ligament. Results demonstrated that allografts were significantly tighter than controls at 3 weeks and they remained tight over time. All allografts, however, had inferior structural and material behaviors as compared with controls. Allograft insertional bone and substance deteriorated to about 60% of contralateral strength at 12 and 48 weeks. Bony insertions became the most common site of graft weakness. Both stress at failure and the elastic modulus of allograft substance similarly reached a plateau at those intervals, but at about 30% of contralateral controls. Cyclic and load relaxation properties of allografts, on the other hand, did not deteriorate and were, in fact, indistinguishable from contralateral and normal values at 48 weeks. Comparison with a series of fresh autografts suggests that, with the exception of this viscoelastic recovery, allografts were mechanically inferior to autografts in their healing at the intervals tested. Collectively, these results suggest that allograft MCL healing in this composite model is dynamic but slow, featuring changes in bone and soft tissue over the first year after transplantation. Although "viable" and vascular, allografts have not normalized mechanically and, in fact, appear to have reached a new equilibrium whereby properties are neither improving nor deteriorating. Despite this apparent equilibrium, the trend for some viscoelastic recovery provides hope that allografts may have further potential for improvement. Longer-term studies of MCL allograft mechanical behaviors are clearly required.

Animals↗
PubMed1991

The effects of initial end contact on medial collateral ligament healing: a morphological and biomechanical study in a rabbit model.

In this investigation, the effect of initial end contact on medial collateral ligament (MCL) healing was studied in the rabbit model. Sixty-eight 1-year-old New Zealand white rabbits were separated into two groups. In one group, a 4 mm saggital Z-plasty was performed in the right MCL midsubstance (contact group), and in the other group, an analogous 4 mm midsubstance segment was removed (gap group). Left knees were unoperated to serve as internal contralateral MCL controls. Animals had unrestricted cage activity until sacrifice in groups of eight at 3, 6, 14, and 40 weeks postoperatively. Early results demonstrated that contact and gap injuries healed with what appeared to be scar tissue both morphologically and biomechanically. In both groups, laxities recovered to their contralateral values within 6 weeks and biomechanical viscoelastic behaviors recovered to 68-92% of contralaterals by 14-40 weeks. Despite these similarities, contacts showed morphological and biomechanical evidence of improved healing over gaps. Contact scars remodeled more quickly, recovered laxity more quickly, and were generally closer to contralaterals than gaps in terms of their structural strength, stiffness, and material behaviors, after 40 weeks of healing. With the exception of appearances and failure stress, all measured properties of contact healing MCLs were statistically indistinguishable from contralateral MCLs at 40 weeks of healing. These advantages of contact healing in this model support speculations that there are differences in the early rate and possibly in the later quality of ligament healing when cut rabbit MCL ends are in proximity. Longer-term studies to define end points and mechanisms of healing are required.

Animals↗
PubMed1989

Non-operative management of acute grade III medial collateral ligament injury of the knee: a prospective study.

In a prospective study, 25 patients who had acute complete rupture of the medial collateral ligament of the knee with associated anterior cruciate ligament injury were treated by cast bracing and physiotherapy. Their average age was 27.6 years (range 15-53 years) with average follow-up of 24.2 months (range 12-48 months). All 25 patients had good or excellent results, with return to the pre-injury level of sporting activities by 1 year and with restoration of medial stability. This study shows that conservation treatment of this injury can restore stability to the medial side of the knee, even in the presence of anterior cruciate ligament damage.

Adolescent↗
PubMed1999

Operative release for elbow contracture: the lateral collateral ligament sparing technique.

This article describes the technique of elbow release and debridement using a lateral approach designed to spare the lateral collateral ligament complex and extensor tendon origins of the elbow. This exposure allows for complete exposure of the anterior and posterior ulnohumeral and radiocapitellar joints through a single incision. Advantages include simplified surgical dissection, minimal operative morbidity, and less potential for postoperative instability after release.

Contracture↗
PubMedDate not supplied

Treatment of the medial collateral ligament injury. I: The importance of anterior cruciate ligament on the varus-valgus knee laxity.

The purpose of this study was to explain the functional roles of the medial collateral ligament (MCL) and the ACL and how they affect the kinematics of the knee joint after isolated MCL injury. Varus-valgus joint laxity was quantitatively measured using a device which allowed various degrees of freedom (DOF) of joint motion during application of a varus-valgus bending moment to the canine knee joint. When the knee motion was limited to 3 DOF (varus-valgus rotation, proximal-distal, and medial-lateral translation), valgus laxity increased significantly (171%) after sectioning the MCL. Thus, the MCL was the primary restraint to the valgus bending moment in the 3 DOF mode. However, the effect of sectioning the MCL on valgus laxity became minimal (21% increase) when the DOF of knee motion was increased to 5 (by adding axial tibial rotation and anterior-posterior translation). In this situation, external and internal tibial axial rotation were coupled with the varus and valgus rotation of the knee joint, respectively, and the ACL also functioned to restrain the varus-valgus rotation. The results of this study suggest that under normal knee joint motion, the functional deficit of the MCL in valgus rotation was compensated for by the remaining structures, especially by the ACL.

Animals↗
PubMed1988

The non operative treatment of isolated complete tears of the medial collateral ligament of the knee. A prospective study.

In a prospective randomized study, 20 patients with isolated grade-III injuries to the medial collateral ligament (MCL) of the knee were treated by two different conservative methods: immediate mobilization (group A) or plaster immobilization (group B). All patients were examined while under anesthesia. Valgus-stress radiographs were performed to document a 2+ opening (6-10 mm) on the medial side. Associated damage to other structures (cruciate ligaments, menisci, cartilage) was ruled out arthroscopically. Average follow-up was 1.5 years. All patients rated good or excellent, although a minimal laxity of 3 mm on valgus-stress radiographs was present in 60% of the cases. No significant differences between the two treatment modalities were identified, except that group-A patients returned to work sooner. These results confirm that isolated grade-III MCL tears can be treated successfully by immediate mobilization.

Bandages↗
PubMed1993

Reinsertion of the ruptured ulnar collateral ligament of the metacarpophalangeal joint with an absorbable self-reinforced polylactide tack.

70 patients with total avulsion or rupture of the ulnar collateral ligament of the first metacarpophalangeal joint were treated surgically, using an absorbable self-reinforced poly-L-lactide mini-tack placed through the ligament and a channel in the base of the proximal phalanx. The device stabilized the joint immediately, and 69 ligaments remained stable at 6 months. The subjective result was good or satisfactory in 66 of the cases. One case needed further surgery for pain in the scar and another developed local infection 9 months post-operatively. On the basis of these findings, the new absorbable fixation method seems to be a suitable method for clinical use.

Absorption↗
PubMed1976

The strength and failure characteristics of rat medial collateral ligaments.

Traumatic loading of the knee joint in man occurs at strain rates ranging from 0.5-1,500 m/m/sec. Experiments on the medial collateral ligament of rats demonstrate that the mode of failure is a function of the strain rate. Avulsions occurred more often at low rates; ligament tearing occurred more often at high rates.

Animals↗
PubMed1983

An in situ study of the influence of a sclerosing solution in rabbit medial collateral ligaments and its junction strength.

A double-blind study was conducted to assess the influence of a sclerosing solution on rabbit medial collateral ligaments (MCL) in situ. It was shown that repeated injections of 5% sodium morrhuate into the MCL and its bony attachments significantly increased its bone-ligament-bone junction strength, ligament mass and thickness when compared to saline-injected controls. Morphometric analysis of electron micrographs showed a highly significant corresponding increase of the collagen fibril diameters in the experimental ligament compared against the control MCL. These composite findings suggested that the sclerosing solution had a significant influence on dense connective tissue at the insertion sites. The mechanisms for these changes are uncertain and are the basis for future investigations.

Animals↗
PubMed1990

The effects of strain rate on the properties of the medial collateral ligament in skeletally immature and mature rabbits: a biomechanical and histological study.

The effects of strain rate on the structural properties of the femur-medial collateral ligament-tibia complex (FMTC) and on the mechanical (material) properties of the medial collateral ligament (MCL) of skeletally immature and skeletally mature rabbits were studied. The FMTCs were tested in tension to failure, at five extension rates (0.008 mm/s-113 mm/s). For the FMTCs from the skeletally immature animals, values of load, elongation, and energy absorbed at failure increased substantially with extension rates. Such increases also existed for skeletally mature animals, but they were much less in magnitude. All samples from the skeletally immature animals failed by tibial avulsion, whereas samples from the skeletally mature animals failed within the ligament substance. The mechanical properties of the ligament substance were minimally strain-rate sensitive for both groups. Histological sections of the ligament substance and insertion sites from the failed samples were examined, and these observations were correlated with the biomechanical findings. For the rabbit model used in this study, we conclude that skeletal maturity has more influence on the biomechanical properties of the MCL than does strain rate.

Aging↗